Neurocysticercosis is the most common parasitic disease of the central nervous system. Praziquantel and albendazole, the two antiparasitic drugs, have been reported to be effective against cysticercosis. Both the drugs effectively destroy the cerebral parenchymal cystic lesions. However, albendazole is possibly more effective in subarachnoidal, ventricular and spinal forms of cysticercosis, and frequently obviates the need for surgery. Initially, longer courses of albendazole and praziquantel had been advocated. Now even shorter treatment regimens are found equally effective. Complete course of praziquantel therapy can be administered in a single day with comparable efficacy instead of conventional treatment of 15 days. Similarly, one week therapy of albendazole is as effective as 30 days' treatment regimen. Recently, there is an intense debate whether anticysticercal treatment is useful and safe. Opponents of anticysticercal therapy argue that effectiveness of therapy is possibly a reflection of natural course of the disease. It has been observed that even if cysticercal lesions are left untreated, they either disappear spontaneously or calcify. Anticysticercal therapy is potentially risky, it may aggravate cerebral oedema, and may produce vasculitis and stroke, and several deaths have also been reported. To minimise these risks, concomitant corticosteroids should be administered especially, if there is a massive parasitic load. It is better to avoid anticysticercal treatment in patients with cysticercotic encephalitis. Doubts have been expressed that anticysticercal therapy really affects ultimate long-term clinical outcomes (e.g. control of seizure and possibility of seizure free state after discontinuation of antiepileptic drugs). So far, definite evidences in this regard, based on finding of well planned placebo-controlled studies, are lacking and an opinion that, there is an urgent need for such a study, has been expressed. Measures for effective prevention like provision for safe drinking water and safe excreta disposal should be emphasisfxed.

Creutzfeldt-Jakob disease (CJD) is increasingly being reported over the last three decades as a result of heightened awareness of the disease. Various studies have reported annual incidence of 0.5-1.5 cases of CJD per million of general population. In India, the disease is still under reported. Over the period spanning from 1968-1997, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore recorded 69 cases of CJD from different parts of India in the CJD registry. This paper describes the clinical experience with cases of CJD managed at the Department of Neurology, G.B. Pant Hospital, New Delhi from 1990-1998. In this series, the mean age of the patients was 53.80 (+/- 7.32) years and there were 5 females and 5 males. Myoclonus was present in all the cases and abnormal behaviour with or without other features was the presenting complaint in 7 of the 10 patients, while one patient of CJD had cerebellar ataxia as the presenting feature. One patient with occipital variant of CJD presented with acute onset cortical blindness and myoclonic jerks. One of the patients had acute psychosis precipitated by emotional stress at the onset. Extrapyramidal features were noted in 7 of the 10 patients before death. The mean duration of symptoms from the onset of disease to death was 6.6 (+/- 6.11) months. Classical EEG changes were observed in all the patients, except in one possible case of occipital variant of CJD, where we did not have access to EEG record. Brain biopsy could be undertaken in 3 patients, and in 2 patients the features of subacute spongiform encephalopathy (SSE) were noted.

The anterior retropharyngeal approach (ARPA) accesses anteriorly situated lesions from the clivus to C3, in patients with a short neck, Klippel Feil anomaly or those in whom the C2-3 and C3-4 disc spaces are situated higher in relation to the hyoid bone and the angle of mandible where it is difficult to approach this region using the conventional anterior approach, due to the superomedial obliquity of the trajectory. The ARPA avoids the potentially contaminated oropharyngeal cavity providing for a simultaneous arthrodesis and instrumentation during the primary surgical procedure. Experience of five patients with high cervical extradural compression, who underwent surgery using this approach between 1994 and 1999, is presented. The surgical procedures included excision of ossified posterior longitudinal ligament (n=2); excision of prolapsed disc and osteophytes (n=2); and excision of a vertebral body neoplasm (n=1). Following the procedure, vertebral arthrodesis was achieved using an iliac graft in all the patients. Only one patient with vertebral body neoplasm required an additional anterior cervical plating procedure for stabilisation the construct. The complications included transient respiratory insufficiency and neurological deterioration in two patients; and, pharyngeal fistula and donor site infection in one patient.

