Factors Influencing Long-Term Outcomes of Single-Session Gamma Knife Radiosurgery in Large-Volume Meningiomas >10 cc.

INTRODUCTION: Meningiomas are the most common primary intracranial tumour. Gamma knife radiosurgery (GKRS) is a frequently employed non-invasive method of treatment, with good remission rates and low morbidity in literature. However, the role of GKRS in the management of "large" meningiomas is unclear, with reported outcomes that vary by centre. We aimed to assess the factors that influence long-term outcomes following GKRS in meningiomas >10 cc in volume. METHODS: A retrospectively analysed all patients with meningiomas exceeding 10 cc in volume who underwent GKRS between January 2006 and December 2021 at the National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru. Demographic, clinical, radiological, and follow-up data were acquired, and factors associated with progression following GKRS were assessed. RESULTS: The cohort comprised 76 patients 29 males (38.2%) and 47 females (61.8%) with a mean age of 46.3 ± 11.02 years. Thirty-nine patients had been previously operated (51.3%). Meningiomas were most frequently located in the parasagittal region (26 tumours, 34.2%) and sphenopetroclival region (23 tumours, 30.3%), with mean lesion volume of 12.55 ± 5.22 cc, ranging 10.3 cc-25 cc. The mean dose administered to the tumour margin was 12.5 Gy ± 1.2 Gy (range 6-15 Gy). The median duration of clinical follow-up was 48 months, over which period radiological progression occurred in 14 cases (20%), with unchanged tumour volume in 20 cases (28.6%) and reduction in size of the tumour in 36 cases (51.4%). Progression-free survival after GKRS was 72% at 5 years, was significantly poorer among meningiomas with tumour volume >14 cc (log-rank test p = 0.045), tumours presenting with limb motor deficits (log-rank test p = 0.012), and tumours that underwent prior Simpson grade 3 or 4 excision (log-rank test p = 0.032). CONCLUSIONS: Meningiomas >10 cc in volume appear to display a high rate of progression and subsequent need for surgery following GKRS. Primary surgical resection, when not contraindicated, may be considered with GKRS serving an adjuvant role, especially in tumours exceeding 14 cc in volume, and presenting with limb motor deficits. Long-term clinical and radiological follow-up is essential following GKRS as the response of large meningiomas may be unpredictable.

Surgical Outcome of Torcula Herophili Meningioma: An Institutional Experience.

INTRODUCTION: Resection of meningiomas (THMs) at the torcular Herophili poses challenges to surgeons due to complex regional anatomy. The current study aims to evaluate factors affecting the extent of resections, progression-free survival, and the role of radiation. METHODS: We did a retrospective study of all the THM patients treated at our institute between May 1987 and June 2022. The demographic data, signs and symptoms, surgical notes, postoperative details, and radiotherapy were gathered retrospectively. Survival analysis was done with Kaplan-Meier tests along with predictors of the extent of resection as well as recurrence. RESULTS: A total of 39 patients qualified to be included in the study, with 10 male patients (male:female 1:2.9) and an average age of 50.8 years. The average follow-up duration was 75.9 months. Simpson's grade 2 excision was achieved in 19 (48.7%) patients, followed by Simpson's grade 3 excision in 17 patients (43.6%). Progression-free survival in subtotal resection was 60 months, and 100 months in gross total resection. Statistically, the extent of the resection was determined by the involvement of sinuses/torcula and the number of quadrants involved around torcula. A total of 16 patients received radiosurgery for the residual or small reccurrence of the lesion. Follow-up revealed reccurrence in 5 cases. CONCLUSIONS: Torcular meningiomas are relatively uncommon, described in few reports, and represent a therapeutic dilemma. Though some experts recommend complete removal of tumor and reconstruction of the sinus, others suggest maximum safe resection, followed by radiosurgery. The present study reflects reasonable control of the residual lesion with radiosurgery after maximum safe resection.

Hermite-scan imaging for differentiating glioblastoma from normal brain: Simulations and ex vivo studies for applications in intra-operative tumor identificationa).

