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Although intramedullary spinal cord cavernous malformations are now well described, there have been, to our knowledge, no prior reports focusing on presentation after trauma. We report a patient with a thoracic intramedullary cavernous malformation presenting with hematomyelia and acute neurologic deterioration after spinal chiropractic manipulation. A review of previously published case reports then identifies additional cases of deterioration after spinal cord trauma or exertion. Traumatic injury and exertion may be uncommon but real causes of hematomyelia in intramedullary cavernous malformations of the spinal cord. The frequency of such presentations is estimated to be 1.37% to 4.79%.Copyright © 2006 by Elsevier Inc. [ABSTRACT FROM AUTHOR]

Background: Traumatic brain injury (TBI) can cause sensorimotor deficits, and recovery is slow and incomplete. There are no effective pharmacological treatments for recovery from TBI, but research indicates potential for anti-Nogo-A antibody (Ab) therapy. This Ab neutralizes Nogo-A, an endogenous transmembrane protein that inhibits neuronal plasticity and regeneration., Objective: We hypothesized that anti-Nogo-A Ab treatment following TBI results in disinhibited axonal growth from the contralesional cortex, the establishment of new compensatory neuronal connections, and improved function., Methods: We modeled TBI in rats using the controlled cortical impact method, resulting in focal brain damage and motor deficits like those observed in humans with a moderate cortical TBI. Rats were trained on the skilled forelimb reaching task and the horizontal ladder rung walking task. They were then given a TBI, targeting the caudal forelimb motor cortex, and randomly divided into 3 groups: TBI-only, TBI + Anti-Nogo-A Ab, and TBI + Control Ab. Testing resumed 3 days after TBI and continued for 8 weeks, when rats received an injection of the anterograde neuronal tracer, biotinylated dextran amine (BDA), into the corresponding area contralateral to the TBI., Results: We observed significant improvement in rats that received anti-Nogo-A Ab treatment post-TBI compared to controls. Analysis of BDA-positive axons revealed that anti-Nogo-A Ab treatment resulted in cortico-rubral plasticity to the deafferented red nucleus. Conclusions . Anti-Nogo-A Ab treatment may improve functional recovery via neuronal plasticity to brain areas important for skilled movements, and this treatment shows promise to improve outcomes in humans who have suffered a TBI., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Cases of isolated intramedullary spinal neurocysticercosis are extremely rare. Only 25 cases have been reported before 2022. Due to its rarity, the diagnosis of spinal neurocysticercosis may be missed., Case Presentation: We describe a 37-year-old female patient who developed back pain and lower extremity weakness and was found to have an intramedullary thoracic spine cystic lesion. She was taken to the operating room for resection of the lesion. Pathology revealed a larval cyst wall consistent with neurocysticercosis. The patient was started on albendazole and dexamethasone. Her exam improved post-operatively, and she was able to ambulate with minimal difficulty at the time of follow up., Conclusion: The case provides insights on the diagnosis and treatment of isolated intramedullary spinal neurocysticercosis. Review of the literature suggests that combined surgical and medical intervention results in significant improvement in the patient's neurological exam, and decreases morbidity associated with the disease. We propose a treatment paradigm for this rare manifestation of neurocysticercosis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Andino, Tsiang, Pecoraro, Jani, Iordanou, Zakaria, Borys, Pasquale, Nockels and Schneck.)

Background: To describe the use of intraoperative anteroposterior long cassette radiographs (APLCRs) to guide kickstand rod application in adult spinal deformity., Methods: A retrospective chart review was performed to identify patients with adult thoracolumbar and coronal plane deformity undergoing open segmental decompression with spinopelvic fixation and deformity correction between October 2017 and June 2019 who had APLCRs after rod placement. In patients with persistent intraoperative coronal deviations, a kickstand rod was placed. This supplemental rod was anchored to an iliac screw and to the construct via a pair of side-to-side connectors. A distractor was expended between a vice grip plyer on the kickstand and side-to-side connector to apply a lateralizing force to reduce the degree of deviation., Results: Of 15 patients who underwent T3-ilium fusion with spinal deformity correction with intraoperative APLCRs, 7 underwent kickstand placement. Mean preoperative coronal deviation was similar between cohorts (4.3 cm vs. 2.2 cm, P = 0.09), but was greater intraoperatively in the kickstand cohort (4.3 cm vs. 0.6 cm, P < 0.001). Postoperative coronal deviation was similar between groups (2.1 cm vs. 1.8 cm, P = 0.37). Preoperative fractional lumbar curve was significantly greater in patients requiring a kickstand (23° vs. 35°, P = 0.02), but the major thoracolumbar curve was similar between groups (43° vs. 35°, P = 0.14)., Conclusions: Intraoperative APLCRs can help guide application of a kickstand rod in adult thoracolumbar deformity correction. Patients with a greater fractional lumbar curve may derive greater benefit of kickstand usage, independent of major curve magnitude., (Copyright © 2022. Published by Elsevier Inc.)

Objective: Spinal cord stimulation (SCS) has become a popular nonopioid pain intervention. However, the treatment failure rate for SCS remains significantly high and many of these patients have poor sagittal spinopelvic balance, which has been found to correlate with increased pain and decreased quality of life. The purpose of this study was to determine if poor sagittal alignment is correlated with SCS treatment failure., Materials and Methods: Comparative retrospective analysis was performed between two cohorts of patients who had undergone SCS placement, those who had either subsequent removal of their SCS system (representing a treatment failure cohort) and those that underwent generator replacement (representing a successful treatment cohort). The electronic medical record was used to collect demographic and surgical characteristics, which included radiographic measurements of lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Also included were data on pain medication usage including opioid and nonopioid therapies., Results: Eighty-one patients met inclusion criteria, 31 had complete removal, and 50 had generator replacements. Measurement of sagittal balance parameters demonstrated that many patients had poor alignment, with 34 outside normal range for LL (10 vs 24 in removal and replacement cohorts, respectively), 30 for PI (12 [38.7%] vs 18 [36.0%]), 46 for PT (18 [58.1%] vs 28 [56.0%]), 38 for SS (18 [58.1%] vs 20 [40.0%]), and 39 for PI-LL mismatch (14 [45.2%] vs 25 [50.0%]). There were no significant differences in sagittal alignment parameters between the two cohorts., Conclusions: This retrospective cohort analysis of SCS patients did not demonstrate any relationship between poor sagittal alignment and failure of SCS therapy. Further studies of larger databases should be performed to determine how many patients ultimately go on to have additional structural spinal surgery after failure of SCS and whether or not those patients go on to have positive outcomes., (Copyright © 2022. Published by Elsevier Inc.)

