136 results on '"Steven D. Schaefer"'
Search Results
2. Quantity and Three-Dimensional Position of the Recurrent and Superior Laryngeal Nerve Lower Motor Neurons in a Rat Model
- Author
-
Aaron Bender, Michael J. Pitman, Sansar C. Sharma, Philip A. Weissbrod, and Steven D. Schaefer
- Subjects
Stilbamidines ,Rat model ,Electromyography ,Lower motor neuron ,Laryngeal Nerve Injuries ,Rats, Sprague-Dawley ,Superior laryngeal nerve ,Neurotrophic factors ,Recurrent laryngeal nerve ,Animals ,Medicine ,Fluorescent Dyes ,Nucleus ambiguus ,medicine.diagnostic_test ,Rhodamines ,business.industry ,Laryngeal Nerves ,Dextrans ,General Medicine ,Anatomy ,Rats ,Disease Models, Animal ,medicine.anatomical_structure ,Otorhinolaryngology ,Recurrent Laryngeal Nerve Injuries ,Female ,Laryngeal Muscles ,business ,Brain Stem ,Reinnervation - Abstract
Objectives: We sought to elucidate the 3-dimensional position and quantify the lower motor neurons (LMNs) of the recurrent laryngeal nerve (RLN) and the superior laryngeal nerve (SLN) in a rat model. Quantification and mapping of these neurons will enhance the usefulness of the rat model in the study of reinnervation following trauma to these nerves. Methods: Female Sprague-Dawley rats underwent microsurgical transection of the RLN, the SLN, or both the RLN and SLN or sham surgery. After transection, either Fluoro-Ruby (FR) or Fluoro-Gold (FG) was applied to the proximal nerve stumps. The brain stems were harvested, sectioned, and examined for fluorolabeling. The LMNs were quantified, and their 3-dimensional position within the nucleus ambiguus was mapped. Results: Labeling of the RLN was consistent regardless of the labeling agent used. A mean of 243 LMNs was documented for the RLN. The SLN labeling with FR was consistent and showed a mean of 117 LMNs; however, FG proved to be highly variable in labeling the SLN. The SLN LMNs lie rostral and ventral to those of the RLN. In the sham surgical condition, FG was noted to contaminate adjacent tissues — In particular, in the region of the SLN. Conclusions: Fluorolabeling is an effective tool to locate and quantify the LMNs of the RLN and SLN. The LMN positions and counts were consistent when FR was used in labeling of either the RLN or the SLN. Fluoro-Gold, however, because of its tendency to contaminate surrounding structures, can only be used to label the RLN. Also, as previously reported, the SLN LMNs lie rostral and ventral to those of the RLN. This information results in further clarification of a rat model of RLN injury that may be used to investigate the effects of neurotrophic factors on RLN reinnervation.
- Published
- 2011
- Full Text
- View/download PDF
3. Electromyographic and histologic evolution of the recurrent laryngeal nerve from transection and anastomosis to mature reinnervation
- Author
-
Steven D. Schaefer, Philip A. Weissbrod, Sansar C. Sharma, Rick M. Roark, and Michael J. Pitman
- Subjects
medicine.diagnostic_test ,business.industry ,Rat model ,Specific time ,Anatomy ,Electromyography ,Anastomosis ,medicine.disease ,Visual grading ,medicine.anatomical_structure ,Otorhinolaryngology ,Anesthesia ,medicine ,Recurrent laryngeal nerve ,Vocal cord paralysis ,business ,Reinnervation - Abstract
Objectives: To describe the natural evolution of recurrent laryngeal nerve (RLN) reinnervation in an animal model. Study Design: Twenty Sprague Dawley rats underwent unilateral RLN transection and anastomosis. Animals were sacrificed at 4, 8, 12, 16, and 20 weeks. Prior to sacrifice, each rat underwent electromyography (EMG) and visual grading of vocal fold motion. Bilateral RLNs were harvested and evaluated histologically. Results: EMG revealed synkinetic reinnervation at all time periods except at 4 weeks. EMG evolution plateaued at 16 weeks. Vocal fold motion was slight in three rats at 4 weeks but was otherwise absent except for one rat at 12 weeks. Histologic changes of the axons and their myelin sheaths were consistent at each time period. At 16 weeks, histologic changes plateaued. Conclusions: Consistent EMG, histologic, and vocal fold motion changes occur at specific time periods during RLN reinnervation after transection and anastomosis in a rat model. Reinnervation is mature at 16 weeks. Findings corroborate theories of preferential and synkinetic reinnervation after RLN transection. Use of a rat model to investigate the effect of interventions on RLN reinnervation requires a minimum of 16 weeks between transection and investigation to allow for maturation of reinnervation. Laryngoscope, 2011
- Published
- 2011
- Full Text
- View/download PDF
4. From virtual reality to the operating room: The endoscopic sinus surgery simulator experiment
- Author
-
Joseph B. Jacobs, Marc J. Gibber, Marvin P. Fried, Steven D. Schaefer, Douglas A. Ross, Sanjay R. Parikh, John P. Bent, Richard A. Lebowitz, Clarence T. Sasaki, and Babak Sadoughi
- Subjects
Predictive validity ,Operating Rooms ,medicine.medical_specialty ,Time Factors ,Trainer ,education ,Video Recording ,Virtual reality ,Statistics, Nonparametric ,law.invention ,User-Computer Interface ,Patient safety ,Randomized controlled trial ,law ,Paranasal Sinuses ,Paranasal Sinus Diseases ,Humans ,Medicine ,Prospective Studies ,Hospitals, Teaching ,Reliability (statistics) ,Simulation ,business.industry ,Internship and Residency ,Reproducibility of Results ,Endoscopy ,Otorhinolaryngology ,Mann–Whitney U test ,Feasibility Studies ,New York City ,Surgery ,business ,Computer-Assisted Instruction - Abstract
Establish the feasibility of a predictive validity study in sinus surgery simulation training and demonstrate the effectiveness of the Endoscopic Sinus Surgery Simulator (ES3) as a training device.Prospective, multi-institutional controlled trial.Four tertiary academic centers with accredited otolaryngology-head and neck surgery residency programs.Twelve ES3-trained novice residents were compared with 13 control novice residents.Subjects were assessed on the performance of basic sinus surgery tasks. Their first in vivo procedure was video recorded and submitted to a blinded panel of independent experts after the panel established a minimum inter-rater reliability of 80 percent. The recordings were reviewed by using a standardized computer-assisted method and customized metrics. Results were analyzed with the Mann-Whitney U test. Internal rater consistency was verified with Pearson moment correlation.Completion time was significantly shorter in the experimental group (injection P = 0.003, dissection P0.001), which, according to the rater panel, also demonstrated higher confidence (P = 0.009), demonstrated skill during instrument manipulation (P = 0.011), and made fewer technical mistakes during the injection task (P = 0.048) compared with the control group. The raters' post hoc internal consistency was deemed adequate (r0.5 between serial measurements).The validity of the ES3 as an effective surgical trainer was verified in multiple instances, including those not depending on subjective rater evaluations. The ES3 is one of the few virtual reality simulators with a comprehensive validation record. Advanced simulation technologies need more rapid implementation in otolaryngology training, as they present noteworthy potential for high-quality surgical education while meeting the necessity of patient safety.
- Published
- 2010
- Full Text
- View/download PDF
5. The voice and laryngeal dysfunction in stroke: A report from the Neurolaryngology Subcommittee of the American Academy of Otolaryngology‐Head and Neck Surgery
- Author
-
Jean Abitbol, Kenneth W. Altman, Joel H. Blumin, Yolanda D. Heman-Ackah, Donna S. Lundy, Steven D. Schaefer, Nicole Maronian, Stellan Hertegård, Gou Pei Yu, and Roy R. Casiano
- Subjects
Adult ,Male ,medicine.medical_specialty ,Scope of practice ,medicine.medical_treatment ,Population ,MEDLINE ,Laryngeal Diseases ,030507 speech-language pathology & audiology ,03 medical and health sciences ,0302 clinical medicine ,Epidemiology ,medicine ,Humans ,030223 otorhinolaryngology ,Intensive care medicine ,education ,Stroke ,Aged ,Cause of death ,Aged, 80 and over ,education.field_of_study ,Voice Disorders ,Rehabilitation ,business.industry ,Stroke Rehabilitation ,Middle Aged ,medicine.disease ,Cross-Sectional Studies ,Otorhinolaryngology ,Physical therapy ,Female ,Surgery ,Deglutition Disorders ,0305 other medical science ,business - Abstract
Objective Stroke is the third leading cause of death in the United States, behind heart disease and cancer. It affects as many as 5% of the population over 65 years old, and this number is growing annually due to the aging population. A significant portion of stroke patients that initially survive are faced with the risk of aspiration, as well as quality-of-life issues relating to impaired communication. The goal of this paper is to define the scope of practice in otolaryngology for these patients, and to review pertinent background literature. Study Design Consensus report and retrospective literature review. Results Otolaryngology involvement in these patients is critical to their rehabilitation, which often requires an interdisciplinary team of specialists. This committee presentation explores epidemiological data regarding the impact of stroke and its complications on hospitalizations. A pertinent review of neuroanatomy as it relates to laryngeal function is also discussed. State-of-the-art diagnostic and therapeutic procedures are presented. Conclusion There is a well-defined set of diagnostic and therapeutic options for laryngeal dysfunction in the stroke patient. Significance Otolaryngologists play a critical role in the interdisciplinary rehabilitation team.
