Postoperative Seizure Control in Adult Diffuse Insular Gliomas Presenting with Seizures: A Retrospective Single-Center Experience and Proposal of a Novel Risk Scoring System.

Background: Studies on insular gliomas (IGs) generally focus on the oncological endpoints with a relative scarcity of literature focusing on the seizure outcomes. Objectives: To study the predictors of long-term postoperative seizure control in IG and propose a novel risk scoring system. Methods: Histopathologically proven, newly diagnosed adult IGs (>18 years) operated over a 10-year period were studied for postoperative seizure control as per International League Against Epilepsy (ILAE) grades at 6 weeks and at last follow-up (minimum of 6 months, median 27 months). Logistic regression analysis was performed and regression coefficients with nearest integers were used to build a risk prediction model. Receiver operator curve (ROC) analysis determined the predictive accuracy of this model. Results: The 6-week postoperative seizure freedom dropped to 41% at the last follow-up. The seizure-free group lived longer (100.69 months, 95% CI = 84.3-116.99 (60%)) than those with persistent postoperative seizures (27.92 months, 95% CI = 14.99-40.86). Statistically significant predictors (preoperative seizure control status, extent of resection, tumor extension to temporal lobe, and lack of postoperative adjuvant therapy) were used to compute a risk score, the score ranging from 0 to 9. A score of four most optimally distinguished the risk of postoperative seizures with an area under the ROC of 91.4% (95% CI: 84.1%, 98.7%, P < 0.001). Conclusion: In our experience, around 60% of patients obtained seizure freedom after surgery, which reduces over time. Control of seizures paralleled survival outcomes. Our proposed scoring system may help tailor management strategies for these patients.

Looking Beyond the Anterolateral Skull Base with Frontotemporal Dural Fold Unlocking and Extradural Clinoidectomy: A Series of 17 Cases Deciphering the Translation from a Cadaver to Real, and Real to Pathologically Distorted Anatomy.

Objective: This article aims to discuss the surgical nuances and major adjustments necessary in unlocking the frontotemporal dural fold (FTDF) and extradural anterior clinoidectomy (EDAC) in actual cases, allowing translation from the cadaveric to a clinical scenario. Materials and Methods: We retrospectively reviewed the technical details of 17 procedures over 8 years, where both the initial steps (FTDF unlocking and EDAC) were performed. Lesions involving or extending to the anterolateral skull base, like the suprasellar cistern, optico-carotid cistern, interpeduncular cistern, petrous apex, and cavernous sinus, were included. The clinical data of the patients were retrieved retrospectively from the hospital information system (HIS) and in-patient records. This study was approved as a multicenter individual project with IEC No: 2020-342-IP-EXP-34. Results: An illustrated note of the common steps and outcome of the 17 procedures of unlocking the FTDF and EDAC done is presented. The technique provided adequate exposure in performing aneurysmal clipping (posterior communicating artery [P. com], basilar top, and superior hypophyseal artery [SHA] aneurysm), giant pituitary adenoma (Wilson Hardy grade 4E, n = 2), fifth nerve schwannoma (n = 4), right Meckel's cave melanoma, cavernous hemangioma (n = 4), petroclival meningioma (n = 2), and clival chordoma. Temporary and permanent cranial nerve palsy as a procedure-related complication was seen in 11.8% (n = 2) each. Complete excision was achieved in 13 (n = 13/14) patients with tumors. Conclusion: FTDF unlocking and EDAC are elegant procedures providing reasonable access to the anterolateral skull base for myriad pathologies. Brain bulge, cavernous sinus bleeding, and losing the plane of dural duplication were significant challenges in switching from cadaveric to a clinical scenario.

Microneurosurgery for Spinal Dural Arteriovenous Fistula- Operative Video.

Background and Introduction: Spinal dural arteriovenous fistula (SDAVF) is a rare but curable condition. Microsurgery is a highly effective and readily affordable treatment modality. Objective: We present a surgical video of SDAVF to demonstrate the operative nuances involved. Surgical Technique: A 53-year-old wheelchair-bound man with spastic paraparesis for 1.5 years was found to have a SDAVF at L1/2 level with a single fistula point. During surgery, a L1-L2 laminectomy and durotomy revealed a dilated vein accompanying the nerve root exiting L1/2 foramen that showed early filling on indocyanine green (ICG) video angiography. This vein was occluded, and a segment of this vein was removed during surgery, which led to resumption of normal spinal cord perfusion. Results: The patient showed gradual recovery of lower limb motor power and improved to assisted ambulation after 3 months. Conclusions: Surgery is a simple, effective, and cost-effective treatment option in SDAVF.

