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Silicones are inorganic compounds that have been used for the purpose of shunting ventricular fluid since the mid-20th century [1]. Complications of ventriculoperitoneal shunts have rarely been attributed to silicone allergy, with only a handful of cases reported in literature. The classic presentation of allergy to silicone ventriculoperitoneal shunt, i.e., abdominal pain with recurrent skin breakdown along the shunt tract, is nonspecific and difficult to distinguish clinically from other causes of shunt-related symptoms. It can be diagnosed by detection of antisilicone antibodies and is treated with removal of the shunt and replacement, if needed, with a polyurethane shunt system. We report the first case of suspected silicone allergy presenting as clinical peritonitis without overt colonic perforation.

Background: Onset of trigeminal neuralgia (TN) is uncommon in young adults with less favorable benefit from surgical interventions. The aim of this study was to evaluate the role of concomitant psychosomatic disorders in long-term surgical outcomes in this population., Methods: Twenty-one patients younger than 30 years of age were diagnosed initially as having medically refractory TN, and each patient underwent microvascular decompression (MVD) as initial surgical management. Correlation of clinical outcome and psychosomatic disorders (DSM-IV) was evaluated during a 15-year interval., Results: A total of 93 procedures were performed for the management of TN and subsequent iatrogenic craniofacial pain disorders. At a median of 81 months, 8 of 21 patients were free of facial pain. Fourteen patients with concomitant major depressive disorder (MDD) or other anxiety disorders underwent a higher median of procedures compared with 7 patients without known MDD or anxiety (4.5 versus 1 intervention, P = 0.038). Two of 14 patients who were diagnosed with MDD or other anxiety disorders were free of craniofacial pain, whereas 6 of 7 patients without mood or anxiety disorders were free of craniofacial pain ( P = 0.0005). Thirteen patients developed treatment-related complications that required further surgical procedures. Presence of MDD or other anxiety disorders was associated with higher rate of complications ( P = 0.026). One patient with past medical history of severe anxiety died of unknown causes., Conclusions: In young patients with TN, comorbid MDD or anxiety disorders was associated with seeking multiple invasive procedures in multiple academic centers with limited benefit and high rates of surgical induced complications.

Introduction Preservation of the temporal branches of the facial nerve during anterolateral craniotomies is important. Damaging it can inflict undesirable cosmetic defects to the patient. The supraorbital trans-eyebrow approach (SOTE) is a versatile keyhole craniotomy but still has a high rate of frontalis muscle (FM) palsy. Objective Anatomical study to implement the interfascial dissection during the SOTE to preserve the nerves to the FM. Methods Slight modification of the standard technique of the SOTE was performed in 6 cadaveric specimens (12 sides). Results Distal rami to the FM were exposed. The standard "u-shape" incision of the FM can cross over the nerves. Alternatively, an "l-shape" incision was performed until the superior temporal line (STL). An interfascial dissection was performed near to the STL and the interfascial fat pad was used as a protective layer for the nerves. Conclusion Various pathologies can be addressed with the SOTE. In the majority of the cases the cosmetic results are good, but FM palsy remains a drawback of this approach. The interfascial dissection may be used in an attempt to prevent frontalis rami palsy.

OBJECT The aim of this study was to evaluate the value of intraoperative neurophysiological monitoring (IONM) using electromyography (EMG), brainstem auditory evoked potentials (BAEPs), and somatosensory evoked potentials (SSEPs) to predict and/or prevent postoperative neurological deficits in pediatric patients undergoing endoscopic endonasal surgery (EES) for skull base tumors. METHODS All consecutive pediatric patients with skull base tumors who underwent EES with at least 1 modality of IONM (BAEP, SSEP, and/or EMG) at our institution between 1999 and 2013 were retrospectively reviewed. Staged procedures and repeat procedures were identified and analyzed separately. To evaluate the diagnostic accuracy of significant free-run EMG activity, the prevalence of cranial nerve (CN) deficits and the sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS A total of 129 patients underwent 159 procedures; 6 patients had a total of 9 CN deficits. The incidences of CN deficits based on the total number of nerves monitored in the groups with and without significant free-run EMG activity were 9% and 1.5%, respectively. The incidences of CN deficits in the groups with 1 staged and more than 1 staged EES were 1.5% and 29%, respectively. The sensitivity, specificity, and negative predictive values (with 95% confidence intervals) of significant EMG to detect CN deficits in repeat procedures were 0.55 (0.22-0.84), 0.86 (0.79-0.9), and 0.97 (0.92-0.99), respectively. Two patients had significant changes in their BAEPs that were reversible with an increase in mean arterial pressure. CONCLUSIONS IONM can be applied effectively and reliably during EES in children. EMG monitoring is specific for detecting CN deficits and can be an effective guide for dissecting these procedures. Triggered EMG should be elicited intraoperatively to check the integrity of the CNs during and after tumor resection. Given the anatomical complexity of pediatric EES and the unique challenges encountered, multimodal IONM can be a valuable adjunct to these procedures.

We present a rare case of skull-base hemorrhagic chondrosarcoma in a patient with Ollier disease. Chondrosarcomas complicated by intracranial hemorrhage are very uncommon, with few reported cases in the literature. To our knowledge, this is the first such reported case.

Objectives To evaluate the incidence and discuss the pathogenesis of early postoperative conductive hearing loss (CHL) after microvascular decompression (MVD) for hemifacial spasm (HFS). Design Pre- and postoperative audiogram data and brainstem auditory evoked potentials (BAEPs) from patients who had underwent MVD for HFS were analyzed. Setting The study was conducted at the University of Pittsburgh Medical Center. Participants MVD for HFS patients who had pre- and postoperative audiogram data, BAEP data, and normal structure of the external and middle ear were included in the study. Main Outcome Measures CHL was diagnosed if there was an air-bone gap in pure tone audiometry of at least 10 dB at 0.5, 1, 2, or 4 kHz. Results The incidence of early postoperative CHL in the ipsilateral ear was 18.7% postoperatively. No CHL was observed in the contralateral side. No significant relationship between CHL and intraoperative BAEP changes was found. Demographic parameters were not significantly different between groups with and without CHL. Conclusions Early postoperative CHL is a significant complication after MVD. Fluid entering the mastoid air cells and/or bone-dust deposition during craniotomy may result in CHL. Long-term audiograms will be needed to evaluate the risk factors that lead to permanent CHL.

Background: Increasing use of endoscopic endonasal surgery for suprasellar lesions with extension into the optic canal (OC) has necessitated a better endonasal description of the OC., Objective: To identify the osseous OC transcranially and then investigate its anatomic relationship to the key endonasal intrasphenoidal landmarks. We also aimed to determine and describe the technical nuances for safely opening the falciform ligament and intracanalicular dura (surrounding the optic nerve [ON]) endonasally., Methods: Ten fresh human head silicon-injected specimens underwent an endoscopic transtuberculum/transplanum approach followed by 2-piece orbitozygomatic craniotomy to allow identification of 20 OCs. After completing up to 270° of endonasal bony decompression of the OC, a dural incision started at the sella and continued superiorly across the superior intercavernous sinus. Subsequently the dural opening was extended anterolaterally across the dura of the prechiasmatic sulcus, limbus sphenoidale, and planum., Results: Endonasally, the length of the osseous OC was approximately 6 mm and equivalent to the length of the lateral opticocarotid recess, as measured anteroposteriorly. The ophthalmic artery arose from the supraclinoidal carotid artery at approximately 2.5 mm from the medial osseous OC entrance. Transcranial correlation of the endonasal dural incision confirmed medial detachment of the falciform ligament and exposure of the preforaminal ON., Conclusion: The lateral opticocarotid recess allows distinction of the preforaminal ON, roofed by the falciform ligament from the intracanalicular segment in the osseous OC. This facilitates the preoperative surgical strategy regarding the extent of OC decompression and dural opening. Extensive endonasal decompression of the OC and division of the falciform ligament is feasible.

