Predictors of Delayed Hyponatraemia After Surgery for Pituitary Tumour.

Delayed hyponatraemia(DH) is a common complication following trans-sphenoidal surgery(TSS) for pituitary tumour. We evaluated the prevalence of DH following TSS, and assessed the factors associated with DH, including early post-operative diabetes insipidus(EPDI). This retrospective study included 100 TSS for pituitary tumours in 98 patients, over a period of 26 months. Subjects were divided into two groups: those who developed hyponatraemia and those who did not develop hyponatraemia, during post-operative days 4 to 14. The clinical characteristics and peri-operative parameters were compared between the two groups, to identify factors predicting DH. The mean age of the patients was 42.0±13.6 years, 58 (59%) were females and 61 (61%) had functional tumours. Thirty-six patients(36%) developed DH following TSS of whom majority(58%) were diagnosed on post-operative days 7 and 8; only 8/36 (22%) were symptomatic. Syndrome of inappropriate antidiuretic hormone secretion(SIADH) was found to be the most common aetiology of DH. On logistic regression analysis, intra-operative cerebrospinal fluid(CSF) leak (OR 5.0; 95% CI 1.9-13.8; p=0.002), EPDI (OR 3.4; 95% CI 1.3-9.2; p=0.015) and peri-operative steroid use (OR 3.6; 95% CI 1.3-9.8; p=0.014) were found to be significantly associated with DH. In conclusion, EPDI, intra-operative CSF leak and peri-operative steroid use were significant predictors of DH. EPDI predicts moderate to severe hyponatraemia with 80% specificity but has low sensitivity(47%). As most patients have asymptomatic hyponatraemia, serum sodium measurement on POD 7 to 10 would be helpful to identify DH in patients at increased risk.

A Negative-Pressure Face-Mounted System Reduces Aerosol Spread during Endonasal Endoscopic Surgery.

Purpose Due to the potential risk of COVID-19 transmission during endonasal surgery, we studied methods to reduce droplet and aerosol generation during these procedures. Methods Droplet spread was assessed using ultraviolet light and a camera that detected fluorescence in the operative field and surgeon's personal protective equipment. Density of aerosols sized <10 µm was measured using a photometric particle counter. We designed a face-mounted negative-pressure mask placed on the patients' face during endoscopic endonasal surgery. Sixteen patients were recruited between October 2020 and March 2021 and randomly assigned to the mask and no-mask groups. We compared droplet spread and aerosols generated in both groups, with copious irrigation and continuous suction during drilling forming the mainstay of surgical technique in all cases. Results Droplet contamination due to direct spillage of fluorescein from the syringe was noted in two patients. Aerosol density rose during sphenoid drilling in both groups, with no significant difference when continuous suction and irrigation were employed (1.27 times vs. 1.07 times the baseline, p = 0 .248 ). Aerosol density rose significantly when suction and irrigation were interrupted in the no-mask group (44.9 times vs. 1.2 times, p = 0 .028) , which was not seen when the mask was used. Conclusion Aerosol generation increases during drilling in endonasal procedures and is a concern during this pandemic. The use of a rigid suction close to the drill along with copious irrigation is effective in reducing aerosol spread. The use of a negative pressure mask provides additional safety when inadvertent blockage of suction and inadequate irrigation occur.

Impact of Grade on Survival in Pleomorphic Xanthoastrocytoma and Low Prevalence of BRAF V600E Mutation.