Hermite-scan (H-scan) imaging is a tissue characterization technique based on the analysis of raw ultrasound radio frequency (RF) echoes. It matches the RF echoes to Gaussian-weighted Hermite polynomials of various orders to extract information related to scatterer diameter. It provides a color map of large and small scatterers in the red and blue H-scan image channels, respectively. H-scan has been previously reported for characterizing breast, pancreatic, and thyroid tumors. The present work evaluated H-scan imaging to differentiate glioblastoma tumors from normal brain tissue ex vivo. First, we conducted 2-D numerical simulations using the k-wave toolbox to assess the performance of parameters derived from H-scan images of acoustic scatterers (15-150 µm diameters) and concentrations (0.2%-1% w/v). We found that the parameter intensity-weighted percentage of red (IWPR) was sensitive to changes in scatterer diameters independent of concentration. Next, we assessed the feasibility of using the IWPR parameter for differentiating glioblastoma and normal brain tissues (n = 11 samples per group). The IWPR parameter estimates for normal tissue (44.1% ± 1.4%) were significantly different (p < 0.0001) from those for glioblastoma (36.2% ± 0.65%). These findings advance the development of H-scan imaging for potential use in differentiating glioblastoma tumors from normal brain tissue during resection surgery.

Factors predicting recurrence in benign spinal nerve sheath tumors: A retrospective study of 457 patients from a single institution.

BACKGROUND: Benign Nerve sheath tumors (NST) comprise almost one-third of primary spinal tumours. The majority are sporadic. They have low rates of recurrence but an occasional recurrence may need re-surgery. The present study was designed to identify the variables that can predict the risk of their recurrence. METHODS: A retrospective chart review was done including all the histologically proven benign spinal NSTs operated between 2001 and 2019 in our institute. Demographic, operative and postoperative follow-up data were recorded. Recurrence was defined as local reappearance after definite surgical excision or symptomatic increase in size of a residual tumour on follow-up imaging studies. Statistical analysis was done to determine the significant variables associated with local recurrence. RESULTS: 457 patients with a median age of 38 years operated for 459 NSTs qualified for the study. The most frequent location of occurrence of tumours was found to be Low Cervical level (C3-C7 levels). Majority of Schwannoma were located intradurally while Neurofibroma were dumb-bell shaped and extradural. Most of the tumours had solid consistency. Post operatively, 7.7% patients developed complications. 7.8% tumours developed local recurrence after median period of 12 months. The patients developing recurrence were younger compared to nonrecurring tumors. On univariate analysis, male gender, Low cervical and Cervicothoracic junction location were associated with higher recurrence. On multivariate analysis, location at Cervicothoracic junction reached significance. CONCLUSION: Overall recurrence risk among all NST was 7.8% with a median progression free survival of 36 months. The location of tumour at cervicothoracic location was the significant risk factors for recurrence of tumour in our study.

Gamma Knife Radiosurgery for Large Vestibular Schwannoma More Than 10 cm 3 : A Single-Center Indian Study.

Introduction Gamma Knife radiosurgery (GKRS) is an effective treatment for benign vestibular schwannomas (VSs). The established cutoffs have recently been challenged, as recent literature expanded the horizon of GKRS to larger tumors. Even though microsurgery remains the primary option for large VS, GKRS can provide reasonable tumor control and is more likely to avoid cranial neuropathies associated with open surgery. Methods We analyzed patients with VS with volume exceeding 10 cm 3 who underwent GKRS at our center from January 2006 to December 2016. Clinicoradiological and radiosurgical data were collected from medical records for statistical analysis. Follow-up was performed every 6 months with a clinical assessment along with magnetic resonance imaging (MRI) of the brain and audiometric evaluation in patients with serviceable hearing. Results The study included 34 patients (18 males and 16 females) with an average age of 45.5 years. The mean tumor volume was 10.9 cm 3 (standard deviation [SD], ± 0.83), with a median tumor dose of 12 Gy (interquartile range, 11.5-12) and a mean follow-up of 34.7 months (SD, ± 23.8). Tumor response was graded as regression in 50%, stable in 44.1%, and increase or GKRS failure in 2 cases (5.8%). Treatment failure was noted in five cases (14.7%), requiring microsurgical excision and a ventriculoperitoneal shunt post-GKRS. The tumor control rate for the cohort is 85.3%, with a facial preservation rate of 96% (24/25) and hearing loss in all (5/5), while three patients developed new-onset hypoesthesia. We noted that gait ataxia and involvement of cranial nerve V or VII at initial presentation were associated with GKRS failure in univariate analysis. Conclusion Microsurgery should remain the first-choice treatment option for large VSs. GKRS is a viable alternative with good tumor control and improved or stabilized cranial neuropathies with a low complication rate.

Paediatric chronic subdural haematoma: what are the predisposing factors and outcomes in management of these cases?