Background: Correction of kyphotic deformities of the spine is a common problem faced by spine surgeons. Unfortunately, there are no clear published guidelines available regarding the extent of spinal fusion required to achieve and maintain lasting deformity correction. We aim to share a set of novel radiographic parameters ("the Circle") that can be used as a guideline for determining the extent of fusion required in surgical correction of spinal kyphotic deformity., Methods: A Google forms survey was distributed among spine surgeons and trainees to evaluate differences in recommended extent of posterior-approach fusions for cervical spinal kyphotic deformities before and after introduction to the Circle. Extent of fusion before and after use of the Circle were qualitatively and quantitatively analyzed. Data were anonymized and stored in a secure database., Results: Twenty-seven neurosurgical attendings (n = 14), residents (n = 9), and fellows (n = 3) responded to the survey. Variance between predicted upper and lower instrumented vertebrae, and length of construct, was statistically significantly decreased after application of the Circle in almost all cases. Respondents rated the ease of use of the Circle an average of 4.2 out of 5 (5 = the most ease). The majority of participants (92 [6%]; n = 25 of 27) stated that they would or would likely use the Circle as a radiographic tool in the surgical planning for correction of cervical spinal kyphotic deformities in the future., Conclusions: The Circle is a novel set of radiographic parameters that may be used to educate and guide surgical plans and extent of fusion when aiming to correct spinal kyphotic deformities., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Surgical correction of spinal deformities with coexisting intraspinal pathology (SDCIP) requires special consideration to minimize risks of further injury to an already abnormal spinal cord. However, there is a paucity of literature on this topic. Here, the authors present a pediatric patient with a residual pilocytic astrocytoma and syringomyelia who underwent surgical correction of progressive postlaminectomy kyphoscoliosis. Techniques employed are compared to those in the literature to compile a set of guidelines for surgical correction of SDCIP., Methods: A systematic MEDLINE search was conducted using the following keywords; "pediatric," "spinal tumor resection," "deformity correction," "postlaminectomy," "scoliosis correction," "intraspinal pathology," "tethered cord," "syringomyelia," or "diastematomyelia." Recommendations for surgical technique for pediatric SDCIP correction were reviewed., Results: The presented case demonstrates recommendations that primarily compressive forces on the convexity of the coronal curve should be used when performing in situ correction of SDCIP. Undercorrection is favored to minimize risks of traction on the abnormal spinal cord. The literature yielded 13 articles describing various intraoperative techniques. Notably, seven articles described use of compressive forces on the convex side of the deformity as the primary mode of correction, while only five articles provided recommendations on how to safely and effectively surgically correct SDCIP., Conclusion: The authors demonstrated with their case analysis and literature review that there are no clear current guidelines regarding the safe and effective techniques for in situ correction and fusion for the management of pediatric SDCIP., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Surgical Neurology International.)

Lack of blood flow to the brain, i.e., ischemic stroke, results in loss of nerve cells and therefore loss of function in the effected brain regions. There is no effective treatment to improve lost function except restoring blood flow within the first several hours. Rehabilitation strategies are widely used with limited success. The purpose of this study was to examine the effect of electrical stimulation on the impaired upper extremity to improve functional recovery after stroke. We developed a rodent model using an electrode cuff implant onto a single peripheral nerve (median nerve) of the paretic forelimb and applied daily electrical stimulation. The skilled forelimb reaching test was used to evaluate functional outcome after stroke and electrical stimulation. Anterograde axonal tracing from layer V pyramidal neurons with biotinylated dextran amine was done to evaluate the formation of new neuronal connections from the contralesional cortex to the deafferented spinal cord. Rats receiving electrical stimulation on the median nerve showed significant improvement in the skilled forelimb reaching test in comparison with stroke only and stroke with sham stimulation. Rats that received electrical stimulation also exhibited significant improvement in the latency to initiate adhesive removal from the impaired forelimb, indicating better sensory recovery. Furthermore, axonal tracing analysis showed a significant higher midline fiber crossing index in the cervical spinal cord of rats receiving electrical stimulation. Our results indicate that direct peripheral nerve stimulation leads to improved sensorimotor recovery in the stroke-impaired forelimb, and may be a useful approach to improve post-stroke deficits in human patients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Tsai, Schreiber, Adamczyk, Wu, Ton, Hofler, Walter, O'Brien, Kartje and Nockels.)

A case of cervical spinal cord injury in 12-year-old angular craniopagus twins is presented, with a description of the planning and execution of surgical treatment along with subsequent clinical outcome. The injury occurred following a fall from a standing position, resulting in quadriparesis in one of the twins. Imaging revealed severe craniocervical stenosis resulting from a C1-2 dislocation, and T2-weighted hyperintensity of the cervical spinal cord. After custom halo fixation was obtained, a posterior approach was utilized to decompress and instrument the occiput, cervical, and upper thoracic spine with intraoperative reduction of the dislocation. Early neurological improvement was noted during the acute postoperative phase, and 27 months of follow-up demonstrated intact instrumentation with continued neurological improvement to near baseline. The complexity of managing such an injury, inclusive of the surgical, anesthetic, biomechanical, and ethical considerations, is described in detail.