Background: The majority of chordomas show activation of the platelet-derived growth factor receptor (PDGFR). Based on in vitro intertumoral variation in response to recombinant PDGF protein and PDGFR inhibition, and variable tumor response to imatinib, we hypothesized that chordomas resistant to PDGFR inhibition may possess downstream activation of the pathway., Methods: Molecular profiling was performed on 23 consecutive chordoma primary tissue specimens. Primary cultures established from 20 of the 23 specimens, and chordoma cell lines, UCH-1 and UCH-2, were used for in vitro experiments., Results: Loss of heterozygosity (LOH) at the phosphatase and tensin homolog (PTEN) locus was observed in 6 specimens (26%). PTEN disruption statistically correlated with increased Ki-67 proliferation index, an established marker of poor outcome for chordoma. Compared to wild type, PTEN deficient chordomas displayed increased proliferative rate, and responded less favorably to PDGFR inhibition. PTEN gene restoration abrogated this growth advantage. Chordomas are characterized by intratumoral hypoxia and local invasion, and histone deacetylase (HDAC) inhibitors are capable of attenuating both hypoxic signaling and cell migration. The combination of PDGFR and HDAC inhibition effectively disrupted growth and invasion of PTEN deficient chordoma cells., Conclusions: Loss of heterozygosity of the PTEN gene seen in a subset of chordomas is associated with aggressive in vitro behavior and strongly correlates with increased Ki-67 proliferative index. Combined inhibition of PDGFR and HDAC attenuates proliferation and invasion in chordoma cells deficient for PTEN.

Background: Skull base tumors comprise many common benign brain tumors. Treatment has advanced, allowing many survivors to return to work. However, literature is limited about the neuropsychological status of these patients prior to treatment. Literature pertaining to the relationship between neuropsychological functioning and occupational ability prior to surgical intervention is even more limited. The purpose of this analysis was to evaluate the impact of neuropsychological function on work productivity in persons with skull base tumors prior to resection., Methods: Neuropsychological function and work productivity were assessed in adults newly diagnosed with skull base tumors ( n = 45) prior to surgical intervention. Univariate analyses identified potential predictors of work limitations; variables with P < .10 were analyzed using multivariate regression analyses controlled for age, sex, tumor type, and education., Results: Poorer mental attention and flexibility (MF) and higher depressive symptoms (DS) were significantly associated with poor time management at work (MF: β = -0.59, P = .01; DS: β = 3.42, P < .01; R 2 = 0.54). Difficulty meeting physical work demands was significantly associated with poorer visuospatial ability (VA) and higher depressive symptoms (VA: β = -3.30, P = .05; DS: β = 2.29, P < .01; R 2 = 0.29). Lower learning and memory scores (LM) and higher depressive symptoms were significantly associated with difficulty meeting mental-interpersonal work demands (LM: β = -3.39, P = .04; DS: β = 3.25, P < .01; R 2 = 0.47) and overall health-related loss of work productivity (LM: β = -0.72, P = .05; DS: β = 0.659, P < .001; R 2 = 0.43)., Conclusion: Domains of neuropsychological function that predicted work productivity were identified. Future research should examine neuropsychological function, depressive symptoms, and work productivity across the care trajectory from diagnosis through long-term survivorship.

Purpose: To evaluate if adding cranial nerves (CNs) V and VI to standard intraoperative neurophysiological monitoring (IONM) of microvascular decompressions for glossopharyngeal neuralgia improve its efficacy., Methods: We reviewed all patients who received a microvascular decompression for glossopharyngeal neuralgia at our institution between January 2008 and August 2012. All received upper extremity somatosensory evoked potentials, brainstem auditory evoked potentials, and free-running electromyography of muscles innervated by ipsilateral CNs VII, IX, and X. The sample was divided into 12 patients who received additional monitoring of CNs V and VI and 15 who did not., Results: No difference on neurotonic activity presence was found on CN V (standard IONM: 0% versus additional CNs IONM: 8.33%; p = 0.423), CN VI (never present on the additional CN patients), CN VII (standard IONM: 73.33% versus additional CNs IONM: 66.64%; p = 0.973), CN IX (standard IONM: 40.0% versus additional CNs IONM: 25.0%; p = 0.683), or CN X (standard IONM: 46.67% versus additional CNs IONM: 33.33%; p = 0.701) between groups. Additionally, no differences of brainstem auditory evoked potentials wave V's delay, and amplitude at the end of the decompression, or closing of the case were found between groups., Conclusions: Monitoring free-running electromyography of additional CNs V and VI does not improve the efficacy of IONM of microvascular decompressions for glossopharyngeal neuralgia.

Background: High-definition fiber tractography (HDFT), an advanced white matter (WM) imaging technique, was evaluated in the management of supratentorial cavernous malformations., Objective: To investigate the relationship of cavernous malformations to the relevant perilesional WM tracts with HDFT and to characterize associated changes first qualitatively and then quantitatively with our novel imaging measure, quantitative anisotropy (QA)., Methods: Imaging analysis was carried out by researchers blinded to the clinical details. Contralateral WM tracts were used for comparison. Mean QA values were obtained for whole WM tracts. Qualitatively affected superior longitudinal fasciculus/arcuate fibers and corticospinal tracts were further analyzed with the use of mean QA values for the perilesional segments., Results: Of 10 patients, HDFT assisted with the decision-making process and the offer of surgical resection in 2 patients, lesion approach and removal in 7 patients, and conservative management in 1 patient. Of 17 analyzed WM tracts, HDFT demonstrated partial disruption in 2 tracts, complete disruption in 2 tracts, a combination of displacement and partial disruption in 1 tract, displacement only in 7 tracts, and no change in 5 tracts. Qualitative changes correlated with clinical symptoms. Mean QA values for the whole WM tracts were similar, with the exception of 1 case demonstrating complete disruption of 2 WM tracts. QA-based perilesional segment analysis was consistent with qualitative data in 5 assessed WM tracts., Conclusion: HDFT illustrated the precise spatial relationship of cavernous malformations to multiple WM tracts in a 3-dimensional fashion, optimizing surgical planning, and demonstrated associated disruption and/or displacement, with both occurring perilesionally. These changes were supported by our quantitative marker, which needs further validation.

Objective: To assess intracranial pressure (ICP), body mass index (BMI), surgical repair, and cerebrospinal fluid (CSF) diversion in patients presenting with spontaneous CSF otorrhea., Study Design: Retrospective series review., Setting: Tertiary referral center., Patients: Thirty-two patients were treated surgically from 2004 to 2013 for spontaneous CSF otorrhea by the principal investigators. Patients with a history of chronic ear disease and cholesteatoma, previous mastoid surgery, head trauma, or iatrogenic injury were excluded. Average age was 56 years. Twenty-two patients (69%) were female., Intervention(s): Middle fossa repair, transmastoid repair, lumbar puncture, V-P shunt, L-P shunt, and magnetic resonance imaging., Main Outcome Measure(s): Patients underwent middle fossa or transmastoid repair of tegmen defects. Intracranial pressures were determined with lumbar puncture at time of surgical repair or shortly after surgery. CSF diversion procedures were performed in patients who were found to have elevated ICP, which was not controlled medically, presented with recurrent leak or had ICP of 25 cm or greater of H2O. Preoperative BMI was calculated., Results: Thirty-two patients underwent 37 operations. Average BMI was 35.0 kg/m2 (median, 34.7; range, 18.7-53.2 kg/m2). There were 21 repairs on the left and 16 on the right. The majority underwent a middle fossa craniotomy for repair (27/32). Two patients had bilateral repairs. Three patients (8%) underwent revision surgery, of which, 2 had untreated intracranial hypertension (ICP 24.5 and 24 cm H2O). ICP measurements were available for 29 patients. The mean ICP was 23.4 cm H2O (median, 24; range, 13-36 cm H20). Twenty-two patients (69%) had ICP of 20 cm or greater of H20; of those, 13 had an ICP of 25 cm or greater of H20. Seventeen patients (53%) underwent CSF diversion procedures., Conclusion: Our findings of elevated ICP and BMI in patients presenting with spontaneous CSF otorrhea are consistent with previous reports in the literature. The percentage of patients that underwent CSF diversion procedures was high at 53% and represents an aggressive stance in managing elevated ICP in a population that may be at risk for subsequent leaks.