INTRODUCTION: Chronic subdural hematoma (cSDH) is a disease of the elderly population. Incidence in paediatric population is relatively uncommon. Child abuse, birth trauma, coagulopathy and shunt surgeries represent major causes. Major impact of the disease on life of patient due to recurrence and repeat surgical procedure is significant, not to mention the burden on health care system. MATERIAL AND METHODS: We retrospectively reviewed our institute data for chronic sub-dural cases for the past 10 years (2008-2018) and collected data on the demography, clinical features, metabolic workup, mode of treatment, recurrence rates, predisposing factors, laterality, hematoma characteristics and factors associated with recurrence in all cases with less than or equal to 18 years of age. RESULTS: A total of 30 such cases were found in a period of 10 years (2008-2018). The mean patient age was 7.3 years (range 2 months-17 years), with 20 males (66.67%) and 10 females (33.33%). Raised intracranial pressure (n = 9) was the commonest presenting symptom in 30% of cases followed by seizures in 26.67% (n = 8). The previous shunt was the commonest predisposing factor seen in 43.33% (n = 13). cSDHs were unilateral in 56.67% cases (n = 17) and bilateral in 43.33% (n = 13). Burr hole craniostomy was done in 27 cases (90%), and conservative management was done in three cases (10%). Follow up was available for 27 cases (90%) with a mean follow up duration of 24 months. Recurrence rate was 30% (n = 9). Shunt surgery contributed to 77% of bilateral disease (p = 0.009). Child abuse was not reported in our series. CONCLUSION: Presence of paediatric cSDH is alarming, and the physician should be alerted to look for underlying cause and rule out child abuse. Detailed metabolic, skeletal workup is required. Treatment of primary pathology should be the goal as CSF diversion is not the solution to all problems, but can definitely be the cause of all the problems.

Central nervous system high grade neuroepithelial tumor with BCOR immunopositivity: Is there a molecular heterogeneity?

Central nervous system high grade neuroepithelial tumor - BCOR altered is a newly defined entity which is characterised by internal tandem duplication (ITD) in exon 15 of BCOR. These tumors resemble high grade glioma histologically and exhibit BCOR immunopositivity. However, recently fusions of BCOR are also described in CNS lower grade gliomas, thus questioning the sensitivity and specificity of BCOR immunohistochemistry for identification of BCOR-ITD. We describe four cases of high grade neuroepithelial tumor with BCOR immunopositivity which were diagnosed over a period of one year at our institute. Amongst these, only one tumor revealed BCOR-ITD on sequencing. SATB2 immunopositivity which is a sensitive marker of BCOR-ITD, BCOR fusions and YWHAE fusions was noted in three out of four cases. Our study suggests that BCOR immunopositive CNS high grade tumors are molecularly heterogeneous and could harbour genetic alterations other than BCOR-ITD.

Diagnostic Utility of CUSA Specimen in Histopathological Evaluation of Tumors of Central Nervous System.

INTRODUCTION: Cavitron Ultrasonic Surgical Aspirator (CUSA) is a technique used for the surgical treatment of tumors that aids the surgeon in highly selective tumor sampling with minimal injury to surrounding tissues. The utility of the tissue obtained from CUSA for histopathological diagnosis of central nervous system tumors is not as well-known as its surgical benefits. Even though a few studies have evaluated the diagnostic accuracy of CUSA specimen, these have dealt with very few cases. METHODOLOGY: In this study, we nil analysed 73 cases of CNS tumors (glial and non-glial) where CUSA specimen was available for histopathological examination and compared with findings on conventional samples as gold standard. RESULTS: Most frequent types of artefacts induced by CUSA included tissue breakdown resembling necrosis, empty spaces in tissues, and crush artefacts particularly in cellular tumors, that interfered with interpretation. CUSA samples were found optimal for diagnosis of non-glial tumors (45/73), (mainly mesenchymal), wherein the diagnostic utility was comparable to the conventional samples. Difficulties were encountered in glial neoplasms, medulloblastomas and meningiomas. In glial neoplasms (28/73), accurate grading was not possible (9/28, 32%) utilising CUSA samples alone as necrosis and mitosis were not represented. Similarly in meningiomas, mitosis and brain invasion, essential for grading, was not recognizable in CUSA samples. In medulloblastomas, extensive crush artefacts interfered with diagnosis and histological subtyping making it mandatory to examine conventional tissue samples and CUSA. Immunohistochemistry results were optimal with CUSA tissue, wherever performed. CONCLUSION: The greatest benefits of CUSA, is its ability to sample multiple areas enhancing the yield in heterogenous tumors like gliosarcomas and its utility in tumors at surgically inaccessible sites. As a policy, we recommend that it is beneficial that all surgically excised tissues including those from the CUSA bottle and suction be sent for histopathological analysis for optimising diagnostic accuracy.