Background: Pseudohypoxic brain swelling (PHBS), also known as postoperative intracranial hypotension-associated venous congestion, is a rare complication after neurosurgery characterized by rapid and often severe postoperative deterioration in consciousness and distinct imaging findings on brain magnetic resonance imaging. Imaging findings associated with PHBS include computed tomography and magnetic resonance imaging findings that resemble hypoxic changes and intracranial hypotensive changes in basal ganglia and thalamus, telencephalic, and infratentorial regions without notable changes in intracranial vasculature., Case Description: This report describes the case of an L4-5 microdiskectomy with posterior decompression and fusion complicated by clinical and radiographic findings resembling PHBS without a known intraoperative durotomy., Conclusions: Spine surgeons should be alerted to the possibility that PHBS may occur in patients even after an operation without known durotomy or cerebrospinal fluid leakage and with spontaneous clinical resolution unrelated to suction drainage changes or epidural blood patches., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Postoperative blindness is a devastating surgical complication. Although usually associated with prolonged cardiac and prone spinal operations, it may follow other procedures as well. Postoperative blindness is most commonly caused by a vascular etiology, but it can more rarely be caused by status epilepticus. We have previously reported a case of this phenomenon following a staged spinal deformity surgery., Case Description: Here we report 2 additional cases following a skull base procedure and a single stage lumbar spine surgery. In all instances, rapid recognition that the patients' blindness was due to occipital seizures resulted in acute antiepileptiform treatment and full restoration of vision., Conclusions: Although a rare phenomenon, this syndrome, first recognized and described by Tarik F. Ibrahim, should be considered in any patient with postoperative visual impairment., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Remote cerebellar hemorrhage is rare but potentially fatal complication of cranial and spinal surgeries. The pathophysiology of this condition following spinal surgery is thought to be related to venous bleeding from cerebellar sagging and cerebrospinal fluid (CSF) hypotension. Most reported cases in the literature following spinal surgery involve intraoperative CSF leakage. We present a case of remote cerebellar hemorrhage following uncomplicated lumbar spinal decompression and fusion without CSF leakage., (Copyright © 2018. Published by Elsevier Inc.)

Objective: Management of adolescent idiopathic scoliosis (AIS) in neurosurgery residency training may have a significant impact on resident experience, even though few trainees are likely to pursue careers in the field of AIS. The impact of this exposure on resident knowledge in adult spinal disease management is the subject of our retrospective analysis., Methods: An analysis was performed of all adolescent patients undergoing surgical correction of spinal deformity between 2006 and 2016. Patient characteristics, including age at operation, Cobb angles, length of stay, operative time, blood loss, and complications, were collected. Objective benchmarks were created for resident education in the management of AIS. A survey was sent to the last 7 years of graduates to assess the impact of exposure to AIS during neurosurgery training on their current practice., Results: Nine male and 37 female patients ages 11 to 22 years were identified. Neurosurgical residents assisted in all procedures without fellows or surgical assistants. Average operative time was 336 minutes (range, 215-575 minutes), and blood loss per procedure was 603 mL (range, 200-4000 mL). The average Cobb angle correction was 72.2% (range, 35.3%-90.9%). Zero of the past 7 graduates currently treat AIS surgically. All 7 graduates agreed that exposure to AIS during residency enhanced their knowledge of adult spinal disease management., Conclusions: Treatment of AIS by surgeons with specialized training can be effective and safe. Resident exposure to these patients enhances their understanding of spinal biomechanics and deformity correction, which is applicable to treating AIS and adult spinal deformity., (Copyright © 2019. Published by Elsevier Inc.)

OBJECTIVEAtlantoaxial instability is an important cause of pain and neurological dysfunction in patients with Down syndrome (DS), frequently requiring instrumented fusion of the upper cervical spine. This study provides a quantitative analysis of C2 morphology in DS patients compared with their peers without DS to identify differences that must be considered for the safe placement of instrumentation.METHODSA retrospective chart review identified age-matched patients with and without DS with a CT scan of the cervical spine. Three-dimensional reconstructions of these scans were made with images along the axis of, and perpendicular to, the pars, lamina, facet, and transverse foramen of C2 bilaterally. Two of the authors performed independent measurements of anatomical structures using these images, and the average of the 2 raters' measurements was recorded. Pedicle height and width; pars axis length (the distance from the facet to the anterior vertebral body through the pars); pars rostrocaudal angle (angle of the pars axis length to the endplate of C2); pars axial angle (angle of the pars axis length to the median coronal plane); lamina height, length, and width; lamina angle (angle of the lamina length to the median coronal plane); and transverse foramen posterior distance (the distance from the posterior wall of the transverse foramen to the tangent of the posterior vertebral body) were measured bilaterally. Patients with and without DS were compared using a mixed-effects model accounting for patient height.RESULTSA total of 18 patients with and 20 patients without DS were included in the analysis. The groups were matched based on age and sex. The median height was 147 cm (IQR 142-160 cm) in the DS group and 165 cm (IQR 161-172 cm) in the non-DS group (p < 0.001). After accounting for variations in height, the mean pars rostrocaudal angle was greater (50.86° vs 45.54°, p = 0.004), the mean transverse foramen posterior distance was less (-1.5 mm vs +1.3 mm, p = 0.001), and the mean lamina width was less (6.2 mm vs 7.7 mm, p = 0.038) in patients with DS.CONCLUSIONSPatients with DS had a steeper rostrocaudal trajectory of the pars, a more posteriorly positioned transverse foramen posterior wall, and a narrower lamina compared with age- and sex-matched peers. These variations should be considered during surgical planning, as they may have implications to safe placement of instrumentation.

Postoperative vision loss (POVL) is a devastating complication and has been reported after complex spine procedures. Anterior ischemic optic neuropathy and posterior optic neuropathy are the 2 most common causes of POVL. Bilateral occipital lobe seizures causing complete blindness are rare and have not been reported as a cause of POVL after spine surgery with the patient prone. The authors report the case of a 67-year-old man without a history of seizures who underwent a staged thoracolumbar deformity correction and developed POVL 6 hours after surgery. Imaging, laboratory, and ophthalmological examination results were nonrevealing. Routine electroencephalography study results were negative, but continuous electroencephalography captured bilateral occipital lobe seizures. The patient developed nonconvulsive status epilepticus despite initial treatment with benzodiazepines and loading doses of levetiracetam and lacosamide. He was therefore intubated for status epilepticus amauroticus and received a midazolam infusion. After electrographic seizure cessation for 48 hours, the patient was weaned off midazolam. The patient was maintained on levetiracetam and lacosamide without seizure recurrence and returned to his preoperative visual baseline status.

