Several neurological complications are associated with complicated and severe falciparum malaria. Cerebral malaria is one of the most dreaded complication. The children are particularly more vulnerable to have this complication. Despite availability of several potent antimalarial drugs in recent past, the mortality status has not changed. A large number of survivors are left with disabling neurological sequelae. Few patients may experience post-malaria neurological syndrome after recovery from complicated falciparum infection. Various psychiatric syndromes have been described either as early manifestation of cerebral malaria or part of post malaria neurological syndrome. From Indian subcontinent several patients of delayed cerebellar ataxia have also been described following recovery from clinical malaria. In paediatric patients, convulsions of cerebral malaria need to be differentiated from febrile convulsions. Falciparum malaria is also associated specifically with convulsions in uncomplicated patients of malaria. Several isolated case reports of various other neurological syndromes like peripheral neuropathies, various movement disorders, myelopathies and stroke like syndrome have been described. However association of these neurological manifestations with malaria remains doubtful.

Bilateral optic nerve injury is a rare condition and is reported in 5-6 percent of all optic nerve injuries. However, there is no published series on bilateral optic nerve injury. Analysis of 31 cases of bilateral optic nerve involvement seen amongst 275 patients with optic nerve injury (11.5 percent) is discussed. Road traffic accident which is the most common cause of optic nerve injury, was recorded in 61 percent. Shotgun injury and blast in jury was the cause in 22.5 percent of cases. All the patients except 4 received steroids. Anterior cranial fossa fracture and opacity of paranasal sinuses were recorded in a third of the patients. Visual evoked potentials were recorded in 27 patients. Improvement in vision was noticed in 23 patients (74 percent). However, among the 62 eyes, 39 eyes showed improvement (62.8 percent). Possible reasons for better outcome in bilateral optic nerve injury are discussed.

Trigeminal evoked potentials (TEP) were recorded by electrical stimulation of the lips in 7 patients with symptomatic trigeminal neuralgia due to CT proved mass lesions involving the trigeminal nerve. All the patients showed TEP abnormalities on the affected side. Chronic compression and irritation of the trigeminal nerve may be responsible for these changes. The results obtained were compared with other similar studies and TEP abnormalities observed in idiopathic trigeminal neuralgia. As all the patients had unequivocal compression of the trigeminal nerve and all of them had TEP changes, it can be concluded that TEP abnormality is an accurate predictor of trigeminal nerve compression. TEPs may be a valuable aid in demonstrating a compressive element in patients with trigeminal neuralgia.

Although many patients with epilepsy achieve control of their seizures with medication, a substantial number ultimately develop intractable epilepsy. Patients with intractable epilepsy form the group for whom surgical procedures may be beneficial. We retrospectively analyzed the clinical profile and outcome of 141 patients operated for intractable epilepsy at Vellore between 1949 and 1990. The operative procedures done for suprasylvian epilepsy were topectomy (24 cases) and lobectomy (2 cases). For temporal lobe epilepsy the surgical procedures done were topectomy (28 cases), temporal lobectomy with amygdalectomy (25 cases), temporal lobectomy with amygdalectomy and hippocampectomy (10 cases), amygdalectomy (15 cases) and topectomy with amygdalectomy in one case. Hemispherectomy was done for 12 cases with multilobe epilepsy. For multifocal epilepsy, four patients underwent stereotactic ansotomy. Post operative complications included infections (10 cases) and acute post operative haematoma in one patient. There was transient neurological deterioration in ten patients. Three patients operated prior to 1960 died due to peri operative complications. Follow up data of 80 patients, ranging from 1 to 42 years (mean 10 years) was analysed. Total or near total seizure control was obtained in 53% patients and a worthwhile outcome in 20% patients. Mental retardation, pre operative scalp electroencephalography and post excision electrocorticography has been shown to be predictors of outcome with respect to seizures.

The effect of 'Mentat', a herbal preparation, was studied on pharmacokinetics of single and multiple doses of phenytoin in rabbits. No significant effect was found after single oral dose of 'Mentat' on single dose kinetics of phenytoin. However, 'Mentat' administration for 7 days increased the steady state kinetic parameters. Peak plasma phenytoin concentration, area under the implasma concentration and elimination half life were significantly increased and t-max was significantly reduced, indicating the suppression of phenytoin metabolism by 'Mentat'.

Somatosensory evoked potentials by paraspinal stimulation were studied in 6 patients with acute transverse myelitis. In one patient in whom posterior tibial somatosensory evoked potentials were not recordable, a poorly formed response was seen with paraspinal stimulation. Slowing of conduction across the involved segment was seen in the remaining 5 patients and fairly correlated with the clinical localization.

Moyamoya disease (MMD) is an uncommon entity outside Japan. Though the clinical and radiological features are well described, involvement of the posterior circulation has not been highlighted. Out of 10 patients of MMD studied, the posterior circulation was involved in 9 (3 bilateral, 6 unilateral). The P1 segment was most commonly affected. Interestingly, no infarcts were seen in the territory of the posterior circulation in any patient. Five patients showed recent haemorrhages on scan. It was thalamic haemorrhage in four and subarachnoid in one patient. The posterior circulation is frequently involved in MMD as evident on angiography. However, ischaemic events of the posterior circulation are not frequent, as the posterior circulation acts as collateral pathway for the diseased anterior circulation till later stages of the disease.