Microcystic Meningiomas: MRI-Pathologic Correlation.

BACKGROUND AND PURPOSE: Microcystic meningiomas (MM) are a distinctive, rare subtype of Grade I meningiomas with limited radiological descriptions. We intend to identify unique imaging phenotypes and seek radiopathological correlations. METHODS: Retrospective analysis of histopathologically proven MM was undertaken. Clinicodemographic profiles, imaging, and histopathological characteristics were recorded. Spearman rank correlations among radiological and pathological attributes were performed. RESULTS: Twenty-eight cases were analyzed (mean age = 45.5 years; M:F = 1:1.54; mean volume = 50.1 mL; supratentorial n = 27). Most lesions were markedly T2 hyperintense (higher than peritumoral brain edema-a unique finding) (89.3%) and showed invariable diffusion restriction, severe peritumoral brain edema (edema index >2 in 64.3%), a "storiform" pattern on T2-weighted images (T2WI) (75%), reticular pattern on postcontrast T1 (78.6%)/diffusion-weighted images (DWI) (65.4%), hyperperfusion, T1 hypointensity (84.6%), and absence of blooming on susceptibility-weighted image (80.9%). Storiform/reticular morphology correlated with large cysts on histopathology (ρ = .56; P = .005753).  Lesion dimension positively correlated with reticular morphology on imaging (ρ = .59; P = .001173), higher flow voids (ρ = .65; P = .00027), and greater microcystic changes on histopathology (ρ = .51; P = .006778). Peritumoral brain edema was higher for lesions demonstrating greater angiomatous component (ρ = .46; P = .014451). CONCLUSIONS: We have elucidated varied neuroimaging features and highlighted pathological substrates of crucial imaging findings of MM. MM ought to be considered as an imaging possibility in an extra-axial lesion with a marked hypodensity on noncontrast computed tomography, markedly T2-hyperintense/T1-hypointense signal, and a storiform/reticular pattern on T2W/GdT1w//DWI.

Spontaneous Recovery of Complete Foot Drop in Case of Lumbar Disk Herniation: Catcher in the Rye?

BACKGROUND: Foot drop is defined as inability to dorsiflex the foot at the ankle joint. Although a well-documented entity with a myriad of causes along the neuraxis, starting from parasagittal intracranial pathologies to peripheral nerve lesions, treatment has always remained uniform (i.e., elimination of the causative pathology. A conservative approach with complete recovery has never been documented with video evidence). CASE DESCRIPTION: A 74-year-old female presented with dorsiflexion weakness of the left ankle secondary to a prolapsed disk at the L4-5 level. The duration of the foot drop was short (3 days). She was planned for surgery but kept under close observation considering the consistent recovery of the symptoms. To our astonishment she had rapid pain relief in the next 5 days. Motor power improved over 3 weeks, and she had complete recovery in 4 weeks. Video recordings were made to document the improved power at both stages. CONCLUSIONS: Spontaneous recovery of complete foot drop is possible, and there is a role for the conservative management even with dense neurologic deficit in cases of lumbar disk herniation. Careful repeated examination is the key for conservative management before jumping to aggressive surgical intervention.

Supratentorial Pure Cortical Ependymoma: An Unusual Lesion Causing Focal Motor Aware Seizure.

Ependymomas usually arise from the ependymal lining cells of the ventricular system and central canal of the spinal cord. Supratentorial ependymoma is a rare entity with the variable clinical course. In a small number of cases, ependymoma arises from supratentorial parenchyma. Only a few cases are reported in the literature. We report a case of 3-year-old girl with left frontal mass. Total removal of the mass lesion was performed without any neurological deficit. Pathological examination of the excised tumor was consistent with anaplastic ependymoma. We have discussed management strategy of this rare entity.

Surgical management of colloid cysts in children: experience at a tertiary care center.