Treading Toward Anterolateral Skull Base by Unlocking the Frontotemporal Dural Fold Along with Extradural Clinoidectomy: Translation from A Cadaver to Clinical Scenario.

BACKGROUND AND INTRODUCTION: Unlocking of the frontotemporal dural fold (FTDF) and extradural removal of the anterior clinoid process (EACP) are challenging but mandatory skills for micro-neurosurgeons. Despite the presence of an extensive body of literature on this subject, the translation of this cadaveric and 3D simulation to a real patient turns out to be a very demanding and difficult task. OBJECTIVE: This video is aimed to address the surgical nuances and major adjustments necessary in the unlocking of the FTDF and extradural ACP removal in an actual case for an early-career neurosurgeon. SURGICAL TECHNIQUE: A 40-year lady presented with features of acromegaly with radiological evidence of significant component of the tumor in the right cavernous sinus along with sellar suprasellar component. To achieve a good hormonal control, a complete tumor excision was required, which was achieved with FTDF and EACP removal. The cavernous sinus was approached through the Parkinson's triangle. RESULTS: The patient had uneventful recovery and good hormonal control at the 3-month follow-up. CONCLUSION: FTDF unlocking and EACP are elegant procedures and need to be learned by all neurosurgeons. This article will provide excellent teaching material for young neurosurgeons.

Modified Retromastoid Approach and Clipping of "High-Riding" VA-PICA Junction Aneurysm: An Operative Video.

BACKGROUND AND INTRODUCTION: Clipping an aneurysm on an elongated and tented V4 segment near the origin of the posterior inferior cerebellar artery (high-riding VA-PICA junction aneurysm) can be challenging. OBJECTIVE: We demonstrate the microsurgical clipping technique of such an aneurysm using a modified retromastoid approach (MRMA) and glossopharyngeal-cochlear triangle (GCT). SURGICAL TECHNIQUE: A 50-year-old female with a ruptured high-riding left VA-PICA junction aneurysm underwent an MRMA. Using segmental vessel isolation with proximal and distal temporary clips, this aneurysm was occluded through the GCT by applying a tandem clipping technique while preserving the PICA. RESULTS: The procedure was uneventful. Apart from transient ataxia, she recovered completely and maintains a good status at follow-up. CONCLUSION: In high-riding VA-PICA junction aneurysms, a conventional far lateral approach may create awkward viewing and working angles. An MRMA with a horizontal trajectory through the GCT may be a more appropriate strategy.

Spinal Dermoid and Epidermoid Cyst: An Institutional Experience and Clinical Insight into the Neural Tube Closure Models.

Objectives The spinal dermoid and epidermoid cysts (SDECs) are rare entities comprising less than 1% of pediatric intraspinal tumors. The present study aims to extrapolate the clinicoradiological data, in order to identify the most plausible neural tube closure model in human and provide a retrospective representation from our clinical experience. Materials and Methods We collected the details of all histologically proven, newly diagnosed primary SDECs who underwent excision over the past 20 years. Secondary or recurrent lesions and other spinal cord tumors were excluded. Surgical and follow-up details of these patients as well as those with associated spinal dysraphism were reviewed. Clinical and radiological follow-up revealed the recurrence in these inborn spinal cord disorders. Results A total of 73 patients were included retrospectively, having a mean age of 22.4 ± 13.3 years, and 41 (56.2%) cases fell in the first two decades of life. Twenty-four (32.9%) dermoid and 49 (67.1%) epidermoid cysts comprised the study population and 20 of them had associated spinal dysraphism. The distribution of SDECs was the most common in lumbosacral region ( n = 30) which was 10 times more common than in the sacral region ( n = 3). Bladder dysfunction 50 (68.5%) and pain 48 (65.7%) were the most common presenting complaints. During follow-up visits, 40/48 (83.3%) cases showed sensory improvement while 11/16 (68.7%) regained normal bowel function. There was no surgical mortality with recurrence seen in eight till the last follow-up. Conclusions The protracted clinical course of the spinal inclusion cysts mandates a long-term follow-up. The results of our study support the multisite closure model and attempt to provide a retrospective reflection of neural tube closure model in humans by using SDECs as the surrogate marker of neural tube closure defect.

Trigeminal Neuralgia from an Arteriovenous Malformation of the Trigeminal Root Entry Zone with a Flow-Related Feeding Artery Aneurysm: The Role of a Combined Endovascular and "Tailored" Surgical Treatment.