BACKGROUND: The prevalence of BRAFV600E mutations in pleomorphic xanthoastrocytoma (PXA) World Health Organization (WHO) Grade 2 and PXA WHO Grade 3 reported varies from 60% to 80%, yet the prognostic implications remain unclear. METHODS: We reviewed the demographic and clinicoradiologic data of 20 PXAs WHO Grade 2 and 13 PXAs WHO Grade 3, operated between 2007 and 2020, to ascertain extent of excision, recurrence, progression-free survival (PFS), and overall survival (OS). PXAs WHO Grade 3 were defined by the presence of >5 mitoses/high-power field. PXAs WHO Grade 3 received adjuvant radiation therapy and chemotherapy whereas PXAs received radiation therapy if subtotally excised. All samples were analyzed for the presence of BRAFV600E mutation using DNA obtained from paraffin blocks using droplet-digital polymerase chain reaction. RESULTS: The median patient age at diagnosis was 22 years with a male preponderance. BRAFV600E mutations were noted in 30% of tumors; 8 PXAs WHO Grade 2 and 2 PXAs WHO Grade 3. Recurrence occurred in 6 of 13 PXA WHO Grade 3 (55%) and 1 of 20 PXAs WHO Grade 2 (5%). At median follow-up of 45 months, the OS was 54 months and 33 months in the PXA WHO Grade 2 and PXA WHO Grade 3 groups, respectively (P = 0.02). OS and PFS did not differ between BRAF-mutated and BRAF-negative tumors. CONCLUSIONS: BRAFV600E mutations are less frequent in our population than reported in the literature. The BRAF mutation does not significantly impact OS and PFS. PXAs WHO Grade 3 are a distinct clinical entity, associated with worse PFS and OS than PXAs WHO Grade 2.

Mass Spectrometry Imaging Deciphers Dysregulated Lipid Metabolism in the Human Hippocampus Affected by Temporal Lobe Epilepsy.

Temporal lobe epilepsy (TLE) is the most prevalent form of human epilepsy, often accompanied by neurodegeneration in the hippocampus. Like other neurological diseases, TLE is expected to disrupt lipid homeostasis. However, the lipid architecture of the human TLE brain is relatively understudied, and the molecular mechanism of epileptogenesis is poorly understood. We performed desorption electrospray ionization mass spectrometry imaging of 39 fresh frozen surgical specimens of the human hippocampus to investigate lipid profiles in TLE with hippocampal sclerosis (n = 14) and control (non-TLE; n = 25) groups. In contrast to several previous studies on animal models of epilepsy, we report reduced expression of various important lipids, notably phosphatidylcholine (PC) and phosphatidylethanolamine (PE), in the human TLE hippocampus. In addition, metabolic pathway analysis suggested the possible dysregulation of the Kennedy pathway in TLE, resulting in striking reductions of PC and PE levels. This revelation opens up opportunities to further investigate the associated molecular mechanisms and possible therapeutic targets for TLE.

Adapting management strategies for sellar-suprasellar lesions during the COVID-19 pandemic: a pragmatic approach from the frontline.

PURPOSE: During the ongoing COVID-19 pandemic, endonasal surgeries for sellar-suprasellar lesions were discouraged due to the risk of transmission of the disease. We reviewed the changes in our management protocol for these lesions as our disease understanding and preparedness evolved. MATERIALS AND METHODS: This was a retrospective observational study including patients with sellar-suprasellar and clival lesions presenting to us between March and October 2020. Management protocols were divided into three phases based on the prevalence of the disease and the number of mandatory preoperative COVID-19 tests being conducted. The surgical approach used was analyzed in relation to the preferred approach during pre-COVID times, and surgical outcomes and complications were noted. RESULTS: A total of 31 cases were operated during this period. During Phase I (low prevalence; no preoperative COVID testing) endonasal surgeries were largely abandoned in favor of transcranial approaches. In Phase II (medium prevalence; one preoperative COVID test) we gradually resumed endonasal surgeries for 'emergent' and 'essential' cases, and subsequently in Phase III (high prevalence; two preoperative COVID tests), we had no hesitation in performing 'elective' endonasal surgeries with additional barriers for prevention of aerosol transmission. No patient developed COVID-19 infection postoperatively. Eight HCWs in our department acquired the disease during this period, none of whom were directly involved in the surgeries for the above cohort of patients. CONCLUSIONS: With a strict preoperative COVID testing protocol, adherence to proper drilling techniques and using additional barriers to prevent droplet and aerosol spread, endonasal surgeries for sellar-suprasellar lesions are safe during this COVID-19 pandemic.

Clinical Profile and Mutations Associated with Multiple Endocrine Neoplasia-Type1 (MEN1) and Their First-Degree Relatives at Risk of Developing MEN1: A Prospective Study.