Objective Reconstruction of large clival defects after an endoscopic endonasal procedure is challenging. The objective is to analyze the morphology, indications, and limitations of the extended nasoseptal flap, which adds the nasal floor and inferior meatus mucosa, compared with the standard nasoseptal flap, for clival reconstruction. Design Twenty-seven sides of formalin-fixed anatomical specimens and 13 computed tomography (CT) scans were used. Under 0-degree endoscopic visualization, a standard flap on one side and an extended flap on the other side were performed, as well as exposure of the sella, cavernous sinus, and clival dura mater. Coverage of both flaps was assessed, and they were incised and extracted for measurements. Results The extended flap has two parts: septal and inferior meatal. The extended flaps are 20 mm longer and add 774 mm(2) of mucosal area. They cover a clival defect from tuberculum to foramen magnum in 66.6% cases and from below the sella in 91.6%. They cover both parasellar and paraclival segments of the internal carotid arteries. The lateral inferior limits are the medial aspect of the hypoglossal canals and Eustachian tubes. CT scans can predict the need or limitation of an extended nasoseptal flap. Conclusions The nasal floor and inferior meatus mucosa adds a significant area for reconstruction of the clivus. A defect laterally beyond the hypoglossal canals is not likely covered with this variation of the flap. Preoperative CT scans are useful to guide the reconstruction techniques.

The objective of this study is to investigate late repeat microvascular decompression (MVD) with persistent or recurrent hemifacial spasm (HFS) and to compare the clinical characteristics, intraoperative findings, complications, and outcomes with first MVD. We analyzed MVDs performed at the University of Pittsburgh Medical Center between January 1, 2000 and December 31, 2007. Thirty-three patients who underwent late redo MVDs were classified as group I and 243 patients who underwent their first MVD as group II. Clinical data were collected to analyze the difference between the two groups. The mean follow-up period was 54.48 months (range, 9-102 months). There is no significant difference in preoperative clinical characteristics (gender, age, side of MVD, botox usage, facial weakness) between the two groups. In present study, we found a vein as the offending vessel in significantly more number of patients who underwent repeat MVD as compared to first MVD (P = 0.02). The lateral spread response disappeared in 66% of patients during repeat MVDs, which is not different from those undergoing their first MVD. No difference in the relief rate was found during the immediate postoperative, discharge, or follow-up stages between repeat and first MVD. Moreover, no difference was found in the incidence of complications between repeat MVD and first MVD. Late repeat MVD for HFS is an effective and safe procedure. No specific preoperative clinical characteristics were identified in patients with repeat MVD. Intraoperative monitoring with lateral spread response (LSR) is an effective tool to evaluate adequate decompression. In patients with persistent LSR at the end of the procedure, facial nerve compression from a vein should be examined. We believe that it is important to undergo a repeat MVD for failed HFS relief irrespective of the timing of the operation.

Salmonella enterica serovar Typhimurium definitive type 2 (DT2) is host restricted to Columba livia (rock or feral pigeon) but is also closely related to S. Typhimurium isolates that circulate in livestock and cause a zoonosis characterized by gastroenteritis in humans. DT2 isolates formed a distinct phylogenetic cluster within S. Typhimurium based on whole-genome-sequence polymorphisms. Comparative genome analysis of DT2 94-213 and S. Typhimurium SL1344, DT104, and D23580 identified few differences in gene content with the exception of variations within prophages. However, DT2 94-213 harbored 22 pseudogenes that were intact in other closely related S. Typhimurium strains. We report a novel in silico approach to identify single amino acid substitutions in proteins that have a high probability of a functional impact. One polymorphism identified using this method, a single-residue deletion in the Tar protein, abrogated chemotaxis to aspartate in vitro. DT2 94-213 also exhibited an altered transcriptional profile in response to culture at 42°C compared to that of SL1344. Such differentially regulated genes included a number involved in flagellum biosynthesis and motility. IMPORTANCE Whereas Salmonella enterica serovar Typhimurium can infect a wide range of animal species, some variants within this serovar exhibit a more limited host range and altered disease potential. Phylogenetic analysis based on whole-genome sequences can identify lineages associated with specific virulence traits, including host adaptation. This study represents one of the first to link pathogen-specific genetic signatures, including coding capacity, genome degradation, and transcriptional responses to host adaptation within a Salmonella serovar. We performed comparative genome analysis of reference and pigeon-adapted definitive type 2 (DT2) S. Typhimurium isolates alongside phenotypic and transcriptome analyses, to identify genetic signatures linked to host adaptation within the DT2 lineage.

Objectives: To evaluate the value of intraoperative neurophysiological monitoring (IONM) using brainstem auditory evoked potential (BAEP) and somatosensory evoked potential (SSEP) monitoring to predict and/or prevent postoperative neurological deficits during endoscopic endonasal surgery (EES)., Methods: We retrospectively identified 138 consecutive patients who had BAEP monitoring in addition to SSEP monitoring during EES at our institution. We reviewed the postoperative clinical outcomes and neurophysiological changes independently., Results: The total of number of patients with any IONM changes was 10. The incidence of BAEP changes was 3.62%. The incidence of SSEP changes was 3.62% as well. One patient had changes in both BAEPs and SSEPs. Majority of the changes were observed during changes in mean arterial pressure (MAP) without any postoperative neurological deficits. There were two postoperative neurological deficits., Discussion: BAEPs and SSEPs provide unique information about integrity of brainstem function during EES procedures involving tumors in the and around clival region. We advocate a comprehensive multimodality approach to IONM during EESs including BAEPs and SSEPs depending on the location of the neural structures at risk.

Objective To evaluate the value of free-run electromyography (f-EMG) monitoring of extraocular cranial nerves (EOCN) III, IV, and VI during expanded endonasal surgery (EES) of the skull base in reducing iatrogenic cranial nerve (CN) deficits. Design We retrospectively identified 200 patients out of 990 who had at least one EOCN monitored during EES. We further separated patients into groups according to the specific CN monitored. In each CN group, we classified patients who had significant (SG) f-EMG activity as Group I and those who did not as Group II. Results A total of 696 EOCNs were monitored. The number of muscles supplied by EOCNs that had SG f-EMG activity was 88, including CN III = 46, CN IV = 21, and CN VI = 21. There were two deficits involving CN VI in patients who had SG f-EMG activity during surgery. There were 14 deficits observed, including CN III = 3, CN IV = 2, and CN VI = 9 in patients who did not have SG f-EMG activity during surgery. Conclusions f-EMG monitoring of EOCN during EES can be useful in identifying the location of the nerve. It seems to have limited value in predicting postoperative neurological deficits. Future studies to evaluate the EMG of EOCN during EES need to be done with both f-EMG and triggered EMG.