The concept of semi-rigid fixation (SRF) has driven the development of spinal implants that utilize nonmetallic materials and novel rod geometries in an effort to promote fusion via a balance of stability, intra- and inter-level load sharing, and durability. The purpose of this study was to characterize the mechanical and biomechanical properties of a pedicle screw-based polyetheretherketone (PEEK) SRF system for the lumbar spine to compare its kinematic, structural, and durability performance profile against that of traditional lumbar fusion systems. Performance of the SRF system was characterized using a validated spectrum of experimental, computational, and in vitro testing. Finite element models were first used to optimize the size and shape of the polymeric rods and bound their performance parameters. Subsequently, benchtop tests determined the static and dynamic performance threshold of PEEK rods in relevant loading modes (flexion-extension (F/E), axial rotation (AR), and lateral bending (LB)). Numerical analyses evaluated the amount of anteroposterior column load sharing provided by both metallic and PEEK rods. Finally, a cadaveric spine simulator was used to determine the level of stability that PEEK rods provide. Under physiological loading conditions, a 6.35 mm nominal diameter oval PEEK rod construct unloads the bone-screw interface and increases anterior column load (approx. 75% anterior, 25% posterior) when compared to titanium (Ti) rod constructs. The PEEK construct's stiffness demonstrated a value lower than that of all the metallic rod systems, regardless of diameter or metallic composition (78% < 5.5 mm Ti; 66% < 4.5 mm Ti; 38% < 3.6 mm Ti). The endurance limit of the PEEK construct was comparable to that of clinically successful metallic rod systems (135N at 5 × 10(6) cycles). Compared to the intact state, cadaveric spines implanted with PEEK constructs demonstrated a significant reduction of range of motion in all three loading directions (> 80% reduction in F/E, p < 0.001; > 70% reduction in LB, p < 0.001; > 54% reduction in AR, p < 0.001). There was no statistically significant difference in the stability provided by the PEEK rods and titanium rods in any mode (p = 0.769 for F/E; p = 0.085 for LB; p = 0.633 for AR). The CD HORIZON(®) LEGACY(™) PEEK Rod System provided intervertebral stability comparable to currently marketed titanium lumbar fusion constructs. PEEK rods also more closely approximated the physiologic anteroposterior column load sharing compared to results with titanium rods. The durability, stability, strength, and biomechanical profile of PEEK rods were demonstrated and the potential advantages of SRF were highlighted.

Minimally invasive transforaminal lumbar interbody fusion (TLIF) offers equivalent postoperative fusion rates compared to posterior lumbar fusion (PLF) and minimizes the amount of iatrogenic injury to the spinal muscles. The objective of this study was to examine the difference in pain perception, stress, mood disturbance, quality of life, and immunological indices throughout the perioperative course among patients undergoing TLIF and PLF. A prospective, nonrandomized descriptive design was used to evaluate these measures among patients undergoing TLIF (n = 17) or PLF (n = 18) at 1 week prior to surgery (T1), the day of surgery (T2), 24 hours postoperatively (T3), and 6 weeks postoperatively (T4). Among TLIF patients, pain, stress, fatigue, and mood disturbance were significantly decreased at the 6-week followup visit (T4) compared to patients who underwent PLF. The TLIF group also demonstrated significantly higher levels (near baseline) of CD8 cells at T4 than the PLF group. Interleukin-6 levels were significantly higher in the TLIF group as well, which may be an indicator of ongoing nerve regeneration and healing. Knowledge concerning the effect of pain and the psychological experience on immunity among individuals undergoing spinal fusion can help nurses tailor interventions to improve outcomes, regardless of the approach used.

Object: Instability of the occipitocervical junction may result from degenerative disease, infection, tumor, and trauma. Surgical stabilization involving screw fixation and rigid implants has been found to be biomechanically superior to wire-based implants. To evaluate the long-term results in a large and diverse patient population, the authors prospectively studied a consecutive group of 69 patients., Methods: All patients underwent occipitocervical fusion in which rigid posterior instrumentation included either plates or rods and screws. Patients ranged in age from 11 to 90 years (mean 51.4 years); there were 34 female and 35 male patients. The mean follow-up duration was 37 months (range 6-66 months). Fifty-seven (83%) of the 69 patients had long-standing occipitocervical anomalies, whereas the remainder presented with acute instability. Basilar invagination was present in 20 patients., Results: Correction of a severe cervical kyphotic deformity was accomplished in six patients. There were no fatalities or medical complications associated with the procedures. During the follow-up period, 87% of the patients exhibited improvement in their myelopathic symptoms; in 13% the symptoms were unchanged. Complications were minimal. Stability was demonstrated on flexion/extension studies in all cases. There were no treatment-related deaths, although four patients died within the follow-up period, all due to progression of metastatic disease., Conclusions: The authors found that rigid internal fixation of the occipitocervical complex was safe, effective, and technically possible for spine surgeons familiar with occipital bone anatomy and lateral mass fixation.

