Occipital encephalocele: a retrospective analysis and assessment of post-surgical neurodevelopmental outcome.

BACKGROUND: Encephalocele represent a group of disorders which is characterised by extracranial herniation of the leptomeninges, brain, and CSF through a structural defect in the cranium. They are usually associated with other intracranial anomalies which may impact the neurological development. AIM: This study aimed to assess the predictors of neurological development of patients undergone surgical excision of occipital encephalocele. METHODS: All patients with occipital encephaloceles operated over the last decade (2012-2022). The sac size, presence of hydrocephalous, and associated anomalies were noted. The biopsy of these patients were reviewed and categorised as those which contains mature neural tissue and those without. The neurological outcomes were assessed by social, language, cognitive, and motor milestone and has been stratified into no delay, mild (1 of 4), moderate (2 or 3 of 4), and severe development delay (4 of 4). RESULTS: Total of 35 patients were included with median age of 10 months (IQR = 5-20 months). Fifteen (42.9%) patients had sac size of ≥ 5 cm, and 23 (65.7%) patients had mature neural tissues on biopsy. The median follow-up period was 6.4 years (IQR = 4.38-10.65) years. Seventeen (49.6%) patients had moderate to severe developmental delay. The sac size of ≥ 5 cm (AOR = 33.5; 95%CI = 3.35-334.8) (p = 0.003) and presence of mature neural content in the sac (AOR = 13.32; 95%CI = 1.1-160.36) (p = 0.041) were associated with significant neurodevelopmental delay. CONCLUSION: The presence of a large sac of ≥ 5 cm and the presence of mature neural tissues on histopathological specimen of patients with encephalocele point towards the possibility of poor neurological development.

Aspergillus infections of lateral skull base: a case series.

PURPOSE: While extensive research with accurate classification has been done in mycoses of the paranasal sinuses and anterior skull base, a similar understanding of lateral skull base fungal pathologies is lacking due to relative rarity and diagnostic difficulties. We introduce a series of eleven cases and two different invasive entities of Aspergillus temporal bone diseases-fungal skull base osteomyelitis (SBO)/malignant otitis externa (MOE) and chronic invasive granulomatous fungal disease (CIGFD). METHODOLOGY: A retrospective observational study was conducted at the neuro-otology unit of a tertiary care referral center between July 2017 and November 2022. Diagnosed cases of lateral skull base osteomyelitis with atypical symptoms and lack of response to culture-directed antibiotics were evaluated for fungal origin. Patient data, including history, laboratory findings, serum galactomannan assay, CT and MRI imaging findings, clinical examination findings, and co-morbidities, were analyzed. The treatment course and response were assessed. RESULTS: A total of 11 cases were included in the study. Of these, 9 were cases of Aspergillus-induced skull base osteomyelitis (SBO) and 2 of Aspergillus-induced chronic invasive granulomatous fungal disease (CIGFD). CIGFD presented with persistent ear discharge and slowly progressive post-aural swelling, while all patients of fungal SBO had lower cranial nerve palsies. CIGFD responded to excision and antifungals, while SBO responded well to conservative anti-fungal treatment. CONCLUSION: In cases of lateral SBO not responding to antibiotic therapy, the possibility of fungal etiology should be considered. Aspergillus spp. seems to be the major fungal pathogen.

Contralateral supraorbital eyebrow approach for tuberculum sellae meningioma.

BACKGROUND: The main challenge in tuberculum sellae meningioma (TSM) resection is the safe dissection of the optic nerves, which many a times are compressed and distorted by the tumor. While intuitive, an approach from the side of predominant tumor extension makes tumor dissection from the medial surface of the ipsilateral optic nerve rather blind. We describe here a contralateral supraorbital eyebrow approach (c-SEA) to address this "blind spot." METHOD: c-SEA was performed using a 2 × 2 cm craniotomy. The patient improved after surgery and postoperative imaging confirmed the totality of the tumor resection. CONCLUSION: c-SEA can be an excellent minimally invasive option for asymmetric TSM.

Insular glioblastoma: surgical challenges, survival outcomes and prognostic factors.