Multiple Endocrine Neoplasia type-1 (MEN1) is an autosomal dominant disorder with a combined occurrence of tumours of parathyroid glands, pancreatic islets, and anterior pituitary. About 90% of these patients carry mutations in the MEN1 gene, though the spectrum is not well defined in India. Forty clinically suspected cases of MEN1 were enrolled prospectively over six years; 32 patients (23 index-cases and nine affected relatives) with≥2 classical endocrine tumours of MEN1 were considered definite, and eight were categorised as 'MEN1-like'. Details of their clinical presentation, treatment and mutational analysis including MEN1 gene, 3' and 5' untranslated regions (UTR) of MEN1, CDKN1B, and CaSR genes were collated. Asymptomatic first-degree relatives were also screened. Among the 32 definite MEN1 patients, all had primary hyperparathyroidism, 22 (68.7%) had gastroentero-pancreatic neuroendocrine tumours, and 21 (66%) had pituitary adenoma. Of the 23 definite index-cases, 13 (56.5%) carried mutations in the MEN1 gene. Five of nine affected first-degree relatives (55.5%), and four of 10 asymptomatic relatives (40%) also had MEN1 mutations. Seven of 10 MEN1 mutation-negative definite index-cases harboured p.V109G polymorphism in the CDKN1B gene. All eight MEN1-like cases were negative for mutations and large deletions in MEN1, mutations in 3' and 5' UTR of MEN1, CaSR and CDKN1B genes. The study has helped to clearly document the pattern of mutations among Indian MEN1 patients. However, the absence of MEN1 mutation in ~44% of cases and the presence of p.V109G polymorphism in CDKN1B gene raise the question whether such polymorphisms could independently contribute to pathogenesis.

Progressive midbrain clefts after head trauma and decompressive surgery: a report of two patients.

This report describes two patients with acute-onset ptosis, oculomotor dysfunction, ataxia and drowsiness, referable to the midbrain tegmentum. Both patients had previously suffered severe closed head injuries requiring craniotomy for cerebral decompression. Serial brain scans in both cases revealed a newly developing cleft in the midbrain, with features suggestive of abnormal cerebrospinal fluid (CSF) flow across the aqueduct. A trial of acetazolamide was initiated to reduce CSF production, followed by a third ventriculostomy for CSF diversion in one patient, which resulted in arrested disease progression and partial recovery. There are only two previous reports in the literature of midbrain clefts that developed as remote sequelae of head trauma. We postulate that altered CSF flow dynamics in the aqueduct, possibly related to changes in brain compliance, may be contributory. Early recognition and treatment may prevent irreversible structural injury and possible death.

Long-term outcomes following maximal safe resection in a contemporary series of childhood craniopharyngiomas.

BACKGROUND: The optimal management of pediatric craniopharyngiomas remains controversial. This study aimed to characterize long-term outcomes in a contemporary cohort of children undergoing surgery for craniopharyngiomas. METHODS: This was a retrospective review of 37 consecutive children who underwent surgery for craniopharyngioma with a median follow-up duration of 79 months (range 5-127 months). Patients were stratified by extent of resection (EOR) and need for adjuvant radiation therapy (RT). Imaging studies were reviewed to grade extent of hypothalamic involvement. Data on functional outcomes, pituitary function, and obesity were analyzed. RESULTS: Gross total resection was achieved in 16 patients (43.2%), near total resection in six patients (16.2%), and subtotal resection (STR) in 15 patients (40.5%). The recurrence-free survival rate was 81.1% and 70.3% at 5- and 10-year follow-up, respectively. Survival analysis showed superior disease control in patients undergoing STR + RT (p = 0.008). Functional outcomes were independent of EOR, postoperative RT or recurrence. Diabetes insipidus was present in 75% and 44.4% of patients required >2 hormone replacements at last follow-up. Obesity was present in 36.1% patients after treatment, and was associated with preoperative obesity (p = 0.019), preoperative hypothalamic involvement (p = 0.047) and STR + RT (p = 0.011). CONCLUSIONS: Gross or near total resection may be achieved safely in almost 60% of cases; however, radical surgery does not eliminate the risk of recurrence. Over long-term follow-up, STR + RT offers the best disease control rates. Patients with preoperative hypothalamic involvement, obesity, and those with tumors not amenable to radical resection are at risk for developing obesity on long-term follow-up.