Objectives: The objective of this study is to investigate the clinical characteristics, intraoperative findings, complications, and outcomes in these patients with hemifacial spasm (HFS) caused by venous compression., Methods: We analyzed 15 patients who underwent microvascular decompression (MVD) for HFS caused by venous compression performed at the University of Pittsburgh Medical Center between 1 January 2000 and 31 December 2007. Thirteen of 15 patients underwent repeat MVD, and two patients underwent their first MVD. Clinical data were collected to verify vein as real offending vessel for all of 15 patients with HFS. The mean follow-up period was 4·13 years (range: 1·29-6·76 years)., Results: Thirteen patients with repeat MVDs had vein as the offending vessel, such as series of small venule, small veins, and dilated venous stump. The remaining two patients who underwent the first MVD had vein as the only offending vessel. In the first MVD for 13 patients, lateral spread response (LSR) disappeared in five patients (38·5%). In the repeat MVD for these 13 patients, LSR disappeared after the vein was decompressed completely in nine patients (69·2%). An excellent surgical outcome was observed in all the 11 patients with four patients lost during the follow-up period. Post-operative complications were observed in 12 patients included hearing loss, cerebrospinal fluid leakage, worsening facial palsy, difficulty swallowing, dilpopia, and ataxia., Conclusions: Vein can play an important role and can be the offending vessel in MVD for HFS. Women with platysmal involvement and tonus seem to have higher chance of vein as an offending vessel. These patients that have residual LSR at the end of the procedure should undergo exploration for a vein to prevent persistent HFS. Intraoperative monitoring with LSR is an effective tool to evaluate adequate decompression to vein. Although the long-term outcome is excellent for venous compression, the complication rate is much higher. To decrease the complication rate, gentle retraction of the cerebellum and 'low-power' coagulation of the vein might be helpful.

Object: The primary aim of this study was to evaluate the incidence and discuss the pathogenesis of high-frequency hearing loss (HFHL) after microvascular decompression (MVD) for hemifacial spasm (HFS)., Methods: Preoperative and postoperative audiogram data and brainstem auditory evoked potentials (BAEPs) from 94 patients who underwent MVD for HFS were analyzed. Pure tone audiometry at 0.25-2 kHz, 4 kHz, and 8 kHz was calculated for all individuals pre- and postoperatively ipsilateral and contralaterally. Intraoperative neurophysiological data were reviewed independently. An HFHL was defined as a change in pure tone audiometry of more than 10 dB at frequencies of 4 and 8 kHz., Results: The incidence of HFHL was 50.00% and 25.53% ipsilateral and contralateral to the side of surgery, respectively. The incidence of HFHL adjusted for conductive and nonserviceable hearing loss was 26.6% ipsilaterally. The incidence of HFHL at 4 and 8 kHz on the ipsilateral side was 37.23% and 45.74%, respectively, and it was 10.64% and 25.53%, respectively, on the contralateral side. Maximal change in interpeak latency Waves I-V compared with baseline was the only variable significantly different between groups (p < 0.05). Sex, age, and side did not increase the risk of HFHL. Stepwise logistic regression analysis did not find any changes in intraoperative BAEPs to increase the risk of HFHL., Conclusions: High-frequency hearing loss occurs in a significant number of patients following MVD surgery for HFS. Drill-induced noise and transient loss of CSF during surgery may impair hearing in the high-frequency ranges on both the ipsilateral and contralateral sides, with the ipsilateral side being more affected. Changes in intraoperative BAEPs during MVD for HFS were not useful in predicting HFHL. Follow-up studies and repeat audiological examinations may be helpful in evaluating the time course and prognosis of HFHL. Prospective studies focusing on decreasing intraoperative noise exposure, as well as auditory shielding devices, will establish causation and allow the team to intervene appropriately to decrease the risk of HFHL.

Object: The objective of this study was to investigate the clinical characteristics, intraoperative findings, complications, and outcomes after the first microvascular decompression (MVD) in patients with and without previous botulinum neurotoxin treatment for hemifacial spasm (HFS)., Methods: The authors analyzed 246 MVDs performed at the University of Pittsburgh Medical Center between January 1, 2000, and December 31, 2007. One hundred and seventy-six patients with HFS underwent botulinum neurotoxin injection treatment prior to first MVD (Group I), and 70 patients underwent their first MVD without previous botulinum neurotoxin treatment (Group II). Clinical outcome data were obtained immediately after the operation, at discharge, and at follow-up. Follow-up data were collected from 177 patients with a minimum follow-up period of 9 months (mean 54.48 ± 27.84 months)., Results: In 246 patients, 89.4% experienced immediate postoperative relief of spasm, 91.1% experienced relief at discharge, and 92.7% experienced relief at follow-up. There was no significant difference in outcomes and complications between Group I and Group II (p > 0.05). Preoperatively, patients in Group I had higher rates of facial weakness, tinnitus, tonus, and platysmal involvement as compared with Group II (p < 0.05). The posterior inferior cerebellar artery and vertebral artery were intraoperatively identified as the offending vessels in cases of vasculature compression in a significantly greater number of patients in Group II compared with Group I (p = 0.008 and p = 0.005, respectively, for each vessel). The lateral spread response (LSR) disappeared in 60.48% of the patients in Group I as compared with 74.19% in Group II (p > 0.05). No significant differences in complications were noted between the 2 groups., Conclusions: Microvascular decompression is an effective and safe procedure for patients with HFS previously treated using botulinum neurotoxin. Intraoperative monitoring with LSR is an effective tool for evaluating adequate decompression.

Background: The middle clinoid is an osseous prominence that arises from the body of the sphenoid bone at the anterolateral margin of the sella., Objective: To illustrate the radiological and surgical anatomy of the middle clinoid and describe the technical nuances for endonasal endoscopic middle clinoid removal., Methods: The fine-cut head CT-angiogram scans of 100 patients and 50 anatomic specimens were examined. The middle clinoid was categorized as: absent, small, prominent, or caroticoclinoidal ring. Ten colored silicon-injected anatomic specimens were used to study the surgical anatomy for the endonasal middle clinoidectomy. Extensive surgical experience allowed for intraoperative observations regarding the surgical anatomy of the middle clinoid and the technical nuances for its removal., Results: The middle clinoid was identifiable in 60% of scans (bilateral in 35%), and 20% had at least one caroticoclinoidal ring (bilateral in 6%). When present, the middle clinoid is located at the transition between the intracavernous internal carotid artery (ICA) and paraclinoidal ICA, and covers the anteromedial roof of the cavernous sinus. Endonasal removal of the middle clinoid improves access to the parasellar region. The middle clinoidectomy is completed exposing the following structures sequentially: sellar dura, anterior wall of the cavernous sinus, dura of the lateral tuberculum sella, and paraclinoidal ICA. When a caroticoclinoidal ring is identified, progressive reduction of the middle clinoid can be achieved without fracturing the ring., Conclusion: Recognition of the middle clinoid and caroticoclinoidal ring on preoperative imaging is critical for surgical planning and middle clinoid removal in endonasal skull base surgery.

Researching the origin of the terms that we use to identify neuroanatomical structures is a helpful and fascinating exercise. It can provide neuroscientists with a better insight and understanding of the macroscopic anatomy of the cranium and its contents. It can also help the novice to this discipline to become acquainted with structures whose three dimensional anatomy is often difficult to appreciate. The purpose of this article was to investigate the etymology of some of the terms referring to the macroscopic anatomical structures of the skull and the intracranial cavity. We observed how each name unravels an interesting story, sometimes linked to mythological creatures, other times to the shape of animals or objects and tools of everyday life. We conclude that even without a deep knowledge of the Greek, Latin, or Arabic language, learning who described a particular structure and how they decided to name it, makes the study of neuroanatomy more complete and fulfilling., (Copyright © 2012 Wiley Periodicals, Inc.)

