Medial trigonal arteriovenous malformations.

A retrospective analysis of 48 patients of medial paratrigonal arteriovenous malformations (AVMs) which constituted 18% of the total 258. AVMs surgically managed in our institute for 16 years was carried out to study their clinical presentation, radiological features, operative approaches and functional outcome. While hemorrhage was the initial presenting symptom in 35, it was longstanding headache in 10, focal seizures in two and progressive weakness in one. However, 41 of these presented with bleed at the time of admission to our hospital and in 15 there was history of multiple bleeds. Twelve and eleven patients had field cut and hemiparesis respectively. Arterial supply to the malformation was quite uniform with posterior (43 patients) and anterior cerebral (25 patients) being the most frequent source. Venous drainage was predominantly into the galenic system (70%). Preoperative embolization was carried out in six patients. While the AVM was excised through a parasagittal interhemispheric approach in 34 patients, the nidus was approached through a direct transcortical (superior parietal lobule) approach in fourteen patients. There was only one operative mortality. Twelve patients whose preoperative fields were normal developed field cut postoperatively. An improvement of the preoperative field deficit was noted only in one patient. While eight of the ten patients with preoperative weakness improved and remained independent the remaining two were moderately disabled. Only two of the 10 patients who developed postoperative weakness remained severely disabled. Our operative results suggest that these AVMs which are prone to recurrent bleeds can be resected with acceptable morbidity. Hemianopia resulting from bleed or surgery is unlikely to improve.

Suprasellar meningioma subsequent to treatment for a pituitary adenoma: case report.

The authors report a case of suprasellar meningioma that developed 16 years after surgery and radiation therapy for a pituitary adenoma. The patient had significant recovery of visual loss following excision of the meningioma. We believe that this tumor was induced by radiation received by the patient previously and we stress that tissue diagnosis should be obtained in patients who develop a recurrent tumor after a long period following initial radiotherapy. Radiation induced meningioma has to be considered in the differential diagnosis of any patient who has a recurrence after therapeutic radiation. This is especially essential in the absence of biochemical and clinical signs of a previously functioning pituitary adenoma and before the initiation of medical therapy for recurrent pituitary adenomas.

Granular cell tumour (choristoma) of the neurohypophysis--a report of two cases.

Granular cell tumours of the neurohypophysis are uncommon and only 30 cases are documented in the literature till 1994. In this communication, the salient clinical and histomorphological features in two patients with granular-cell tumour of the neurohypophysis are described.

Dysembryoplastic neuroepithelial tumour of the central nervous system--a case report.

Dysembryoplastic neuroepithelial tumour (DNT) of the central nervous system is a recently recognized entity. We describe the clinical and characteristic histomorphological features in a patient with DNT. As this lesion carries a favourable prognosis, it becomes essential to make an accurate histopathological diagnosis.

Gliomatosis cerebri--a case report.

Gliomatosis cerebri is a vary rare neoplastic lesion of the central nervous system. An intra-vitam diagnosis of gliomatosis cerebri can be suggested with a steleolactic biopsy of the lesion in conjunction with Magnetic Resonance Imaging (MRI) findings in the brain.

Central nervous system ganglioglioma. A clinicopathologic study.

Gangliogliomas are one of the uncommon tumours of central nervous system. Since these tumours have been associated with an indolent clinical course and benign biological behaviour, it is essential to make an accurate histopathological diagnosis of ganglioglioma. In this study the salient clinical and histopathological features in six patients with intracranial ganglioglioma are described.

Craniospinal and spinal enterogenous cysts--report of three cases.

We report three cases of enterogenous cyst, one craniospinal and two spinal manifesting with features of spinal cord compression. In one the cyst was intramedullary in location and in the other two it was intradural, extramedullary. The unusual clinical presentation, location and magnetic resonance imaging (MRI) characteristics are discussed. None of the three patients had any vertebral anomaly or other congenital malformation. All patients had excellent outcome following surgery.

Effect of temporary vascular occulsion during surgery of cerebral aneurysms.

Temporary vascular occulsion during surgery for cerebral aneurysms has been slow to gain acceptance as an elective procedure. This study presents the outcome in 115 cases in whom temporary vascular occulsion was needed during aneurysmal surgery. Elective temporary clipping was used in 55 cases and emergency temporary vascular occulsion was performed in 60 cases. Judicious use of temporary clips did not increase the overall morbidity or mortality. Rescue temporary clipping as an emergency measure inthe face of intraoperative rupture has a deleterious effect as against elective use on the immediate as well as long term outcome of the patient. Use of elective temporary clipping in conjunction with adequate cerebral protective measures in advocated indifficult cases to facilitate definitive clipping of the aneurysm in order to improve the overall outcome.