The P300 event related potential (P3ERP) latency has recently been advocated for detection of cognitive disturbances in early encephalopathy associated with chronic liver disease. The present study was undertaken to assess the magnitude of cognitive dysfunction, a marker of subclinical hepatic encephalopathy (SHE), in India, using this widely recommended test. One hundred and one patients with cirrhosis of the liver (17 females, 84 males; Age 43.3 +/- 11 years, 33 alcoholic, 49 viral induced, 19 cryptogenic) attending our tertiary care hospital were studied. P300 responses were elicited by the standard 'auditory odd ball paradigm'. A value of mean+2SD of the latency obtained in 40 age matched controls was established as a cut off to define latency prolongation in patients. The mean P3ERP latency of cirrhotics (363.6 +/- 32.1 msec) was significantly longer (p<0.05) than those of controls (347.8 +/- 24.8 msec). No difference was found in the latencies of cirrhotics with or without alcoholic aetiology of liver disease. 21 (20.8%) cirrhotics were found to have SHE i.e. latency prolongation beyond the cutoff value. A higher proportion of patients in advanced stage of liver disease had prolongation in latencies (p<0.02) compared to less severe cases. Till the time a gold standard is derived for detection of SHE, P3ERP latencies seem to be a reasonable method for detection as well as follow up of patients. Since SHE is considered as a preclinical stage of overt encephalopathy, it would be worthwhile screening cirrhotics for cognitive disturbances using P3ERP latencies and administering prompt therapeutic action.

The proprioceptive inputs from the cervical musculature play an important role in head-eye co-ordination and postural processes. Deep cervical muscles in humans are shown to have high spindle content. The density, distribution and morphology of muscle spindles were studied in superior oblique capitis, inferior oblique capitis and rectus capitis posterior major and minor three small suboccipital muscles. The muscles were obtained, post-mortem from stillborn human foetus. The spindle density was calculated as the ratio of mean spindle content to the mean wet weight of that muscle in grams. The distribution and arrangement of spindles within the muscle and their arrangement was studied. The spindle density of superior oblique muscle was found to be 190, that of inferior oblique was 242 and the rectus capitis posterior contained 98 spindles per gram of muscle. No tendon organs were seen. The serial transverse sections of inferior oblique muscle revealed muscle spindles of varying sizes, length varying between 100-650 microns and, diameter 50-250 microns. A complex parallel arrangements of group of large spindles were seen in the belly of the inferior oblique muscle, while the polar regions contain few small isolated spindles. The relevance of such high spindle receptor content in these tiny muscles is discussed.

All patients admitted with provisional diagnosis of an encephalitic illness over a period of 30 months, were studied. Special investigations included CSF analysis, EEG, CT scan and MRI. Herpes simplex virus (HSV) antibody estimation in CSF and blood was done simultaneously using ELISA. Patients with diagnosis of cerebral venous thrombosis, cerebral malaria, tubercular meningitis etc, who resembled herpes simplex encephalitis (HSE), were excluded systematically with relevant investigations. 28 patients showed electroencephalographic, serologic and/or neuroradiological evidence of herpes simplex encephalitis. Males were affected more than females. Age ranged from 4 years to 65 years. Main clinical features included altered sensorium (100%) and seizures (89%). Serological test for HSV antibody in CSF and blood was positive in 14 patients. Fronto-temporal localisation was seen in EEG of 18 patients. CT and MRI were fairly characteristic with bilateral asymmetric fronto-temporal lesions. Patients with mild disease and who reported earlier responded well to treatment with acyclovir. Mortality was higher if treatment was delayed or if the disease was severe. Delayed treatment even in less severe cases produced neurological deficit in many survivors. Despite limitations of non-availability of CSF-PCR and serial estimation of HSV antibodies, the study is an attempt to highlight the value of high index of suspicion of HSE on clinical grounds, systematically excluding cases with different aetiologies resembling HSE and planning early antiviral therapy to reduce both mortality and morbidity associated with this fatal disease.

Periodic limb movement disorder (PLMD) is one of the commonest neurological disorders and causes significant disability, if left untreated. However, it is rarely diagnosed in clinical practice, probably due to lack of awareness and/or lack of necessary diagnostic facilities. Restless leg syndrome (RLS), aging, pregnancy, uraemia, iron deficiency, polyneuropathy are some of the common causes of secondary PLMD. Clinical presentation, polysomnographic findings and management of six patients of PLMD have been discussed in this report.

