V. S. Mehta

Awake craniotomy versus surgery under general anesthesia for resection of intrinsic lesions of eloquent cortex—A prospective randomised study

OBJECTIVES Complete removal of a brain tumor without inflicting neurological deficits is a desirable end result in neurosurgical practice. Currently no prospective randomized surgical series in the literature exists comparing tumor resection under general versus local anesthesia awake surgery may achieve more aggressive tumor resection and minimize postoperative neurological morbidity. PATIENT AND METHODS We thence conducted a prospective randomized comparative study of results of surgery under awake versus surgery under general anesthesia for intrinsic eloquent area lesions. Fifty-three patients with intrinsic brain tumors in eloquent areas were prospectively randomized (26 patients in awake group and 27 for surgery under general anesthesia). At 3 months follow up, 23% patients in awake group had permanent deficits compared to 14.8% in GA group. RESULTS More than 90% tumor excision was observed in 57% patients in awake group versus 73.7% in GA group. CONCLUSIONS The mean operative time, blood loss was found to be was found to be less in GA group patients than in awake group. Better tumor cytoreduction, neurological improvement was seen in GA group (motor improvement in 35.7%, speech improvement in 62.5%) than in awake group patients (motor improvement in 18.7%, speech improvement in 14.3%).

Spontaneous Decompression of a Posterior Fossa Arachnoid Cyst: A Case Report

The authors present a case of spontaneous regression of a posterior fossa, supracerebellar arachnoid cyst causing hydrocephalus in a 7-month-old male child. The patient presented with macrocrania, bulging fontanelle and upgaze paresis of the eyes. There was complete improvement of these symptoms on the morning of the day of surgery without any obvious precipitating factors, including trauma. CT scan showed complete resolution of the cyst and hydrocephalus. The child was doing well at 1 year of follow-up. To the best of our knowledge, this is the first case report of spontaneous resolution of a posterior fossa arachnoid cyst.

Recurrence in craniopharyngiomas: Analysis of clinical and histological features

The aim of this study was to investigate the recurrence patterns and significance of various clinical and histological features as predictors of recurrence in craniopharyngiomas. A series of 234 craniopharyngiomas (156 males, 78 females; age range 1.6-65 years) was reviewed. The mean follow-up period was 18.53 months (range 1-120 months). Peri-operative mortality was 7.4% and tumor recurrence was observed in 26 patients (20.3%). Of the patients with recurrence, one had total tumor excision (recurrence-free survival (RFS) 14 months), four had near-total excision (mean RFS 18.2 months) and 21 had subtotal tumor excision (RFS for symptomatic recurrence 7.1 months). Histologically, an adamantinous pattern was seen in 81.4% of cases and a papillary pattern was seen in 18.6%. Brain tissue was included in 67 cases and brain invasion was noted in 44 (all were of adamantinous histology). No correlation was noted between histopathological subtyping or brain invasion and recurrence. The significant clinical factors predictive of recurrence included the extent of resection, tumor size greater than 4 cm and cystic tumors.

Recurrent astrocytic tumours — a study of p53 immunoreactivity and malignant progression

Recurrence and progression to higher grade lesions are characteristic of the clinical course of astrocytic tumours. Though p53 gene mutation is an impor tant initiating event in astrocytic tumourigenesis, its role in malignant progression remains controversial. We have therefore analysed p53 protein expression in paired histological samples from 48 cases of astrocytic tumours and their recurrences - 29 diffuse astrocytoma, 10 anaplastic astrocytoma and 14 glioblastoma multiforme (GBM). Malignant progression at recurrence was noted in 93% of diffuse and 64% of anaplastic astrocytomas. An association was observed of p53 protein immunopositivity and malignant progression at recurrence. Thus, 27 of 48 (56%) primary tumours were initially p53 positive, while in recurrent tumours associated with malignant progression this frequency increased to 71% (34/48 cases). This was because seven of the 13 cases (4/8 diffuse and 3/5 anaplastic astrocytoma) that were initially p53 negative acquired immunopositivity on malignant progression at recurrence. In contrast, none of the 19 tumours that recurred to the same grade showed any change of p53 status at recurrence. Furthermore recurrence was associated with increase in the percentage of p53 immunopositive cells (p53 labelling index), which was also higher in tumours with progression. This new acquisition of p53 immunopositivity on progression at recurrence has not been documented in earlier studies in English language literature, though increase in p53 LI has been documented. Thus, this study conclusively indicates the role of p53 in malignant progression of astrocytic tumours. Also, it suggests a potential role of p53 LI in predicting malignant progression at recurrence because the highest initial LI was noted in those tumours which progressed to GBM as compared with those which recurred to the same grade or progressed to anaplastic astrocytoma. No correlation could, however, be demonstrated between p53 immunoreactivity and interval to recurrence.