Neuroimaging of pediatric infratentorial tumors and the value of diffusion-weighted imaging (DWI) in determining tumor grade.

BACKGROUND: Diffusion-weighted imaging (DWI) provides information about the cellular density of tumors. This feature is useful in grading and identifying different tumor types. PURPOSE: To assess the value of diffusion restriction and apparent diffusion coefficient (ADC) values in differentiating pediatric infratentorial tumors. MATERIAL AND METHODS: This was a retrospective review of the magnetic resonance imaging (MRI) of 82 children (age range 1-16 years) with infratentorial tumors. Histopathological grading after surgical excision/biopsy was categorized as low grade (WHO grades I and II) (n = 31; 29 pilocytic astrocytomas, 2 ependymomas) and high grade (WHO grade III and IV) (n = 51; 40 medulloblastomas, 8 anaplastic ependymomas, 1 anaplastic astrocytoma, 2 atypical rhabdoid teratoid tumors [ATRT]). MRI features and ADC values were compared among tumor types and grades using a two-tailed t test, Mann-Whitney U test for continuous data and Chi-square test for categorical variables. RESULTS: Diffusion restriction and low ADC value was a feature of high-grade tumors (P<0.001). The mean ADC values of the low-grade and high-grade tumors were 1.567 × 10-3mm2/s and 0.661 × 10-3mm2/s, respectively. Using 0.9 × 10-3mm2/s as the cut-off value, the sensitivity, specificity, positive and negative predictive values for differentiating the grades was 87%, 100%, 100%, and 81.8%, respectively. Significant differences were found between the mean ADC values of the individual tumor types (P<0.05), except between medulloblastoma and ATRT. CONCLUSION: ADC values and visual assessment of diffusion restriction are useful in tumor grading. The individual tumor types can be identified by an algorithmic approach, using DWI in conjunction with other described MRI features.

Age-Dependent Reduction in Severity and Discrete Topographical Patterns in Rasmussen Encephalitis: A Link to Cortical Maturation?

BACKGROUND: Autopsy studies in Rasmussen encephalitis reveal areas of sparing within the affected hemisphere. Clinical progression and inflammation are milder with an older onset. We sought to demonstrate radiological corroboration for these patterns. METHODS: In our retrospective study, 38 cases were dichotomized into severe pan-hemispheric (all lobes involved) and sub-hemispheric groups (others) to identify age demographics and other severity predictors. The extent and patterns of radiological pathology in the cortex and subcortical structures were assessed by structured visual grading. Relevant clinical data were also reported. RESULTS: Children with pan-hemispheric involvement were younger at onset (P < 0.001) and were more likely to present with status epilepticus (odds ratio 8.5, 95% confidence interval 1.5 to 50.0, P = 0.022). A history of perinatal asphyxia/hospitalization (P < 0.001) and delayed milestones (P = 0.013) were encountered exclusively in this group, and progression to a low-amplitude record background on electroencephalography, suggesting that cortical damage was identified frequently (P = 0.038, odds ratio = 5.7, 95% confidence interval 1.3 to 25.0). Visual grading revealed significant differences among both cortical (P < 0.001) and subcortical (P < 0.001) regions. On multivariate analysis, the odds for pan-hemispheric disease decreased per year of age at onset (P = 0.022, odds ratio 0.51, 95% confidence interval 0.085 to 0.725). Epilepsy surgery (n = 14) was associated with Engel Class 1 seizure control (P < 0.001). Immunosuppressive therapy (n = 20) did not demonstrate a significant seizure remission (P = 0.157, odds ratio 0.39, 95% confidence interval 0.10 to 1.55). CONCLUSIONS: Our case series confirms the presence of specific topographical patterns of macroscopic radiological pathology over the affected hemisphere with a marked age-associated reduction in the odds for severe pan-hemispheric disease.

Secondary Bacterial Infection of a Solitary Cysticercus Granuloma.

