Malignant transformation of vestibular schwannoma following radiosurgery-a case report and review of the literature.

Malignant transformation of vestibular schwannoma (VS) post-radiosurgery is an extremely rare but life-threatening complication. We present a patient who underwent two surgeries for a benign VS and received Gamma Knife radiosurgery for residual tumour. Five and a half years post-radiosurgery, the patient was reoperated for symptomatic recurrence of the tumour. Histopathology confirmed the diagnosis of a high-grade spindle cell sarcoma. Although near-total resection was uneventful, the patient deteriorated rapidly, and comfort care was chosen. This report is the 13th documented case of histopathologically confirmed malignant transformation of a benign VS that strictly meets the modified Cahan's criteria, suggesting the direct link to radiosurgery-induced malignancy.

Treatment Strategies and Current Results of Petroclival Meningiomas.

Petroclival meningiomas (PCMs) are complex skull-base tumors that continue to pose a formidable surgical challenge to neurosurgeons because of their deep-seated location/intimate relationship with the brainstem and neurovascular structures. The advent of stereotactic radiosurgery (SRS), along with the shifting of management goals from complete radiological cure to maximal preservation of the patient's quality of life (QOL), has further cluttered the topic of "optimal management" in PCMs. Not all patients with PCM need treatment ("watchful waiting"). However, many who reach the neurosurgeons with a symptomatic disease need surgery. The goal of the surgery in PCMs is a GTR, yet this can be achieved in only less than half of the patients with acceptable morbidity. The remainder of the patients are better treated by STR followed by SRS for residual tumor control or close follow-up. A small subset of patients with PCM may be best treated by primary SRS. In this chapter, we have tried to summarize the scientific evidence pertaining to the management of PCMs (including the senior author's series), particularly those regarding the available treatment strategies and current outcomes, and discuss the decision-making process to formulate an "optimal management" plan for individual PCMs.

Cystic recurrence of vestibular schwannoma post-radiosurgery: an institutional experience.

BACKGROUND: Stereotactic radiosurgery effectively controls vestibular schwannoma (VS). However, in certain cases, microsurgical resection may be necessary for post-radiosurgery tumour progression. The characteristics and microsurgical challenges of uncommon cystic recurrences post-radiosurgery are rarely addressed. METHOD: We retrospectively analysed 24 consecutive patients who underwent microsurgical intervention for recurrent VS post-radiosurgery by the senior author. RESULTS: Tumour recurrence post-radiosurgery occurred as solid growth in 19 patients (79%), while 5 patients (21%) developed large brainstem-compressing cysts. The median time interval for tumour recurrence post-radiosurgery was similar between cystic and non-cystic recurrent VS (30 vs. 25 months; p=0.08). Cystic recurrences occurred in primarily cystic VS in 3 patients, and new cysts developed in 2 patients with primarily solid VS. Intra-operatively, tumours were firm in 18 cases (75%) and strongly adhered to surrounding structures in 14 cases (58%). All cystic cases underwent cyst decompression, while complete resection of solid tumour components was avoided due to neurovascular adherence. At a mean follow-up of 42±39 months, 12 patients (50%) showed contrast-enhancing tumour residuals in follow-up imaging, including all cystic recurrent cases. Tumour residuals remained stable without requiring further intervention, except for one patient revealing malignant tumour transformation. House-Brackmann grade I/II was preserved in 15 patients (62%). Three patients (13%) developed new facial palsy, and two patients (8%) improved to House-Brackmann grade II. Cystic recurrences had a significantly higher frequency of tumour residuals compared to solid recurrences (100% vs. 37%; p=0.01) but similar rates of facial palsy (60% vs. 32%; p=0.24) CONCLUSIONS: Cyst development in VS post-radiosurgery is more common in primary cystic lesions but can also occur in rare cases of primary solid VS. Symptomatic cysts require microsurgical decompression. However, complete resection of the solid tumour component is not crucial for long-term tumour control and should be avoided if it risks neurological function in this delicate area.

Long-term hormonal and imaging outcomes of adjunctive gamma knife radiosurgery in non-functioning pituitary adenomas: a single center experience.