Study Design: This study was an exploratory repeated measures design comparing patients undergoing two magnitudes of surgery in the lumbar spine: lumbar herniated disc repair and posterior lumbar fusion., Objective: The present study evaluated and compared the effect of perceived pain, perceived stress, anxiety, and mood on natural killer cell activity (NKCA) and IL-6 production among adult patients undergoing lumbar surgery., Summary of Background Data: Presurgical stress and anxiety can lead to detrimental patient outcomes after surgery, such as increased infection rates. It has been hypothesized that such outcomes are due to stress-immune alterations, which may be further exacerbated by the extent of surgery. However, psychologic stress, anxiety, and mood have not been previously characterized in patients undergoing spinal surgery., Methods: Pain, stress, anxiety, and mood were measured using self-report instruments at T1 (1 week before surgery), T2 (the day of surgery), T3 (the day after surgery), and T4 (6 weeks after surgery). Blood (30 mL) was collected for immune assessments at each time point., Results: Pain, stress, anxiety, and mood state were elevated at baseline in both surgical groups and were associated with significant reduction in NKCA compared with the nonsurgical control group. A further decrease in NKCA was observed 24 hours after surgery in both surgical groups with a significant rise in stimulated IL-6 production, regardless of the magnitude of surgery. In the recovery period, NKCA increased to or above baseline values, which correlated with decreased levels of reported pain, perceived stress, anxiety, and mood state., Conclusions: This study demonstrated that patients undergoing elective spinal surgery are highly stressed and anxious, regardless of the magnitude of surgery and that such psychologic factors may mediate a reduction in NKCA.

Study Design: A literature review., Objective: To evaluate the mechanisms of action and effectiveness of posterior dynamic stabilization devices in the management of painful spinal disorders., Summary of Background Data: Dynamic stabilization may provide pain relief by altering the transmission of abnormal loads across the degenerated disc space., Methods: A Medline search was conducted., Results: Articles supporting abnormal load transmission across the disc space and clinical reviews of currently available posterior dynamic systems were included., Conclusions: Posterior dynamic stabilization systems may provide benefit comparable to fusion techniques, but without the elimination of movement. Further study is required to determine optimal design and clinical indications.

Background: Intracranial dural arteriovenous fistulas account for 10 to 15% of all intracranial arteriovenous malformations. Tentorial dural arteriovenous fistulas with spinal medullary venous drainage causing spinal cord myelopathy are very rare, but have been previously described. We describe a case using a cranio-orbito zygomatic approach with intraoperative angiography for the surgical treatment of a tentorial artery dural arteriovenous fistula causing spinal cord myelopathy., Case Presentation: A 42-year-old male presented complaining of a 1-year history of incoordination and dizziness and a 2-month history of progressive myelopathy with bowel and bladder incontinence. The patient had magnetic resonance imaging (MRI) performed along with cerebral and spinal angiography that revealed a right tentorial artery dural arteriovenous fistula with spinal medullary venous involvement down to T11. Angiographic embolization was attempted, but selective catheterization was unsuccessful. The patient underwent a cranio-orbito zygomatic approach with obliteration of the dural arteriovenous fistula. An intraoperative angiogram confirmed complete obliteration of the dural arteriovenous fistula., Conclusion: Intracranial dural arteriovenous fistulas are a rare cause of spinal cord myelopathy. When a patient presents with suspicion of spinal dural fistula and negative spinal angiography, an intracranial origin should be suspected and a cerebral angiogram performed. Skull base approaches along with intraoperative angiography provide an alternative modality for obliteration of the dural arteriovenous fistula nidus, thereby eliminating the venous congestion and hence the spinal cord ischemia.

Advances in transport, imaging, and stabilization of the injured patient have made the topic of acute management more important than ever in patients with spinal cord injury. Optimal treatment requires prompt delivery of care for life-threatening respiratory and hemodynamic events in a manner that will not further damage the unstable spinal elements. The application of these treatment principles broadly to injured patients is necessitated by our inability to determine, on an acute basis, those patients who might eventually recover meaningful neurologic function from those who will not. Therefore, nonoperative management of acute spinal cord injury requires consideration of two goals: 1) the preservation of the patient's life and 2) optimizing the potential for recovery of neurologic function. The first consideration requires not only an understanding of the novel systemic consequences of spinal cord injury but also of treatments directed at combating them. The second includes the application of resuscitative measures without further damaging the spinal cord and, in some cases, the use of traction and immobilization. In the past these efforts were aimed primarily at increasing the survival rate of patients with spinal cord injury, whereas current care may also play an important role in the eventual recovery of neurologic function. Despite many advances in our understanding of the basic mechanisms of paralysis, clinical management of spinal cord injury remains a significant challenge and one that requires continuing efforts at improving acute and postacute therapies.

Object: The authors sought to analyze prospectively the outcome of surgery for complex spinal deformity in the pediatric and young adult populations., Methods: The authors evaluate all pediatric and adolescent patients undergoing operative correction of complex spinal deformity from December 1997 through July 1999. No patient was lost to follow-up review (average 21.1 months). There were 27 consecutive pediatric and adolescent patients (3-20 years of age) who underwent 32 operations. Diagnoses included scoliosis (18 idiopathic, five nonidiopathic) and four severe kyphoscoliosis. Operative correction and arthrodesis were achieved via 21 posterior approaches (Cotrel-Dubousset-Horizon), seven anterior approaches (Isola or Kaneda Scoliosis System), and two combined approaches. Operative time averaged 358 minutes (range 115-620 minutes). Blood loss averaged 807 ml (range 100-2,000 ml). Levels treated averaged 9.1 (range three-16 levels). There was a 54% average Cobb angle correction (range 6-82%). No case was complicated by the patient's neurological deterioration, loss of somatosensory evoked potential monitoring, cardiopulmonary disease, donor-site complication, or wound breakdown. There was one case of hook failure and one progression of deformity beyond the site of surgical instrumentation that required reoperation. There were 10 minor complications that did not significantly affect patient outcome. No patient received undirected banked blood products. There was a significant improvement in cosmesis, and no patient experienced continued pain postoperatively. All patients have been able to return to their preoperative activities., Conclusions: Compared with other major neurosurgical operations, segmental instrumentation for pediatric and adolescent spinal deformity is a safe procedure with minimal morbidity and there is a low risk of needing to use allogeneic blood products.