BACKGROUND: Insular gliomas are unique, challenging and evoke a lot of interest amongst neurosurgeons. Publications on insular glioma generally focus on the surgical intricacies and extent of resection pertaining to the low-grade gliomas. Insular glioblastomas (iGBM) have not been analysed separately before. METHODS: Histologically proven WHO grade IV gliomas involving the insula over a 9-year period were studied. Their clinical presentation, radiological features, surgical findings and survival outcomes were assessed. Statistical methods were used to determine the favourable predictors of survival. RESULTS: Out of 27 patients (M:F = 2.9:1), 18 (66%) patients had a tumour extension beyond the insula, 10 (37%) of whom had basal ganglia involvement. Total, near total and subtotal excisions were performed in 7 (26%), 9 (33%) and 11 (40.7%) patients, respectively. Twenty-three patients had glioblastoma, while four had gliosarcoma. IDH mutation was negative in six of the seven patients where it was done. Median overall survival was 5 months. Multivariate analysis showed that a female gender (p = 0.013), seizures in the preoperative period (p = 0.048) and completion of adjuvant therapy (p = 0.003) were associated with a longer survival. CONCLUSION: Insular glioblastomas have a poor prognosis. Insular location and certain tumour characteristics often limit the extent of resection of iGBMs. Moreover, postoperative complications sometimes negate the advantages of a radical resection. A female gender, presentation with seizures and completion of adjuvant chemoradiotherapy appear to be good prognostic factors.

Non-aneurysmal subarachnoid hemorrhage: Is the deep venous system the hidden culprit?

AIM: The exact cause of bleeding in non-aneurysmal sub-arachnoid hemorrhage (SAH) is yet to be established. The present study intends to evaluate the morphological variants of deep cerebral venous drainage, especially basal veins of Rosenthal (BVR), and to correlate if such a venous anomaly is associated with increased incidence of non-aneurysmal SAH. METHODS: A prospective analysis of all the patients of age more than 12 years with spontaneous non-aneurysmal SAH and undergone 4-vessel DSA for the diagnosis of the source of bleeding was included in the study (n = 59). The anatomy of the basal venous distribution was evaluated and was divided into 3 different types, namely normal (Type A), normal variant (Type B), and primitive (Type C), based on DSA findings. The follow-up of these cases was noted. The three groups were compared with one another. RESULTS: The median age of presentation was 51 years with slight male predominance (52%). Primitive venous drainage was associated with a poorer grade at presentation (p = 0.002), more severe bleed (p = 0.001), vasospasm (p = 0.045), and a poorer outcome at 6 months (p = 0.019). Hydrocephalous and vasospasm were seen in patients with primitive venous drainage. On multivariate regression analysis for poorer outcome, it was observed that a worse grade at presentation, extensive bleed, primitive venous drainage are independent predictors of an adverse outcome. CONCLUSION: The presence of primitive venous drainage has a linear relationship with the development of non-aneurysmal SAH with multi-cisternal hemorrhage, worse grade at presentation, and unfavorable outcome.

"Extra-cranial proximal pica aneurysm - a rare and surreptious cause of posterior fossa sah: case report and review of literature".

BACKGROUND: Extra-cranial posterior inferior cerebellar artery (PICA) aneurysms are rare with only 22 cases been reported so far. Intra-dural type of extra-cranial PICA aneurysm is even rarer with few case reports available. We report a previously unreported type of proximal PICA aneurysm in which the PICA aneurysm had intra-dural location at the C2 vertebral level. CASE DESCRIPTION: A 51 year old gentleman presented with sub-arachnoid haemorrhage and intra-ventricular haemorrhage, predominantly involving the fourth ventricle and had no focal neurological deficit. CT angiogram was negative however a dedicated four vessel angiogram demonstrated an abnormal extracranial origin of right PICA at C1-C2 level, with associated aneurysm in its proximal segment. A C1 posterior arch excision with partial C2 laminectomy and clipping of the aneurysm was done. CONCLUSION: Aneurysm associated with extracranial intra-dural PICA origin is a rare cause of SAH, and may not be detected with CT angiography. Such cases often require dedicated four vessel angiography, with careful study for any possibility of extra-cranial aneurysm. This variant has important surgical implication and requires preservation of the Lateral spinal artery (LSA-PICA communication), and that such aneurysm approached only with posterior cervical exposure without the need of a craniotomy. Such cases remind us the need to have an in-depth understanding of the variations of the posterior circulation.

Temporal lobe angiocentric glioma with oligodendroglioma-like areas: a rare association of an uncommon tumor. A case report with review of literature.