PURPOSE: Gamma Knife Radiosurgery(GKRS) is an established modality for treatment of non-functioning pituitary adenomas(NFPA). The objective of the study was to assess long-term hormonal and imaging outcomes after adjunctive GKRS in patients with NFPA. METHODS: A retrospective review of records of 109 patients with NFPA, from 1996 to 2020, who received adjunctive GKRS, was performed. Patients who had received GKRS as the primary modality of treatment for NFPA were not included. RESULTS: Sixty-three (57.8%) patients were available for follow up at our institute. The median follow-up period was 47 months (range, 6-260). At a median time of 38 months (range, 8-97), 25 (39.7%) patients developed ≥ 1 new pituitary hormone deficiency. Median time to cortisol deficiency was 38 months (range, 8-55), thyroid hormone deficiency was 45.5 months (range, 12-97) and gonadotropin deficiency was 45 months (range, 21-75). The actuarial risk of developing a new pituitary hormone deficit at 1, 3, 5, 7, and 10 years was 2.5%, 11%, 26.3%, 28% and 29.7%, respectively. Adenoma size decreased in 36 (57.1%) patients, remained unchanged in 19 (30.2%) patients, and increased in 8 (12.7%) patients. Overall tumor control rate was 87.3%. Endocrinopathy-Free Survival was 47.1%, and tumor Progression-Free Survival was 93.3%, at 5 years. Five (4.6%) patients required additional treatment after GKRS. One (1.6%) patient each had worsening of headache, optic atrophy and cerebellar infarct after GKRS therapy. CONCLUSION: GKRS offers a safe adjunctive treatment modality, with satisfactory long-term preservation of hormone functions and a high rate of tumor control, in patients with NFPA.

Delayed symptomatic cerebral vasospasm following vestibular schwannoma resection: illustrative case.

BACKGROUND: Symptomatic cerebral vasospasm following posterior fossa extraaxial tumor resection is a rare phenomenon, with only 13 cases previously reported in the literature. The condition appears similar to vasospasm following supratentorial tumor resection, intraaxial posterior fossa tumor resection, and aneurysmal subarachnoid hemorrhage (aSAH). The majority of patients were not evaluated for vasospasm prior to symptom onset, leading to a delay in diagnosis. OBSERVATIONS: The authors present their experience in a 56-year-old female who developed delayed cerebral vasospasm after excision of a solid-cystic vestibular schwannoma. Routine postoperative brain computed tomography showed evidence of subarachnoid hemorrhage in the basal cisterns. She was discharged on the 9th postoperative day. On the 11th day after tumor excision, she developed left hemiparesis, dysarthria, and dysphagia and was readmitted. Angiography confirmed bilateral diffuse cerebral vasospasm. The patient responded to standard hyperdynamic therapy used for vasospasm secondary to aSAH. LESSONS: Symptomatic distant cerebral vasospasm after posterior fossa extraaxial tumor excision is a rare but challenging complication with a very high morbidity rate in reported cases. A high index of suspicion is required for early diagnosis and prompt management for a favorable outcome.

Thoracic Epidural Chronic Inflammatory Lesion: A Case Report and Review of Literature.

Chronic inflammatory lesions (CIL) in the body are rare and inflammatory pseudotumor (IPT) is a subtype of CIL. Spine is an uncommon location of CIL, with most cases reported in the thoracic spine. Our objective was to review the current literature on IPT. To the best of our knowledge only about 13 cases are reported till date. A retrospective review of 13 existing cases was done. The etiopathogenesis of CIL is uncertain and total surgical excision remains the mainstay. It's a diagnosis of exclusion after ruling out commonly found lesions, both clinically and radiologically. Only histopathology can confirm the diagnosis. Total surgical resection remains the mainstay of treatment with adjuvant treatment only if there is a residue or a recurrence. CILs are rare lesions in the body with IPT being the commonest. Surgical excision remains the mainstay of treatment and a long-term follow up is warranted.

SRS for Vestibular Schwannomas - Current Status.