The most common presenting form of neurocysticercosis in the Indian subcontinent is a solitary cysticercus granuloma (SCG). Patients with typical SCGs almost never require any form of surgical intervention. Herein, we report an extremely rare case of bacterial superinfection of a left frontal SCG in a 23-year-old female, resulting in severe perilesional edema and mass effect. The patient had to undergo an emergency left decompressive hemicraniectomy and excision of the infected granuloma. Serum enzyme-linked immunoelectrotransfer blot (EITB) for cysticercal antibodies was positive and histopathological examination of the lesion revealed a cysticercus. The culture of the pus from within the lesion grew vancomycin-resistant Enterococcus spp. for which she was treated with linezolid for 6 weeks. At 6 months follow-up, she had residual motor dysphasia, right homonymous hemianopia, and right hemiparesis but was steadily improving. Secondary bacterial infection of an SCG is very uncommon and can be devastating. A high index of suspicion is therefore required when there is disproportionate perilesional edema and mass effect.

Dynamic imaging of the craniovertebral junction is mandatory in patients with posterior circulation strokes.

INTRODUCTION: The course of the vertebral artery after exiting from the C1 foramen transversarium and prior to entering the dura lends itself to compression in C1-2 instability. However, atlantoaxial dislocation presenting with vertebrobasilar insufficiency and posterior circulation stroke (PCS) is rare. METHODS: In this retrospective study, we identified 96 patients with PCS who had complete radiological data. Ten (10.4%) patients had craniovertebral junction (CVJ) anomalies, of which six underwent surgery and four were managed conservatively. The clinical and functional outcomes were measured in the two groups. RESULTS: Left-sided strokes were seen in 7/10 patients, the majority of whom had left dominant vertebral arteries. The mean age at presentation in those with CVJ anomalies was 27.2 ± 12.8 years that was significantly lower than those without CVJ anomalies, 52.2 ± 14.5 years (p ≤ 0.001). The etiologies of PCS in those < 50 years were CVJ anomalies (30%), atherosclerosis (30%) and vasculitis (27%); however, the overwhelming majority of strokes in the > 50 year age group was atherosclerosis (91%). Postoperatively, there were no recurrent strokes in the operated patients, who also obtained significant clinical improvement on the modified Rankin Scale, Nurick Scale and modified McCormick Scale as compared to those who did not undergo surgery. CONCLUSION: Early diagnosis and surgical treatment of CVJ instability prevent recurrent strokes and improve outcomes in patients with PCS. Physicians and spine surgeons need to be sensitized regarding CVJ anomalies as a cause of PCS enabling early diagnosis with dynamic imaging particularly in the younger age group. These slides can be retrieved under Electronic Supplementary Material.

Phosphoproteomic analysis reveals Akt isoform-specific regulation of cytoskeleton proteins in human temporal lobe epilepsy with hippocampal sclerosis.

Akt is one of the most important downstream effectors of phosphatidylinositol 3-kinase/mTOR pathway. Hyperactivation and expression of this pathway are seen in a variety of neurological disorders including human temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). Nevertheless, the expression and activation profiles of the Akt isoforms, Akt1, Akt2, and Akt3 and their functional roles in human TLE-HS have not been studied. We examined the protein expression and activation (phosphorylation) patterns of Akt and its isoforms in human hippocampal tissue from TLE and non-TLE patients. A phosphoproteomic approach followed by interactome analysis of each Akt isoform was used to understand protein-protein interactions and their role in TLE-HS pathology. Our results demonstrated activation of the Akt/mTOR pathway as well as activation of Akt downstream substrates like GSK3ß, mTOR, and S6 in TLE-HS samples. Akt1 isoform levels were significantly increased in the TLE-HS samples as compared to the non-TLE samples. Most importantly, different isoforms were activated in different TLE-HS samples, Akt2 was activated in three samples, Akt2 and Akt1 were simultaneously activated in one sample and Akt3 was activated in two samples. Our phosphoproteomic screen across six TLE-HS samples identified 183 proteins phosphorylated by Akt isoforms, 29 of these proteins belong to cytoskeletal modification. Also, we were able to identify proteins of several other classes involved in glycolysis, neuronal development, protein folding and excitatory amino acid transport functions as Akt substrates. Taken together, our data offer clues to understand the role of Akt and its isoforms in underlying the pathology of TLE-HS and further, modulation of Akt/mTOR pathway using Akt isoforms specific inhibitors may offer a new therapeutic window for treatment of human TLE-HS.