The authors report their experience with 42 patients in whom anterior lumbar fusion was performed using titanium cages as a versatile adjunct to treat a wide variety of spinal deformity and pathological conditions. These conditions included congenital, degenerative, iatrogenic, infectious, traumatic, and malignant disorders of the thoracolumbar spine. Fusion rates and complications are compared with data previously reported in the literature. Between July 1996 and July 1999 the senior authors (C.I.S., R.P.N., and M.J.R.) treated 42 patients by means of a transabdominal extraperitoneal (13 cases) or an anterolateral extraperitoneal approach (29 cases), 51 vertebral levels were fused using titanium cages packed with autologous bone. All vertebrectomies (27 cases) were reconstructed using a Miami Moss titanium mesh cage and Kaneda instrumentation. Interbody fusion (15 cases) was performed with either the BAK titanium threaded interbody cage (in 13 patients) or a Miami Moss titanium mesh cage (in two patients). The average follow-up period was 14.3 months. Seventeen patients had sustained a thoracolumbar burst fracture, 12 patients presented with degenerative spinal disorders, six with metastatic tumor, four with spinal deformity (one congenital and three iatrogenic), and three patients presented with spinal infections. In five patients anterior lumbar interbody fusion (ALIF) was supplemented with posterior segmental fixation at the time of the initial procedure. Of the 51 vertebral levels treated, solid arthrodesis was achieved in 49, a 96% fusion rate. One case of pseudarthrosis occurred in the group treated with BAK cages; the diagnosis was made based on the patient's continued mechanical back pain after undergoing L4-5 ALIF. The patient was treated with supplemental posterior fixation, and successful fusion occurred uneventfully with resolution of her back pain. In the group in which vertebrectomy was performed there was one case of fusion failure in a patient with metastatic breast cancer who had undergone an L-3 corpectomy with placement of a mesh cage. Although her back pain was immediately resolved, she died of systemic disease 3 months after surgery and before fusion could occur. Complications related to the anterior approach included two vascular injuries (two left common iliac vein lacerations); one injury to the sympathetic plexus; one case of superficial phlebitis; two cases of prolonged ileus (greater than 48 hours postoperatively); one anterior femoral cutaneous nerve palsy; and one superficial wound infection. No deaths were directly related to the surgical procedure. There were no cases of dural laceration and no nerve root injury. There were no cases of deep venous thrombosis, pulmonary embolus, retrograde ejaculation, abdominal hernia, bowel or ureteral injury, or deep wound infection. Fusion-related complications included an iliac crest hematoma and prolonged donor-site pain in one patient. There were no complications related to placement or migration of the cages, but there was one case of screw fracture of the Kaneda device that did not require revision. The authors conclude that anterior lumbar fusion performed using titanium interbody or mesh cages, packed with autologous bone, is an effective, safe method to achieve fusion in a wide variety of pathological conditions of the thoracolumbar spine. The fusion rate of 96% compares favorably with results reported in the literature. The complication rate mirrors the low morbidity rate associated with the anterior approach. A detailed study of clinical outcomes is in progress. Patient selection and strategies for avoiding complication are discussed.

Study Design: A standardized rat contusion model was used to test the hypothesis that progesterone significantly improves neurologic recovery after a spinal cord injury that results in incomplete paraplegia., Objectives: To compare the effect of progesterone versus a variety of control agents to determine its effectiveness in promoting neurologic recovery after an incomplete rat spinal cord injury., Summary of Background Data: Progesterone is a neurosteroid, possessing a variety of functions in the central nervous system. Exogenous progesterone has been shown to improve neurologic function after focal cerebral ischemia and facilitates cognitive recovery after cortical contusion in rats., Methods: A standardized rat contusion model of spinal cord injury using the New York University impactor that resulted in rats with incomplete paraplegia was used. Forty mature male Sprague-Dawley rats were randomly assigned to four groups: laminectomy with sham contusion, laminectomy with contusion without pharmacologic treatment, laminectomy with contusion treated with dimethylsulfoxide and dissolved progesterone, and laminectomy with contusion treated with dimethylsulfoxide. Functional status was assessed weekly using the Basso-Beattie-Bresnehan (BBB) locomotor rating scale for 6 weeks, after which the animals were killed for histologic studies., Results: Rats treated with progesterone had better outcomes (P = 0.0017; P = 0.0172) with a BBB score of 15.5, compared with 10.0 in the dimethylsulfoxide control group and 12.0 in the spinal cord contusion without pharmacologic intervention group. This was corroborated in histologic analysis by relative sparing of white matter tissue at the epicenter of the injury in the progesterone-treated group (P < 0.05)., Conclusions: Rats treated with progesterone had a better clinical and histologic outcome compared with the various control groups. These results indicate potential therapeutic properties of progesterone in the management of acute spinal cord injury.

This study was conducted to determine the safety, efficacy, and complication rate associated with the anterior approach in the use of a new titanium mesh interbody fusion cage for the treatment of unstable thoracolumbar burst fractures. The experience with this technique is compared with the senior authors' (C.S., R.W., and M.S.) previously published results in the management of patients with unstable thoracolumbar burst fractures. Between 1996 and 1999, 21 patients with unstable thoracolumbar (T12-L3) burst fractures underwent an anterolateral decompressive procedure in which a titanium cage and Kaneda device were used. Eleven of the 21 patients had sustained a neurological deficit, and all patients improved at least one Frankel grade (average 1.2 grades). There was improvement in outcome in terms of blood loss, correction of kyphosis, and pain, as measured on the Denis Pain and Work Scale, in our current group of patients treated via an anterior approach when compared with the results in those who underwent a posterior approach. In our current study the anterior approach was demonstrated to be a safe and effective technique for the management of unstable thoracolumbar burst fractures. It offers superior results compared with the posterior approach. The addition of the new titanium mesh interbody cage to our previous anterior technique allows the patient's own bone to be harvested from the corpectomy site and used as a substrate for fusion, thereby obviating the need for iliac crest harvest. The use of the cage in association with the Kaneda device allows for improved correction of kyphosis and restoration of normal sagittal alignment in addition to improved functional outcomes.