Stereotactic radiosurgery (SRS) is an established modality of treatment for vestibular schwannomas (VS). We aim to summarize the evidence-based use of SRS in VSs and address the specific considerations pertaining to the same, along with our own clinical experiences. A thorough review of the literature was done to gather evidence regarding the safety and efficacy of SRS in VSs. Additionally, we have reviewed the senior author's experience in treating VSs (N = 294) between 2009 and 2021 and our experiences with microsurgery in post-SRS patients. Available scientific evidence upholds the role of SRS in VSs, in small-to-medium-sized tumors (5-year local tumor control >95%). The risk of adverse radiation effects remains minimal, while the hearing preservation rates are variable. Our center's post-GammaKnife VS follow-up cohort (sporadic - 157, neurofibromatosis-2 - 14) showed excellent tumor control rates at the last follow-up of 95.5% (sporadic) and 93.8% (neurofibromatosis-2), with a median margin dose of 13 Gy and mean follow-up periods of 3.6 (sporadic) and 5.2 (neurofibromatosis-2) years. Microsurgery in post-SRS VSs poses a formidable challenge due to the resulting thickened arachnoid and adhesions to critical neurovascular structures. Near-total excision is the key to better functional outcomes in such cases. SRS is here to stay as a trusted alternative in the management of VSs. Further studies are required to propose means of accurate prediction of hearing preservation rates and also to compare the relative efficacies of various SRS modalities.

Safety and Efficacy of Gamma Knife Radiosurgery for the Management of Trigeminal Neuralgia: A Retrospective and Cross-Sectional Study.

Background: Medical management is the first line of care for patients with trigeminal neuralgia (TN), and carbamazepine is the drug of choice used alone or in combination with other drugs. Gamma knife radiosurgery (GKRS) has been an established option in the management of refractory TN based on its noninvasiveness and robust safety profile. Our study aims to confirm the safety and assess the efficacy of GKRS in the management of TN. Material and Methods: A retrospective review of the patients with refractory TN treated with GKRS from 1997 to March 2019 by the senior author was carried out. Out of 194 eligible patients, detailed clinical information was not available in 41 patients. The remaining 153 patients' case files (post-GKRS cohort) were reviewed, and data obtained were collated, computed, and analyzed. An additional cross-sectional analysis was carried out telephonically in the post-GKRS cohort in January 2021 using Barrow Neurological Institute (BNI) pain scoring, to obtain the long-term efficacy of GKRS in TN. Results: The majority of the patients (96.1%) received a radiation dose of 80 Gy. At 6 months, 94.8% of patients had satisfactory response to GKRS. Follow-up ranged between 1 and 7.5 years. The recurrence rate was 9.2% and the complication rate was 4.6%. Facial numbness was the commonest complication. No mortality was reported. The cross-sectional arm of the study had a response rate of 39.2% (60 patients). Adequate pain relief (BNI I/II/IIIa/IIIb) was reported in 85% of patients. Conclusion: GKRS is a safe and effective modality of treatment for TN without any major complications. Both short-term and long-term efficacies are excellent.

Bilateral blindness following flow diverter placement in a giant thrombosed cavernous carotid aneurysm: illustrative case.

BACKGROUND: The best treatment option for giant intracranial aneurysms (GIAs) is still debated. The authors report a case of a giant thrombosed cavernous carotid artery (CCA) aneurysm for which two sessions of flow diverter (FD) placement failed, leading to bilateral blindness. OBSERVATIONS: A 66-year-old man presented to an outside center with a history of rapid-onset right-sided retro-orbital pain, visual deterioration, and restricted eye movements associated with headache, vomiting, and diminished sensations on the right side of the face. He was diagnosed with an unruptured thrombosed giant CCA aneurysm and was treated twice with unsuccessful FDs. At follow-up, he developed blindness in both eyes. After 1.5 years, he presented to the authors' institution with headache, vomiting, and epistaxis, for which he underwent high-flow external carotid artery-M2 segment of the middle cerebral artery bypass grafting using the radial artery as a conduit and ligation of the internal carotid artery in the neck without any added neurological deficits. LESSONS: This dreadful complication of bilateral blindness after being treated with repeated unsuccessful FDs has not been reported in the literature. It could have been avoided if microsurgery had been the primary modality of treatment.

Validation of the Penn Acoustic Neuroma Quality of Life (PANQOL) Scale for Hindi-Speaking Patients Recently Diagnosed with Vestibular Schwannoma.

