Detailed analysis of muscle biopsy using histological and enzyme histochemical staining techniques forms the basis of diagnosis of muscular dystrophies, while clinical features and family history are important adjuncts in categorising the type of dystrophy. However, in a significant proportion of cases having overlapping clinical and histological features, it is not possible to provide accurate diagnosis. These conditions can be grouped as Limb girdle muscular dystrophy (LGMD), Decker muscular dystrophy (BMD), early onset Duchenne muscular dystrophy (DMD), Congenital muscular dystrophy (CMD), Severe childhood autosomal recessive muscular dystrophy (SCARMD), and SCARMD in girls/manifesting DMD carriers. Immunohistochemical staining procedures demonstrating the presence/absence of dystrophin, adhalin and merosin are found to be of immense value in arriving at a conclusive opinion specifying the type of muscular dystrophy. It is also evident that muscular dystrophy in young girls resembling DMD is not uncommon and that these are mostly cases of SCARMD in girls having adhalinopathy. In addition, a significant proportion of patients (9 in the present series) with clinical and histopathological diagnosis of DMD are likely to be cases of SCARMD in boys after immunohistochemical study of muscle biopsies.

Neurocysticercosis is the most frequently encountered parasitic infestation in nervous system. Epilepsy is the most common clinical manifestation. Cysticidal drugs are helpful in upto 96 of parenchymal cysts and 80 of intraventricular cysts. Surgery is considered when diagnosis is uncertain, cysts exhibit tumour like behaviour, oedema (pseudotumour) is refrectory to medical treatment, or when hydrocephalus develops.

Haematological investigations in the haematoma fluid and venous blood along with histological changes in the haematoma membrane were studied in twenty five patients of chronic subdural haematoma. Their median age was 60 years with a marked male predominance. Haemoglobin level in the haematoma fluid was unrelated to its age. Prolongation of prothrombin time and activated partial thromboplastin time was observed in all the haematoma fluid samples. Fibrinogen and antithrombin III levels were significantly decreased in haematoma fluid and fibrin degradation products were positive in 44 of these specimens. The neo-membrane showed 'giant' capillaries and abundant eosinophils with an inverse relationship between the presence of inflammatory cells andfibroblasts. These findings suggest a localized consumption coagulopathy and hyperfibrinolysis with reactive formation of a leaky neo-membrane resulting in recurrent haemorrhages and progressive enlargement of chronic subdural haematoma.

It has been identified that the expansion of normally polymorphic CTG repeats in myotonin protein kinase (DM-PK) gene in myotonic dystrophy (DM) and CAG repeats in huntingtin gene in Huntington's disease (HD) acts as the causative mutation. This hasimproved the ability of molecular diagnosis of these diseases. On molecular genetic screening of 40 normal chromosomes from people living in and around Calcutta, we have obtained 10 distinct alleles at the DM locus, with an estimated heterozygosity of 0.83. We have also observed 10 alleles at the HD locus on 32 chromosomes, with an estimated heterozygosity of 0.79. We further report here that at the DM locus, in two clinically diagnosed heterozygous individuals, the expanded alleles were of sizes 330 repeats and 1400 repeats respectively; the allele on the homologous chromosome was within the normal repeat range for both these individuals. Of two HD patients, one carried an expanded allele of size of 57 repeats, the other allele being in the normal range; while the second patient had both the alleles in the normal range.

Clinical features of five patients with POEMS syndrome and one with Castleman's disease, who presented with chronic, progressive motor sensory peripheral neuropathy are described. Papilloedema was seen in all patients with POEMS syndrome. Four of them also had bone lesions, biopsy of which established the diagnosis. Lymph node biopsy revealed angiofollicular lymphoid hyperplasia in the patient with Castleman's disease. Response to therapy was not satisfactory. The clinical features are compared with other reported series. A high index of suspicion, meticulous clinical examination and investigations are essential for establishing the diagnosis.

Twenty five cases of post operative cranial vault defects were repaired using tailor made silastic implants in the last three years. Twenty four patients are tolerating the implant without any problems. All of them had symptomatic, relief and achieved an excellent cosmetic skull contour. Ten patients had subgaleal serous collection postoperatively, probably due to reaction to the implanted material, which usually subsided within three weeks. Only in one patient, the implant had to be removed due to infection. In conclusion, silastic is a good implant material for cranioplasty.

Spinal muscular atrophy constitutes one of the major disease entities amongst infantile neuro-muscular disorders. On the basis of morphological evidence, it had been suggested that the infantile spinal muscular atrophy (ISMA) is due to maturation arrest of the myofibres at 20 weeks gestation. Therefore, in the present study morphological features of skeletal muscles from patients with ISMA was compared with foetal muscle obtained at different gestational ages (9-36 weeks, n=18). Of the 35 cases ofISMA, 22 were diagnosed as having SMA-I and 13 cases an SMA-II, characterised histologically by fascicles composed of groups of small, normal, intermediate sized and hypertrophic fibres. The former ones belonged to both histochemical fibre types, while the hypertrophic fibres in 21/35 cases were type I in nature. Redundant basal lamina was a predominant finding at ultrastructural level. Mature myotubes, a feature seen during foetal muscle development was not noticed in any of the cases of ISMA. Our observations suggest denervation atrophy to be the basic pathogenic mechanism rather than arrest in maturation. This was further supported by the changes seen in the spinal cord specimen of a 20 day old infant from a case of SMA I which revealed marked fallout of motor neurons in the anterior horn, chromatolysis and gliosis. Thus ISMA is a dynamic and progressive neurogenic atrophy secondary to degeneration and loss of spinal motor neurons possibly resulting in lack of trophic factors.

