The interest in oligodendrogliomas has increased since it became evident that a subset of these tumors respond to chemotherapy or radiation. This interest was augmented when the combined loss of the short arm of chromosome 1 and the long arm of chromosome 19 was identified as a powerful prediction factor for response. Lack of stringent morphological criteria allow high-interobserver variation with regard to classification and grading of oligodendroglial tumors. The prospect of beneficial chemotherapy prompted neuropathologists to diagnose more 'oligodendroglioma' than before. Therefore, there is great demand for unambiguous classification of oligodendroglial tumors. Supplementary analysis of the integrity of chromosomal arms 1p and 19q may greatly assist diagnostic characterization of tumors with oligodendroglial phenotype. The underlying mechanisms for these deletions are not known. Tumor suppressor genes on 1p and 19q relevant for oligodendroglioma have not yet been identified. Knowledge of these genes and the mechanisms of their inactivation might help to understand why oligodendroglial tumors do respond better to chemotherapy and radiotherapy than astrocytomas. This review compiles clinical, pathological and molecular genetic findings on oligodendrogliomas and oligoastrocytomas of WHO Grades II and III to present a brief overview on recent developments.

Positron emission tomography (PET) is the study of human physiology by electronic detection of positron-emitting radiopharmaceuticals. It is one of the noninvasive technologies that can measure the metabolic and functional activity of living tissue. Positron emission tomography finds its clinical applications in broadly three specialties - oncology, cardiology, and neurology. The current review focuses on its indications in neurological diseases. Recently published literature on the use of PET in neurology has been thoroughly analyzed. Several reports regarding the usage of PET in epilepsy, stroke, dementia, and movement disorders are available. Positron emission tomography does not appear to be useful as a primary or sole imaging technique in these conditions. On the other hand, it is useful in very specific situations, which have been elaborated in the review. It is also noteworthy that PET is complementary to the computed tomography/magnetic resonance imaging findings and data obtained from combining these modalities can be valuable in situations such as localization of the epileptogenic focus in cases of refractory epilepsy or for prediction of the outcome after thrombolysis in acute ischemic stroke. The major handicaps in widespread use of PET appear to be its lack of availability and its relatively high cost. Nevertheless, a review such as this would be helpful in judiciously selecting those patients who would benefit from undergoing a PET scan, at a time when PET imaging facility is likely to be available soon in the Indian private sector.

Background : Rasmussen encephalitis (RE) is a chronic epileptic disorder of unknown etiology, and is clinically characterized by progressive neurological deterioration, focal seizures often progressing to intractable epilepsy, cognitive decline and hemispheric atrophy. Aims : We report the spectrum of neuropathological changes seen in RE, and discuss the evolutionary mechanisms of this disease. Materials and Methods: Surgically obtained specimens from RE patients diagnosed during 2002-2004 at this institute were evaluated for the presence and extent of different histopathological features of RE. The H&E and immunohistochemistry stained slides were also evaluated for the type and distribution pattern of inflammatory infiltrates, along with a semiquantitative evaluation for the severity of inflammation. Results : Four cases of RE were admitted during the study period, all of which presented with partial seizures with successive deterioration to intractable epilepsy. The age at onset varied between 5 and 10 years (mean 7.8 years), with three male and one female patients. Subsequently, all four patients underwent hemispherotomy. Histopathological features of perivascular lymphocytic infiltrate, neuronal loss, microglial nodules, and reactive astrocytosis, with or without evidence of neuronophagia confirmed a diagnosis of RE. These cases also had varying degrees of T-cell-rich (CD3-positive) inflammatory infiltrates and CD68-immunopositive microglial proliferation. It was observed that the severity of inflammation had a trend to inversely correlate with the duration of symptoms. Conclusion : It is proposed that an accurate evaluation and histopathological grading of these lesions may possibly have a role in patient prognostication.