Based on the evidence that hyperglycaemia aggravates ischaemic cerebral injury, it has been suggested that blood glucose levels be kept within 200 mg/dL during intracranial neurosurgery. Hypoglycaemia, however, can be a serious problem if glucose-containing solutions are avoided during the first four hours, as suggested in some studies. In order to explore the possibility of administering glucose in moderation so that the blood glucose levels are within acceptable limits, but at the same time the risk of hyoglycaemia is eliminated, we compared two intraoperative fluid regimens. Of the 52 neurosurgical patients studied, 32 patients received alternately 500 ml of 5% dextrose in normal saline and Ringer's lactate (DNS/RL Group) and 18 patients received alternately 500 ml of Ringer's lactate and normal saline (RL/NS Group). Blood glucose concentrations were determined at the end of each unit of fluid, until the patient received 4 units of fluid. In the DNS/RL group, blood glucose values peaked with the administration of each unit of DNS and tended to return towards the baseline with the subsequent RL, but remained higher than the previous control value. In the RL/NS group, there was a progressive increase in blood glucose values throughout the study period, but the increase was not statistically significant. The blood glucose levels were significantly different between the two groups after each unit of fluid except at the end of the fourth unit. Two patients in the RL/NS group had hypoglycaemia. In conclusion, the DNS/RL regimen maintains blood glucose levels within acceptable limits while avoiding the risk of hyperglycaemia. Withholding glucose completely, lowers blood glucose levels, but carries a risk of hypoglycaemia in some patients.

Cysticercus cellulosae antigen has been frequently used to detect antibodies for immunodiagnosis of neurocysticercosis. We have, for the first time, used membrane extract of cysticercus fasciolaris, the larval stage of Taenia taeniaeformis, in ELISA, with successful results. IgM and IgG antibodies against cysticercus were measured in serum from cases of neurocysticercosis (217), normal and diseased controls (89). 203 sera from cases of neurocysticercosis were positive for either or both IgG and IgM antibodies while 157/217 cases showed IgM and 158/217 showed IgG antibodies. Ten controls showed false postivity in IgG ELISA. Eight of these cases also had IgM antibodies. The test had an overall sensitivity of 93.54% and a specificity of 84.2% with a positive predictive value of 93.54% and a negative predictive value of 84.2%. Cysticercus fasciolaris can be conveniently produced in the experimental laboratory host, Rattus rattus, and would be of practical value in the immunodiagnosis of cysticercosis in humans.

It is unusual for a medulloblastoma to occur in the cerebellopontine angle (CPA). Four of the total 63 cases of medulloblastoma managed in our department between 1988 to 1998, presented with a mass in the cerebellopontine angle. There were two children amongst these four patients, aged eight and nine years. The other two patients were young adults. Three patients had primary CPA medulloblastoma, while the fourth case had a recurrence in this region, following the excision of the primary vermian tumour. All the four cases were managed by gross total microsurgical excision and craniospinal irradiation. One of the two children, developed subfrontal recurrence after 1 year and 8 months of initial treatment, while the other child developed a large recurrence at primary site, within three months of post-operative irradiation. However, the adult patient developed CPA recurrence and subsequent cervical intramedullary metastasis within two and a half years of diagnosis. These three cases succumbed to their disease, between three months to thirty months of their initial management. However the fourth patient, a 20 years female with desmoplastic variant, was well at two and a half years of follow up.

Vertebral artery dissection is an important cause of brain stem stroke, especially in the young. Dissections of carotid and vertebral arteries in neck account for about 20% of strokes in young compared with 2.5% in the elderly. Three patients of vertebral artery dissection related to indirect neck trauma are described. The first patient developed the symptoms while dancing, the second after a trivial fall and the third while he was on a dental chair. None of them had a direct severe neck trauma or concomitant risk factor like hypertension, connective tissue disease or migraine. Clinical symptomatology was similar in all the patients and included occipito-nuchal pain, headache and brain stem dysfunction chiefly in the posterior inferior cerebellar artery (PICA) territory. One of the patients also had associated ischaemic myelopathy. MRA and DSA confirmed dissection in all with a predominant steno-occlusive picture. Cases of so called trivial neck movement/torsion related dissection have been described previously but have not received any major importance. Usually classified as 'spontaneous' or 'traumatic', there is a possible ambiguity in literature about appropriate terminology. We emphasise that a history of such subtle precipitating events be taken while diagnosing young patients with brain stem strokes, to recognise this clinical entity. Although mechanisms are not absolutely clear, yet there seems to be an important relationship between arterial dissection and neck movements or minor trauma.