- Published
- 2007
- Full Text
- View/download PDF
6. Pilot Study Using SELDI-TOF−MS Based Proteomic Profile for the Identification of Diagnostic Biomarkers of Thyroid Proliferative Diseases
- Author
-
Stimson P. Schantz, Ashok Bt, Robert Suriano, Lin Y, Steven D. Schaefer, Geliebter J, and Raj K. Tiwari
- Subjects
Proteomics ,inorganic chemicals ,Oncology ,endocrine system ,medicine.medical_specialty ,Protein Array Analysis ,Normal tissue ,Pilot Projects ,Biochemistry ,Internal medicine ,SELDI-TOF-MS ,Biomarkers, Tumor ,medicine ,Humans ,Diagnostic biomarker ,Thyroid Neoplasms ,Thyroid cancer ,Univariate analysis ,Proteomic Profile ,business.industry ,digestive, oral, and skin physiology ,Thyroid ,Reproducibility of Results ,General Chemistry ,medicine.disease ,Carcinoma, Papillary ,medicine.anatomical_structure ,Endocrinology ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Multivariate Analysis ,Biomarker (medicine) ,business - Abstract
Biomarkers for thyroid cancer (TCa) lack specificity. To develop TCa specific biomarkers, SELDI-TOF-MS was used to examine the proteomic profile of biopsies obtained from papillary TCa along with adjacent normal tissue. Sixty-three potential biomarkers were categorized by univariate analysis into single biomarker candidates and segregated by multivariate analysis into normal and cancerous groups. Our studies demonstrate the sensitivity and reproducibility of this approach to detect biomarkers for TCa.
- Published
- 2006
- Full Text
- View/download PDF
7. Zones of Approach for Craniofacial Resection: Minimizing Facial Incisions for Resection of Anterior Cranial Base and Paranasal Sinus Tumors
- Author
-
Augustine Moscatello, Richard R. Orlandi, William T. Couldwell, Martin H. Weiss, David Decker, James K. Liu, and Steven D. Schaefer
- Subjects
Adult ,Male ,Nasal cavity ,Maxillary sinus ,Skull Base Neoplasms ,Postoperative Complications ,Clivus ,Humans ,Minimally Invasive Surgical Procedures ,Medicine ,Child ,Craniofacial surgery ,Sinus (anatomy) ,Aged ,Base of skull ,business.industry ,Anatomy ,Middle Aged ,Radiography ,medicine.anatomical_structure ,Paranasal sinuses ,Face ,Cavernous sinus ,Female ,Surgery ,Neurology (clinical) ,business ,Craniotomy ,Paranasal Sinus Neoplasms - Abstract
OBJECTIVEAnterior cranial base tumors are surgically resected with combined craniofacial approaches that frequently involve disfiguring facial incisions and facial osteotomies. The authors outline three operative zones of the anterior cranial base and paranasal sinuses in which tumors can be resected with three standard surgical approaches that minimize transfacial incisions and extensive facial osteotomies.METHODSThe zones were defined by performing dissections on 10 cadaveric heads and by evaluating radiographic images of patients with anterior cranial base tumors. The three approaches performed on each cadaver were transbasal, transmaxillary, and extended transsphenoidal.RESULTSThree zones of approach were defined for accessing tumors of the anterior cranial base, nasal cavity, and paranasal sinuses. Zone 1 is exposed by the transbasal approach, which is limited anteriorly by the supraorbital rim, posteriorly by the optic chiasm and clivus, inferiorly by the palate, and laterally by the medial orbital walls. This approach allows access to the entire anterior cranial base, nasal cavity, and the majority of maxillary sinuses. The limitation imposed by the orbits results in a blind spot in the superolateral extent of the maxillary sinus. Zone 2 is exposed by a sublabial maxillotomy approach and accesses the entire maxillary sinus, including the superolateral blind spot and the ipsilateral anterior cavernous sinus. However, access to the anterior cranial base is limited. Zone 3 is exposed by the transsphenoidal approach. This approach accesses the midline structures but is limited by the lateral nasal walls and intracavernous carotid arteries. An extended transsphenoidal approach allows further exposure to the anterior cranial base, clivus, or cavernous sinuses. The use of the endoscope facilitates tumor resection in the nasal cavity and paranasal sinuses.CONCLUSIONThe operative zones outlined offer minimally invasive craniofacial approaches to accessing lesions of the anterior cranial base and paranasal sinuses, obviating facial incisions and facial osteotomies. Case illustrations demonstrating the approach selection paradigm are presented.
- Published
- 2003
- Full Text
- View/download PDF
8. Endoscopic and Transconjunctival Orbital Decompression for Thyroid-Related Orbital Apex Compression
- Author
-
David Della Rocca, Gu‐Pei Yoo, Peyman Soliemanzadeh, James Milite, Steven D. Schaefer, Robert C. Della Rocca, and Elizabeth Maher
- Subjects
Adult ,Male ,medicine.medical_specialty ,Visual acuity ,genetic structures ,Decompression ,Eye disease ,Visual Acuity ,Optic neuropathy ,Optic Nerve Diseases ,Preoperative Care ,Diplopia ,medicine ,Exophthalmos ,Humans ,Exophthalmus ,Prospective Studies ,Aged ,Retrospective Studies ,Aged, 80 and over ,Postoperative Care ,biology ,business.industry ,Nerve Compression Syndromes ,Thyroid ,Endoscopy ,Middle Aged ,Decompression, Surgical ,biology.organism_classification ,medicine.disease ,Compression (physics) ,Graves Disease ,eye diseases ,Surgery ,medicine.anatomical_structure ,Otorhinolaryngology ,Female ,medicine.symptom ,business ,Conjunctiva ,Orbit - Abstract
Objective To evaluate the efficacy and safety of a combined endoscopic and transconjunctival orbital decompression in patients with thyroid-related orbitopathy with orbital apex compression. Study Design Retrospective review. Methods A sequential series of patients with thyroid-related orbitopathy presenting with orbital apex compressive myopathy with and without optic neuropathy who were undergoing combined endoscopic and transconjunctival decompression by the same surgeons from 1992 to 2001 was reviewed. Patients were regularly evaluated preoperatively and postoperatively over a 3- to 55-month period to record the effects of this approach on visual acuity, Hertel exophthalmometry, and diplopia. Complications and secondary ophthalmological procedures were reviewed. Results Between 1992 and 2001, 72 combined endoscopic and transconjunctival decompressions were performed on 41 patients with orbital apex compression. Visual acuity improved in 89.3% of the patients with compressive optic neuropathy (P
- Published
- 2003
- Full Text
- View/download PDF
9. Anatomy of the Nose and Paranasal Sinuses
- Author
-
Samuel Marquez, Jeffrey T. Laitman, Bradley N. Delman, Steven D. Schaefer, Michael Papaxanthos, William Lawson, and Anthony Pagano
- Subjects
Rhinology ,Frontal sinus ,medicine.medical_specialty ,Paranasal sinuses ,medicine.anatomical_structure ,Nasolacrimal duct ,Paranasal Sinus Diseases ,Agger nasi ,Maxillary sinus ,otorhinolaryngologic diseases ,medicine ,Anatomical terminology ,Anatomy - Abstract
The study of paranasal sinus diseases spans a 2000-year history from the earliest known investigators to the present. After an exhaustive historical review of the classification for each sinus, an operational definition of the anatomical status of the paranasal sinus system is presented from a developmental perspective. A comprehensive examination of nomenclature is undertaken to clarify discrepancies and vagaries in anatomical terminology, which have been a major source of confusion among those studying or operating upon the nasal complex – nose and paranasal sinuses. Primary original sources of nomenclature were consulted to clarify persistent confusions encountered in the literature, which will permit better communication in addition to eliminating redundant terminology. Morphological entities such as the agger nasi versus agger nasi cells, frontal cell, frontal recess, lateral recess, ethmoid infundibulum, hiatus semilunaris, “nasofrontal duct,” and nasolacrimal duct are examined from an embryologic, comparative anatomical, and evolutionary frame of reference in order to identify their importance in sinus disease processes. Multiple approaches are used to describe the anatomy of the nasal complex utilizing the diverse backgrounds of the authors, who are comparative evolutionary anatomists, radiologist, and ENT surgeons from France and the USA with a combined clinical experience of 120 years of surgical practice. Methods used for this chapter include CT and endoscopic nasal imaging of living humans, examination of dry cranial material, fresh tissue anatomical dissections, and three-dimensional volume-rendering methods that allow for digitization of spaces within the nasal complex for graphical examination. Given the great complexity and extreme variability of the paranasal sinus system, otolaryngology is arguably among the most challenging of surgical fields. Indeed, when afflicted with a viral or bacterial infection, or presenting with one of many types of carcinomas, their formidable clinical manifestations challenge the depth of the ENT surgeon’s knowledge and experience. As such, a dizzying array of anatomical terms has been applied to these densely clustered, disease-prone spaces and their associated structures. It is thus the charge of the otolaryngologist to master the anatomy of the paranasal sinuses and greater nasal complex, which clinically may be considered the last frontier in craniofacial biology.
- Published
- 2014
- Full Text
- View/download PDF
10. Lateral craniofacial approaches to the skull base and infratemporal fossa
- Author
-
Steven D. Schaefer and Daniel I. Branovan
- Subjects
Skull Base ,Orthodontics ,business.industry ,Infratemporal fossa ,General Medicine ,Skull Base Neoplasms ,Skull ,Skull Base Neoplasm ,medicine.anatomical_structure ,Cranial Fossa, Posterior ,Otorhinolaryngology ,Skull base surgery ,Humans ,Medicine ,Craniofacial ,Temporal fossa ,business - Abstract
The field of skull base surgery has expanded dramatically the surgical horizons in the treatment of skull base neoplasms, which, previously, were considered inoperable because of their locations and relation to vital structures. This article aims to offer improved understanding of surgical indications and appreciation for some of the details of surgical techniques involved.