Primary progressive aphasia (PPA), a degenerative disorder, is often misdiagnosed as Alzheimer's disease. Its subtypes, semantic dementia (SD), and progressive nonfluent aphasia (PNFA), are often difficult to differentiate from each other. Our objective was to highlight the differences in the language profiles of patients with SD and PNFA. To bring out these differences, we report two patients with PPA, one with SD and the other with PNFA. They were administered the Western aphasia battery (WAB) and a semantic battery, which assesses semantic memory. The profiles of language impairment on the WAB indicated that the patient with PNFA had syntactic errors in expressive speech but relatively preserved semantics and comprehension, whereas the patient with SD had preserved syntax but made semantic errors in expressive speech, and had impaired comprehension. There were differences in their performance on the semantic battery too. The patient with SD made relatively less errors on confrontation naming, although on the pointing task he failed to point to those line drawings, which he was unable to name on confrontation. In contrast, the finding of the PNFA patient was the reverse of this. Supplementing conventional neuropsychological tests with formal tests for assessment of language functions is useful in the early diagnosis of PPA. The performance of PPA patients on a detailed assessment of language that includes use of formal tests such as the semantic battery helps to differentiate PNFA from SD.

Background : Debilitating backache due to different types of vertebral lesions is a common cause of morbidity in all age groups. Percutaneous vertebroplasty (PV) gives substantial pain relief and stabilizes the weak vertebrae. Most of the information regarding PV comes from the Western literature. The effect of PV in our population should be studied. Aims : The primary objective is to assess the therapeutic benefit of PV in alleviating back pain and improving the functional status in patients with painful pathologic vertebrae. The secondary objectives are to study the technical aspects of the procedure and their relation to outcome and complications. Settings and Design : This is a retrospective hospital-based (tertiary teaching hospital) study. Materials and Methods : From January 2001 to December 2004, 46 patients underwent PV procedures. Sixty-five vertebroplasties were done in 13 males and 33 female patients. Twenty-four (36.92%) procedures were done for osteoporotic compression collapse, 26 (40.0%) for hemangioma, and 15 (23.07%) for different vertebral body tumors and metastasis. The Wilcoxon signed rank test was used to evaluate the statistical significance of differences between the preoperative and postoperative levels of pain, mobility and analgesic usage. Results: Most of the patients had pain relief within 48 h. Only minor side effects were encountered. No patient had any deficit related to the procedure. On follow up of 3-48 months, all patients had statistically significant improvement in clinical condition (P < 0.001). Conclusion : Percutaneous vertebroplasty is a safe and effective procedure in relieving debilitating backache and can be used to treat vertebral lesions in selected cases.

Aim : To study the clinical features, precipitating stressful life events and prognosis of nonepileptic attack disorder (NEAD) among married women. Design: Prospective cohort study with 1-year follow-up. Setting: A tertiary care teaching hospital. Subjects: Of the 1020 patients with epilepsy referred to the epilepsy clinic during 2002-2003, 30 were married women with NEAD. Materials and Methods: The diagnostic criteria for NEAD included normal EEG during ictal and post-ictal phase of the generalized 'attack.' The data collected included clinical characteristics, semiology of the attacks, precipitating stressful events, and co-morbid psychiatric disorders. The control group included 30 age-matched married women with generalized tonic-clonic seizures. The long-term outcome and factors influencing the outcomes were analyzed. Results: The mean duration of illness was 18 months, and the pattern of the attack was 'fall and lying still' in 53% and 'fall with generalized motor movements' in 47%. The frequency was one or more per week in 57% and occasionally in 43%. The important stressful events were matrimonial discord following illegal relationship of the husband with another woman (c2 = 9.02, P = 0.003) and constant quarrel with other family members (c2 = 5.19, P = 0.02). The prevalence of sexual abuse was low (7%). Co-morbid psychiatric disorder was observed in 70%. At the end of 1 year, 39% were free from the attack. Resolution of the stressful life events (c2 = 4.52, P = 0.03) and lower frequency of attack at the time of reporting (c2 = 3.88, P = 0.05) correlated with good outcomes. Conclusion : Among patients with NEAD in India, the major precipitating factors were matrimonial discord following illegal relationship of the husband with another woman and constant quarrel with other family members and not sexual abuse. Women with low frequency of attack at the time of reporting and the remission of the stressful events had better outcomes.