A randomized controlled trial to determine the role of intraoperative lumbar cerebrospinal fluid drainage in patients undergoing endoscopic transsphenoidal surgery for pituitary adenomas.

BACKGROUND: Intraoperative cerebrospinal fluid (CSF) leaks are a frequent cause of morbidity in patients undergoing transsphenoidal surgery. This prospective study was performed to examine the impact of intraoperative lumbar subarachnoid drainage (LSAD) on the incidence of this complication and on the extent of resection in patients undergoing endoscopic transsphenoidal surgery for pituitary adenomas. MATERIALS AND METHODS: This prospective study was conducted in a single large academic medical center. All patients with pituitary adenomas who had not undergone prior transsphenoidal surgery were eligible for inclusion in the study. Patients were randomly assigned to undergo transsphenoidal surgery with intraoperative lumbar drain insertion (LSAD group) or no lumbar drain insertion (no LSAD group). An otolaryngologist independently determined the occurrence of an intraoperative CSF leak. Extent of tumor resection was determined by volumetric analysis of postoperative magnetic resonance images in patients with nonfunctional tumors or functional adenomas with a large suprasellar component. RESULTS: Sixty patients were eligible for inclusion, of which 30 were assigned to the LSAD group and 30 to the no LSAD group. There were no statistically significant differences in patient demographics, tumor pathology, or radiology between the two groups. The LSAD catheter was successfully inserted in all patients in the LSAD group. Intraoperative CSF drainage significantly reduced the incidence of CSF leak from 46.7% in the no LSAD group to 3.3% in the LSAD group (P < 0.001). However, there were no statistically significant differences in the incidence of postoperative CSF rhinorrhea between the two groups. There were no major catheter-related complications. There was no statistically significant difference in the extent of resection between the two groups. CONCLUSIONS: Controlled intraoperative CSF drainage significantly reduces the incidence of intraoperative CSF leakage in patients undergoing endoscopic transsphenoidal surgery for pituitary adenomas.

Implications of the World Health Organization definition of atypia on surgically treated functional and non-functional pituitary adenomas.

BACKGROUND: The World Health Organization (WHO) defines atypical pituitary adenomas as tumours with a MIB-1 labelling index ≥3%, p53 positivity and increased mitotic activity. Although a few reports have described the clinical and radiological correlates of atypia in pituitary adenomas, its impact on postoperative outcomes is not clearly defined. METHOD: We reviewed preoperative and postoperative records of patients undergoing surgery for pituitary adenomas. Postoperative outcomes for functional adenomas (FPAs) were assessed according to contemporary definitions of remission and recurrence. For non-functional pituitary adenomas (NFPAs), extent of resection and disease progression were defined on the basis of postoperative magnetic resonance imaging. RESULTS: Of 394 patients included for analysis, 29 cases (7.4%) fulfilled criteria for atypia. Patients with atypical tumours were significantly younger than those with typical adenomas. Remission was possible in 47.4% of FPAs, and was unrelated to the presence of atypia. In NFPAs, local invasiveness was negatively associated with extent of resection (OR, 0.255; 95% CI, 0.086-0.753; p < 0.001). In 93 NFPAs followed postoperatively with serial imaging over a mean duration of 37.5 months, disease progression/recurrence was significantly associated with the presence of atypia (OR, 5.058; 95% CI, 1.273-20.098; p = 0.021) on multivariate analysis. CONCLUSIONS: Patients with atypical non-functional pituitary adenomas are at risk for postoperative recurrence and disease progression, suggesting a need for adjuvant therapy. However, only a small fraction of pituitary tumours demonstrate atypia, as defined by the WHO, limiting its clinical utility.

Three-dimensional computed tomography angiographic study of the vertebral artery in patients with congenital craniovertebral junction anomalies.