Object: Microsurgical management of foramen magnum meningiomas (FMMs) can be associated with significant morbidity and mortality. Stereotactic radiosurgery may be an efficient and safe alternative treatment modality for such tumors. The object of this study was to increase the documented experience with Gamma Knife surgery (GKS) for FMMs and to delineate its role in an overall management paradigm., Methods: The authors report on their experience with 24 patients harboring FMMs managed with GKS. Twelve patients had primary symptomatic tumors, 5 had asymptomatic but enlarging primary tumors, and 7 had recurrent or residual tumors after a prior surgery., Results: Follow-up clinical and imaging data were available in 21 patients at a median follow-up of 47 months (range 3-128 months). Ten patients had measurable tumor regression, which was defined as an overall volume reduction > 25%. Eleven patients had no further tumor growth. Two patients died as a result of advanced comorbidities before follow-up imaging. One patient was living 8 years after GKS but had no clinical evaluation. Ten of 17 symptomatic patients with at least 6 months of follow-up had symptom improvement, and 7 remained clinically stable. Smaller tumors were more likely to regress. No patient suffered an adverse radiation effect after radiosurgery., Conclusions: Gamma Knife surgery was a safe management strategy for small, minimally symptomatic, or growing FMMs as well as for residual tumors following conservative microsurgical removal.

The endoscopic endonasal approach (EEA) is a surgical technique where a small aperture, the nostrils, can give access to the whole ventral skull base. Its principles differ from the ones of traditional skull base approaches where a wide external opening is often accompanied by a relatively small working area. Most of the results of EEAs published in the literature come from retrospective case series and the follow-up is still limited, however the consensus is that this technique is safe and effective in selected cases and when performed within dedicated skull base centres. This article sets to give an overview of the current state of endoscopic skull base surgery, based on the recent evidence and our centre's experience with nearly 2000 EEAs. The team's experience with endoscopic as well as open approaches plays a critical role in achieving satisfactory results when treating pathologies of the skull base. Guided by the principle of least neural and vascular manipulation, the team should be able to select the least traumatic route (open or endoscopic) and be able to approach the skull base from all angles.

Background: The jugular tubercle is a rounded bony prominence that arises from the inferolateral margin of the clivus. In a previous publication, we described the surgical anatomy of the expanded endonasal approach to the jugular tubercle., Objective: To illustrate the translation of laboratory work to the operating room describing the anatomic and technical nuances of the endonasal approach to the jugular tubercle., Methods: We review the relevant surgical anatomy needed to perform an endonasal approach to the jugular tubercle, and we select 4 different lesions to illustrate the application of our laboratory findings., Results: In the first case, exposure and partial drilling of the jugular tubercle was critical to gain an adequate corridor to the meningioma, particularly to its inferolateral margin. This allowed for early devascularization, safe extracapsular dissection, and preservation of surrounding neurovascular structures. In addition, the jugular tubercle was hyperostotic and its resection, along with generous dural removal, provided a grade I Simpson tumor resection. In the second (chondrosarcoma) and third (chordoma) cases, the jugular tubercle was infiltrated by tumor, and consequently its complete resection was essential to achieve total tumor removal. In the last case, an unusual adrenocorticotropic hormone-secreting adenoma recurrence at the jugular tubercle region, the technical modification of the transclival approach presented here was successfully applied to achieve complete resection and Cushing disease remission., Conclusion: The transjugular tubercle variant of the expanded endonasal transclival approach allows for direct access to ventrolateral lesions in the inferior clival/petroclival region with no cerebral or cerebellar retraction, or cranial nerve manipulation during the approach.

Objective The main objective of this study was to evaluate the value of free-run electromyography (f-EMG) monitoring of cranial nerves (CNs) VII, IX, X, XI, and XII in skull base surgeries performed using endoscopic endonasal approach (EEA) to reduce iatrogenic CN deficits. Design We retrospectively identified 73 patients out of 990 patients who had EEA in our institution who had at least one CN monitored. In each CN group, we classified patients who had significant (SG) f-EMG activity as group I and those who did not as group II. Results We monitored a total of 342 CNs. A total of 62 nerves had SG f-EMG activity including CN VII = 18, CN IX = 16, CN X = 13, CN XI = 5, and CN XII = 10. No nerve deficit was found in the nerves that had significant activity during procedure. A total of five nerve deficits including (CN IX = 1, CN X = 2, CN XII = 2) were observed in the group that did not display SG f-EMG activity during surgery. Conclusions f-EMG seems highly sensitive to surgical manipulations and in locating CNs. It seems to have limited value in predicting postoperative neurological deficits. Future studies to evaluate the EMG of lower CNs during EEA procedures need to be done with both f-EMG and triggered EMG.

Purpose: Facial nerve microvascular decompression (MVD) for hemifacial spasm (HFS) provides relief to most patients. Due to the proximity of the cochlear and facial nerves, hearing loss is a potential MVD complication, however, there is a wide range in the reported incidence of hearing loss (HL) in the literature. In order to better understand the HL incidence in our MVD population, we utilized the combination of speech discrimination scores (SDS) and air and bone pure tone threshold averages (PTA) to identify patients with no hearing change, sensorineural hearing loss, or conductive hearing loss. We also assessed the predictive value of patient-reported hearing deficits on the ultimate audiometric diagnosis of hearing loss., Methods: One hundred and fifty one patients underwent facial nerve MVD at the University of Pittsburgh Medical Center between January 2000 and December 2007. Peri-operative audiometric data, including changes in air and bone pure tone thresholds and speech discrimination scores, were analyzed retrospectively. Criteria from the 1995 American Academy of Otolaryngology Committee on Hearing and Equilibrium consensus were used to analyze post-operative hearing loss. Patient-reported hearing disturbances obtained in the immediate post-operative period were compared to seven-day post-operative conductive and sensorineural HL status., Results: Non-functional, non-serviceable HL (Class D) occurred in 6.6% of patients, while 10.6% developed cumulative non-functional HL (Class C and D). Twenty-nine patients (18.7%) exhibited conductive HL. While patient-reported complaints were predictive of Class C/D HL (<0.0001) with a 56.3% sensitivity and 92.6% specificity, patient-reported complaints were not strongly associated with conductive HL status (p = 0.369) with 17.2% sensitivity and 88.5% specificity., Conclusions: Perioperative hearing evaluations, in conjunction with careful scrutiny of patient complaints and air-bone pure tone testing enables the physician to more precisely quote complication rates and rapidly distinguish potentially reversible conductive hearing pathologies from permanent sensorineural disorders., (Copyright © 2012. Published by Elsevier B.V.)