BACKGROUND: Angiocentric glioma (AG) is a relatively uncommon clinico-pathological entity that presents in childhood. Angiocentric glioma displays various histopathological features which resemble cortical ependymoma, astroblastoma, and pilomyxoid astrocytoma and schwannoma. The astrocytes in angiocentric glioma appear peculiarly elongated, bipolar in shape, and characteristically arranged around blood vessels. They resemble radial glia and tanycytes morphologically. Unlike ependymomas, AG is a diffusely infiltrating lesion and perivascular processes are often much thicker than those in classic ependymomas. CASE PRESENTATION: AG usually present clinically as seizures, often as medically intractable epilepsy. In the indexed case, apart from unusual presentation with features of raised intra-cranial tension, an unusual histological picture of a more cellular oligodendroglioma like component was also seen. CONCLUSION: The appropriate diagnosis is critical as AG is usually slowly growing and treatable by surgical excision alone.

Application of diffusion tensor imaging in brain lesions: A comparative study of neoplastic and non-neoplastic brain lesions.

PURPOSE: To evaluate the role of diffusion tensor imaging (DTI) in the differentiation of neoplastic and non-neoplastic brain lesions, on the basis of DTI parameters, fractional anisotropy (FA) and mean diffusivity (MD) from the lesion (L) and the perilesional edema (PE). MATERIAL AND METHODS: Patients with newly diagnosed 25 neoplastic [10 high grade gliomas (HGG), 11 metastases, 4 low grade glioma (LGG)] and 25 non-neoplastic [13 tuberculomas and 12 neurocysticercosis (NCC)] brain lesions underwent an MRI, including the DTI sequences. Fractional anisotropy from the lesion (FAL) and mean diffusivity from the lesion (MDL), as well as fractional anisotropy from the perilesional edema (FAPE), and mean diffusivity from the perilesional edema (MDPE) were calculated and quantified using region of interest (ROI) based assessment on DTI derived FA and MD parametric maps. The mean values of FAL, FAPE, MDL and MDPE from the two groups were compared by the independent sample t-test. RESULTS: In the non-neoplastic group, perilesional edema showed a significantly higher (P = 0.015) MD compared to the neoplastic group. Perilesional FA and lesional FA and MD showed no such statistically significant difference. On further subgroup analysis, MDPE was higher in metastases compared to HGG (P < 0.001), reflecting an increase in the vasogenic edema. Perilesional FA was higher in HGG compared to metastases and tuberculomas (P < 0.001) reflecting tumour infiltration in addition to vasogenic edema. FAL was higher in tuberculomas compared to metastases (P < 0.001), pointing to a more microstructural destruction in metastases. CONCLUSION: Quantitative DTI parameters, FA and MD, from the lesion and from the area of perilesional edema are helpful in the evaluation and differentiation of brain lesions.

Surgical excision of large-to-giant petroclival meningiomas focusing on the middle fossa approaches: The lessons learnt.