PURPOSE: To describe vertebral artery (VA) course at the C0-C1-C2 complex in patients with congenital bony craniovertebral junction (CVJ) anomalies. METHODS: We studied the course of 169 VAs in 86 patients with congenital bony CVJ anomalies [basilar invagination (42), os odontoideum (33), and irreducible atlantoaxial dislocation (11)]. Occipitalized atlas occurred in 41 patients (30 complete and 11 partial). Using axial, coronal and sagittal three-dimensional computed tomography (3D-CT) angiograms, we traced the VA bilaterally at the CVJ and correlated the course to the presence or absence of occipitalization of the atlas. RESULTS: Of the 73 arteries associated with occipitalization of atlas, all had an abnormal course-58 (78.4 %) coursed through a canal within the C0-C1 fused complex and 15 (20.3 %) coursed below the C1 posterior arch, and it was absent unilaterally in one patient. There were 96 arteries associated with a non-occipitalized atlas and only 15 (15.3 %) were abnormal-eight coursed below the C1 posterior arch, four coursed above the C1 arch in the absence of a C1 foramen transversarium, one passed through a canal in C0-C1 and two arteries were absent unilaterally. Sixty vertebral arteries (34 on the right and 26 on the left side) had a redundant loop situated at a distance of ≥5 mm from the C1 lateral mass in patients with os odontoideum and irreducible atlantoaxial dislocation. CONCLUSIONS: In occipitalization of the atlas, the VA course is usually abnormal-typically passing through a canal within the C0-C1 fused complex or below the C1 arch. A redundant VA loop is more likely to be seen in os odontoideum and irreducible atlantoaxial dislocation. Careful study of the vertebral artery course with 3D CT angiography is mandatory while contemplating CVJ realignment surgery in congenital anomalies of the CVJ.

Endoscopic Transmaxillary Transposition of Temporalis Flap for Recurrent Cerebrospinal Fluid Leak Closure.

Objective To describe the technique of endoscopic transmaxillary temporalis muscle flap transposition for the repair of a persistent postoperative sphenoidal cerebrospinal fluid leak. Design The repair of a recurrent cerebrospinal fluid leak for a patient who had undergone endoscopic transsphenoidal excision of an invasive silent corticotroph Hardy C and Knosp Grade IV pituitary adenoma was undertaken. The patient had completed postoperative radiotherapy for the residual tumor and presented with cerebrospinal fluid leak, 1 year later. The initial two attempts to repair the cerebrospinal fluid leak with free grafts failed. Therefore, an endoscopic transmaxillary transposition of the temporalis muscle flap was attempted to stop the cerebrospinal fluid leak. Results The endoscopic transmaxillary transposition of the vascularized temporalis muscle flap onto the cerebrospinal fluid leak repair site resulted in successful closure of the cerebrospinal fluid leak. Conclusion Endoscopic transmaxillary transposition of the temporalis flap resulted in closure of recurrent cerebrospinal fluid leak in a patient with recurrent pituitary adenoma, who had undergone previous surgery and radiotherapy. This technique has advantages over the endoscopic transpterygoid transposition of the same flap and could be used as a complementary technique in selected patients.

Principles in Skull Base Reconstruction following Expanded Endoscopic Approaches.

OBJECTIVES: This study aims to describe the types of anterior skull base defects following expanded endoscopic approaches (EEA) and to outline the techniques involved in the repair of these defects. DESIGN: We retrospectively analyzed 63 cases of endoscopic skull base reconstruction (ESBR) following tumor excision, done from September 2011 to January 2015. These tumors consisted of 14 pituitary adenomas, 20 craniopharyngiomas, and 29 other miscellaneous tumors. The classification of skull base defects by Tabaee et al and the classification of cerebrospinal fluid (CSF) leaks by Esposito et al were considered during the ESBR. Recurrence of CSF leak was considered as failure of reconstruction. RESULTS: The 63 skull base defects included in this study occurred following EEA for tumor excision. Failure of reconstruction occurred in 6 six patients. All were successfully repaired, however, three patients in this series died due to tumor-related complications. CONCLUSION: The adherence to the general principles of reconstruction, appreciating the subtle differences in the nature of the various defects and the ability to adopt different strategies are the prerequisites for the successful closure of skull base defects.