The effect of intravenous lignocaine on intracranial pressure (ICP) was studied on thirty patients of either sex, aged above 5 years and scheduled for elective ventriculoperitoneal shunt surgery. The patients were randomly divided into 3 groups, which received intravenous lignocaine in the dose of 1 mg, 1.5 mg and 2 mg/kg body weight respectively. Intracranial pressure, heart rate, ECG, arterial pressure and arterial blood gases were monitored at various intervals for a period of 30 minutes. Maximum decrease in ICP was seen at 2 minutes after IV lignocaine in all the three groups (p<0. 001). The fall in ICP was significantly more in group II and group III (35.65% and 37.5% respectively) as compared to group I (17.47%) (p<0.001). This fall in ICP in all the three groups persisted below the basal level, throughout the study period. None of the groups showed any significant change in the heart rate, but a statistically significant fall in arterial pressure was observed in group III (p<0. 05). In conclusion intravenous lignocaine, in a dose of 1.5 mg/kg, causes significant fall in ICP without causing any untoward cardiovascular effects and is recommended for routine clinical use.

Antiphospholipid antibodies syndrome has emerged as an important entity responsible for stroke in young. Seven cases of young stroke (< 40 years of age) with mean age of 30.1 years (age range 25-39 years, 2 males and 5 females), who tested positive for antiphospholipid antibodies are being reported. All subjects had completed strokes. Six had arterial ischaemic and one patient had venous stroke. One patient suffered from four episodes, three ischaemic and one intracerebral haemorrhage. Two patients suffered from foetal loss. Generalised tonic clonic seizures occurred in three patients. Deep vein thrombosis was observed in one case. Thrombocytopenia was not observed in any case. All the patients had elevated anticardiolipin antibodies (aCL) IgM or IgG, while Lupus anticoagulant (LA) was elevated in 4 cases. Six cases belonged to primary antiphospholipid antibodies syndrome and one to lupus like illness. Oral anticoagulants were administered to maintain a high intensity international normalized ratio (INR). No recurrences were observed during a follow up period of 6-18 months.

An extremely unusual case of a cystic schwannoma in the region of the inferior vermis and posterior to the fourth ventricle in a fifteen year old boy is reported. The cystic tumour caused partial obstruction to the outflow of cerebrospinal fluid from fourth ventricle and resulted in development of supratentorial hydrocephalus. On investigations, the schwannoma simulated a Dandy-Walker cyst. The boy presented with symptoms of increased intracranial pressure. On surgery, the lesion was not arising from any cranial nerve, nor was it attached to brain parenchyma, blood vessel or to the dura. The possible histogenesis of the cystic schwannoma in a rare location is discussed.

Pure acute or subacute dysautonomia is a rare entity. Its etiology is as yet unknown. However, majority of these cases have a preceding viral infection such as herpes simplex, infectious mononucleosis, rubella or coxsackie B. A unique patient in whom acute dysautonomia followed mumps is reported.

An adult male presenting with acute onset opsoclonus, myoclonus and cerebellar ataxia is being reported. Patient had myoclonus involving limbs and palate. There are only a few reported cases associated with palatal myoclonus. Patient showed gradual spontaneous recovery. Possibility of underlying malignancy was excluded by detailed investigations.

Two non-twin brothers were found to have intracranial malignant neoplasms. The age of presentation was third and fourth decade but the onset was simultaneous, at the same time. Diagnosis in each of them was made by computed tomography and confirmed by histopathology. Elder among them had cellular ependymoma and the younger had oligodendroglioma. Both the brothers received radiotherapy post operatively and were surviving asymptomatically without any neurological deficit, leading active life as police constable, 12 months after surgical treatment.

Primary progressive aphasia is due to focal left perisylvian degeneration and manifests with progressive decline in language function for two or more years. There is preservation of cognitive functions and activities of daily living continue to be normal. We report a case of progressive aphasia in a 65 year old lady.

A 12 year old boy with acute lymphoblastic leukaemia had received prophylactic cranial irradiation (2000 cGy/15 days) and intrathecal methotrexate. Six years later he was diagnosed to have glioblastoma in left temporoparietal region. There is a strong possibility that the glioma may have been radiation and/or chemotherapy induced.

A 15 year old male, who had earlier been operated for intraspinal intramedullary ependymoma, subsequently developed a right cerebello pontine (CP) angle mass. A diagnosis of right CP angle ependymoma was considered, in view of established histology of previously operated spinal lesion. Histopathological examination of the well defined extra-axial mass, which was attached with ninth cranial nerve, however revealed a schwannoma. A diagnosis of Neurofibromatosis-2 (NF2) is strongly suspected, because of well established fact, that the spinal ependymomas may have association with lower cranial nerve schwannomas in NF2. Cranial and spinal MRI screening for early diagnosis of associated, asymptomatic lesions, in suspected cases of NF2, particularly in children, is recommended.

Suprasellar arachnoid cysts (SSAC) are uncommon intracranial lesions. Two patients of SSAC presenting with precocious puberty are described. In both the cases partial excision of the cyst wall, through a pterional craniotomy, establishing communication with the basal subarachnoid spaces was carried out. The endocrinological symptoms regressed after surgery. The clinical presentations of SSAC and the treatment options available are reviewed.

CSF rhinorrhoea is associated with high morbidity and mortality. Bone and dural defects may result from trauma or enlarging 'pitholes' or breach in lateral recess of sphenoid sinus. Unless surgically corrected, they tend to cause meningitis and rhinorrhoea. Unusually delayed rhinorrhoea is a diagnostic problem.

A deficiency of plasma antithrombin III has been identified as a potential risk factor for thrombosis. In a pilot study of 56 patients aged less than 40 years who presented with ischaemic stroke of unknown etiology, we detected only one case of plasma antithrombin III deficiency. Antithrombin III activity was estimated by a chromogenic assay. Hence, antithrombin III deficiency, though rare, should be considered while evaluating young patients with stroke of unknown etiology.