Background: The Penn Acoustic Neuroma Quality-of-Life (PANQOL) scale is a disease specific quality-of-life instrument for vestibular schwannoma, developed in English and subsequently validated in four major languages of the world. No such validated version of PANQOL exists for Hindi-speaking population. Objective: To translate and examine the validity of the PANQOL scale in a sample of Hindi-speaking patients recently diagnosed with vestibular schwannoma. Materials and Methods: A cross-sectional study was done at a corporate tertiary care hospital. The PANQOL questionnaire was translated into Hindi by a language expert according to the accepted rules of forward-backward translation. In total, 30 consecutive patients (n = 30) diagnosed with vestibular schwannoma between September 2017 and March 2018 were included in the study. Quality-of-life at the time of diagnosis was measured with the generic Short Form -36 (SF-36) and the disease-specific PANQOL questionnaires. The internal consistency and reliability of the PANQOL domains, as well as the relationship with SF-36 dimensions, were statistically analyzed.The PANQOL scores of the patients in the current study were compared with those of similar such published studies worldwide. Results: Mean age of the patients was 46.3 ΁ 13.25 years. The sex ratio of male to female patients was 19:11. The mean PANQOL total score was 71.6. All its domains had good internal consistency except pain. Most PANQOL domains were correlated with those of the SF-36 dimensions, with the exception of facial dysfunction domain. Conclusions: Good internal consistencies and strong correlations between PANQOL domains and SF-36 dimensions in the current study support the validity of the PANQOL Hindi version.

Correlation of Preoperative Functional Magnetic Resonance Imaging (fMRI) with Intraoperative Cortical Stimulation in Surgeries of Eloquent Brain Lesions.

Background: Direct Cortical Stimulation (DCS) represents the gold standard for mapping of eloquent brain cortex. However, DCS is an invasive and time-consuming procedure. fMRI has become a useful tool to delineate motor and sensory eloquent cortex from the areas of planned neurosurgical resection. In our study, we will be studying the reliability of preoperative imaging when compared with the intraoperative DCS. Objectives: The aim of this study was to assess the reliability of fMRI by comparing it with DCS. Methods and Materials: Thirty patients with eloquent cortex lesions were admitted. Preoperative fMRI sequences were loaded into a neuro-navigational system. Intraoperative motor mapping was done by DCS. The location of all cortical stimulated points was correlated with the cortical functional structures. Based on it, specificity, sensitivity, positive predictive value, negative predictive value of fMRI was calculated. Preoperative and postoperative Karnofsky score and MRC grading was then noted. Results: Concordance between fMRI and DCS was noted in 26 cases. Overall mean sensitivity, specificity, positive and negative predictive value of fMRI as compared to DCS was 95%, 92.48%, 85.56%, and 96.08%, respectively. Preoperative and Postoperative Karnofsky score stayed same in most of the cases [25/30]. Conclusions: DCS remains the gold standard for mapping eloquent cortex in-spite of its invasiveness, side effects such as seizures and cost concerns. Although fMRI cannot replace DCS, it can guide and increase the efficacy in resection, select high-risk patients for intraoperative monitoring, help in preoperative stratification of risk counseling and preservation of neurological status in eloquent brain lesions.

Long-term outcome of adjunctive Gamma Knife radiosurgery in skull-base chordomas and chondrosarcomas: An Indian experience.

Skull-base chordomas (CD) and chondrosarcomas (CS) are locally-invasive tumors, have similar clinical presentations, while differing in their nature of growth and outcomes. In this study, we compare the long-term outcomes of Gamma Knife Radiosurgery (GKRS) as an adjunctive treatment modality for residual skull-base CD and CS. A retrospective analysis of clinico-radiological, pathological, radiotherapeutic and outcome data was carried out in patients who underwent adjunctive GKRS for residual skull-base CD and CS at P D Hinduja Hospital, Mumbai, between 1997 and 2020. All 27 patients included had either histopathologically proven CD (20 patients) or CS (7 patients). Brachyury immunohistochemistry in CD specimens gave 70.6% positivity. Total sessions of GKRS in CD and CS groups were 22 and 7, respectively. Mean tumor volume and mean margin dose in CD group were 6.53 ± 4.18 cm3 and 15.95 ± 1.49 Gy respectively, while for CS group, they were 4.16 ± 2.79 cm3 and 18.29 ± 3.15 Gy. With mean follow-up periods of 5.25 ± 4.73 years and 6 ± 2.07 years respectively, the CD and CS groups showed 5-year progression free survival (PFS) of 56.8% and 57.1%, and a 5-year overall survival (OS) of 82.1% and 100%. Sub-group analysis in both CD and CS groups revealed a better 5-year PFS with the following factors - CS histopathology, patient age < 45 years, margin dose > 16 Gy, tumor volume < 7 cm3 (p-value < 0.05), gross total resection, and brachyury positivity. Adjunctive radiotherapy for skull-base CD and CS holds promise.