INTRODUCTION: Petroclival meningiomas are based on or arising from the petro-clival junction in upper two-thirds of clivus, medial to the fifth cranial nerve. This study focuses on the surgical experience in resecting large-giant tumors >3.5 in size predominantly utilizing middle fossa approaches. MATERIAL AND METHODS: 33 patients with a large or a giant petroclival meningioma (size >3.5 cm) were included. Clinical features, preoperative radiological details, operative findings, and postoperative clinical course at the follow-up visit were reviewed. Group A tumors (n = 17,51.5%) were sized 3.5cm-5cm, and Group B (n = 16,48.48%) tumors were of size >5 cm. Extent of resection was described as 'gross total' (no residual tumor), 'near total' (<10% residual tumor) and 'subtotal resection' (>10% residual tumor). Glasgow outcome scale (GOS) quantitatively scored postoperative neurological outcome (mean follow up: 35.77months; range 1-106 months). RESULTS: 25 (75.8%) patients had tumour extension into both supratentorial and infratentorial compartments. Extension into Meckel's cave (n = 25,75.8%), cavernous sinus (n = 17,48.4%], sphenoid sinus (n = 12,38.7%] and suprasellar area [12,38.7%] was often seen. In 31 (93.9%) patients, the tumor crossed the midline in the premedullary, prepontine, and interpeduncular cisterns. In 20 (60.6%) patients, the tumour extended below and posterior to the internal auditory meatus (IAM), while in 13 (39.4%) patients, the tumor was located above and anterior to the IAM. Kawase's approach was the most commonly used approach in 16 (48.48%) patients and resulted in maximum tumor resection. Other approaches included half-and-half (trans-Sylvian with subtemporal) [n = 6, 18.18%]; frontotemporal craniotomy with orbitozygomatic osteotomy [n = 1, 3%] and retromastoid suboccipital craniectomy (RMSO) [n = 7, 21.21%]. In 2 (6.06%) patients, staged anterior petrosectomy with RMSO; and, in 1, staged presigmoid with half-and-half approach was used. Gross total excision was achieved in 12 (36.36%), near-total excision in 15 (45.45%) and subtotal excision in 6 (18.18%) patients. 20 (60.6%) patients had a good functional outcome; 6 patients succumbed due to meningitis, pneumonitis, perforator injury or a large tumor recurrence. CONCLUSIONS: Half-and-half approach was used in tumors with middle and posterior cranial fossae components often extending to the suprasellar region. Kawase's anterior petrosectomy was utilized in resecting tumors with predominant posterior fossa component (along with a small middle fossa component) that was crossing the midline anterior to the brain stem, and mainly situated superomedial to the IAM. Tumors confined to the posterior fossa, that extended laterally and below the IAM were resected utilizing the RMSO approach. Occasionally, a combination of these approaches was used. Middle fossa approaches help in significantly avoiding morbidity by an early devascularisation and decompression of the tumor. In tumors lacking a plane of cleavage, a thin rim of capsule of tumor may be left to avoid brain stem signs.

Constipation in degenerative cervico-thoracic spine myelopathy: a simple co-existence or a complex inter-relationship?

PURPOSE: Identify factors affecting constipation and post surgical improvement in patients of myelopathy. METHODS: Sixty-four patients with myelopathy due to extradural spine pathologies (47 cervical; 17 thoracic spine, male:female-5.4:1 with mean age 46.16) underwent evaluation including Bristol stool scale (BSS), PFT and uroflowmetry. All cases were evaluated by gastroenterologist to rule out any intrinsic bowel disease. Chi-square test, Kruskal-Wallis/Mann-Whitney U test and Wilcoxon signed rank test were employed to ascertain statistical significance. RESULTS: The presence of constipation was associated with male sex (p = 0.01), degree of constipation with duration bladder symptoms (p = 0.008) and numbness (p = 0.04). The improvement in BSS after surgery (p = 0.006) was associated with local pain (p = 0.02), duration of weakness (p = 0.04) and overall symptoms (p = 0.01), also with pulmonary function tests (p = 0.002) and pre-operative Nurick's grade (p = 0.01). CONCLUSION: Constipation is a myelopathic symptom as it is relieved by cord decompression and the gender, PFT and the duration of symptoms play an important role in defining constipation and expected improvement in these patients.

Recurrent or symptomatic residual posterior fossa hemangioblastomas: how are they different from their primary counterparts?

BACKGROUND: Posterior fossa hemangioblastomas are WHO grade I benign lesions with a surprisingly high recurrence rate. This study determines the factors responsible for recurrence and the clinico-radiological and histopathological differences between primary (group A; n = 60) and recurrent/symptomatic residual (group B; n = 24) tumors. METHODS: Radiologically, tumors were differentiated into cystic, cystic with a mural nodule, solid-cystic/microcystic and solid. Surgery was undertaken via a midline or lateral suboccipital approach. Histopathology differentiated them into reticular, cellular or mixed subtypes. RESULTS: Truncal-appendicular ataxia in group A and von Hippel-Lindau (VHL) disease and raised intracranial pressure in group B were the predominant presentations. VHL patients in group B had a longer duration of symptoms (median 72 months) than those with non-VHL recurrences (median: 36 months). Multicentric mural nodules (n = 9/24, 37.50%, P = 0.0001) and bilateral cerebellar hemispheric involvement (n = 6/24, 25%, P = 0.0003) were exclusively seen in the preoperative radiology of group B tumors. Brainstem involvement was seen in the tumors of ten (16.67%) patients in group A and six (25.00%) patients in group B. One subset of patients required several resurgeries for repeated recurrences. Abnormal vascular proliferation and papillary projections into adjacent brain, and highly cellular stroma were unique histological features at recurrence. Total resection was achieved in 45 group A and 19 group B patients. The outcome based on the Karnofsky performance scale (KPS) was assessed at follow-up at 6 weeks (A: n = 60, B: n = 24): KPS0: A = 4, B = 1; KPS10-40 (dependent): A: 4, B = 5; KPS50-70 (independent for daily needs): A = 36, B = 16; KPS80-100 (fully independent): A = 16; B = 2. CONCLUSIONS: In recurrent/residual tumors, the radiological as well as histopathological features showed a distinctive change toward a more aggressive nature. Higher incidences of multiple mural nodules, bilateral spread, remote recurrence and VHL disease at preoperative radiology; as well as proliferative angioarchitecture, an irregular brain tumor interface and highly cellular stroma at histology were found in these patients compared to their primary counterparts.