INTRODUCTION: Colloid cysts are uncommon lesions in the pediatric age group, which most commonly occur in the fourth through fifth decades. The authors hereby report a series of 36 patients with colloid cysts in the pediatric age group. MATERIAL AND METHOD: A retrospective chart review was conducted on all patients with colloid cyst who underwent surgery in our institute between November 2003 and December 2016 (13 years). Patients above the age of 18 were excluded from the study. They were analyzed based on clinical presentation, radiological findings, surgical approaches, and outcome. RESULTS: There were 36 pediatric patients selected for the study. Age ranged from 8 to 18 years. The male-to-female ratio was 3.5:1. Headache and vomiting were the most common symptoms, and papilledema is the most common clinical sign. The mean duration of symptoms was 9 months (range 1 day to 5 years), but 27 (75%) of the children had precipitous symptoms just before presentation. Preoperative CT showed a hyperdense non-enhancing lesion in the majority of cases. Endoscopic excision was done in 13; 5 patients underwent transcortical transventricular excision, while transcallosal approach was opted for in 17 patients. In one patient, the colloid cyst could not be removed endoscopically and had to be converted to transcortical transventricular approach. Postoperatively, five patients developed CSF leak. They were successfully managed conservatively. One patient had operative site extra dural hematoma and underwent re-exploration, and two patients had transient hemiparesis which improved spontaneously. The median follow-up period was 9 months in the 30 available patients. Though no formal neuropsychological testing was done at follow-up, all children appeared to be doing well without memory disturbances. CONCLUSION: Pediatric colloid cysts are less common and may show rapid deterioration. Timely surgery results in a permanent cure with minimum morbidity. The results of either micro neurosurgical or endoscopic operative excision of colloid cysts in children are excellent. All children who are symptomatic with raised intracranial pressure due to a third ventricular colloid cyst should undergo definitive surgery. There were no major permanent deficits in memory or disconnection syndromes observed with the limited anterior colostomy.

Abscess within a Glioblastoma: Mimicking a Matryoshka Doll.

BACKGROUND: Abscess coexisting within a brain tumor is rare. Case reports in the literature primarily consist of sellar pathology and parenchymal lesions, including meningioma, glioma, and metastases. We report a case of glioblastoma with an intratumoral abscess in a middle-aged patient with no prior invasive procedure or systemic focus of infection. CASE DESCRIPTION: A 45-year-old woman presented with new-onset generalized seizures and rapidly progressive left hemiparesis. Imaging showed a right frontal necrotic lesion with a peripherally enhancing wall and solid component posteriorly. There was no diffusion restriction within the lesion. She was afebrile, and there was no systemic focus of infection. With provisional diagnosis of malignant glioma, she underwent surgical resection of the lesion. A differential diagnosis of abscess was considered preoperatively because of the rapid increase in size of the lesion. At surgery, there was a pus-filled cavity with a few areas of grayish, soft, flimsy wall and thrombosed veins. This raised a strong suspicion of a coexisting abscess within a malignant glioma, which was confirmed by histopathologic and microbiologic examination. CONCLUSIONS: It is important for neurosurgeons to be aware of this rare entity. The treatment protocol remains controversial and is primarily guided by expert opinion. It is important to aggressively treat the patient with antibiotics followed by adjuvant therapy for malignancy. The timing and administration of adjuvant therapy are unclear. We suggest a delay of chemotherapy until at least 4 weeks of therapy with sensitive antibiotics.

Apolipoprotein E polymorphism and the risk of aneurysmal subarachnoid hemorrhage in a South Indian population.

BACKGROUND: The rupture of a brain aneurysm causes bleeding in the subarachnoid space. This is known as aneurysmal subarachnoid hemorrhage (aSAH). We evaluated the association of apolipoprotein E (APOE) polymorphism and the risk of aSAH in a South Indian population. METHODS: The study was performed on 200 subjects with aSAH and 253 healthy control subjects. Blood samples (5 ml) were used to isolate DNA and genotyping was performed for rs7412 and rs429358 using a Taqman allelic discrimination assay. Statistical software R.3.0.11 was used to statistically analyze the data and a p value < 0.05 was considered as statistically significant. RESULTS: We found a significant association with the risk of aSAH in ε3/ ε4 genetic model (OR = 1.91, 95% CI = 1.16-3.14, p = 0.01). However, in the other genetic models and allele frequency, there was no significant association with the risk of aSAH. In subtyping, we found a significant association of ε2 allele frequency with posterior communicating artery (PCOM) aneurysm (OR = 3.59, 95% CI = 1.11-11.64, p = 0.03). CONCLUSION: Our results suggest that APOE polymorphism has an influence on the risk of aSAH in this South Indian population, specifically in the PCOM subtype.