- Published
- 2001
- Full Text
- View/download PDF
11. Evaluation and Management of Bilateral Vocal Cord Immobility
- Author
-
Haskins K. Kashima, Michael S. Benninger, Paul W. Flint, Steven D. Schaefer, Andrew Blitzer, Roger L. Crumley, Allen D. Hillel, and Ira Sanders
- Subjects
medicine.medical_specialty ,Weakness ,Cord ,Stridor ,Electromyography ,Cricoid Cartilage ,03 medical and health sciences ,0302 clinical medicine ,otorhinolaryngologic diseases ,Paralysis ,medicine ,Humans ,Psychogenic disease ,Laryngospasm ,030223 otorhinolaryngology ,medicine.diagnostic_test ,business.industry ,Bilateral vocal cord paralysis ,Plastic Surgery Procedures ,Surgery ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Anesthesia ,Tracheotomy ,medicine.symptom ,business ,Vocal Cord Paralysis ,Arytenoid Cartilage - Abstract
Bilateral vocal cord immobility can be life threatening for some patients. Others, who have an open glottic chink, may have a breathy dysphonia, intermittent dyspnea, and stridor. These signs and symptoms may also be found in a number of other conditions that cause weakness or paradoxical motion of the vocal cords that mimics paralysis. These other conditions include central nervous system diseases, neuromuscular disorders, laryngospasm, and psychogenic disorders. In addition, patients with cricoarytenoid joint immobility or interarytenoid scar can also have similar symptoms at presentation. It is critical to consider the differential diagnosis of an assumed bilateral vocal cord paralysis and understand the management of paradoxical movement, weakness, joint fixation, interarytenoid scar, laryngospasm, and psychogenic disorders. The treatment for bilateral immobility should proceed only after a thorough evaluation, which might include electromyography and/or examination during general anesthesia under dense anesthetic paralysis. Reconstructive procedures are the treatments of choice, and destructive procedures should be chosen only as a last resort.
- Published
- 1999
- Full Text
- View/download PDF
12. Clinical evaluation of rhinosinusitis: History and physical examination
- Author
-
Steven D. Schaefer and James A. Hadley
- Subjects
medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Endoscopy ,Physical examination ,Olfaction Disorders ,Nasal Polyps ,Cough ,Otorhinolaryngology ,Facial Pain ,Physical therapy ,Humans ,Medicine ,Surgery ,Medical physics ,Nasal Obstruction ,Sinusitis ,Medical History Taking ,business ,Physical Examination ,Clinical evaluation ,Rhinitis - Published
- 1997
- Full Text
- View/download PDF
13. Treatment considerations in frontal sinus disease
- Author
-
Jonas T. Johnson and Steven D. Schaefer
- Subjects
Frontal sinus ,medicine.anatomical_structure ,Surgical approach ,Otorhinolaryngology ,Maxillary sinus ,business.industry ,Medicine ,Surgery ,Crista galli ,Anatomy ,business ,Surgical treatment ,Sinus (anatomy) - Abstract
EDITOR'S NOTE: The best surgical approaches for the treatment of chronic inflammatory frontal sinus disease have been hot ly d e b a t e d ove r the las t 100 years. The pendulum has been swinging back and forth between i n t r anasa l and e x t e r n a l approaches. This "Di f f icul t Decisions" article is dedicated to this topic. Four cases have been presented to two authorities in this field, Dr. Jonas Johnson and Dr. Steven Schaefer. The following issues are discussed: radiologic findings; pathophysiology; medical and surgical treatment; advantages and disadvantages of techniques; complications; and followup. Representative CT images are presented; however, not all the images provided to the authors are i nc l uded . We hope the reader will f ind the discussion stimulating and educational. Note: The following abbreviations are used in the illustrations accompanying the CT scans: FS, frontal sinus; C, crista galli; MT, middle turbinate; NS, nasal sinus; MS, maxillary sinus; LP, lamina papyracea; IT, inferior turbinate.
- Published
- 1995
- Full Text
- View/download PDF
14. Management of acute blunt and penetrating external laryngeal trauma
- Author
-
Steven D. Schaefer
- Subjects
Larynx ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,Laryngoscopy ,Wounds, Penetrating ,Thyrotomy ,Wounds, Nonpenetrating ,Surgery ,Blunt ,medicine.anatomical_structure ,Tracheotomy ,Otorhinolaryngology ,medicine ,Intubation ,Humans ,Cricothyrotomy ,Airway ,business ,Algorithms - Abstract
Objectives/Hypothesis Improve the care of acute external laryngeal trauma by reviewing controversies and the evolution of treatment. Data Source Internet-based search engines, civilian and military databases, and manual search of references from these sources over the past 90 years. Review Methods Utilizing the above-mentioned sources, electronic and manual searches of primary topics such as laryngeal trauma or injury, emergency tracheotomy, airway trauma, intubation versus tracheotomy, cricothyrotomy, esophageal trauma, and emergent management of airway injuries in civilian and combat zones. Citations were reviewed, selected reports analyzed, and the most relevant articles referenced. Results Optimal treatment of acute laryngeal trauma includes early identification of injuries utilizing a directed history and physical examination. Timely management of the wounded airway is essential. The choice of intubation, tracheotomy, or cricothyrotomy must be individualized. Computed tomography (CT) may assist in differentiating patients who can be observed versus those who require surgical exploration. In selected patients, laryngeal electromyography and stroboscopy may also be useful. Surgery should begin with direct laryngoscopy and rigid esophagoscopy to evaluate the hard and soft tissues of the larynx, and to visualize the pharynx and esophagus. Minor endolaryngeal lacerations and abrasions may be observed, whereas more significant injuries require primary closure via a thyrotomy. Laryngeal skeletal fractures should be reduced and fixated. Endolaryngeal stenting is reversed for massive mucosal trauma, comminuted fractures, and traumatic anterior commissure disruption. Conclusions Acute external injury to the larynx is both life threatening and a potential long-term management challenge. Although a rare injury, sufficient experience now exists to recommend specific treatments, and to preserve voice and airway function. Laryngoscope, 124:233–244, 2014
- Published
- 2012
15. Instrumentation for Endoscopic Sinus Surgery
- Author
-
Jonathan A. Lesserson and Steven D. Schaefer
- Subjects
medicine.medical_specialty ,Frontal sinus ,Maxillary sinus ,medicine.diagnostic_test ,business.industry ,medicine.disease ,Surgery ,Endoscopy ,Endoscopic sinus surgery ,medicine.anatomical_structure ,Chronic disease ,Otorhinolaryngology ,Laser therapy ,medicine ,Instrumentation (computer programming) ,Sinusitis ,business - Published
- 1994
- Full Text
- View/download PDF
16. Electromyographic and histologic evolution of the recurrent laryngeal nerve from transection and anastomosis to mature reinnervation
- Author
-
Michael J, Pitman, Philip, Weissbrod, Rick, Roark, Sansar, Sharma, and Steven D, Schaefer
- Subjects
Rats, Sprague-Dawley ,Electromyography ,Recurrent Laryngeal Nerve ,Anastomosis, Surgical ,Animals ,Female ,Rats - Abstract
To describe the natural evolution of recurrent laryngeal nerve (RLN) reinnervation in an animal model.Twenty Sprague Dawley rats underwent unilateral RLN transection and anastomosis. Animals were sacrificed at 4, 8, 12, 16, and 20 weeks. Prior to sacrifice, each rat underwent electromyography (EMG) and visual grading of vocal fold motion. Bilateral RLNs were harvested and evaluated histologically.EMG revealed synkinetic reinnervation at all time periods except at 4 weeks. EMG evolution plateaued at 16 weeks. Vocal fold motion was slight in three rats at 4 weeks but was otherwise absent except for one rat at 12 weeks. Histologic changes of the axons and their myelin sheaths were consistent at each time period. At 16 weeks, histologic changes plateaued.Consistent EMG, histologic, and vocal fold motion changes occur at specific time periods during RLN reinnervation after transection and anastomosis in a rat model. Reinnervation is mature at 16 weeks. Findings corroborate theories of preferential and synkinetic reinnervation after RLN transection. Use of a rat model to investigate the effect of interventions on RLN reinnervation requires a minimum of 16 weeks between transection and investigation to allow for maturation of reinnervation.
- Published
- 2011
17. Anatomy
- Author
-
Frank G. Shechtman, Warren M. Kraus, and Steven D. Schaefer
- Subjects
Otorhinolaryngology ,General Medicine - Published
- 1993
- Full Text
- View/download PDF
18. Difficult Decisions in Endoscopic Sinus Surgery
- Author
-
David W. Kennedy, Ernest A. Weymuller, Dale H. Rice, and Steven D. Schaefer
- Subjects
Endoscopic sinus surgery ,medicine.medical_specialty ,Paranasal sinuses ,medicine.anatomical_structure ,Otorhinolaryngology ,Paranasal Sinus Diseases ,medicine.diagnostic_test ,business.industry ,General surgery ,medicine ,General Medicine ,business ,Endoscopy - Abstract
In this article, case studies from four separate clinicians are presented along with comments. These cases offer unusual examples of problems that occur with endoscopic sinus surgery.
- Published
- 1993
- Full Text
- View/download PDF
19. Consequence of dysphagia in the hospitalized patient: impact on prognosis and hospital resources
- Author
-
Gou-Pei Yu, Kenneth W. Altman, and Steven D. Schaefer
- Subjects
Adult ,Male ,medicine.medical_specialty ,Comorbidity ,Aspiration pneumonia ,Risk Factors ,Cause of Death ,otorhinolaryngologic diseases ,medicine ,Humans ,Intensive care medicine ,Stroke ,Survival rate ,Cause of death ,Aged ,Esophageal disease ,business.industry ,General Medicine ,Length of Stay ,Middle Aged ,medicine.disease ,Prognosis ,Dysphagia ,United States ,Hospitalization ,Survival Rate ,Intervertebral disk ,Early Diagnosis ,Otorhinolaryngology ,Health Care Surveys ,Emergency medicine ,Surgery ,Female ,medicine.symptom ,business ,Deglutition Disorders - Abstract
Objective To determine if comorbid dysphagia in all hospitalized patients has the potential to prolong hospital stay and increase morbidity. Dysphagia is increasingly prevalent with age and comorbid medical conditions. Our research group has previously shown that dysphagia is a bad prognostic indicator in patients with stroke. Design Analysis of national database. Main Outcome Measures The National Hospital Discharge Survey (NHDS), 2005-2006, was evaluated for presence of dysphagia and the most common comorbid medical conditions. Patient demographics, associated disease, length of hospital stay, morbidity and mortality were also evaluated. Results There were over 77 million estimated hospital admissions in the period evaluated, of which 271 983 were associated with dysphagia. Dysphagia was most commonly associated with fluid or electrolyte disorder, esophageal disease, stroke, aspiration pneumonia, urinary tract infection, and congestive heart failure. The median number of hospitalization days for all patients with dysphagia was 4.04 compared with 2.40 days for those patients without dysphagia. Mortality increased substantially in patients with dysphagia associated with rehabilitation, intervertebral disk disorders, and heart diseases. Conclusions Dysphagia has a significant impact on hospital length of stay and is a bad prognostic indicator. Early recognition of dysphagia and intervention in the hospitalized patient is advised to reduce morbidity and length of hospital stay.