Carotid endarterectomy: results and long-term follow-up of a single institution.

OBJECTIVES: To document our experiences, technical procedure and outcomes of carotid endarterectomy (CEA) in patients with symptomatic carotid stenosis. MATERIAL AND METHODS: A total of 49 consecutive patients underwent 53 CEAs (three bilateral, one redo) for severe carotid artery stenosis. There were 39 males and 10 females, with mean age of 63 years. All patients underwent neck Doppler, computed tomography/magnetic resonance angiography/digital substraction angiography and a detailed cardiological evaluation. Antiplatelet drugs were continued perioperatively. Surgery was performed under general anesthesia with propofol cerebral protection, mild hypothermia and continuous electroencephalogram monitoring. The procedure was done under microscope and closure was done using 6-0 prolene. Clinical and radiological follow-up was done. RESULTS: Our mean follow-up was 4.69 years. All patients underwent primary suturing except one redo CEA done with venous patch graft. Three patients required intraoperative shunting. One patient died secondary to myocardial infarction peroperatively prior to carotid manipulation. One patient had stroke within 6 h, secondary to operative site intraluminal thrombus and was re-explored. Two patients had transient postoperative hemiparesis and aphasia while two patients had altered sensorium, all self-limiting, with normal imaging. One patient developed temporary twelfth-nerve paresis. One patient had persistent transient ischemic attack on the follow-up. Thus, the perioperative mortality rate was 1.89% and stroke rate was 1.89%. CONCLUSIONS: CEA for severe carotid stenosis is a safe procedure with good protection from ischemic events. Detailed preoperative cardiac evaluation and appropriate patient selection is essential.

Quality of life in patients of unilateral vestibular schwannoma treated with microsurgery: A South-Asian tertiary care Hospital experience.

Majority of the published literature on the impact of microsurgery over quality-of-life (QOL) in vestibular schwannoma (VS) patients is retrospective in nature, with variable results, and there has been very little contribution from South-Asia. The authors designed this study to investigate the role of microsurgery in QOL alterations in VS patients, and to compare obtained QOL scores with that of control population. Between February 2017 and March 2018, a prospective/retrospective study was done at our institute. Prospective and retrospective cohorts included, 30 and 34 consecutive patients, respectively, of unilateral VS undergoing microsurgery. QOL assessment was done using Short Form-36 (SF-36), and the Penn Acoustic Neuroma Quality-Of-Life (PANQOL) questionnaires. Prospective cohort underwent QOL assessment at 3 junctures - pre-surgery, 3-months & 1-year post-surgery; while retrospective cohort was assessed only once, at 1-year post-surgery. Age- & sex- matched normal population and diabetic patients were used as controls. In the prospective cohort, patients showed drop in all PANQOL domain/ SF-36 dimension scores at 3-month post-surgery, exception being vitality and general health in SF-36; showed improvement at 1-year follow-up, with majority either levelling or improving their respective pre-surgery scores. Gross total resection, tumors ≤ 3 cm, and age ≤ 45 years had better PANQOL scores at 1-year post-surgery across all the domains. Patients in both the cohorts showed worse QOL compared to normal population, but the gap got narrower at 1-year post-surgery. Our study adds a South-Asian perspective to the pool of prospective knowledge available on QOL following microsurgery in VS patients.

Microsurgery of Giant Intracranial Aneurysm: A Single Institution Outcome Study.