Thirty patients of bacterial meningitis (age >12 years) were randomised into two treatment groups. Group I (n=14) received intravenous dexamethasone with antibiotics and group II (n=16)received only antibiotics. Baseline demographic, clinical and laboratory features of the two groups were similar. Four patients died, three in control group and one in dexamethasone group (p=0.60). Focal neurological deficits at discharge were found in three patients receiving dexamethasone and two in control group (p=0.64). Audiological sequelae were found in seven (23) patients, four in group I and three in group II (p = 1.00) but there were no statistically significant differences between the two groups. No steroid side effects were noted. In the present study, dexamethasone treatment was not found to significantly improve survival but sample size was too small to reliably exclude clinically important benefit of dexamethasone. Larger randomised controlled studies in adult population are needed to reliably estimate the effects of dexamethasone as adjunctive therapy in acute bacterial meningitis in adults.

Kinnow juice produces a marked and variable increase in carbamazepine bioavailability. The pharmacokinetics of carbamazepine was studied after drug administration with 300 ml water or kinnow juice in a randomized cross over trial on nine healthy male volunteers. With kinnow juice peak serum concentration (Cmax) and area under the serum concentration time curve (AUC) was significantly (P < 0.05) increased and time to reach peak serum concentration (tmax) was significantly decreased (p < 0.05) as compared with water. No change was observed in the elimination half life (t1/2) of drug. The mechanism by which kinnow juice enhances carbamazepine bioavailability could be due to inhibition of cytochrome P-450 enzyme, since kinnow juice contains naringin which is considered to be inhibitor of liver microsomal dihydropyridine oxidation.

An adult male with thymomatous myasthenia gravis (MG) and a motor neuron syndrome simulating amyotrophic lateral sclerosis is reported. After thymectomy and corticosteroid therapy, the MG remitted. During 4 years of follow-up, the lower motor neuronsigns in the upper limbs and upper motor neuron signs in the lower limbs remained unchanged. Literature concerning paraneoplastic neurological syndromes associated with thymoma has been reviewed.

Neurological manifestations in three cases of hypoparathyroidism, two of the idiopathic variety and one consequent to thyroidectomy are reported. The rare manifestations included the presentation as paroxysmal kinesogenic choreoathetosis in a twelveyear old boy who had history of seizures in childhood. He responded to carbamazepine. The second case, a known epileptic well controlled on sodium valproate, presented with mental dullness, bone pain and showed features of neuromuscular irritability. Thethird patient presented with raised intracranial tension. He had history of thyroidectomy in the past. The diagnosis was confirmed by the classical blood changes of hypoparathyroidism and the presence of basal ganglia calcification in the two idiopathic cases. All the cases finally responded to combination of calcium and D3.

Herpes simplex virus type-I is the commonest cause of focal encephalitis in immunocompetent adults. We report a 35 year old man, who presented with acute ascending myelitis which progressed to encephalitis within one week. The patient's MRI revealed nonhaemorrhagic lesions in frontotemporal areas and midbrain without any evidence of herniation. The CSF was positive for IgM and IgG antibodies against herpes simplex virus 1 (HSV1) and serum was positive for HIV by ELISA and Western blot techniques. The patient died on 18th day of illness due to resistant pseudomonas septicaemia.The presence of disseminated involvement of the central nervous system in HSV infection should raise the suspicion of the HIV coinfection.

A 30 year old man presented with history suggestive of a parasellar tumour. Computerised tomography of brain revealed a hyperdense lesion on either side of sphenoid ridge having extension to floor of middle cranial fossa on the left side, enhancing homogenously with contrast and suggestive of a meningioma. Paranasal sinuses and orbit were free of tumour. He did not have any predisposing factor to harbour oppurtunistic infection. Craniotomy and total excision of the lesion was done. Histopathology was reported as aspergilloma.

A seventeen year old male patient presented with clinical features suggestive of raised intracranial pressure. CT Scan and MRI of brain revealed two mass lesions, one in trigone of each lateral ventricle. They were imageologically alike, appearing as mirror image masses. Both ware totally excised through occipitoparietal transventricular approach on the respective side of the lesion. Postoperative period was uneventful. Repeat CT Scan showed no residue of the lesions. Histopathological examination showed meningioma. To the best of our knowledge this is the first published report on bilateral trigonal meningiomas.

A 30 year old man, who had a fall from the top of a vehicle, was operated for frontal extradural haematoma. In the post-operative period he was noted to have features of central cord syndrome. MRI of the cervical spine revealed a multiseptate cervicothoracic syringomyelia, suggesting a long standing but asymptomatic syrinx. A syrinx-subarachnoid shunt was placed through a C6 and C7 hemilaminectomy. Patient improved in neurological status postoperatively. The possible mechanism of conversion of an asymptomatic syrinx to symptomatic syrinx following cranial and possible spinal trauma shall be discussed.