Surgery for superior hypophyseal artery aneurysms: A new classification and surgical considerations.

BACKGROUND: Superior hypophyseal artery (SHA) aneurysms form a unique subgroup of paraclinoid aneurysms having a propensity to grow to a large size in the suprasellar region resulting in compression of the optic nerve, chiasma, and/or tract. AIM: A new classification of SHA aneurysms is proposed that helps in identifying the surgical issues encountered during surgical clipping of these medially directed aneurysms located at different segments of the medial surface of the internal carotid artery (ICA). SETTINGS AND DESIGN: This descriptive study was conducted at a tertiary care university hospital. MATERIAL AND METHODS: In 14 patients operated for a SHA (mean age: 49.43 ± 11.28 years; presenting either with subarachnoid hemorrhage (n = 11; 78.57%) or mass effect (n = 3; 21.42%), 4 parameters having a bearing on surgery [a. size: (small <1 cm n = 5, large 1-2.5 cm n = 7, giant >2.5 cm n = 2); b. origin of SHA aneurysmal neck and direction of its fundus; c. relationship of the aneurysm to important neurovascular structures; and, d. whether the aneurysms were saccular or fusiform] were used to divide SHA aneurysms into 7 categories a. Antero-supero-medial (n = 2); b. Antero-infero-medial (n = 1); c. Supero-medial (n = 3); d. Infero-medial (n = 3); e. Postero-medial (n = 2); f. Fusiform (n = 1); and, g. Giant (n = 2). Modified Rankin Scale (MRS) score was utilized to assess outcome [favorable: mRS 0-2; unfavorable: mRS 3-6] at discharge and follow up. RESULTS: Modified Hunt and Hess grade at admission was 0 = 3; I = 3; II = 3; III = 2; IV = 3 (favorable mRS: 10; 71.42%; unfavorable mRS: 4; 28.57%); and, Fisher grade was I = 3; II = 6; III = 2; IV = 3. Twelve patients required anterior clinoid process drilling/carotid collar opening to facilitate optic nerve mobilization, for proximal ICA control, and to assess the proximal part of the neck of aneurysm for aneurysmal clipping (n = 13) or wrapping (n = 1). Fenestrated clip was applied in 5 patients. In the supero-medial group (antero-supero-medial, supero-medial, and postero-supero-medial), the aneurysmal fundus was found directly below the ipsilateral optic apparatus, elevating it; in the postero-supero-medial group, the fundus often lay in close proximity to A1 artery, Heubner's recurrent artery, ICA bifurcation, or dorsum sellae. Optic pathway, hypothalamic, and medial lenticulostriate perforators also required careful separation. Antero-infero-medial SHA aneurysm was hidden from view, embedded in the anterior wall of sella below tuberculum sellae. At a median follow-up of 17.5 ± 26.78 months (range: 8-84 months), 9 (64.28%) patients had a favorable mRS and 5 (35.71%) an unfavorable one. CONCLUSION: Systematically classifying SHA aneurysms and anticipating the surgical risk based upon their anatomical variations helps in achieving a good surgical outcome.

Craniovertebral junction anomalies: When is resurgery required?