Object: The aim of this study was to report the results in a consecutive series of patients who had undergone an endoscopic endonasal approach (EEA) for drainage of a petrous apex cholesterol granuloma (CG)., Methods: Seventeen cases with a confirmed diagnosis of petrous apex CG were identified from a database of more than 1600 patients who had undergone an EEA to skull base lesions at the authors' institution in the period from 1998 to 2011. Clinical outcomes were reviewed and compared with those in previous studies of open approaches., Results: Nine patients underwent a transclival approach and 8 patients underwent a combined transclival and infrapetrous approach. A Silastic stent was used in 11 patients (65%), a miniflap in 4 (24%), and a simple marsupialization of the cyst in 3 (18%). All symptomatic patients had partial or complete improvement of their symptoms postoperatively and at the follow-up (mean follow-up 20 months, range 3-67 months). Complications developed in 3 patients (18%) including epistaxis, chronic serous otitis media, eye dryness, and a transient sixth cranial nerve palsy. Two patients (12%) had a symptomatic recurrence of the cyst requiring repeat endoscopic endonasal drainage. There were no instances of internal carotid artery injuries, CSF leaks, or new hearing loss. The mean postoperative hospital stay was 2 days (range 0.7-4.6 days). These results were comparable with those in previous studies of open approaches to petrous apex CGs. There was a strong correlation between the size of the cyst and the type of approach chosen (Rpb [point biserial correlation coefficient] = +0.67, p = 0.003359) and a very strong correlation between the degree of medial extension (defined by the V-angle) and the choice of approach (Rpb = +0.81, p < 0.0001). Based on these observations, the authors developed an algorithm for guiding the choice of the most appropriate route of drainage., Conclusions: The EEA is a safe and effective alternative to traditional open approaches to petrous apex CGs.

Objectives/hypothesis: To describe the clinical presentation, pathophysiology, and treatment of spontaneous cerebrospinal fluid (CSF) leaks of the sphenoid bone, with an emphasis on a previously undescribed form in this location, in which CSF is trapped under the mucosa of the sinonasal cavity or in the soft tissue of the skull base., Study Design: Case series and literature review., Methods: Analysis of cases through medical records and literature review., Results: Four examples of unusual spontaneous CSF leaks of the skull base are presented. In each case, a CSF collection was contained behind the sinonasal mucosa of the sphenoid sinus, resembling a nasal polyp or mucocele on exam or imaging. In one case, the fluid collection was also associated with significant bone resorption and extravasation into the soft tissue of the infratemporal fossa. In each case, small defects of the ventral skull base (sphenoid bone) were the source of the CSF leaks. Successful treatment was achieved after transnasal endoscopic repair of the skull base defects using a combination of free abdominal fat grafts, free fascial grafts, and pedicled nasoseptal flaps. Postoperatively, a ventriculoperitoneal shunt was placed if the intracranial pressure was elevated., Conclusions: Spontaneous CSF leaks arising in the sphenoid sinus may not always present with overt CSF rhinorrhea but with a submucosal fluid collection (pseudomeningocele) that may mimic a mucocele or nasal polyp. These bona fide pseudomeningoceles of the skull base may be associated with elevated intracranial pressure and can be managed using endoscopic endonasal surgery., (Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.)

We report a technical variation of the endoscopic endonasal approach to the sellar and suprasellar regions which relies on the use of a 45-degree angled endoscope. The so-called "infrasellar approach" aims at excising lesions situated within the intermediate and posterior lobes of the pituitary gland without damaging the anterior lobe, thus potentially minimizing endocrinological morbidity. In this regard the endoscopic infrasellar approach might be advantageous in selected cases when compared with the traditional transsphenoidal approach with the microscope. We describe the technique and illustrate it with representative clinical cases.

Background: Intraoperative neurophysiological monitoring, including upper- and lower-extremity somatosensory evoked potentials (SSEPs), has been used to identify and prevent injury to neurovascular structures during conventional skull base surgery. The expanded endonasal approach (EEA) is a novel minimally invasive approach to skull base surgery. However, it carries the risk of injury to neurovascular structures, including the internal carotid artery, anterior cerebral artery, and cranial nerves., Objective: To evaluate the value of SSEP monitoring to predict and/or prevent neurovascular deficits during EEA to skull base surgery., Methods: We retrospectively identified 999 consecutive patients who had intraoperative neurophysiological monitoring during EEA skull base surgery at our institution. A total of 976 patients had SSEP monitoring and a documented postoperative neurological examination., Results: The incidence of changes in SSEP during the procedure was 20 of 976 (2%). The incidence of new postoperative neurological deficits was 5 of 976 (0.5%). The positive and negative predictive values of SSEPs during EEA to predict neurovascular deficits were 80.00% and 99.79%, respectively., Conclusion: Intraoperative SSEP monitoring was able to identify impending risk to neurovascular structures to prevent permanent postoperative neurological deficits. We advocate a comprehensive approach to neurophysiological monitoring during EEAs, including SSEPs, spontaneous and triggered electromyography of the cranial nerves III through XII, brainstem auditory evoked potentials, and electroencephalogram, depending on the surgical approach and location of the neural structures at risk.

Object: The development of endoscopic endonasal approaches, albeit in the early stages, represents part of the continuous evolution of skull base surgery. During this early period, it is important to determine the safety of these approaches by analyzing surgical complications to identify and eliminate their causes., Methods: The authors reviewed all perioperative complications associated with endoscopic endonasal skull base surgeries performed between July 1998 and June 2007 at the University of Pittsburgh Medical Center., Results: This study includes the data for the authors' first 800 patients, comprising 399 male (49.9%) and 401 female (50.1%) patients with a mean age of 49.21 years (range 3-96 years). Pituitary adenomas (39.1%) and meningiomas (11.8%) were the 2 most common pathologies. A postoperative CSF leak represented the most common complication, occurring in 15.9% of the patients. All patients with a postoperative CSF leak were successfully treated with a lumbar drain and/or another endoscopic approach, except for 1 patient who required a transcranial repair. The incidence of postoperative CSF leaks decreased significantly with the adoption of vascularized tissue for reconstruction of the skull base (< 6%). Transient neurological deficits occurred in 20 patients (2.5%) and permanent neurological deficits in 14 patients (1.8%). Intracranial infection and systemic complications were encountered and successfully treated in 13 (1.6%) and 17 (2.1%) patients, respectively. Seven patients died during the 30-day perioperative period, 6 of systemic illness and 1 of infection (overall mortality 0.9%)., Conclusions: Endoscopic endonasal skull base surgery provides a viable median corridor based on anatomical landmarks and is customized according to the specific pathological process. This corridor should be considered as the sole access or may be combined with traditional approaches. With the incremental acquisition of skills and experience, endoscopic endonasal approaches have an acceptable safety profile in select patients presenting with various skull base pathologies.

Objectives: The introduction of the pedicled nasoseptal flap (NSF) has decreased postoperative cerebrospinal fluid (CSF) leak rates from >20% to <5% during expanded endoscopic skull base surgery. The NSF must be raised at the beginning of the operation to protect the posterior pedicle during the expanded sphenoidotomy. However, in most pituitary tumor cases, an intraoperative CSF leak is not expected but at times encountered. In these cases, a "rescue" flap approach can be used, which consists of partially harvesting the most superior and posterior aspect of the flap to protect its pedicle and provide access to the sphenoid face during the approach. The rescue flap can be fully harvested at the end of the case if the resultant defect is larger than expected, or if an unexpected CSF leak develops. This technique minimized septum donor site morbidity for those patients without intraoperative CSF leaks., Results: The rescue flap technique allows for binaural and bimanual access to the sella without compromise of the pedicle during the extended sphenoidotomies and tumor removal. If an intraoperative CSF leak is encountered, the rescue flap is then converted into a normal nasoseptal flap for skull base reconstruction. If no leak is obtained, then the patient does not suffer additional donor site morbidity from the full flap harvest., Conclusions: This new technique allows for sellar tumor removal prior to the nasoseptal harvest, thereby eliminating donor site morbidity for those pituitary tumor patients who do not have an intraoperative CSF leak., (Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.)