Idiopathic trigeminal neuralgia (TN) due to an embedded arteriovenous malformation (AVM) on the trigeminal root entry zone (REZ) is rare but a potentially challenging condition to manage. Herein, we report such a case with an additional unruptured aneurysm on the feeding artery and highlight the role of a multimodality approach to their management. A 50-year-old female presented with drug-resistant right-sided trigeminal neuralgia for one year. The magnetic resonance imaging (MRI) suggested a possibility of AVM, the angiographic study showed an AVM nidus with feeders from the right anterior inferior cerebellar artery (AICA) and a dilated right intrinsic pontine artery, the latter showing a flow-related aneurysm towards its brainstem end. The flow-related aneurysm, as well as the dilated intrinsic pontine artery feeder, was embolized at first. During surgery, the AVM was found embedded inside the root entry zone. Parts of the AVM and its draining vein were partially coagulated followed by microvascular decompression of the AICA loop as well as a feeder emanating from it following which the patient recovered completely. She subsequently received gamma knife surgery (GKS) for the residual AVM and remained asymptomatic after 3.5 years of GKS. AVM-related TN are rare, and the additional presence of a feeding artery aneurysm increases the management complexity. Endovascular management of the aneurysm followed by microvascular decompression (MVD) and tailored AVM coagulation represent a prompt and effective means of pain control. Subsequent GKS is necessary to obliterate the AVM nidus.

A Universal Craniometric Index for Establishing the Diagnosis of Basilar Invagination.

OBJECTIVE: The conventional criteria for defining the basilar invagination (BI) focus on the relationship of odontoid tip to basion and opisthion, landmarks that are intrinsically variable especially in presence of occipitalised atlas. A universal single reference line is proposed that helps in unequivocally establishing the diagnosis of BI, may be relevant in establishing both Goel types A and B BI, as well as in differentiating a 'very high' from 'regular' BI. METHODS: Study design - case-control study. In 268 patients (group I with BI [n = 89] including Goel type A BI [n = 66], Goel type B BI [n = 23], and group II controls [n = 179]), the perpendicular distance between odontoid tip and line subtended between posterior tip of hard palate-internal occipital protuberance (P-IOP line) was measured. Logistic regression analysis determined factors influencing the proposed parameter (p < 0.05). RESULTS: In patients with a 'very high' BI (n = 5), the odontoid tip intersected/or was above the P-IOP line. In patients with a 'regular' BI (n = 84), the odontoid tip was 6.56 ± 3.9mm below the P-IOP line; while in controls, this distance was 12.53 ± 4.28 mm (p < 0.01). In Goel type A BI, the distance was 7.01 ± 3.78 mm and in type B BI, it was 5.07 ± 4.19 mm (p = 0.004). Receiver-operating characteristic curve analysis identified 9.0 mm (8.92-9.15 mm) as the cut-point for diagnosing BI using the odontoid tip-P-IOP line distance as reference. CONCLUSION: The odontoid tip either intersecting the P-IOP line (very high BI) or being < 9 mm below the P-IOP line (Goel types A and B BI) is recommended as highly applicable criteria to establish the diagnosis of BI. This parameter may be useful in establishing the diagnosis in all varieties of BI.

How Important Is to Know the Psychosocial Performance in an Operated Child of Meningioma? Devil Is in the Details.

BACKGROUND: Meningioma constitutes only 0.4%-4.1% of all the pediatric tumors. This article aims to find the impact of the pediatric meningioma surgery on the developmental and scholastic performance among these children over long-term follow-up. MATERIALS AND METHODS: This study is a retrospective analysis of all the histopathological proven pediatric meningioma and a cross-sectional analysis to study the functional outcome, using Malin's Intelligence Scale for Indian children (MISIC); scholastic performance was assessed from behavioral checklist for screening the learning disabled (BCSLD) and subjective self-filled questionnaire to know parent satisfaction. RESULTS: Twenty-eight patients (mean age 14.52 ± 0.722 years) (M:F = 16:12) were analyzed (6 [21.4%] were grade-schooler and 22 [78.5%] were teenage), with most common symptom being headache (n = 20, 71.4%) and mean duration of symptoms was 11.19 ± 16.25 days. The mean intelligent quotient (IQ) of grade-schooler was 83.4 ± 9.072 compared to 75.69 ± 9.903 among teenage group. The BCSLD analyses showed that the postoperative score was poorer. Similarly, an average change in BCSLD was observed among the patients with complications (10) compared to the patients without complication (8). CONCLUSION: The discontinuation in schooling or lack of alternative education may lead to poor MISIC scores, wrongly categorizing the children in poor IQ group. In pediatric benign disease such as meningioma, the holistic approach should be opted from the time of first visit to neurological care team.

Factors affecting seizure outcome in Long-term epilepsy associated tumors (LEATs) in children and young adolescents.

