The lack of animal models for many of the neurodegenerative and psychiatric disorders and the fact that animal models cannot substitute for human tissue led to the establishment of Brain Banks that collect, preserve and provide fresh human tissue for researchers. One such Bank has been set up at the National Institute of Mental Health and Neurosciences funded by Dept. of Biotechnology, Dept. of Science and Technology and ICMR. Brains and tissue fluids (serum and CSF) are collected at autopsy following informed consent from close relatives. One half of the fresh brain from neurodegenerative and psychiatric disorders are frozen at -70' C while the other half and brains from infective conditions are formalin fixed which can be used for pathomorphological studies. Only fresh frozen tissues that are tested and found negative for HIV and HbsAg are provided for research. The neural tissues as well as tissue fluids that are being supplied by the Brain Bank have supported a number of research projects in diverse fields of neurosciences. Many significant discoveries that have contributed towards understanding pathogenesis of disease, their genetic basis, and evolving prognostic and diagnostic markers for neurologic disease in the CSF have been made possible by the existence of such a facility. The continued functioning of such a facility requires the close co-operation of the clinical neuroscientists, pathologists and the other neuroscientists. Increased awareness and commitment amongst the scientific fraternity is necessary to keep alive the demand and ensure uninterrupted supply of fresh tissue for research. This will help usher in the era of molecular neurobiology with the fond hope that many more of the relentlessly progressive neurodegenerative disorders will eventually find a cause and cure.

Seizures are among the typical presentations of intracranial cavernous angiomas (ICA). Twenty-one patients (age range: 2 to 53 years) treated for seizures associated with ICA between 1983 and 1997 were restrospectively studied to evaluate their outcome following medical or surgical intervention. The mean interval between seizure onset and initial presentation at our institution was 7.6 years. Seizures were simple partial in 3 patients, complex partial in 15 and secondarily generalized tonic-clonic in 13. The commonest site of the lesion was the temporal lobe (52%). Multiple angiomas were observed in 5 (24%) patients. Seven (32%) patients were medically-managed with antiepileptic therapy and 14 (68%) underwent either lesionectomy with resection of the epileptogenic zone (9 patients) or temporal lobectomy (5 patients). Mean follow-up time was 4 years (range: 3 months to 14 years). Of the medically-managed patients, 3 (43%) remained seizure-free whereas 4 (57%) continued to have seizures with an average frequency of one per day. Of the surgically-managed patients, 12 (86%) became seizure-free and 2 (14%) had no more than two seizures per year. Surgery appears to be extremely effective in the management of seizures associated with ICA and should receive a strong and early consideration in patients who fail medical therapy.

Differentiating hereditary motor sensory neuropathy (HMSN) from chronic inflammatory demyelinating polyneuropathy (CIDP) is often difficult especially when the disease starts at an early age and has protracted course. This study compares the clinical, electro, physiological and histopathological features of hereditary and acquired chronic demyelinating neuropathies. Records of 26 patients of chronic demyelinating neuropathy who underwent sural nerve biopsy were reviewed; HMSN 9, CIDP 13, chronic relapsing demyelinating polyneuropathy (CRDP)-4, Salient features of the HMSN group were: Consanguineous parentage-4, onset in first decade-9, skeletal markers-7, absence of positive sensory symptoms- 7 and clinically thickened nerves-6. None of the patients with acquired neuropathy had skeletal markers, 11 had positive sensory symptoms and only 4 had nerve thickening. Electrophysiological evaluation in 22 motor nerves in the HMSN group revealed: inexcitable nerves -13, prolonged distal latency - 6, slow conduction velocity-8 and prolonged f wave latency-3. The 44 motor nerves in patients with acquired neuropathy showed: inexcitable nerves- 7, prolonged distal latency-35, slow conduction velocity-34, f wave prolongation-30 and conduction block 9. Elevated CSF protein was noticed only in acquired group (77%). Pathologically in HMSN the fibre loss was always diffuse and onion bulb formation was frequent while endoneural edema and inflammatory infiltration were absent in this group. Selection of patients with chronic demyelinating neuropathies for therapeutic modulation needs comprehensive clinical and laboratory evaluation.

The past two decades have witnessed a rapid increase in the knowledge of the inherited neurometabolic disorders. The precise diagnosis of these disorders which is a challenge to the physician can be best accomplished by biochemical methods. Screening of clinically selected patients with simple chemical urine tests and routine blood chemistry investigations followed by measurement of specific metabolites and assay of the relevant enzymes confirms the diagnosis in most cases. Biochemical diagnosis of inherited neurometabolic disorders although expensive is rapid and confirmatory and therefore aids in treatment and further prevention of these rare disorders.

Neurocysticercosis is one of the common parasitic diseases of central nervous system. We report here a case of histopathologically confirmed case of cysticercus cellulosae presenting as a solitary cyst in the brain stem of a thirty-three year old female patient. This is being reported because of the uncommon anatomical location of the lesion and secondly magnetic resonance imaging features did not contribute to the preoperative diagnosis.

A case of Parkinsonism 'Plus' syndrome with cranial CT scan and MRI showing corpus callosal agenesis is reported. There were no clinical signs of callosal separation. The causes for the discrepancies between the lack of clinical signs of callosal separation and imaging appearances are discussed. The callosal agenesis is in all probability incidental.

Marinesco-Sjogren syndrome (MSS) is a rare genetically determined disorder characterised by bilateral cataract, cerebellar ataxia and mental deficiency. The pattern of inheritance is autosomal recessive but it may be variable. In MSS association of hyperlactacidaemia and hypopyruvicaemia, a defective oxidative phosphorylation in mitochondria, is supposed. We are reporting three patients of MSS along with sensorineural deafness and optic atrophy from a single Indian family.