- Published
- 2010
20. Multichannel Electromyographic Observations in Spasmodic Dysphonia Patients and Normal Control Subjects
- Author
-
Rorert W. Butsch, Rick M. Roark, John Pohl, Ben C. Watson, Frances J. Freeman, George V. Kondraske, and Steven D. Schaefer
- Subjects
Adult ,Male ,medicine.medical_specialty ,Electromyography ,Audiology ,Spasmodic dysphonia ,Speech Acoustics ,03 medical and health sciences ,0302 clinical medicine ,Tongue ,otorhinolaryngologic diseases ,medicine ,Humans ,030223 otorhinolaryngology ,Normal control ,Aged ,Voice Disorders ,medicine.diagnostic_test ,Palate ,business.industry ,Muscles ,Motor control ,General Medicine ,Middle Aged ,medicine.anatomical_structure ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Laryngeal Muscle ,Female ,Laryngeal Muscles ,Abnormality ,medicine.symptom ,business ,Vocal tract - Abstract
Spasmodic dysphonia is primarily a disorder of vocalization. Increasing evidence, however, suggests that individuals with this disorder comprise a heterogeneous population characterized by abnormal motor control throughout the vocal tract. Multichannel simultaneous electromyography was performed on 11 spasmodic dysphonia patients and 10 normal awake subjects to investigate both the distribution of neuromotor abnormality within the vocal tract (eg, intrinsic and extrinsic laryngeal muscles, tongue, and palate) and the contribution of activation of higher central nervous system centers to observed abnormality. Experimental tasks ranged from vegetative (quiet breathing) to simple linguistic (short sentences). Digitized electromyographic signals were analyzed to compute the amplitude envelope and extract a set of parameters that represent amplitude characteristics. Electrode insertions were cross-validated by quantitative analysis of patterns of activation across selected reference tasks and by traditional qualitative methods. Between-group differences were found for measures of normalized median and peak token amplitudes. These differences are both task- and measure-dependent. Results highlight the complex and interactive effects of muscle, task, and quantitative measures on between-group differences.
- Published
- 1992
- Full Text
- View/download PDF
21. Observations of recurrent laryngeal nerve injury and recovery using a rat model
- Author
-
Sansar C. Sharma, Rick M. Roark, Philip A. Weissbrod, Michael J. Pitman, Steven D. Schaefer, and Belachew Tessema
- Subjects
medicine.medical_specialty ,Electromyography ,Rats, Sprague-Dawley ,Random Allocation ,Injury Severity Score ,Reference Values ,Biopsy ,Recurrent laryngeal nerve ,medicine ,Animals ,Respiratory system ,Probability ,medicine.diagnostic_test ,business.industry ,Recurrent Laryngeal Nerve ,Biopsy, Needle ,Recovery of Function ,medicine.disease ,Immunohistochemistry ,Surgery ,Nerve Regeneration ,Rats ,Electrophysiology ,Disease Models, Animal ,Microscopy, Electron ,Otorhinolaryngology ,Anesthesia ,Laryngeal Muscle ,Recurrent Laryngeal Nerve Injuries ,Crush injury ,Female ,business ,Vocal Cord Paralysis - Abstract
Objectives/Hypothesis: To evaluate standardized recurrent laryngeal nerve (RLN) injuries using a rat model via minimally invasive transoral electromyography (ToL EMG) and histologic studies. Methods: Forty-two female Sprague Dawley rats weighing 200 g to 250 g underwent crush injury to the right RLN using a calibrated pressure clip (0.61 N or 1.19 N) for 60 seconds. Following injury, serial ToL EMGs were performed on abductor and adductor laryngeal muscles during respiratory cycles and spontaneous vocal fold abduction on day 4 and then weekly for 6 weeks. Vocal fold motion associated with spontaneous respiration was graded from 0 to 4. Rats were sacrificed at different time points for histologic evaluation of injured nerves. Results: EMG signals showed fibrillation potentials on day 4 in all experimental conditions. Crushed RLN, regardless of force, exhibited polyphasic potentials at 2 weeks postinjury. Normal motor unit potentials and recruitment patterns were observed in EMG signals at 4 weeks for all 0.61 N clip animals. Six weeks following crush injury, motor unit potentials having normal appearance were observed in most animals. Synkinetic EMG signals were observed at 5 weeks and 6 weeks in the 1.19 N clip animals. Endoscopic evaluation of vocal fold mobility was consistently normal at 6 weeks only following 0.61 N crush injury. Conclusions: This model is useful to simulate intraoperative RLN injuries and to better understand the electrophysiologic events during nerve recovery. The severity of injury to the RLN dictates histologic, neurologic and functional recovery of the laryngeal motor system. This model is useful to evaluate the efficacy of systemic and local neurotropic agents in the treatment of RLN injury.
- Published
- 2009
22. Panel one: Applied Surgical anatomy and pathophysiology
- Author
-
Howard L. Levine, James Zinreich, William H. Friedman, John McMahan, Wolfgang Draf, Malte Eric Wigand, David W. Kennedy, Steven D. Schaefer, Heinz Stammberger, and Toshio Ohnishi
- Subjects
medicine.medical_specialty ,Otorhinolaryngology ,Surgical anatomy ,business.industry ,General surgery ,Medicine ,Surgery ,business ,Pathophysiology - Published
- 1991
- Full Text
- View/download PDF
23. Panel two: Surgery for specific problems and pediatrics
- Author
-
Mark May, Rodney P. Lusk, Howard L. Levine, David W. Kennedy, James A. Stankiewicz, Dale H. Rice, Nigel Pashley, Paul H. Toffel, Steven D. Schaefer, Rande H. Lazar, Heinz Stammberger, and Wolf J. Mann
- Subjects
medicine.medical_specialty ,Pediatrics ,Otorhinolaryngology ,business.industry ,medicine ,Surgery ,Intensive care medicine ,business - Published
- 1991
- Full Text
- View/download PDF
24. Laryngeal Electromyography
- Author
-
Steven D. Schaefer
- Subjects
Otorhinolaryngology ,General Medicine - Published
- 1991
- Full Text
- View/download PDF
25. Use of CT Scanning in the Management of the Acutely Injured Larynx
- Author
-
Steven D. Schaefer
- Subjects
Larynx ,medicine.medical_specialty ,education.field_of_study ,business.industry ,Population ,Laryngeal trauma ,General Medicine ,Surgery ,medicine.anatomical_structure ,Otorhinolaryngology ,medicine ,Surgical treatment ,education ,business - Abstract
An update regarding the selective application of CT scanning in acute laryngeal trauma is presented for a period encompassing 9 years. A study group of 16 patients from a larger population of 52 patients was identified as having undergone CT scanning as part of their clinical management. A rationale is presented for the use of scanning in certain injuries, and the outcome of medical and surgical treatment is discussed.
- Published
- 1991
- Full Text
- View/download PDF
26. Development of the ethmoid sinus and extramural migration: the anatomical basis of this paranasal sinus
- Author
-
Samuel Marquez, Peter A. R. Clement, Steven D. Schaefer, and Belachew Tessema
- Subjects
Histology ,Sphenoid Sinus ,Ethmoid Sinus ,Ethmoid sinus ,Pongo pygmaeus ,Paranasal Sinuses ,otorhinolaryngologic diseases ,medicine ,Paranasal Sinus Diseases ,Animals ,Humans ,Sinusitis ,Anatomical terms of location ,Ecology, Evolution, Behavior and Systematics ,Sinus (anatomy) ,Mammals ,business.industry ,Extramural ,Skull ,Ethmoidectomy ,History, 19th Century ,Anatomy ,History, 20th Century ,Maxillary Sinus ,medicine.disease ,eye diseases ,Radiography ,Ethmoid Bone ,medicine.anatomical_structure ,Paranasal sinuses ,Anatomical relationship ,Frontal Sinus ,Nasal Cavity ,business ,Biotechnology - Abstract
Frontal and/or maxillary sinusitis frequently originates with pathologic processes of the ethmoid sinuses. This clinical association is explained by the close anatomical relationship between the frontal and maxillary sinuses and the ethmoid sinus, since developmental trajectories place the ethmoid in a strategic central position within the nasal complex. The advent of optical endoscopes has permitted improved visualization of these spaces, leading to a renaissance in intranasal sinus surgery. Advancing patient care has consequently driven the need for the proper and accurate anatomical description of the paranasal sinuses, regrettably the continuing subject of persistent confusion and ambiguity in nomenclature and terminology. Developmental tracking of the pneumatization of the ethmoid and adjacent bones, and particularly of the extramural cells of the ethmoid, helps to explain the highly variable adult morphology of the ethmoid air sinus system. To fully understand the nature and underlying biology of this sinus system, multiple approaches were employed here. These include CT imaging of living humans (n = 100), examination of dry cranial material (n = 220), fresh tissue and cadaveric anatomical dissections (n = 168), and three-dimensional volume rendering methods that allow digitizing of the spaces of the ethmoid sinus for graphical examination. Results show the ethmoid sinus to be highly variable in form and structure as well as in the quantity of air cells. The endochondral bony origin of the ethmoid sinuses leads to remarkably thin bony contours of their irregular and morphologically unique borders, making them substantially different from the other paranasal sinuses. These investigations allow development of a detailed anatomical template of this region based on observed patterns of morphological diversity, which can initially mask the underlying anatomy. For example, the frontal recess, ethmoid infundibulum, and hiatus semilunaris are key anatomical components of the ethmoid structural complex that are fully documented and explained here on the basis of the template we have developed, as well as being comprehensively illustrated. In addition, an exhaustive 2000-year literature search identified original sources of nomenclature, in order to help clarify the persistent confusions found in the literature. Modified anatomical terms are suggested to permit proper description of the ethmoid region. This clarification of nomenclature will permit better communication in addition to eliminating redundant terminology. The combination of anatomical, evolutionary, and clinical perspectives provides an important strategy for gaining insight into the complexity of these sinuses.