Toxoplasma gondii IgM antibody prevalence study in patients suffering from neurological disorders.

One hundred and twenty seven patients belonging to Neurosurgery (49), Neuromedicine (48), Cardiac medicine (30) wards and Blood donors (30) as healthy controls were investigated for the prevalence of Toxoplasmosis by means of detecting specific IgM antibody against Toxoplasma gondii (T. gondii) employing Enzyme Immuno Assay (EIA). The detection rate of specific IgM antibody against T.gondii was found to be 32.7% (16/49) among Neurosurgery patients, 20.8% (10/48) among Neuromedical patients and 20% (6/30) among Cardiac medical patients. None of the voluntary blood donors tested was found to have T. gondii IgM antibody. Maximum prevalence rate was found among female patients undergoing Neurosurgery (42.3%) followed by Neuromedical patients (40%). There is an increasing rate of prevalence of Toxoplasmosis from the lower age group upto thirty years and a declining prevalence rate among the higher age groups. The present study revealed high prevalence rate of Toxoplasmosis in Neurosurgery patients (32.7%) and in particular among female (35.2%) than male (17.8%) patients.

Spontaneous haemorrhage in acoustic neurinomas.

Gross intratumoural haemorrhage in acoustic neurinoma is rare. The authors describe seven patients, out of a consecutive 99 cases of acoustic neurinoma operated by the first author, who presented with haemorrhage. Risk factors for haemorrhage appear to be large size, mixed Antoni type and secondary vascular changes.

Nucleolar organizer regions in pituitary adenomas.

In this study, thirty-two non-functional and eighteen functional pituitary adenomas were analysed for the presence of argyrophilic nucleolar organizer regions (Ag-NORs) in paraffin sections, using an one-step silver-colloidal staining method. Differences in the mean Ag-NOR numbers of functional pituitary adenomas were statistically significant than those of non-functional pituitary adenomas. It is being emphasised that evaluation of Ag-NOR count is a more reliable index than the presence of mitotic figures in predicting the proliferative activity as well as possibility of recurrence in a patient with pituitary adenoma.

Mycotic aneurysms of the intracranial vessels.

The salient clinical and pathological features are reported of Aspergillus cerebral aneurysms in four young women who had undergone intra-abdominal surgery under spinal anaesthesia and developed clinical features of meningitis 7-16 days postoperatively. The circle of Willis showed ruptured aneurysm in the basilar artery and its branches. The role of iatrogenic factors in the pathogenesis of Aspergillus cerebral aneurysms is highlighted.

Paraganglioma of the cauda equina region--a report of two cases with review of literature.

Among all extra-adrenal locations, paragangliomas are least commonly found within the spinal canal. so far over 60 cases of paragrangliomas in the Cauda equinal region have been reported. In this report we describe the salient clinical and histopathological features of paraganglioma of the cauda equinal region in two patients.

Intraventricular neurocytoma: a report of two cases.

Central neurocytomas are uncommon intracranial neoplasms. More than one hundred cases are documentated in the literature. In this report we describe the clinical and histopathological features in two patients with intraventricular neurocytoma. As the light microscopic features of neurocytoma resemble with that of an oligodendroglioma, it is essential to differentiate these two tumours, using either ultrastructural or immunohistochemical techniques.

Disseminated intra-cerebral microabscesses: a clinico-pathologic study.

In this retrospective study, clinical and neuropathological features were analysed in eight patients with disseminated intracerebral microabscesses. All the patients presented with clinical features, suggestive of an encephalopathic process of an acute onset. Neuroradiological and laboratory investigations were not helpful in establishing the diagnosis in any patient during their hospital stay. All the eight patients died in the hospital and at autopsy disseminated intracerebral microabscesses were the most striking feature. In two patients hyphae of Candida albicans were demonstrated within the microabscesses. Gram negative bacilli in two patients and gram positive and gram positive cocci in one patient were demonstrated in the microabscesses. Disseminated intra-cerebral microabscesses are usually an unrecognised manifestation of central nervous system infections and should be considered in the differential diagnosis of patients with encephalopathy of unknown aetiology.