Dissecting aneurysms of the intracranial arteries are exceedingly rare vascular lesions that can produce acute cerebral or brain stem infarction in young healthy adults. They carry a high mortality rate. Two cases of dissecting vertebral artery aneurysms that presented with bleed, were successfully operated by trapping and excision of the dissecting segment. Both dissecting aneurysms were located distal to PICA origin. Both the patients developed post operative lower cranial nerve paresis and one developed lateral medullary syndrome, which improved subsequently. Dissecting aneurysms presenting with bleed should be surgically managed by trapping and excising the involved segment sparing the PICA origin or by interventional radiological techniques. Revascularisation procedures should be considered in addition to trapping of the main vertebral segment if PICA is involved in the trapped segment. The diagnostic and therapeutic difficulties associated with dissecting vertebral artery aneurysms and the controversies regarding their management have been reviewed.

Yolk sac tumours are rare conditions among the germ cell tumours. Intracerebral germ cell tumours are exceedingly rare. A 15 year old girl presenting with a one week history of raised intracranial pressure is described. She had bilateral papilloedema and a right 6th nerve palsy. CT scan showed an intra-parenchymatous right frontal ring enhancing lesion of 2 cms diameter. The patient underwent microsurgical total excision of the tumour, followed by chemotherapy. She was asymptomatic at three years following surgery.

The co-existence of schwannoma and meningioma as a mixed intracranial tumour is uncommon and so far only eight cases have been published in the literature. Because of rarity, we report a unique case of mixed tumour having schwann cell and meningeal components, in a patient with neurofibromatosis type -2 (NF-2). The possible mechanisms for the occurrence of these mixed tumours are discussed.

A 35 years old male presented with episodic weakness of left upper limb followed by gradually progressive neurological deterioration. MRI revealed an intra medullary cervical cord angiomatous lesion. Histopathology revealed it to be cavernous haemangioma. A complete surgical removal of the haemangioma was carried out.

Corticosteroids are widely used in patients with raised intracranial pressure associated with cerebral neoplasms, cerebral vascular malformations, cerebral ischaemia and benign intracranial hypertension. In general clinical practice, anti-allergic, anti-inflammatory and immuno-suppressive properties of corticosteroids are commonly utilised in the management of allergic and immunological diseases. However in exceptionally rare circumstances, steroids may be the cause of hypersensitive reactions. Authors report two patients with raised intracranial pressure who developed steroid hypersensitivity. A review of the relevant literature is discussed.

The combination of apoplectic symptoms and a sellar mass most often points to a diagnosis of a pituitary adenoma. Sellar tuberculomas are not considered as a cause of 'pituitary apoplexy' and there has been no radiological documentation of haemorrhage associated with them. We report a 27 years old man who presented with 3 previous episodes of pituitary apoplexy. CT scan showed evidence of a sellar mass with haemorrhage. Transsphenoidal biopsy of the intrasellar mass was reported as 'tuberculoma'. The patient had marked reduction in the size of the lesion following antituberculous therapy with no recurrence of symptoms. Intrasellar tuberculomas must be considered as one of the differential diagnosis when patients present with a pituitary apoplexy.

Reflex epilepsy is the commonest form of epilepsy in which seizures are provoked by specific external stimulus. Photosensitive reflex epilepsy is provoked by environmental flicker stimuli. Video game epilepsy is considered to be its variant or a pattern sensitive epilepsy. The mean age of onset is around puberty and boys suffer more commonly as they are more inclined to play video games. Television set or computer screen is the commonest precipitants. The treatment remains the removal of the offending stimulus along with drug therapy. Long term prognosis in these patients is better as photosensitivity gradually declines with increasing age. We present two such case of epilepsy induced by video game.

Amyotrophic lateral sclerosis (ALS) is the most common, progressive motor neurone disease but is rare in the obstetric population. Only 4 cases have been described in the English literature since 1975. We describe a 29 year old woman who presented with ataxia, lower limb weakness and dysarthria 4 weeks after the birth of her first child. The symptoms had onset during the pregnancy but had not been considered remarkable. There were clinical features of upper and lower motor neurone involvement without any sensory loss. MRI of brain and spine was normal. CSF analysis was negative. EMG studies confirmed the presence of widespread anterior horn cell dysfunction compatible with ALS. The patient was commenced on Riluzole and has progressed clinically, at 12 months post diagnosis.