- Published
- 2008
27. Evaluation of functional recovery of recurrent laryngeal nerve using transoral laryngeal bipolar electromyography: a rat model
- Author
-
Steven D. Schaefer, Craig Berzofsky, Rick M. Roark, Michael J. Pitman, Sansar C. Sharma, and Belachew Tessema
- Subjects
Larynx ,medicine.medical_specialty ,Iatrogenic Disease ,Electromyography ,Lesion ,Rats, Sprague-Dawley ,Aneurysm ,medicine ,Recurrent laryngeal nerve ,Animals ,Intraoperative Complications ,Mouth ,medicine.diagnostic_test ,business.industry ,General Medicine ,Recovery of Function ,medicine.disease ,Surgery ,Rats ,Clamp ,medicine.anatomical_structure ,Otorhinolaryngology ,Anesthesia ,Crush injury ,Adductor muscles ,medicine.symptom ,business ,Vocal Cord Paralysis - Abstract
Objectives: We developed a standardized method of minimally invasive transoral laryngeal (ToL) bipolar electromyography (EMG) for evaluation of recurrent laryngeal nerve (RLN) recovery after a controlled crush injury in a rat model. Methods: Ten 200- to 250-g Sprague-Dawley rats underwent a controlled crush injury to the left RLN performed with 60 seconds of use of a calibrated aneurysm clamp with a closing force of 0.61 N. Serial ToL bipolar EMG was performed on adductor muscles and the posterior criocoarytenoid muscle during spontaneous vocal fold motion under anesthesia. Each animal underwent ToL EMG immediately after surgery and 1, 3, and 6 weeks after surgery. Results: The EMG signals showed normal motor unit potentials and recruitment patterns 3 weeks after crush injury. Endoscopic evaluation of vocal fold mobility yielded consistently normal findings 6 weeks after crush injury. Conclusions: We have developed a standardized method of crush injury to the rat RLN model and a minimally invasive transoral bipolar spontaneous EMG technique to serially evaluate and follow nerve injury and recovery in rats. This model is intended to simulate intraoperative RLN injury, to elucidate the electrophysiological events that occur during nerve recovery, and to form the basis for studying agents to enhance such recovery.
- Published
- 2008
28. The effect of intentional cranial deformation on frontal sinus development and morphology
- Author
-
Samuel Marquez, Belachew Tessema, William Lawson, and Steven D. Schaefer
- Subjects
Frontal sinus ,medicine.anatomical_structure ,business.industry ,Genetics ,medicine ,Morphology (biology) ,Anatomy ,business ,Molecular Biology ,Biochemistry ,Cranial deformation ,Biotechnology - Published
- 2008
- Full Text
- View/download PDF
29. Evidence for cortical dysfunction in spasmodic dysphonia: Regional cerebral blood flow and quantitative electrophysiology*1
- Author
-
F. J. Freeman, T. Finitzo, K. D. Pool, B. C. Watson, George V. Kondraske, Michael D. Devous, Sandra B. Chapman, and Steven D. Schaefer
- Subjects
Linguistics and Language ,medicine.medical_specialty ,medicine.diagnostic_test ,Cognitive Neuroscience ,Experimental and Cognitive Psychology ,Magnetic resonance imaging ,Electroencephalography ,Spasmodic dysphonia ,Brain mapping ,Language and Linguistics ,Speech and Hearing ,Electrophysiology ,medicine.anatomical_structure ,Cerebral blood flow ,Cerebral cortex ,Internal medicine ,medicine ,Cardiology ,medicine.symptom ,Psychology ,Neuroscience ,Emission computed tomography - Abstract
Cortical function was evaluated in 26 subjects with spasmodic dysphonia. Quantitative topographic electrophysiologic mapping (QTE) was employed to provide quantitative analyses of EEG spectra and auditory and visual long-latency evoked potentials. Single-photon emission computed tomography (SPECT) of the cerebral transit of Xenon-133 was used to evaluate regional cerebral blood flow. Left hemispheric abnormalities in cortical function were found by both techniques in 10 subjects and by at least one technique in 18 subjects. Right hemispheric abnormalities were observed by both techniques in 8 subjects and by at least one technique in 18 subjects. Most patients with cortical dysfunction in one hemisphere had cortical dysfunction in the other, while only 4 subjects had unilateral lesions as found by one of the two techniques. Eight subjects were normal by all measurements. Underlying structural abnormalities were detected by magnetic resonance imaging in 5/24 subjects. However, functional abnormalities (SPECT or QTE) were not observed at sites of structural abnormalities. SPECT and QTE were significantly related in identification of left hemispheric dysfunction (p = .037) with a trend in the right hemisphere (p = .070), and a significant congruence of SPECT and QTE findings occurred in the left anterior cortical quadrant (p = .011). These findings indicate that dysfunction of cortical perfusion and/or cortical electrophysiology is associated with spasmodic dysphonia in the majority of subjects studied.
- Published
- 1990
- Full Text
- View/download PDF
30. Endoscopic sinus surgery: Posterior approach
- Author
-
Steven D. Schaefer
- Subjects
Endoscopic sinus surgery ,medicine.medical_specialty ,Otorhinolaryngology ,business.industry ,Sinus disease ,otorhinolaryngologic diseases ,medicine ,Surgery ,In patient ,Sinus surgery ,business ,Posterior approach - Abstract
The posterior approach to sphenoethmoidectomy represents an alternative to the better known modifications of endoscopic paranasal sinus surgery. We present our modifications and experience with this technique over the last 4 years, and explain our rationale for selection of patients to be managed by this approach. This operation has proven useful in patients with extensive sinus disease, and/or previous surgery that has resulted in loss of normal anatomic landmarks to the sinuses.
- Published
- 1990
- Full Text
- View/download PDF
31. In endoscopic sinus surgery
- Author
-
Steven D. Schaefer, Dale H. Rice, David W. Kennedy, and Ernest A. Weymuller
- Subjects
Endoscopic sinus surgery ,medicine.medical_specialty ,Otorhinolaryngology ,business.industry ,Medicine ,Surgery ,business - Published
- 1990
- Full Text
- View/download PDF
32. The acute surgical treatment of the fractured larynx
- Author
-
Steven D. Schaefer
- Subjects
Larynx ,medicine.medical_specialty ,Laryngology ,business.industry ,medicine.anatomical_structure ,Otorhinolaryngology ,medicine ,Surgery ,Treatment decision making ,Intensive care medicine ,Surgical treatment ,Airway ,business ,Neck trauma - Abstract
The acute surgical management of the severely injured larynx is among the more demanding problems in laryngology, with early treatment decisions determining the outcome of both the airway and voice. To assist the physician with such decision-making, we report the rationale and operative techniques used at our institution to surgically manage 62 of 120 patients with acute laryngeal injuries for more than two decades. Such experience hopefully will also serve to help resolve several of the prevailing controversies over the care of such patients.
- Published
- 1990
- Full Text
- View/download PDF
33. Dacryocystorhinostomy Surgical Technique
- Author
-
Manuel Tomás-Barberán, Manuel Bernal-Sprekelsen, Steven D. Schaefer, Isam Alobid, and R. C. Della Rocca
- Subjects
medicine.medical_specialty ,Mucosal flap ,Topical anesthesia ,business.industry ,medicine.medical_treatment ,SEPTAL DEVIATION ,Dacryocystorhinostomy ,medicine ,Uncinate Process ,business ,Surgery - Published
- 2007
- Full Text
- View/download PDF
34. Nasolacrimal System Injuries
- Author
-
Syed M Ahmad, R. C. Della Rocca, D. A. Della Rocca, Steven D. Schaefer, and P. Preechawi
- Subjects
Medial orbital wall ,Nasolacrimal duct ,medicine.anatomical_structure ,Lacrimal duct ,business.industry ,medicine ,Anatomy ,business - Published
- 2007
- Full Text
- View/download PDF
35. Assessing and documenting general competencies in otolaryngology resident training programs
- Author
-
Wei-Nchih Lee, Rick M. Roark, Stephen J. Peterson, Steven D. Schaefer, Guopei Yu, and Daniel I. Branovan
- Subjects
Adult ,Male ,medicine.medical_specialty ,Interprofessional Relations ,education ,Graduate medical education ,MEDLINE ,Documentation ,Sensitivity and Specificity ,Otolaryngology ,medicine ,Humans ,Accreditation ,Probability ,Internet ,Physician-Patient Relations ,business.industry ,Internship and Residency ,Usability ,Peer group ,Otorhinolaryngology ,Convergent validity ,Education, Medical, Graduate ,Family medicine ,Feasibility Studies ,Female ,Clinical Competence ,Educational Measurement ,business - Abstract
Objectives: The objectives of this study were to: 1) implement web-based instruments for assessing and documenting the general competencies of otolaryngology resident education, as outlined by the Accreditation Council of Graduate Medical Education (ACGME); and 2) examine the benefit and validity of this online system for measuring educational outcomes and for identifying insufficiencies in the training program as they occur. Methods: We developed an online assessment system for a surgical postgraduate education program and examined its feasibility, usability, and validity. Evaluations of behaviors, skills, and attitudes of 26 residents were completed online by faculty, peers, and nonphysician professionals during a 3-year period. Analyses included calculation and evaluation of total average performance scores of each resident by different evaluators. Evaluations were also compared with American Board of Otolaryngology-administered in-service examination (ISE) scores for each resident. Convergent validity was examined statistically by comparing ratings among the different evaluator types. Results: Questionnaires and software were found to be simple to use and efficient in collecting essential information. From July 2002 to June 2005, 1,336 evaluation forms were available for analysis. The average score assigned by faculty was 4.31, significantly lower than that by nonphysician professionals (4.66) and residents evaluating peers (4.63) (P < .001), whereas scores were similar between nonphysician professionals and resident peers. Average scores between faculty and nonphysician groups showed correlation in constructs of communication and relationship with patients, but not in those of professionalism and documentation. Correlation was observed in respect for patients but not in medical knowledge between faculty and resident peer groups. Resident ISE scores improved in the third year of the study and demonstrated high correlation with faculty perceptions of medical knowledge (r = 0.65, P = .007). Conclusions: Compliance for completion of forms was 97%. The system facilitated the educational management of our training program along multiple dimensions. The small perceptual differences among a highly selected group of residents have made the unambiguous validation of the system challenging. The instruments and approach warrant further study. Improvements are likely best achieved in broad consultation among other otolaryngology programs.