Influence of Tumor Location and Other Variables on Predictive Value of Intraoperative myogenic Motor-Evoked Potentials in Spinal Cord Tumor Surgery.

OBJECTIVE: To study the influence of tumor location (cervical vs. thoracic; extramedullary vs. intramedullary) on predictive value of intraoperative myogenic motor-evoked potentials (iMEP) changes in patients undergoing surgery for spinal cord tumors. METHODS: Three hundred patients retrospective data (91 intramedullary) and 209 (intradural extramedullary) with successful iMEP recordings were analyzed. Responses to transcranial electrical stimulation were recorded from the lower limb muscles. Preoperative clinical variables, iMEPs changes, and postoperative neurologic deficits were noted. Associations between categorical variables and outcome were analyzed with the Fisher exact test. RESULTS: Of the 300 patients 28 (9.3%) had significant intraoperative worsening of iMEPs. New postoperative deficits occurred in 23 of these 28 patients. False-positive decreases in iMEPs were observed in 5 patients. There was a significant association between changes in iMEP and postoperative new motor deficits (P ≤ 0.0001). Multivariate analysis showed that patients with changes in iMEP undergoing surgery for thoracic segment tumors, with longer duration of symptoms (>12 months) and older age (≥21.5 years) were more likely to suffer postoperative neurological decline (odds ratio 4.1, P ≤ 0.001 and odds ratio 5.4 P ≤ 0.0001, respectively). The sensitivity of iMEPs was 100% and specificity 98.2%. The positive and negative predictive values were 82% and 100%; however, the sensitivity and specificity is similar in thoracic intramedullary (TIM) (n = 53) and cervical intramedullary tumors (n = 38) (both were 100% and 97%). The positive predictive value was significantly greater for TIM tumors (93% vs. 50%). CONCLUSIONS: A strong association was observed between worsening of iMEPs and postoperative new neurological deficits in patients with TIM tumor.

Pure endoscopic transsphenoidal surgery for functional pituitary adenomas: outcomes with Cushing's disease.

BACKGROUND: This study was performed to examine patient outcomes following pure endoscopic transsphenoidal surgery (ETS) for Cushing's disease (CD). METHOD: We studied 64 consecutive patients who underwent 69 endoscopic transsphenoidal procedures. Radiological evaluation comprised detailed examination of preoperative magnetic resonance images (MRI), including positron emission tomography (PET) for select cases. Inferior petrosal sinus sampling (IPSS) was not performed for any patient. Remission was defined by the presence of hypocortisolemia with requirement for steroid replacement therapy or eucortisolemia with suppression to <1.8 µg/dl after 1 mg dexamethasone on evaluation at least 3 months after surgery. RESULTS: Preoperative MRI was abnormal in 87.5 % of cases and included 11 macroadenomas (17.2 %). PET was used to localize the adenoma in four cases. For microadenomas, operative procedures executed were as follows: selective adenomectomy (n = 15), enlarged adenomectomy (n = 21) and subtotal/hemihypophysectomy (n = 17). Overall, pathological confirmation of an adenoma was possible in 58 patients (90.6 %). Forty-nine patients (76.6 %) developed hypocortisolemia (<5 µg/dl) in the early postoperative period. Mean follow-up was 20 months (range 6-18 months). Remission was confirmed in 79.7 % of the 59 cases followed up for >3 months and was superior for microadenomas (86.4 %) versus macroadenomas (55.6 %) and equivocal MRI adenomas (66.7 %). Postoperative CSF rhinorrhea occurred in five patients, and new endocrine deficits were noted in 17.1 % patients. A nadir postoperative cortisol <2 µg/dl in the 1st week after surgery was highly predictive of remission (p = 0.001). CONCLUSION: ETS allows for enhanced intrasellar identification of adenomatous tissue, providing remission rates that are comparable to traditional microsurgery for CD. The best predictor of remission remains induction of profound hypocortisolemia in the early postoperative period.