BACKGROUND: Craniovertebral junction (CVJ) abnormalities, such as atlantoaxial dislocation (AAD) with or without basilar invagination (BI), with or without associated Chiari malformation (CM), may cause a high cervical myelopathy. Occasionally, mechanical factors such as inadequate canal decompression, torticollis, and/or scoliosis may lead to lack of improvement following the primary surgery. Furthermore, implant-related factors, requiring implant revision/removal, or the presence of surgical site infections may cause the patient to undergo resurgery. AIMS: This study was aimed at highlighting the underlying etiopathogenesis of resurgery following the primary surgery undertaken in CVJ abnormalities. SETTING AND DESIGN: This was a retrospective study from a tertiary care referral institute focusing on 414 operated cases of CVJ anomalies. MATERIALS AND METHODS: The data of 55 patients who underwent resurgery included their clinicoradiological assessment and operative records. The inclusion criteria included failed primary procedure, repeat procedure for construct failure, infection at the surgical site, or wound dehiscence. Pure CM patients without bony anomalies were excluded from the study. RESULTS: A total of 137 procedures were performed in 55/414 (13%) patients. Causes of resurgery could be divided into ventral [redo or denovo transoral decompression (TOD) or wound-related complications, n = 33, 40.2%] and dorsal causes (implant-related factors/wound infections, n = 49, 59.8%). De novo TOD was done in persisting myelopathy following posterior fusion (PF) with C1-2 distraction (n = 15,18.3%,). Redo TOD was done for residual anterior bony compression [n = 8, 9.6%, OR 0.61; [CI = 0.20-1.86]. Causes for oral wound reexplorations (n = 10, 12.2%) included velopharyngeal insufficiency, wound resuturing, oral bleeding, and cerebrospinal fluid (CSF) leak. Dorsal causes included: (A) Implant factors (n = 27, 32.7%) and (B) neck wound reexplorations (n = 22, 26.8%). Presence of subaxial spine scoliosis, torticollis, and asymmetric joints increased the incidence of reexploration. Occipitocervical fusion rather than C1-2 fusion was more prone towards construct loosening. CONCLUSIONS: Patients undergoing distraction with PF may require transoral surgery due to persisting myelopathy, especially in the presence of torticollis, scoliosis, and symmetrical joints. Single stage TOD+PF increases the chances of implant infection due to tissue contamination, bacteremia, or transfacetal migration of microbes. Chronic/recurrent sinus is usually a harbinger of deeper infection and can be cured with implant removal.

Pediatric anterior visual pathway gliomas: trends in fluid and electrolyte dynamics and their management nuances.

PURPOSE: Trends in pre- and postoperative fluid, electrolyte and osmolarity changes, and incidence of diabetes insipidus (DI) were assessed in pediatric patients with anterior visual pathway gliomas (AVPGs). METHODS: Thirty-three patients with AVPGs (age < 16 years) were divided into two groups: (1) no hypothalamic involvement [NHI; n = 17 (51.5 %) including optic (5, 15.2 %); chiasmal (5, 15.2 %); and optico-chiasmal (7, 21.2 %)] and (2) hypothalamic involvement [HI; n = 16 (48.5 %) including chiasmal-hypothalamic (12, 36.4 %) and optico-chiasmal-hypothalamic (4, 12.1 %)]. Frontotemporal transylvian decompression/biopsy was undertaken in 32 patients, while one patient (with severe diencephalic syndrome) was treated conservatively. Their endocrinal and fluid/electrolyte balance, serum osmolarity, and DI status were noted. Chi-square test compared clinical/endocrinological parameters, and unpaired T test evaluated mean daily water/electrolyte changes (p value < 0.05: significant). RESULTS: Significant visual deterioration (perception of light (PL) positive (left: n = 4; right: n = 4) and PL negative (left: n = 5; right: n = 5) was encountered due to optic atrophy. Larger lesions (>3 cm), hydrocephalus [(NHI: n = 7, 41.18 %; HI: n = 12, 75 %), endocrinopathies (p = 0.047), Na(+)/K(+) derangements, and preoperative DI (n = 8, p = 0.004)] were present in the group HI. Increased postoperative urine output (almost double in those with hypothalamic involvement) and hypernatremia/hyperkalemia were seen in group HI until the sixth postoperative day (p < 0.05). Two patients with progressive hypernatremia without increased urine output showed dehydration on central venous pressure monitoring and improved with vasopressin administration. Five patients [NHI: n = 4 (23.5 %); HI: n = 1 (6.3 %)] had neurofibromatosis types I and 3 (NHI: n = 1, 5.9 %; HI: n = 2, 12.5 %) had a diencephalic syndrome. CONCLUSIONS: Hypothalamic infiltration significantly increases the incidence of DI and fluid and electrolyte disturbances. Strict vigilance over postoperative fluid balance is mandatory during the first postoperative week. Rapidly rising serial serum sodium values without increased urine output mandates immediate central venous pressure measurement to detect DI associated with dehydration.