- Published
- 2006
36. The Edwin Smith Papyrus: the birth of analytical thinking in medicine and otolaryngology
- Author
-
Marc Stiefel, Steven D. Schaefer, and Arlene Shaner
- Subjects
Modern medicine ,media_common.quotation_subject ,Egypt, Ancient ,Ancient Greek ,engineering.material ,symbols.namesake ,Otolaryngology ,Medicine ,Humans ,History, Ancient ,media_common ,Hippocratic Oath ,Civilization ,business.industry ,Papyrus ,Manuscripts, Medical as Topic ,Magic (paranormal) ,language.human_language ,Ancient Greece ,Otorhinolaryngology ,General Surgery ,language ,symbols ,engineering ,Wounds and Injuries ,business ,Mysticism ,Classics - Abstract
The Edwin Smith Papyrus, discovered in 1862 outside of Luxor, Egypt, is the oldest known surgical text in the history of civilization. The surviving scroll, a copy of an earlier text from around 3,000 B.C., gives us remarkable insight into the medical practice of ancient Egyptians in the Nile River bed during the dawn of civilization. The Papyrus is divided into 48 cases, most of which describe traumatic injuries. The text instructs the physician to examine the patient and look for revealing physical signs that may indicate the outcome of the injury. Although in modern medicine we take for granted that the use of physical examination and rational thinking lead to an accurate conclusion, 5,000 years ago, this was extraordinary. The Edwin Smith Papyrus cast aside the prevailing magic and mysticism of that time in favor of logic and deductive reasoning. As Egyptian civilization declined during the next millennium, the teachings of the Papyrus would be lost. It would not be until 300 B.C. when Hippocrates and his disciples in ancient Greece would once again revive logic in medical thinking and teaching. It is believed that the ancient Greeks had knowledge of the contents of the Edwin Smith Papyrus and its teachings and used them as the basis for their writings. As Europe entered the Dark Ages, so did medicine yet again, reverting to spells and prayers instead of judgment and reason. Although Hippocrates teachings were recognized by some scholars during the Middle Ages, they did not make up the basis for mainstream medical knowledge. With the dawn of the Renaissance, medicine would finally purge itself of its past supernatural foundation. Hippocratic teachings were used to form the basis of modern medicine, and medical pioneers in the 17 century studied the ancient Greek texts as the origin for their ideas. Many of the concepts physicians and patients today take as common knowledge originated in the Edwin Smith Papyrus. The authors attempt to uncover some of these fundamental ideas and trace them through time until their incorporation in our modern medical knowledge base. It is the rational, logical, and advanced thinking exhibited in the Edwin Smith Papyrus that mandates its respect from modern otolaryngologists and all physicians alike.
- Published
- 2006
37. A simple method for fixation and microdissection of frozen fresh tissue sections for molecular cytogenetic analysis of cancers
- Author
-
J Mo, L Guo, P G Sacks, Steven A. McCormick, Stimson P. Schantz, Qiang Huang, Steven D. Schaefer, and Codrin Iacob
- Subjects
Histology ,Tissue Fixation ,Biopsy ,DNA Mutational Analysis ,H&E stain ,Cell Culture Techniques ,Biology ,law.invention ,Tissue Culture Techniques ,chemistry.chemical_compound ,law ,Fresh Tissue ,Cell Line, Tumor ,Humans ,Polymerase chain reaction ,Microdissection ,Fixation (histology) ,Chromosome Aberrations ,Cryopreservation ,General Medicine ,DNA, Neoplasm ,Molecular biology ,Staining ,Medical Laboratory Technology ,chemistry ,Cytogenetic Analysis ,Carcinoma, Squamous Cell ,DNA ,Comparative genomic hybridization - Abstract
Microdissection has been widely used for procuring DNA from specific microscopic regions of formalin fixed, paraffin embedded tissue sections. We have developed a method for fixation and microdissection of frozen fresh biopsy tissue sections. Five micrometer frozen fresh tissue sections were fixed with ethanol and stored at room temperature. Well defined regions from hematoxylin and eosin (H & E) stained or unstained sections were briefly steamed and microdissected using a needle. The dissected tissue was digested with proteinase K and DNA was isolated. Whole genome amplifications were obtained by degenerate oligonucleotide primed polymerase chain reaction (DOP-PCR) from these samples. The reliability of this technique was demonstrated by comparing conventional comparative genomic hybridization (CGH) with DOP-PCR-CGH. The advantages of this method are that frozen fresh sections can be fixed easily and stored for more than 4 years, it is easy to microdissect and pick-up very minute regions (0.1 mm(2)), and it is rapid; microdissection and purification can be accomplished within 3 h. Using DNA from microdissected sections, DOP-PCR-CGH revealed genetic abnormalities more accurately than conventional CGH. Although this novel method was demonstrated using DOP-PCR-CGH, we believe that it will be useful for other genetic analyses of specific small regions and cell populations. We also observed whether storage time, H & E staining and crude DNA extracts affected the quality of amplified DNA. DNA integrity was maintained for at least 49 months in ethanol fixed sections that were stored at room temperature, but DNA was gradually degraded after one month if the ethanol fixed sections had been H & E stained and stored. When crude DNA extracts from H & E stained sections were used, the size of the DOP-PCR product was reduced. Our study suggests that ethanol fixed tissue sections may be stored at room temperature for at least 4 years without DNA degradation, the H & E stains may not affect the quality of amplified DNA, but H & E or other components in the staining process may reduce the size of DOP-PCR product, which is critical for the quality of CGH hybridization.
- Published
- 2005
38. 3,3'-Diindolylmethane, a cruciferous vegetable derived synthetic anti-proliferative compound in thyroid disease
- Author
-
Steven D. Schaefer, Augustine Moscatello, Yuangen Chen, Jan Geliebter, Yushan Chang, Raj K. Tiwari, Badithe T. Ashok, Kiranmayi Tadi, Anthony Policastro, and Stimsom P. Schantz
- Subjects
endocrine system ,medicine.medical_specialty ,3,3'-Diindolylmethane ,Goiter ,Indoles ,endocrine system diseases ,genetic structures ,Cell Survival ,Biophysics ,Diindolylmethane ,Apoptosis ,Biology ,Biochemistry ,chemistry.chemical_compound ,Internal medicine ,Cell Line, Tumor ,Vegetables ,medicine ,Anticarcinogenic Agents ,Humans ,Thyroid Neoplasms ,Molecular Biology ,Thyroid cancer ,Cell Proliferation ,Dose-Response Relationship, Drug ,Cruciferous vegetables ,Cell growth ,Plant Extracts ,Thyroid disease ,Thyroid ,Cell Biology ,medicine.disease ,medicine.anatomical_structure ,Endocrinology ,chemistry ,sense organs - Abstract
Considerable epidemiological evidence exists to link thyroid disease with differing patterns of dietary consumption, in particular, cruciferous vegetables. We have been studying the anti-thyroid cancer (TCa) activity of indole-3-carbinol (I3C) found in cruciferous vegetables and its acid catalyzed dimer, 3,3'-diindolylmethane (DIM). There are no studies as yet to elucidate the effect of these compounds on the altered proliferative patterns in goiter or thyroid neoplasia. In this study, we tested the anti-proliferative effects of I3C and DIM on four different thyroid cancer cell lines representative of papillary (B-CPAP and 8505-C) and follicular carcinoma of the thyroid (CGTH-W-1 and ML-1), and primary human goiter cells. Cell survival and IC50 values for I3C and DIM were calculated by the XTT assay and cell cycle distribution analysis was done by flow cytometry. DIM was found to be a better anti-proliferative agent than I3C in both papillary and follicular TCa resulting in a greater cytotoxic effect at a concentration over three fold lower than predicted by the molar ratio of DIM and I3C. The anti-proliferative activity of DIM in follicular TCa was mediated by a G1 arrest followed by induction of apoptosis. DIM also inhibited the growth of primary goiter cells by 70% compared to untreated controls. Contrary to traditional belief that cruciferous vegetables are "goitrogenic", DIM has anti-proliferative effects in glandular thyroid proliferative disease. Our preclinical studies provide a strong rationale for the clinical exploration of DIM as an adjuvant to surgery in thyroid proliferative disease.
- Published
- 2005
39. Neurosurgical implications of allergic fungal sinusitis
- Author
-
William T. Couldwell, Steven D. Schaefer, Augustine Moscatello, and James K. Liu
- Subjects
Adult ,Male ,medicine.medical_specialty ,Rhinitis, Allergic, Perennial ,Endoscope ,Adolescent ,Diagnosis, Differential ,Nasal Polyps ,Immunopathology ,Eosinophilic ,medicine ,Humans ,Sinusitis ,Child ,Mycosis ,Retrospective Studies ,Patient Care Team ,business.industry ,Chronic sinusitis ,Soft tissue ,Endoscopy ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Surgery ,Skull ,Nasal Mucosa ,medicine.anatomical_structure ,Mycoses ,Chronic Disease ,Female ,Radiology ,business ,Tomography, X-Ray Computed ,Craniotomy - Abstract
Object. Allergic fungal sinusitis (AFS) is a form of paranasal mycosis that often involves bone destruction and extension into the orbit and anterior skull base. Treatment consists of surgical extirpation and a course of corticosteroids. Despite frequent intracranial involvement, AFS is rarely reported in the neurosurgical literature. Methods. The records of 21 patients with the histological diagnosis of AFS were reviewed. The histological diagnosis was based on findings of branching septated fungi interspersed with eosinophilic mucin and Charcot—Leyden crystals without fungal invasion of soft tissue. The average age of the 21 patients in this study was 25 years (range 9–46) and the male/female ratio was 3.75:1. All patients were immunocompetent. All had a history of chronic sinusitis and imaging findings of expansile disease involving multiple sinuses. Fifteen patients had nasal polyposis, eight had erosion of bone, which was observed on computerized tomography (CT) scans, eight had disease extending intracranially, and six had disease that involved the lamina papyracea. All patients underwent transnasal and/or transmaxillary endoscopic approaches for debridement and irrigation, six underwent orbital decompression, and three underwent a bifrontal craniotomy for removal of intracranial extradural disease. No patient had a cerebrospinal fluid leak. Postoperatively, one patient was treated with amphotericin B and the other 20 were treated with a short course of corticosteroids. The follow-up period ranged from 2 to 19 years. Conclusions. Allergic fungal sinusitis is a unique form of fungal disease that may mimic anterior skull base and paranasal sinus tumors. A cranial base team approach of neurosurgeons and otolaryngologists is recommended. Most cases can be successfully managed with transnasal and/or transmaxillary endoscopic techniques. A craniotomy is rarely indicated unless there is the suspicion of dural invasion or extensive intracranial and/or intraorbital involvement that is inaccessible from below.