Occipital Intraosseous Hemangioma over Torcula: Unusual Presentation with Raised Intracranial Pressure.

BACKGROUND: Hemangiomas of the bone are benign, uncommon, slow-growing lesions accounting for <1.0% of all bony neoplasms. Intraosseous occipital hemangiomas are rare, and occipital hemangiomas presenting with features of raised intracranial tension are, with only 2 cases reported to date. CASE DESCRIPTION: In this case report, we describe the unique case of a 30-year-old male patient presenting with raised intracranial pressure due to venous obstruction at the torcula. The patient underwent excision of the lesion and became symptom free. CONCLUSIONS: Although these are benign lesions, they can have a varied clinical presentation. An understanding of the different clinical presentations and surgical nuances in excising such tumors can lead to early diagnosis and good patient outcome.

Eosinophilic Granuloma of Skull with Fluid Level and Epidural Hematoma: A Case Report and Review of the Literature.

Intracranial Langerhans cell histiocytosis commonly presents as skull lesions in children. An intratumoral cyst with fluid level and epidural hematoma occurring with eosinophilic granuloma is very rare. We report a 15-year-old boy who presented with a spontaneous epidural hematoma which was the result of a temporal eosinophilic granuloma. Multiple explanations for epidural hematoma in such cases have been discussed. Intratumoral hemorrhage followed by cyst formation and rupture may explain the pathophysiology of epidural hemorrhage formation.

Ipsilateral Hemichorea-hemiballism in a Case of Postoperative Stroke.

BACKGROUND: Ipsilateral hemiballismus refers to the rare occurrence of hemiballism developing on the same side of a brain lesion. CASE REPORT: We describe a rare case of postoperative ipsilateral hemiballism in a patient who underwent pituitary adenoma resection and experienced a right internal cerebral artery territory infarct. We review the literature on hemichorea hemiballismus (HCHB) and explore various mechanisms for its occurrence. DISCUSSION: Only three cases of ipsilateral hemiballism have been described, and the exact pathophysiology remains unknown. A dominant left hemisphere with corpus callosal connections to the right basal ganglia is the most probable explanation for this unusual event.

Surgical treatment of Langerhans cell histiocytosis of cervical spine: case report and review of literature.

INTRODUCTION: Langerhans cell histiocytosis (LCH) is a rare condition, and even rare is cervical spine involvement. CASE REPORT: A 9-year-old girl had neck pain, neck tilt and left upper limb weakness, occasional fever and positive family history of tuberculosis. Imaging showed C5 vertebral body collapse with epidural and prevertebral soft tissue collection causing cord and nerve root compression. The patient underwent C5 corpectomy and fusion. Histopathological was suggestive of LCH. She underwent radiotherapy and was asymptomatic at 1-year follow-up. CONCLUSION: Despite the rarity of the condition, the possibility of LCH should be considered in such cases. When neurologic deficits are present, operative treatment should be considered.

Extended endoscopic endonasal transclival clipping of posterior circulation aneurysms--an alternative to the transcranial approach.

BACKGROUND: Transcranial clipping of most posterior circulation aneurysms is one of the most difficult procedures, with high morbidity, and endovascular coiling is an alternative with less risk, but is not devoid of complications and not suitable for all aneurysms. Here we describe four cases of posterior circulation aneurysms clipped via the extended endoscopic endonasal transclival route. To the best of our knowledge, this is the first report of basilar top and posterior cerebral artery aneurysms being clipped endonasally. METHODS AND RESULTS: Four patients with posterior circulation aneurysms underwent extended endoscopic endonasal transclival clipping of the aneurysm. The age range was 35-70 years. There were two males and two females. Three of the four patients presented after the rupture of aneurysms, and the other patient presented with sudden-onset left hemiparesis probably due to thromboembolism from a large unruptured left posterior cerebral artery (PCA) aneurysm. On evaluation with four-vessel digital subtraction angiography (DSA), two patients had a basilar apex aneurysm, one had a basilar trunk aneurysm, and the other had a PCA (P1) aneurysm. Postoperatively, two patients had good recovery. One patient with a PCA aneurysm and another with a basilar apex aneurysm had fresh postoperative deficits. One patient developed postoperative CSF rhinorrhea. CONCLUSION: Endoscopic extended transnasal surgery is an expanding field in neurosurgery with a steep learning curve. With improvement in techniques and instrumentation the use of this approach for clipping posterior circulation aneurysms can become an effective alternative in the treatment of aneurysms.