Spinal neurenteric cysts: Associated developmental anomalies and rationale of surgical approaches.

BACKGROUND: Neurenteric cysts (NC) occur due to failure of separation of neurectoderm from endoderm at the 3rd week of embryogenesis. This study focuses on key clinico-radiological features of NCs, with emphasis on surgical nuances involved in resecting anteriorly placed NC, especially at the foramen magnum (FM). METHOD: Sixteen consecutive patients having a spinal NC were included. Their clinico-radiological status, surgical nuances and follow-up status were noted. RESULTS: The duration of spasticity/paraparesis/quadriparesis ranged from 15 days to 48 months. Twelve patients had an intradural extramedullary (IDEM; nine anterior and three anterolateral) cyst and four had an intramedullary (IM) cyst. Six of them had an anteriorly placed FM lesion (five IDEM and one IM). Amongst ten subaxial NCs, four were anterior, two antero-lateral and one postero-lateral; three were IM. Three patients had the characteristic stigmata of occult spinal dysraphism: two, a large mesenteric cyst, and one, a posterior mediastinal cyst. Excision was total in 13 patients. Subtotal excision of tumour capsule was performed for two recurrent cysts and an IM cyst. A far lateral approach was adopted for anteriorly placed FM lesions and posterior laminectomy for subaxial lesions. Histopathology revealed eight type A cysts, four type B cysts and four type C cysts. At follow-up (range, 8 months to 12 years; median, 60 ± 45.84 months), complete neurological recovery occurred in seven patients; six patients had persistent spasticity but only minor disability; two patients had difficulty in walking; and one patient with an anteriorly placed thoracic recurrent NC had sustained neurological deterioration. CONCLUSIONS: Surgical difficulties in addressing NCs are related to their anterior or IM location, presence of adhesions and inability to dissect the tumour capsule from the spinal cord due to fibrous or lipomatous connections. The associated developmental anomalies must be specifically sought and addressed.

Risk stratification of vertebral artery vulnerability during surgery for congenital atlanto-axial dislocation with or without an occipitalized atlas.

CONTEXT: Variability in dimensions and course of vertebral artery (VA) makes it vulnerable to injury during surgery for congenital atlanto-axial dislocation (AAD) with or without an occipitalized atlas. AIMS: This prospective study attempts to define anatomical variations that render VA at the craniovertebral junction (CVJ) vulnerable to injury during transoral decompression and posterior stabilization procedures; and, to propose a classification that helps in preoperative risk stratification. SETTINGS AND DESIGN: A prospective study. MATERIALS AND METHODS: 104 patients (65 with AAD; 39 controls) underwent a three-dimensional multiplanar computed tomographic angiogram to study anatomical variations in VA size, course, and anomalous medial deviation as well as in the type of axial isthmus and rotational deformity/tilt at the CVJ. The VA/foramen transversarium diameter; "stretched loop" sign of VA; and C1-2 facet joint angle were also assessed. STATISTICAL ANALYSIS USED: A medial VA deviation that brought it in close proximity to the trajectory of the surgical approach was evaluated (P ≤ 0.05 significant). RESULTS: An increased predisposition to VA injury was present in 23 (35.4%) patients (persistent first intersegmental artery [n = 20; 30%]; fenestrated VA [n = 1; 1.53%], and low-lying posterior inferior cerebellar artery [n = 2; 3.0%]) where VA crossed the C1-2 facet joint; 8 (12%) with an anomalous medial deviation; 12 (18%) with a high-riding VA at C2 and a narrow axial isthmus; and 13 (20%) with rotation/tilt at the CVJ. A normal score of 5 was obtained in 21 patients; and a score of 6-9 (that progressively indicated an increased vulnerability of VA to iatrogenic injury) in 44 patients. The "AAD with an occipitalized atlas" group was associated with a significant medial deviation of VA (right: P = 0.00 and left: P = 0.001). CONCLUSIONS: A preoperative detailed risk assessment of anatomical variations in the size and course of VA at the CVJ significantly reduces chances of its iatrogenic injury.