Object: A randomized double-blind clinical trial was conducted to compare neurological and functional recovery and morbidity and mortality rates 1 year after acute spinal cord injury in patients who had received a standard 24-hour methylprednisolone regimen (24MP) with those in whom an identical MP regimen had been delivered for 48 hours (48MP) or those who had received a 48-hour tirilazad mesylate (48TM) regimen., Methods: Patients for whom treatment was initiated within 3 hours of injury showed equal neurological and functional recovery in all three treatment groups. Patients for whom treatment was delayed more than 3 hours experienced diminished motor function recovery in the 24MP group, but those in the 48MP group showed greater 1-year motor recovery (recovery scores of 13.7 and 19, respectively, p=0.053). A greater percentage of patients improving three or more neurological grades was also observed in the 48MP group (p=0.073). In general, patients treated with 48TM recovered equally when compared with those who received 24MP treatments. A corresponding recovery in self care and sphincter control was seen but was not statistically significant. Mortality and morbidity rates at 1 year were similar in all groups., Conclusions: For patients in whom MP therapy is initiated within 3 hours of injury, 24-hour maintenance is appropriate. Patients starting therapy 3 to 8 hours after injury should be maintained on the regimen for 48 hours unless there are complicating medical factors.

Many studies indicate that spinal canal decompression and stabilization lead to improved neurologic recovery in patients with incomplete neurologic deficits. It is recognized that surgical stabilization of unstable thoracolumbar injuries with complete neurologic deficit or without deficit reduces hospital stay, improves spinal alignment, shortens rehabilitation, and results in fewer medical complications. Unfortunately, many aspects of management remain controversial. For many injuries, more than one treatment method has been shown to be efficacious, although certain injuries have improved outcome with specific treatment modalities. This article is an overview of indications for surgery, operative approaches, types of instrumentation, and treatment options for specific thoracolumbar injuries.

Objective: To compare the efficacy of methylprednisolone administered for 24 hours with methyprednisolone administered for 48 hours or tirilazad mesylate administered for 48 hours in patients with acute spinal cord injury., Design: Double-blind, randomized clinical trial., Setting: Sixteen acute spinal cord injury centers in North America., Patients: A total of 499 patients with acute spinal cord injury diagnosed in National Acute Spinal Cord Injury Study (NASCIS) centers within 8 hours of injury., Intervention: All patients received an intravenous bolus of methylprednisolone (30 mg/kg) before randomization. Patients in the 24-hour regimen group (n=166) received a methylprednisolone infusion of 5.4 mg/kg per hour for 24 hours, those in the 48-hour regimen group (n=167) received a methylprednisolone infusion of 5.4 mg/kg per hour for 48 hours, and those in the tirilazad group (n=166) received a 2.5 mg/kg bolus infusion of tirilazad mesylate every 6 hours for 48 hours., Main Outcome Measures: Motor function change between initial presentation and at 6 weeks and 6 months after injury, and change in Functional Independence Measure (FIM) assessed at 6 weeks and 6 months., Results: Compared with patients treated with methylprednisolone for 24 hours, those treated with methylprednisolone for 48 hours showed improved motor recovery at 6 weeks (P=.09) and 6 months (P=.07) after injury. The effect of the 48-hour methylprednisolone regimen was significant at 6 weeks (P=.04) and 6 months (P=.01) among patients whose therapy was initiated 3 to 8 hours after injury. Patients who received the 48-hour regimen and who started treatment at 3 to 8 hours were more likely to improve 1 full neurologic grade (P=.03) at 6 months, to show more improvement in 6-month FIM (P=.08), and to have more severe sepsis and severe pneumonia than patients in the 24-hour methylprednisolone group and the tirilazad group, but other complications and mortality (P=.97) were similar. Patients treated with tirilazad for 48 hours showed motor recovery rates equivalent to patients who received methylprednisolone for 24 hours., Conclusions: Patients with acute spinal cord injury who receive methylprednisolone within 3 hours of injury should be maintained on the treatment regimen for 24 hours. When methylprednisolone is initiated 3 to 8 hours after injury, patients should be maintained on steroid therapy for 48 hours.

We tested the hypothesis that NGF or BDNF can protect damaged neural structures following spinal cord injury. Spinal contusions were produced in adult rats by a weight drop method. Thereafter, unmodified Rat 1 fibroblasts or fibroblasts engineered to secrete NGF or BDNF were injected into the injury site. Weekly assessments of recovery were made for 6 weeks using a locomotor rating scale. All rats were immediately paraplegic, then began to recover. At 1 week after injury, the ratings of locomotor performance in rats implanted with NGF- or BDNF-secreting fibroblasts were significantly increased over those of rats implanted with unmodified fibroblasts. This trend toward enhanced recovery persisted during the duration of the experiment, although the difference became smaller. Histological examination after 6 weeks showed a larger cross-sectional area of spinal cord at the maximal injury site in the animals treated with NGF or BDNF. These results demonstrate a significant biological effect of treatment with neurotrophins in traumatic spinal cord injury.

The transoral-transpharyngeal approach is a reliable and technically sound method for gaining anterior extradural exposure to the craniocervical junction. We report 23 patients undergoing this approach for pathology lying between the inferior clivus and third cervical vertebra. Pathology included 6 patients with congenital malformations of the odontoid process, 4 patients with basilar invagination caused by rheumatoid arthritis, 2 patients with atlantoaxial subluxation caused by Down's syndrome, and 1 each with Chiari I malformation, pseudogout of C1/C2, ossification of the posterior longitudinal ligament, and chronic dens dislocation caused by trauma. Malignant tumors included 4 chordomas, 2 giant cell tumors of C1-C3, and 1 chondrosarcoma. Orotracheal intubation without tracheotomy was used in 22 patients. Sixteen of these 22 patients were extubated either immediately or within 24 hours. Six complications occurred in 5 patients and included a palatal dehiscence in 2, delayed oropharyngeal hemorrhage, prolonged endotracheal intubation because of severe tongue edema, and 1 case each of meningitis and aspiration pneumonia responsive to intravenous antibiotics. No deaths, local infections, or postoperative cerebrospinal fluid leaks occurred. Neurologic symptoms of cord compression improved or stabilized in all patients. The transoral-transpharyngeal approach is an effective means for extradural decompression of the anterior craniocervical junction and for exposure of selected tumors at this site.