OBJECTIVE: Tumors with seizures as primary mode of presentation are collectively called Long-term epilepsy associated tumors (LEATs or Epileptomas). The overall survival is good so 'seizure outcome' becomes the primary goal rather than neuro-oncological outcome. METHODS: A retrospective analysis of our surgical database (2015-19) was done to find operated patients of intra-axial brain tumors with age less than 25-years and who had presented with seizures. RESULTS: The mean age at presentation was 16.44 years (SD + 6.82 years). Complex partial seizures/focal unaware seizures were the most common type of seizures encountered (n = 22) with mean duration of seizures was 49.50 months (SD + 31.04 months). The most common pathology was glioneuronal tumors (GNTs) (n = 17). Gross total resection (GTR) group had a significantly better seizure outcome as compared with the Subtotal resection (STR) group (p = 0.006). Presence of focal or partial seizure was a significant factor pointing towards a better seizure control (p = 0.005). CONCLUSION: The shorter duration of symptoms, partial/focal seizures and gross total excision were predictors of a good seizure-outcome. Age of the patient and the histopathology of the tumor does not affect seizure-outcome on comparing GNTs with non GNTs.

Postoperative Tinnitus after Vestibular Schwannoma Surgery: A Neglected Entity.

BACKGROUND: This prospective study analyzes the factors responsible for pre and postoperative persistent tinnitus following vestibular schwannoma (VS) surgery and discusses the possible etiopathogenetic mechanisms. MATERIALS AND METHODS: Sixty-seven consecutive patients with unilateral VS operated via the retrosigmoid-suboccipital approach were included in the study. The Cochlear nerve, often unidentifiable from the tumor capsule, was resected during the surgery. Tinnitus Handicap Inventory (THI) score assessed the severity of pre and postoperative tinnitus. RESULT: Twenty-eight (41%) patients had preoperative tinnitus. Out of those 28 patients, 24(85%) had significantly improvement in postoperative THI score. In 15 of the 24 patients, tinnitus subsided completely. In 3 of the 28 (10%) patients, THI scores were unaltered, and in 1 of the 28 (3.5%) patients, THI scores worsened. In 39 (58.2%) patients without preoperative tinnitus, 4 (10%) developed a new-onset postoperative tinnitus. Patients with severe sensory neural hearing loss (SNHL) had significantly higher incidence of postoperative persistent tinnitus (PPT) (P = 0.00) compared to those with mild-to-moderate SNHL. Patients with profound SNHL, however, had a much lower incidence of PPT (P = 0.007; odds ratio = 0. 0.077; 95% CI: 0.009-0.637). Large (P = 0.07) and giant schwannomas (P = 0.03) VS had an increased risk of PPT. Patients with PPT further analyzed with brain stem auditory evoked response (BAER) showed normal contralateral waveform. CONCLUSION: Assessment of tinnitus is mandatory during the management of VS as there are high chances (nearly 46%) of PPT. Preoperative tinnitus, linked to the degree of SNHL (higher incidence in severe SNHL compared to mild-to-moderate/profound SNHL), is dependent on an intact cochlear nerve functioning. However, PPT is dependent on other mechanisms (brain stem/ipsilateral cochlear nuclei compression, and cortical reorganization) as it persists despite cochlear nerve resection.

Peter Plus Syndrome: A Neurosurgeon's Perspective.

Peter plus syndrome (PPS) is a rare, hereditary (autosomal recessive) disorder characterized by a mutation in the beta-1,3-galactosyltransferase-like gene (chromosome 13q12), which causes impaired glycosylation of several structural and functional proteins throughout the body. Clinical signs and symptoms of PPS are highly variable and include structural malformations affecting multiple organ systems including central nervous system. We aim to discuss a neurosurgeon's perspective to PPS in this report. A 2-year-old boy presented with congenital dysmorphic facies, bilateral central corneal opacities, delayed developmental milestones, short-stature (75cm), rhizomelia with brachydactyly, and history of surgery for anal atresia on the second day of life. Screening craniospinal magnetic resonance imaging revealed mild ventriculomegaly, cavum septum pellucidum, cavum velum interpositum, vermian hypoplasia, and normal spine. Cytogenetic analysis showed a mutation in the beta-1,3-galactosyltransferase-like gene on chromosome 13. Clinical picture in our patient suggested the diagnosis of PPS. Parents often seek ophthalmological consultation due to visual impairment predominantly, and this syndrome largely remains unknown among neurosurgeons. Nonetheless, babies with PPS may present with neurological symptoms such as seizures, spastic diplegia, tinnitus, or hearing loss as well as a life-threatening neurosurgical emergency arising due to raised intracranial pressure. Therefore, the role of neurosurgeon becomes crucial in managing these cases.