A I-segment aneurysms: management protocol based on a new classification.

BACKGROUND: Aneurysms of proximal (AI)-segment of anterior cerebral artery (ACA) constitute <1% of all intracranial aneurysms. AIM: Management dilemmas of A1-segment aneurysms were studied utilizing a new classification based upon their location on the longitudinal and circumferential axis of A1-segment. SETTING AND DESIGN: Tertiary care referral center. MATERIALS AND METHODS: This is a retrospective analysis of 14 patients (0.98%; mean age: 38.02 ± 15.74 years) with AI-segment aneurysms. The data collected included clinical features, computed tomography (CT) scan and CT-angiography (CTA)/digital subtraction angiography (DSA) findings, modified Hunt and Hess (H and H) grade, surgical steps and difficulties encountered. RESULTS: The modified Hunt and Hess (H and H) grades in the 14 patients were: grade I in two, grade II in two, grade III in four, grade IV in five and grade V in 1. The mean ictus-admission duration was 5.07 ± 2.30 days (range: 1-10 days). Multiple aneurysms were two. Thirteen patients underwent clipping and one, wrapping. Bilateral lateral ventricle hemorrhage occurred in 8 (66%) patients and frontal intracerebral hematoma in 2 (16.66%) patients. In one patient, the aneurysm could only be detected following the third angiogram. AI-aneurysms were classified as proximal (n = 6), distal (n = 7), and mid-segment (n = 1); and, anterior (n = 2), posterior-inferior (n = 7) and posterior-superior (n = 5). Follow-up (range: 6 months-10 years, mean: 2.9 years) recovery (assessed using Modified Rankin's score or mRS) correlated with preoperative status. The preoperative H and H grade and follow-up mRS status were as follows: H and H I (n = 2): mRS 0 (asymptomatic, n = 2); H and H II (n = 2): mRS 1 (minor symptoms without disability, n = 2); H and H III (n = 4):mRS 1 (n = 2) and mRS 2 (slight disability but performing unassisted activities of daily living, n = 1); H and H IV (n = 5): mRS 3 (moderate disability, requiring help for daily living but unassisted walking, n = 2) and mRS 4 (moderately severe disability, requiring help for daily living and walking, n = 2). One patient each from H and H grade III, IV and V died (mRS 6) during treatment due to severe vasospasm, pneumonitis and septicemia. CONCLUSIONS: AI-segment aneurysms have unique properties: rupturing of small-sized aneurysms; multiplicity; undetectable on initial imaging; frontal lobar/intraventricular bleeding; origin from main trunk and not bifurcating points; neck obscuration by AI-trunk; close proximity to perforators; and, associated AI-segment and ACA anomalies. A new classification identifies surgical difficulties inherent in different sites of origin of A1-aneurysms.

Large/giant meningiomas of posterior third ventricular region: falcotentorial or velum interpositum?

Surgical excision of rare, large-to-giant posterior third ventricular (PTV) meningiomas [including velum-interpositum meningiomas (VIM; postero-superior venous complex displacement; without falco-tentorial attachment) and falco-tentorial meningiomas (FTM; falco-tentorial attachment; displacing major veins antero-inferiorly)] is extremely challenging. To study the management nuances in the excision of large-to-giant PTV meningiomas. Tertiary care referral center. Four patients with large (>3 cm; n = 2) and giant (>5 cm; n = 2) meningiomas (FTM = 2; VIM = 2, mean tumor size = 4.9 cm) underwent occipital transtentorial approach (OTT) for tumor excision. One also underwent a second-stage supracerebellar infratentorial (SCIT) approach. The side of approach was determined by lateral tumor extension and venous displacement (right = 3, left = 1). Near-total removal or subtotal excision (<10% remaining) with radiotherapy was performed in 2 patients each, respectively. At follow-up (mean: 14.75 months), clinical improvement without tumor recurrence/re-growth was achieved. Extent of excision was determined by position of great vein of Galen; tumor attachment to falco-tentorium or major veins; its consistency; its lateral and inferior extent; and, presence of a good tumor-neuraxial arachnoidal plane. OTT is the preferable approach for large-to-giant meningiomas as it provides a wider corridor and better delineation of tumor-neurovascular arachnoidal interface.