Few areas of spinal surgery present a greater challenge than management of occipitocervical abnormalities. This is due to the simultaneous presence of two commanding, yet conflicting treatment principles. First, decompression and protection of the spinal cord at this level is synonymous with the presevation of life itself. Second, however, the degree of cervical movements at this junction is unprecedented in the spine, requiring the preservation movement yet stabilization of discrete motion segemnts. The interrelation of these two critical functions is realized in the complex arrangement of the C0- C1-C2 anatomic configuration. The occipitocervical junction is responsible for 50% of the 90 degrees of head rotation. In addition, 10-15 degrees of flexion and extension are added to the subaxial cervical spine by C0-C1-C2.This duality of function is the primary reasin for the complexity of the facet joints in this location. No lateral bending occurs at this level.

We have previously developed a model of mild, lateral fluid percussive head injury in the rat and demonstrated that although this injury produced minimal hemorrhage, breakdown of the blood-brain barrier was a prominent feature. The relationship between posttraumatic blood-brain barrier disruption and cellular injury is unclear. In the present study we examined the distribution and time course of expression of the stress protein HSP72 after brain injury and compared these findings with the known pattern of breakdown of the blood-brain barrier after a similar injury. Rats were subjected to a lateral fluid percussive brain injury (4.8-5.2 atm, 20 ms) and killed at 1, 3, and 6 h and 1, 3, and 7 days after injury. HSP72-like immunoreactivity was evaluated in sections of brain at the light-microscopic level. The earliest expression of HSP72 occurred at 3 h postinjury and was restricted to neurons and glia in the cortex surrounding a necrotic area at the impact site. By 6 h, light immunostaining was also noted in the pia-arachnoid adjacent to the impact site and in certain blood vessels that coursed through the area of necrosis. Maximal immunostaining was observed by 24 h postinjury, and was primarily associated with the cortex immediately adjacent to the region of necrosis at the impact site. This region consisted of darkly immunostained neurons, glia, and blood vessels. Immunostaining within the region of necrosis was restricted to blood vessels. HSP72-like immunoreactivity was also noted in a limited number of neurons and glia in other brain regions, including the parasagittal cortex, deep cortical layer VI, and CA3 in the posterior hippocampus.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical studies have demonstrated that hypoxia after severe brain injury is common and significantly worsens neurologic outcome. We have, therefore, developed a rat model of posttraumatic hypoxic injury in order to identify the pathophysiologic responses after head injury that are worsened by this secondary insult. We examined the effect of hypoxia after brain injury on permeability of the blood-brain barrier to plasma proteins. Animals were divided into two experimental groups: group I (impact alone) and group IH (impact plus hypoxia). Rats were subjected to a lateral fluid percussive brain injury (4.8-5.2 atm). Animals in group IH were exposed to hypoxic conditions (10% O2) for 45 min immediately after injury. In each group, vascular permeability to endogenous immunoglobulins (IgG) and to horseradish peroxidase (HRP) was examined at the light microscopic level. IgG was immunolocalized in brain sections at 1-24 h after injury. In other studies, HRP was given i.v. either before impact or 10 min before killing. Permeability to this protein was assessed at 1-72 h after injury. The distribution of extravasated proteins was similar between the experimental groups at 1 h postinjury. Pronounced abnormal permeability to IgG and HRP (given before impact) occurred in discrete regions throughout both the ipsilateral and contralateral hemispheres. By 6 h after injury, a differential response of the blood-brain barrier was noted between groups I and IH. Widespread leakage of proteins was observed in the injured hemisphere in group IH. This finding was in sharp contrast to group I, in which extravasated proteins remained more localized in the injured hemisphere. The time course for reestablishment of the blood-brain barrier to HRP (given before killing) was determined. The impact site remained permeable to HRP up to at least 72 h postinjury within groups I and IH. In group I, the blood-brain barrier was reestablished in the parasagittal cortex and deep cortical layer by 6 h postinjury. In contrast, the blood-brain barrier in group IH was not restored in similar brain regions until 24 h postinjury. These studies demonstrate that (1) hypoxia after brain injury exacerbates the regional breakdown of the blood-brain barrier to circulating proteins, (2) this influence of hypoxia on permeability is not apparent immediately after injury but rather is expressed at 6 h after injury, and (3) hypoxia after traumatic brain injury delays recovery of the blood-brain barrier. These findings suggest that secondary posttraumatic hypoxia contributes to the vascular pathogenesis of brain injury.

Experimental brain injury is associated with marked vasogenic edema, as evidenced by an increase in brain water content. This prominent and widespread response raises questions about the vulnerability of microvasculature in the brain to injury. In the present report we further characterize the vascular response by evaluating the integrity of the blood-brain barrier to circulating proteins. Vascular permeability to endogenous immunoglobulins (IgG) and to the protein horseradish peroxidase (HRP) was examined after a lateral, fluid percussive brain injury in the rat. In study 1 IgG was immunolocalized in brain sections 1-24 hr after injury. In studies 2 and 3 HRP was given intravenously either before impact (study 2) or 10 min before sacrifice (study 3). Permeability to this protein was assessed at 1-6 hr (study 2) or at 1-72 hr (study 3) after injury. In studies 1 and 2 the extravascular accumulation of proteins was evaluated. Pronounced abnormal permeability to IgG and HRP occurred within the first hour after injury and was widespread throughout both hemispheres. The intensity of immunostaining for IgG increased with time up to 24 hr after injury. In contrast, maximal extravascular accumulation of HRP occurred within the first hour after injury. In study 3 the time course for re-establishment of the blood-brain barrier to HRP was determined. Maximal permeability occurred at 1 hr after injury. At 24 hr abnormal permeability was restricted to the impact site and this area remained permeable up to 72 hr after injury. In summary this study demonstrates that breakdown of the blood-brain barrier to plasma proteins is a prominent feature of experimental brain injury. This abnormal permeability is characterized by its transient expression and widespread distribution. The time course for re-establishment of the blood-brain barrier to circulating proteins is most delayed at the impact site.