Chronic subdural haematoma and the enigmatic eosinophil

Summary. The membranes from 50 cases of chronic subdural haematomas were examined histologically and correlated with the duration of the lesion. Cases were divided into three groups based on duration from time of trauma and/or onset of clinical symptoms to date of surgery – Group I: 1 to 30 days, Group II: 31 to 90 days and Group III: >90 days. Infiltration with eosinophils was observed in the vascularised and hyalinised granulation tissue of the subdural membrane in 30 of the 50 cases (60%). There was a trend to correlation both of the frequency and the extent of eosinophilic infiltration with duration of haematoma. Thus, eosinophils were encountered in about half the cases with duration up to 3 months which increased to 80% in cases with duration more than 3 months. The extent of eosinophilic infiltration (mild, moderate or severe) also appeared to correlate with duration of haematoma in that mild infiltration was more common in Group I cases while moderate to severe infiltration were more frequently observed in Group II and III cases. No correlation was observed of the eosinophilic infiltrate with age and sex of the patients or with presence of other cellular inflammatory components of the membrane. Interestingly, a finding hitherto unreported in English literature was the demonstration of mast cells in 7 of 16 membranes (44%) which had been stained using toluidine blue. It is possible that the eosinophils appear at this unusual site due to chemotactic stimulus abetted by these mast cells as well as lymphocytes and haemosiderin pigment. The eosinophils may have an important role in the repair and healing process of these membranes.

Arachnoid cyst presenting as subdural hygroma

Arachnoid cysts are developmental lesions which are usually asymptomatic or may present with a variety of clinical features. Subdural hygroma is an extremely unusual complication associated with arachnoid cysts. A case of subdural hygroma that developed after the rupture of an asymptomatic middle cranial fossa cyst, following minor head injury is reported.

The enigmatic origin of subfrontal schwannomas: report of a case without hyposmia

SummarySubfrontal schwannomas are rare intracranial tumors. Most of them are associated with hyposmia/anosmia. The source of origin of these tumors is still incompletely understood. We report a 23-year-old male who presented with recurrent focal motor seizures, but had no hyposmia. The tumor was completely removed by a subfrontal approach. Relevant literature has been reviewed.

Outcome following surgery for ophthalmic segment aneurysms

Ophthalmic segment aneurysms account for about 5% of all intracranial aneurysms. Anatomical complexity of the paraclinoid region makes surgical management of aneurysms arising from the ophthalmic segment challenging. This study was carried out to assess the presenting features, complications and outcomes after surgical treatment of ophthalmic segment aneurysms. The authors retrospectively analysed the clinical records of patients with ophthalmic aneurysms treated at our Institute from January 2001 to September 2008, which constituted about 9% (78/850) of all intracranial aneurysms. Of the 78 ophthalmic segment aneurysms, six patients (8%) had giant aneurysms and 19 (24%) patients had multiple aneurysms. Fifty-six patients underwent microsurgery, with direct clipping in most. The mean age was 42 years (range 12-75 years) and the mean follow-up was 8 months (range, 2-93 months). A good outcome was achieved in 46 (83%) patients (Glasgow Outcome Scale [GOS] score 4-5) and 17% had a poor outcome (GOS score 1-3) at last follow-up. The overall complication rate was 21% (12/56), most of which were transient complications, with 3.5% (2/56) mortality. Direct microsurgical clipping remains our preferred treatment approach, whenever possible, for ophthalmic segment aneurysms. This surgery has an acceptable complication rate and leads to a good outcome in more than 80% of patients with ophthalmic aneurysms. Use of modern microsurgical instrumentation and endovascular adjuncts can further reduce the surgical morbidity associated with these vascular lesions.

Paraganglioma of cauda equina: report of seven cases

The authors report seven uncommon cases of paraganglioma of the cauda equina region with reference to their clinical, radiological, and pathological findings. The common presenting symptoms in all the patients were low backache with radiation to both thighs, sensory and motor deficits in four patients, and urinary retention in three patients. One patient presented with ataxia and superficial sidrosis of the brain. Magnetic resonance imaging (MRI) revealed well-circumscribed lesions that were isointense on T1- and T2-weighted images with flow voids. All the tumors were well circumscribed and could be excised completely; however, one recurred. Histological examination revealed a classic “zellballen” pattern in four tumors. Two mimicked ependymoma but were confirmed as paraganglioma by immunohistochemistry. MIB-1 LI was low in all the tumors. Thus, there were no identifying clinical or radiological features that helped in differentiating paraganglioma from other common tumors, such as ependymoma or neurinoma, in this region, and preoperative diagnosis was not possible in any of the cases. Morphologic features and immunohistochemical analysis proved to be the mainstay of arriving at a correct diagnosis. This report highlights the significance of important morphologic features and immunohistochemistry in the diagnosis of paraganglioma at this unusual site.

Gliofibroma: Mixed glial and mesenchymal tumour. Report of three cases

Gliofibromas are rarely encountered astrocytic tumours comprising of astrocytic and benign fibroblastic components. They commonly occur in first two decades of life. However, the exact behaviour is not fully known and their histogenesis is also still debatable. We report three cases of gliofibroma in which we studied proliferative markers (MIB-1) and p53 protein expression. In these tumours, occurrence in adult life is in contrast to that reported in the literature. Depending upon the morphology and proliferative Labelling Index we classified these tumours into low grade (benign) and high grade (malignant/anaplastic).