Recently, we investigated the molecular mechanisms of the smoking cessation drug varenicline, a nicotinic acetylcholine receptor (nAChR) partial agonist, in its ability to decrease voluntary ethanol intake in mice. Previous to our study, other labs had shown that this drug can decrease ethanol consumption and seeking in rat models of ethanol intake. Although varenicline was designed to be a high affinity partial agonist of nAChRs containing the α4 and β2 subunits (designated as α4β2*), at higher concentrations it can also act upon α3β2*, α6*, α3β4* and α7 nAChRs. Therefore, to further elucidate the nAChR subtype responsible for varenicline-induced reduction of ethanol consumption, we utilized a pharmacological approach in combination with two complimentary nAChR genetic mouse models, a knock-out line that does not express the α4 subunit (α4 KO) and another line that expresses α4* nAChRs hypersensitive to agonist (the Leu9'Ala line). We found that activation of α4* nAChRs was necessary and sufficient for varenicline-induced reduction of alcohol consumption. Consistent with this result, here we show that a more efficacious nAChR agonist, nicotine, also decreased voluntary ethanol intake, and that α4* nAChRs are critical for this reduction.

Hemifacial spasm is a socially disabling condition that manifests as intermittent involuntary twitching of the eyelid and progresses to muscle contractions of the entire hemiface. Patients receiving microvascular decompression of the facial nerve demonstrate an abnormal lateral spread response (LSR) in peripheral branches during facial electromyography. The authors retrospectively evaluate the prognostic value of preoperative clinical characteristics and the efficacy of intraoperative monitoring in predicting short- and long-term relief after microvascular decompression for hemifacial spasm. Microvascular decompression was performed in 293 patients with hemifacial spasm, and LSR was recorded during intraoperative facial electromyography monitoring. In 259 (87.7%) of the 293 patients, the LSR was attainable. Patient outcome was evaluated on the basis of whether the LSR disappeared or persisted after decompression. The mean follow-up period was 54.5 months (range, 9-102 months). A total of 88.0% of patients experienced immediate postoperative relief of spasm; 90.8% had relief at discharge, and 92.3% had relief at follow-up. Preoperative facial weakness and platysmal spasm correlated with persistent postoperative spasm, with similar trends at follow-up. In 207 patients, the LSR disappeared intraoperatively after decompression (group I), and in the remaining 52 patients, the LSR persisted intraoperatively despite decompression (group II). There was a significant difference in spasm relief between both groups within 24 hours of surgery (94.7% vs. 67.3%) (P < 0.0001) and at discharge (94.2% vs. 76.9%) (P = 0.001), but not at follow-up (93.3% vs. 94.4%) (P = 1.000). Multivariate logistic regression analysis demonstrated independent predictability of residual LSR for present spasm within 24 hours of surgery and at discharge but not at follow-up. Facial electromyography monitoring of the LSR during microvascular decompression is an effective tool in ensuring a complete decompression with long-lasting effects. Although LSR results predict short-term outcomes, long-term outcomes are not as reliant on LSR activity.

As endoscopic skull base resections have advanced, appropriate reconstruction has become paramount. The reconstructive options for the skull base include both avascular and vascular grafts. We review these and provide an algorithm for endoscopic skull base reconstruction. One hundred and sixty-six skull base dural defects, reconstructed with an endonasal vascular flap, were examined. As an adjunct, avascular reconstruction techniques are discussed to illustrate all options for endonasal skull base reconstruction. Cerebrospinal fluid (CSF) leak rates are also discussed. Small CSF leaks may be successfully repaired with various avascular grafting techniques. Endoscopic endonasal approaches (EEAs) to the skull base often have larger dural defects with high-flow CSF leaks. Success rates for some EEA procedures utilizing avascular grafts approach 90%, yet in high-flow leak situations, success rates are much lower (50 to 70%). Defect location and complexity guides vascularized flap choice. When nasoseptal flaps are unavailable, anterior/sellar defects are best managed with an endoscopically harvested pericranial flap, whereas clival/posterior defects may be reconstructed with an inferior turbinate or temporoparietal flap. An endonasal skull base reconstruction algorithm was constructed and points to increased use of various vascularized reconstructions for more complex skull base defects.

Background: The expansion of endoscopic endonasal skull base surgery has resulted in an increased demand for reconstructive options. Reconstruction with vascularized tissue has proven indispensable for reliably separating the cranial contents from the paranasal sinuses following extended endoscopic endonasal approaches (EEA). The introduction of the Hadad-Bassagasteguy flap (vascular pedicle nasoseptal flap, HBF) at our institution decreased our postoperative cerebral spinal fluid (CSF) leak rates from more than 20% to less than 5%. The HBF is not always available, as the nasoseptal area or its vascular supply can be compromised by tumor or prior surgery. In an attempt to keep pace with rapidly expanding reconstructive requirements, we present the anatomic and cadaveric foundations for novel modifications of the facial artery musculo (-mucosal) (FAM[M]) and buccinator flaps to allow vascularized reconstruction of the skull base., Study Design: Feasibility. Cadaveric study., Methods: Using cadaver dissections and measurements, we investigated the feasibility of transposing pedicled buccinator myo/myomucosal flaps into the nasal cavity and skull base. Both muscular and myomuscular flaps were raised, and techniques for transposition into the nasal cavity were investigated. Three fresh and six preserved human specimens were dissected., Results: Pedicled facial buccinator flaps with and without mucosa were transposed into the nasal cavity using a variety of maxillary osteotomies. No facial incisions were required. It was demonstrated that the flaps reach the anterior skull base and planum sphenoidale., Conclusions: The transposition of pedicled buccinator muscle flaps with and without mucosa into the nasal cavity could reach the anterior skull base and planum sphenoidale, if the appropriate surgical technique is used. The pedicled Facial Buccinator Flap holds significant potential as a reconstructive alternative for a variety of skull base defects, alone or in combination with existing reconstructive options. 2010.

Endonasal skull base surgery is growing exponentially as a subspecialty. In recent years, advances in endoscopic techniques and intraoperative navigation systems have allowed us to expand the indications of endoscopic skull base surgery. Major skull base centers worldwide are addressing larger and more complex lesions using endoscopic techniques. As a consequence, the skull base defects are more challenging to reconstruct. In this report, we present a novel technique to reconstruct the denuded septum remaining after the use of the vascular pedicled nasoseptal flap.

Introduction: The transclival endoscopic endonasal approach was used to completely remove a prepontine neuroenteric cyst in two different patients., Case Reports: Full clinical improvement without postoperative complication was achieved in both cases. The postoperative hospital stay was limited to 2 and 3 days., Discussion: In comparison to posterolateral skull base approaches, the transclival endoscopic endonasal approach allows direct access to the prepontine cistern without unnecessary manipulation of neurovascular structures at the cerebellopontine angle. In contrast to transoral surgery, patients may have decreased risk of infection and can be fed orally immediately without the risks of palatal and oropharyngeal dehiscence., Conclusion: Neuronavigation technology, strict adherence to microsurgical principles, and significant endoneurosurgical experience are strongly recommended when approaching these challenging lesions.

Background: Understanding the course of the most medially located parasellar cranial nerve, the abducens, becomes critical when performing an expanded endonasal approach., Objective: We report an anatomoclinical study of the abducens nerve and describe relevant surgical nuances to avoid its injury., Methods: Ten anatomic specimens were dissected using endoscopes attached to an high-definition camera. A series of anatomic measurements and relationships of the abducens nerve were noted. Illustrative clinical cases are described to translate those findings into practice., Results: Cisternal, interdural, gulfar, and cavernous segments of the abducens were identified intracranially. The mean distance from the vertebrobasilar junction (VBJ) to the pontomedullary sulcus (PMS) was 4 mm; horizontal distance between both abducens nerves at the PMS was 10 mm, and between both abducens at the interdural segment was 18.5 mm. The upper limit of the lacerum segment of the internal carotid artery was at the same level of the dural entry point of the sixth cranial nerve posteriorly. The sellar floor at the sphenoid sinus marks the level of the gulfar segment in the craniocaudal axis. At the superior orbital fissure, the abducens nerve and V2 were at an average vertical distance of 11.5 mm., Conclusion: Anatomic landmarks to localize the abducens nerve intraoperatively, such as the VBJ for the transclival approach, the lacerum segment of the carotid, and the sellar floor for the medial petrous apex approach, and V2 for Meckel's cave approach, are reliable and complementary to the use of intraoperative electrophysiological monitoring.