- Published
- 2004
40. Use of sodium fluorescein solution for detection of cerebrospinal fluid fistulas: an analysis of 420 administrations and reported complications in Europe and the United States
- Author
-
Steven D. Schaefer, A. Wienke, Wolfgang Draf, Rainer Weber, and Rainer Keerl
- Subjects
Adult ,Male ,medicine.medical_specialty ,Adolescent ,Fistula ,Cerebrospinal Fluid Rhinorrhea ,chemistry.chemical_compound ,Lumbar ,Cerebrospinal fluid ,medicine ,Humans ,Fluorescein ,Adverse effect ,Child ,Injections, Spinal ,Aged ,Cerebrospinal Fluid ,Retrospective Studies ,Aged, 80 and over ,Skull Base ,rhinorrhea ,medicine.diagnostic_test ,business.industry ,Lumbar puncture ,Headache ,Infant ,Middle Aged ,medicine.disease ,United States ,Surgery ,Europe ,Otorhinolaryngology ,chemistry ,Anesthesia ,Child, Preschool ,Female ,Epilepsy, Tonic-Clonic ,medicine.symptom ,business ,Complication ,Grand mal seizure - Abstract
Background Localization of dural fistulas in the region of the anterior or lateral skull base may be difficult. For many years, a sodium fluorescein solution of 0.5 to 5% (2.5-50 mg) has been administered intrathecally by way of the lumbar space. However, fluorescein is not commercially available for this stated purpose in either Germany or the United States. Methods Retrospectively, 420 fluorescein applications by the authors were retrospectively analyzed. Under the Freedom of Information Act, the United States Federal Drug Administration and the manufactures of fluorescein were queried for adverse reaction reports. Results Four hundred twenty fluorescein applications in 305 patients could be evaluated. Mean age of recipients was 46.9 years, ranging from 1 to 82 years. At a concentration of 5% fluorescein, 26 patients on the day of surgery and 69, 37, 34, and 14 patients on days 2 through 4 suffered from minor side effects that may or may not have been related to this drug. Two of these patients had grand mal seizures, which were attributable to simultaneous intrathecal application of contrast medium. All other side effects were thought to be the result of a postspinal headache and related lumbar puncture. At a concentration of 0.5%, the intraoperative intrathecal administration of 0.5 to 2 mL of fluorescein followed by 4 to 5 days of lumbar drainage resulted in some degree of spinal headache without other complications. In both groups, no patient had sequelae longer than 4 weeks. An additional seven complications were reported to the Federal Drug Administration and the fluorescein manufacturers at doses of 100 to 700 mg. Conclusions Complications from intrathecal application of fluorescein appears to be dose dependent. At concentrations of 5%, or preferably lower, side effects are transient. A grand mal seizure can be minimized when following the general cautions of lumbar puncture and dose. The patient should be supervised for 24 hours. A written informed consent from patients for use of fluorescein is recommended.
- Published
- 2004
41. Multiple motor unit recordings of laryngeal muscles: the technique of vector laryngeal electromyography
- Author
-
Rick M. Roark, Alexander Adam, James C. L. Li, Carlo J. De Luca, and Steven D. Schaefer
- Subjects
Larynx ,Adult ,Male ,Motor Neurons ,medicine.diagnostic_test ,business.industry ,Electromyography ,Central nervous system ,Muscle Fibers, Skeletal ,Signal Processing, Computer-Assisted ,Anatomy ,Laryngeal electromyography ,Motor neuron ,Motor unit ,medicine.anatomical_structure ,Otorhinolaryngology ,Laryngeal Muscle ,medicine ,Humans ,Thyroarytenoid muscle ,Female ,Laryngeal Muscles ,business ,Neuroscience - Abstract
Objectives To display time-series firing rate and recruitment data for multiple, simultaneously active motoneurons activating human laryngeal muscles. These data provide specific information about how laryngeal muscle force is being controlled by the central nervous system at the level of the lower motoneuron. Methods A quadrifilar needle electrode was used to record multi-channel myoelectric signals from thyroarytenoid muscle of normal subjects during tasks ranging from quiet breathing to a short sentence. Motor unit action potentials of the signal space were identified and tracked throughout task productions using pattern recognition and Precision Decomposition software. Results We present the first recordings and analyses of multiple motor unit activations in the larynx. The firing times and mean firing rates are plotted for each identified motor unit, which reveal recruitment and decruitment information and the database from which common firing statistics across motor units may be derived. Conclusions This study provides new information about neuromuscular physiology of the larynx. Specifically, the results reveal the ordered recruitment and firing patterns of multiple motor units and the existence of common drive from the central nervous system. The technique may prove fundamental to understanding various neuromuscular pathologies such as laryngeal spasm and to assist clinical prognosis of laryngeal paresis and the diagnosis of certain neurogenic disorders.
- Published
- 2002
42. Modified infratemporal fossa approach via lateral transantral maxillotomy: a microsurgical model
- Author
-
Steven D. Schaefer, Ibrahim Sabit, and William T. Couldwell
- Subjects
Models, Anatomic ,Microsurgery ,Maxillary sinus ,Skull Base Neoplasms ,Postoperative Complications ,stomatognathic system ,Clivus ,otorhinolaryngologic diseases ,Medicine ,Humans ,Trigeminal nerve ,Facial Nerve Injuries ,business.industry ,Infratemporal fossa ,Temporal Bone ,Anatomy ,Maxillary Sinus ,Facial nerve ,Temporomandibular joint ,medicine.anatomical_structure ,Sella turcica ,Cranial Fossa, Posterior ,Cavernous sinus ,Surgery ,Neurology (clinical) ,business - Abstract
BACKGROUND Lateral approaches have traditionally been used to gain access to lesions of the infratemporal fossa (ITF). However, dysfunction of the facial nerve secondary to its translocation, conductive hearing loss, and dental malocclusion because of mandibular head resection or dislocation are significant limitations associated with some of these approaches. Although facial nerve translocation and extended maxillotomy approaches avoid some of these drawbacks, they are invasive and require extensive osteotomies and facial incisions. To avoid these potential complications and maintain an extranasal/extraoral exposure, we studied the use of a lateral and posterior extension of an anterior transmaxillary approach to the cavernous sinus. METHODS The study was performed on 12 cadaver specimens and two dry skulls. An initial nasolabial fold incision, followed by an en bloc osteotomy of the anterior and lateral maxilla provides a window into the medial ITF. After osteotomy of the pterygoid plate and the posterior maxillary wall, the floor of the middle fossa is exposed to reveal the mandibular and maxillary divisions of the trigeminal nerve exiting their respective foramina. The floor of the middle fossa is then drilled postero-medial to the foramen ovale to gain access to the course of the C3-C4 portion of the petrous carotid artery and the eustachian tube. The upper two-thirds of the clivus and the pituitary gland are accessed after drilling of the floor of the sella turcica and form the posterior limit of this exposure. RESULTS The technique offers a trajectory to the medial ITF and skull base that does not necessitate palatal splitting or opening of the nasopharynx. The anterior route avoids temporomandibular joint disruption, and spares the lacrimal apparatus and all branches of the facial nerve. In addition, the reflected pterygoid muscle can be used as a vascularized flap for closure of the skull base defect. CONCLUSION The approach may be an alternative less invasive approach to the ITF and may be suitable for ITF lesions that have minimal lateral or intracranial extension.
- Published
- 2002
43. Approaches to the sellar and parasellar region: anatomic comparison of the microscope versus endoscope
- Author
-
William T. Couldwell, Augustine Moscatello, Chedioze Nwagu, William R. Spencer, Eugene J. Wenk, Steven D. Schaefer, and Kaushik Das
- Subjects
medicine.medical_specialty ,Microscopy ,Microscope ,Surgical approach ,medicine.diagnostic_test ,Endoscope ,business.industry ,medicine.medical_treatment ,Endoscopy ,Microsurgery ,law.invention ,Surgery ,Sella turcica ,medicine.anatomical_structure ,Otorhinolaryngology ,law ,Cadaver ,medicine ,Humans ,Sella Turcica ,Nuclear medicine ,business ,Operating microscope - Abstract
Objective Traditionally, surgical approaches to the sellar region require the use of the operating microscope. Over the past decade endoscopic surgery has gained much popularity because of advances in optics and illumination. Endoscopic surgery of the sellar region has been performed successfully. The goal of the present study was to quantify the amount of exposure to the sellar and suprasellar region that the endoscope provides versus the microscope, with three different anterior approaches to the sellar region. Methods The transethmoidal, endonasal-transsphenoidal, and sublabial-transsphenoidal approaches were performed on 14 formalin-fixed cadaver heads with a 0 degrees endoscope and repeated with the operative microscope. The distances of relevant surgical landmarks and the amount of exposure superior and anterior to the dorsum sella, as well as the lateral exposure, were measured. The mean distances were then used to calculate the volume of exposure for each of the approaches. Results It was found that the endoscope provided greater view than the operating microscope in all three approaches. The difference was statistically significant using a paired Student t test and a signed-rank test (P Conclusion The authors believe that endoscopic surgery of the sellar region can be performed safely and effectively, while providing the surgeon with a view that is superior to that afforded by the operating microscope.