BACKGROUND: Giant intracranial aneurysms (GIAs) are treacherous lesions and in spite of the many advances, endovascular therapy (EVT) of GIAs is challenging. OBJECTIVE: A retrospective analysis of our results with microsurgery of GIAs is presented to examine the role of microsurgery in the current trend of EVT. MATERIALS AND METHODS: Between 1996 and 2019, 134 patients with 147 GIAs had microsurgery by the senior author in a single institute. The medical and imaging records for all the patients were reviewed. The patient outcome was determined by modified Rankin scale (mRS); ≤3 was considered as a good outcome. Statistical analysis was done using the SPSS program and odds ratios and their 95% confidence intervals were computed; a probability value of < 0.05 was considered significant. RESULTS: There were 123 aneurysms (83.7%) in the anterior circulation and 24 aneurysms (16.3%) in the posterior circulation. Overall 103 out of 134 (76.8%) patients had a good outcome postoperatively. Good preoperative mRS score (≤3) had an overall good prognosis in the postoperative period and was statistically significant (P = 0.000, odds ratio: 0.036, 95% CI: 0.008-0.171). Presence of subarachnoid hemorrhage (SAH) was also statistically significant for good outcome (P = 0.04, odds ratio: 2.898, 95% CI: 1.051-7.991), but age was not a significant prognostic factor. Mortality within 30 days of treatment was 4.47%. CONCLUSION: GIAs need treatment because of their dismal natural history. Results of microsurgical treatment by a single surgeon of the large current series compare well with the results of EVT and justifies pursuing microsurgery for GIAs.

Skull base chondrosarcoma presenting with parenchymal hemorrhage: A case report.

Chondrosarcoma (CS) is a locally invasive, slow growing malignant neoplasm. Intracranial chondrosarcoma are extradural osseous lesions and intradural location with intratumoral hemorrhage is very rare. We report a rare case of 65-year-old male presenting with a small mass in left posterior skull base and later, suddenly deteriorating due to large cerebellar hemorrhage. A brief review of literature of such cases is also presented.

Skull Base Chordoma: Long-Term Observation and Evaluation of Prognostic Factors after Surgical Resection.

BACKGROUND: Skull base chordoma (SBC) is relatively rare and data on its clinical outcome after surgical resection and adjuvant radiotherapy are still limited. OBJECTIVE: Analyzing the clinical postoperative outcome of SBC patients and defining prognostic factors regarding current treatment modalities. METHODS AND MATERIAL: In this study, 41 SBC patients from 2001 to 2017 were retrospectively analyzed in this single-center study. RESULTS: The most common clinical symptoms were headache (63%) and problems concerning vision (54%) like diplopia. The follow-up controls took place from 1 to 192 months. The mean survival time for the patients was 123.37 months (95% CI 90.89-155.86). The 5- and 10-year survival rates were 73.3 and 49%, respectively. Regarding the Karnofsky-Performance Scale (KPS), Cox regression showed a significant relationship between the survival rates in the overall study population and pre-surgery KPS (P = 0.004). This was further supported with a positive significant correlation between the pre-surgery KPS and the KPS at the last follow-up (P = 0.039). CONCLUSION: Statistical analysis showed that repeat surgical resection and radiotherapy could be prognostic factors. Furthermore, we were able to show that mortality decreased by 4.5% with each 10 points increase of pre-surgery KPS. This could be a major prognostic factor when deciding treatment modalities. Nevertheless, further standardized clinical studies with a larger patient population should be carried out to extrapolate prognostic factors and improve treatment modalities.

Meningioma in a patient with Werner syndrome.

Werner syndrome (WS), also known as adult progeria, is extremely rare, with about 1300 known cases in the world, with over 1000 of these in Japan. It occurs due to loss of function mutations in the WRN gene located on chromosome 8p12. WS is characterized by premature aging and increased risk of neoplasms, with meningiomas being the commonest intracranial tumor. We report the case of a 39-year-old male patient, who presented with occasional numbness in right arm for three weeks. The patient had developed signs and symptoms of premature aging which started in his adolescence. MRI brain done was suggestive of left frontal convexity extra-axial lesion, suggestive of meningioma. Genetic analysis performed has identified an autosomal recessive, apparently homozygous c.3383+3A>G mutation, a mutation not previously reported. As per the existing literature, this is the index case of meningioma in Werner syndrome from India. A new mutation has been identified.