Object: In rare cases, children with a Chiari malformation Type I (CM-I) suffer from concomitant, irreducible, ventral brainstem compression that may result in cranial neuropathies or brainstem dysfunction. In these circumstances, a 360 degrees decompression supplemented by posterior stabilization and fusion is required. In this report, the authors present the first experience with using an endoscopic transnasal corridor to accomplish ventral decompression in children with CM-I that is complicated by ventral brainstem compression., Methods: Two children presented with a combination of occipital headaches, swallowing dysfunction, myelopathy, and/or progressive scoliosis. Imaging studies demonstrated CM-I with severely retroflexed odontoid processes and ventral brainstem compression. Both patients underwent an endoscopic transnasal approach for ventral decompression, followed by posterior decompression, expansive duraplasty, and occipital-cervical fusion., Results: In both patients the endoscopic transnasal approach provided excellent ventral access to decompress the brainstem. When compared with the transoral approach, endoscopic transnasal access presents 4 potential advantages: 1) excellent prevertebral exposure in patients with small oral cavities; 2) a surgical corridor located above the hard palate to decompress rostral pathological entities more easily; 3) avoidance of the oral trauma and edema that follows oral retractor placement; and 4) avoidance of splitting the soft or hard palate in patients with oral-palatal dysfunction from ventral brainstem compression., Conclusions: The endoscopic transnasal approach is atraumatic to the oral cavity, and offers a more superior region of exposure when compared with the standard transoral approach. Depending on their comfort level with endoscopic surgical techniques, pediatric neurosurgeons should consider this approach in children with pathological entities requiring ventral brainstem decompression.

Object: Rathke cleft cysts (RCCs) are benign lesions that can be diagnosed as an incidental finding associated with headaches, pituitary dysfunction, or vision deterioration. Typically, they occur in a sellar or suprasellar location. The aim of this study was to review the clinical presentation and outcomes associated with endoscopic endonasal resection of these lesions., Methods: The authors retrospectively reviewed a series of 35 patients with a diagnosis of RCC after endoscopic endonasal resection at the University of Pittsburgh between January 1998 and July 2008., Results: All 35 patients underwent a purely endoscopic endonasal approach (EEA). The average patient age was 34 years (range 12-67 years), and the average follow-up was 19 months (range 1-60 months). Clinical follow-up data were available for 32 patients, and radiographic follow-up data were accessible for 33 patients. All of the patients underwent complete removal of the cyst contents, and according to radiography studies 2 patients had a recurrence, neither of which required reoperation. The mean cyst volume was 1052.7 mm(3) (range 114-6044 mm(3)). Headache was a presenting symptom in 26 (81.2%) of 32 patients, with 25 (96.1%) of 26 having postoperative improvement in their headaches. Fifteen (57.7%) of the 26 patients had complete pain resolution, and 10 (38.5%) had a > 50% reduction in their pain scores. Six (18.8%) of 32 patients initially presented with pituitary dysfunction, although 2 (33.3%) had postoperative improvement. Three (9.4%) of 32 patients had temporary pituitary dysfunction postoperatively, although there was no permanent pituitary dysfunction. Neither were there any intraoperative complications, postoperative CSF leaks, or new neurological deficits. The average hospital stay was 1.8 days (range 1-5 days)., Conclusions: The EEA is a safe and effective approach in the treatment of RCCs. None of the patients in this study experienced any worsening of their preoperative symptoms or pituitary function, and 96% of the patients who had presented with headache experienced complete or significant pain relief following treatment.

Objective: The endoscopic endonasal transclival approach is a valid alternative for treatment of lesions in the clivus. The major limitation of this approach is a significant lateral extension of the tumor. We aim to identify a safe corridor through the occipital condyle to provide more lateral exposure of the foramen magnum., Methods: Sixteen parameters were measured in 25 adult skulls to analyze the exact extension of a safe corridor through the condyle. Endonasal endoscopic anatomic dissections were carried out in nine colored latex-injected heads., Results: Drilling at the lateral inferior clival area exposed two compartments divided by the hypoglossal canal: the jugular tubercle (superior) and the condylar (inferior). Completion of a unilateral ventromedial condyle resection opens a 3.5 mm (transverse length) * 10 mm (vertical length) lateral surgical corridor, facilitating direct access to the vertebral artery at its dural entry point into the posterior fossa. The supracondylar groove is a reliable landmark for locating the hypoglossal canal in relation to the condyle. The hypoglossal canal is used as the posterior limit of the condyle removal to preserve more than half of the condylar mass. The transjugular tubercle approach is accomplished by drilling above the hypoglossal canal, and increases the vertical length of the lateral surgical corridor by 8 mm, allowing for visualization of the distal cisternal segment of the lower cranial nerves., Conclusion: The transcondylar and transjugular tubercle "far medial" expansions of the endoscopic endonasal approach to the inferior third of the clivus provide a unique surgical corridor to the ventrolateral surface of the ponto- and cervicomedullary junctions.

Tumours affecting the nose, paranasal sinuses and adjacent skull base are fortunately rare. However, they pose significant problems of management due their late presentation and juxtaposition to important anatomical structures such eye and brain. The increasing application of endonasal endoscopic techniques to their excision offers potentially similar scales of resection but with reduced morbidity. The present document is intended to be a state-of-the art review for any specialist with an interest in this area 1. to update their knowledge of neoplasia affecting the nose, paranasal sinuses and adjacent skull base; 2. to provide an evidence-based review of the diagnostic methods; 3. to provide an evidence-based review of endoscopic techniques in the context of other available treatments; 4. to propose algorithms for the management of the disease; 5. to propose guidance for outcome measurements for research and encourage prospective collection of data. The importance of a multidisciplinary approach, adherence to oncologic principles with intent to cure and need for long-term follow-up is emphasised.

Objective: To develop a new staging system for juvenile nasopharyngeal angiofibroma that reflects changes in surgical approaches (endonasal), route of intracranial extension, and the extent of vascular supply from the internal carotid artery., Design: Retrospective review of case series., Setting: Academic medical center., Patients: Patients undergoing endoscopic endonasal surgery for juvenile nasopharyngeal angiofibroma at the University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, from 1998 through 2008., Intervention: Patients were staged according to current systems and compared with a new staging system that also incorporated the route of skull base extension and tumor vascularity., Main Outcome Measures: Estimated blood loss, number of operations, and tumor recurrence., Results: Skull base erosion was observed in 74% of cases. Following embolization of external carotid artery tributaries, residual vascularity from the internal carotid artery was seen in 51% of patients. Residual vascularity, classified as UPMC stage IV and V, strongly correlated with blood loss, requirement for multiple procedures, and residual or recurrent tumor., Conclusions: Tumor size and extent of sinus disease are less important in predicting complete tumor removal with endonasal surgical techniques. The UPMC staging system for juvenile nasopharyngeal angiofibroma accounts for 2 important prognostic factors, route of cranial base extension, and vascularity and is applicable to endoscopic or open approaches. Compared with other staging systems, the UPMC staging system provides a better prediction of immediate morbidity (including blood loss and need for multiple operations) and tumor recurrence.