- Published
- 1999
44. Endoscopic frontal sinusotomy
- Author
-
Steven D. Schaefer
- Subjects
medicine.medical_specialty ,Frontal sinus ,business.industry ,Surgery ,Frontal sinusotomy ,medicine.anatomical_structure ,Otorhinolaryngology ,Frontal recess ,Intranasal approach ,Frontal Sinusitis ,Medicine ,Initial treatment ,business ,Chronic frontal sinusitis - Abstract
For 11 years, we primarily relied on frontal sinus oblit eration with fat via an osteoplastic flap approach to treat the majority of patients with medically refractive, chronic frontal sinusitis. For the past 4 years, we have primarily used an endoscopic, intranasal approach for initial surgi cal management of patients with disease similar to those treated in the earlier ll-year period. We made this tran sition to endoscopic frontal sinusotomy because of the following: 1. The advent of rigid fiberoptic endoscopes provides excellent visualization of the frontal recess and medial frontal sinus. 2. Recognition of the role of the anterior ethmoids in recurrent frontal sinusitis and the ability afforded to op erate at this site by endoscopes. 3. Knowledge of such surgery being used in Europe. 4. Our desire to minimize the surgical technique for the initial treatment of medically refractive disease.l" Last year, we reported our initial experience with en doscopic frontal sinusotomy. This article updates that experience and better describes our surgical technique. 1
- Published
- 1990
- Full Text
- View/download PDF
45. An anatomic approach to endoscopic intranasal ethmoidectomy
- Author
-
Steven D. Schaefer
- Subjects
Adult ,Male ,Reoperation ,medicine.medical_specialty ,Adolescent ,Sphenoid Sinus ,Intranasal ethmoidectomy ,Nasal Polyps ,Ethmoid Sinus ,medicine ,Humans ,Revision rate ,Ethmoidectomies ,Sinusitis ,Child ,Sinus (anatomy) ,Aged ,Retrospective Studies ,Aged, 80 and over ,Skull Base ,business.industry ,Ethmoidectomy ,Retrospective cohort study ,Endoscopy ,Maxillary Sinus ,Middle Aged ,Surgery ,Airway Obstruction ,Skull ,medicine.anatomical_structure ,Otorhinolaryngology ,Acute Disease ,Chronic Disease ,Frontal Sinus ,Female ,University teaching ,Safety ,business ,Paranasal Sinus Neoplasms ,Follow-Up Studies - Abstract
Objectives: To develop an anatomic and functionally based approach to endoscopic intranasal ethmoidectomy. To develop such an approach using the salient features of the anterior to posterior (AP) and posterior to anterior (PA) intranasal sinus operations. To assess the safety of this form of ethmoidectomy in a patient population. Study Design: Retrospective chart review of patients undergoing ethmoidectomy by author or by residents under his direct supervision. Setting : University teaching hospital. In the 509 patients meeting study criteria, 168 anterior ethmoidectomies, 586 total ethmoidectomies, 264 sphenoidotomies, 290 frontal sinusotomies, and 838 antrostomies were performed between April 1992 and August 1997. Results: A complication rate of 0.98% and revision rate 2.9% were observed. Conclusions: Combining an AP approach to conserve sinus anatomy with a PA approach to avoid surgery directed toward the skull base provides a functional and safe procedure as demonstrated by the reported results.
- Published
- 1998
46. Subcommittee on Neurolaryngology
- Author
-
Charles Kashima, Paul W. Flint, Michael S. Benninger, Steven D. Schaefer, Ira Sanders, Al Hillel, and Andrew Blitzer
- Subjects
medicine.medical_specialty ,Otorhinolaryngology ,business.industry ,Family medicine ,Medicine ,Surgery ,business - Published
- 1995
- Full Text
- View/download PDF
47. Time-frequency analyses of thyroarytenoid myoelectric activity in normal and spasmodic dysphonia subjects
- Author
-
Ben C. Watson, R.D. DeGroat, Eric M. Dowling, Steven D. Schaefer, and Rick M. Roark
- Subjects
Adult ,Male ,Linguistics and Language ,medicine.medical_specialty ,Sound Spectrography ,Time Factors ,Feature vector ,medicine.medical_treatment ,Electromyography ,Audiology ,Spasmodic dysphonia ,Severity of Illness Index ,Language and Linguistics ,Standard deviation ,Speech Acoustics ,Speech and Hearing ,Phonetics ,medicine ,Valsalva maneuver ,Humans ,Thyroarytenoid muscle ,Center frequency ,Mathematics ,Aged ,Voice Disorders ,medicine.diagnostic_test ,Spectral density ,Middle Aged ,Muscle Spasticity ,Female ,medicine.symptom ,Laryngeal Muscles - Abstract
Digital recordings of thyroarytenoid (TA) myoelectric activity (via percutaneous hooked-wire electrodes) were obtained for 10 normal control subjects and 10 subjects with spasmodic dysphonia during performance of five tasks of varying complexity: quiet breathing, Valsalva maneuver, whispered / i /, voiced / i /, and “beep beep went the heap.” Time-frequency power spectral density functions, PSD ( f , t ), were determined for a selected segment of the signals, and measures of median frequency, mean frequency, bandwidth, and center frequency of PSD ( f , t ) were derived for each sample point. Statistical median, mean, standard deviation, minimum, maximum, and mode of the power spectral density measures were computed to compose feature vectors for each TA myoelectric recording. Statistical pattern recognition procedures using maximum likelihood classification tests were applied to the feature space to discriminate disordered from normal speakers for each task. Findings indicate a high level of discriminability between subject groups for phonated speaking tasks in contrast to low levels of discriminability for whispered and nonspeech tasks. Graphical presentations of three-dimensional PSD ( f , t ) plots are given that illustrate changes in spectral characteristics of TA EMG at the onset of laryngospasm.
- Published
- 1995
48. Atlas of Lacrimal Surgery
- Author
-
Rainer K. Weber, Rainer Keerl, Steven D. Schaefer, Robert C. Rocca, Rainer K. Weber, Rainer Keerl, Steven D. Schaefer, and Robert C. Rocca
- Subjects
- Lacrimal apparatus--Surgery--Atlases
- Abstract
This is the first book to cover all currently available methods to manage pre-, intra- and post-lacrimal sac stenosis. Comprehensive multidisciplinary approaches in adults and children are described. International experts provide a stepwise analysis and describe the clinical management of these patients with detailed medical and surgical treatment plans. With this guide's highly structured and reader-friendly format, the reader will be able to solve any problem that may occur with the reconstruction of a disturbed or damaged lacrimal system.
- Published
- 2007
49. Role of fine-needle aspiration in the evaluation of neck masses
- Author
-
Bradford S. Patt, Steven D. Schaefer, and Frank Vuitch
- Subjects
medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Cysts ,Biopsy, Needle ,General Medicine ,Salivary Gland Neoplasms ,Surgery ,Diagnosis, Differential ,Fine-needle aspiration ,Head and Neck Neoplasms ,Biopsy ,Medicine ,Humans ,Radiology ,Thyroid Neoplasms ,business ,Head and neck ,Lymphatic Diseases ,Algorithms ,Neck - Abstract
Fine-needle aspiration has assumed a large role in the evaluation of head and neck masses. It has been found to be simple, quick, accurate, and cost-effective in the workup of patients with unknown head and neck masses. This article reviews these advantages and the role of fine-needle aspiration in the evaluation of head and neck masses.
- Published
- 1993
50. Abstract 520: Inhibition of uPAR and uPA reduces invasion and degradative potential in papillary thyroid carcinoma cells
- Author
-
Augustine Moscatello, Stimson P. Schantz, Jan Geliebter, Steven D. Schaefer, Raj K. Tiwari, Codrin Iacob, Theodore S. Nowicki, Nina Suslina, Nicolas T. Kummer, and Edward Shin
- Subjects
Urokinase ,Cancer Research ,medicine.medical_specialty ,Plasmin ,Cancer ,Transfection ,Biology ,medicine.disease ,Metastasis ,Papillary thyroid cancer ,Blot ,Urokinase receptor ,Endocrinology ,Oncology ,Internal medicine ,medicine ,Cancer research ,medicine.drug - Abstract
Papillary thyroid cancer (PTC) is the most prevalent endocrine and thyroid malignancy. The ability of PTC to invade and migrate great distances contributes to distant metastases, which represent the most common cause of PTC-related death. The urokinase plasminogen activator (uPA) and the urokinase plasminogen receptor (uPAR) are key mediators of tumor invasion. Upon binding to uPAR, pro-uPA is converted to its active form, which is then capable of cleaving plasminogen to plasmin. Plasmin can then degrade components of the basement membrane and extracellular matrix, a prerequisite for tumor cell invasion and metastasis. The binding of uPA by uPAR also seems to mediate several signaling events that contribute to a migratory phenotype, as well as various growth signals. In this study, we analyzed uPA and uPAR expression in PTC and normal thyroid tissue, and examined in vitro how uPA and uPAR contribute to an invasive/metastatic phenotype, as well as the functional consequences of inhibiting this system. uPA and uPAR RNA were also significantly higher in patients with metastatic disease. Casein-plasminogen zymography and western blotting demonstrated increased active uPA secreted by BCPAP cells compared to NTHY-Ori-3-1. Fluorimetric assays revealed that BCPAP CM was able to activate plasminogen, resulting in measureable casein hydrolysis. This casein hydrolysis was prevented by the addition of several specific uPA inhibitors. The in vitro invasion phenotype of BCPAP cells was augmented by the addition of plasminogen, and this augmentation was reversed by inhibitory anti-uPA and anti-uPAR antibodies. Cells transfected with siRNA against uPAR demonstrated decreased migratory and invasive potentials as measured by Matrigel invasion assays. Finally, uPAR-knockdown cells exhibited decreased proliferation when compared to non-targeting siRNA transfectant cells. These data provide new functional evidence of the uPA/uPAR system's role in PTC invasion/metastasis and demonstrate the attractiveness of uPA and uPAR as molecular biomarkers and therapeutic targets. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 520.
- Published
- 2010
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.