Background: Tissue thromboplastin (TTP) is an integral membrane protein contributing to coagulopathy after trauma of brain, which is a rich source of TTP. Aims: A study was undertaken to establish the TTP content of various areas of normal brain and estimate the changes in TTP activity of brain in response to varying degrees of trauma. Materials and Methods: Samples from different areas of brain of ten cadavers were used as controls and they were compared with contused brain tissue obtained after surgery in 25 head injury (HI) patients of varying severity. Results: In the study group, the TTP activity of the frontal, parietal, and temporal lobes after HI was significantly raised in contrast to that of the control group. The TTP activity was also significantly higher in the severe HI patients than those having moderate HI. The mode of injury and the time lapse after HI had no significant bearing on the TTP activity. Subjects above 40 years of age demonstrated a higher mean TTP activity after HI, though it was not statistically significant. Conclusion: The study provides quantitative data on TTP activity of normal brain and highlights the role of TTP in coagulopathy following HI through its increased activity after HI, more so in the severe HI group.

Background and Aims: The aim of the study is to search the lesion localization of the pure isolated facial paresis-dysarthria syndrome in patients who were admitted to our neurology clinic in a prospective study. Methods: Over a period of six years, the patients who had no prominent sensorimotor dysfunction were examined by neurologists and underwent computerized tomography (CT) and/or magnetic resonance imaging (MRI). Results: Eleven patients out of more than 2000 had the aforementioned clinical picture. Lacunar infarctions were identified at the corona radiata in nine patients, and at the internal capsule in two patients. As reported previously, facial paresis was usually mild and temporary. Six of our eleven patients were seen at the outpatient clinic one month later. Four of them had completely recovered and the other two had mild dsyarthria without any facial paresis. The other five could not be reached after leaving the hospital. Conclusions: Dysarthria-facial paresis is a rare clinical entity and possibly a variation of dysarthria-clumsy hand syndrome, and we suggest that pure facial paresis (FP) and pure dysarthria should be considered as very extreme examples of this syndrome.

Background: The microsurgical anatomy of the middle cerebral artery (MCA) is of particular interest to the cerebrovascular surgeon. The purpose of this study was to define the microsurgical anatomy of the MCA and its various branches in the Indian population. Methods: Ten MCAs were studied from five cadaveric brain specimens. The authors studied the outer diameter, length, branches, perforators and site of these on the main trunk (M1), the division of the main trunk, the secondary trunks and their various cortical branches using the operating microscope under 5-20x magnification. Results: The outer diameter of the MCA main trunk ranges from 2.5 to 4 mm with a mean of 3.35 mm. The superolateral branches consisted of polar temporal artery and anterior temporal artery that had a common origin and sometimes the uncal artery or the accessory uncal artery. Perforators or lenticulostriate arteries were seen in the inferomedial surface all along the length of M1. Eight bifurcations and two trifurcations were noted. Cortical branches and their origin are discussed. Conclusion: Although the microsurgical anatomy of the MCA in Indian population correlated with the findings in the western literature, some structural and statistical variations were noted.

Background: In India, tuberculous meningitis (TBM) is still a major cause of neurological disabilities and death. Aim: To identify the clinical variables which predict the outcome in childhood TBM. Setting: Tertiary teaching hospital. Design: Prospective observational study. Materials and Methods: Thirty-six clinical variables were analyzed in 123 consecutive children with TBM admitted between May 2000 and August 2003. The outcome was assessed in terms of survival or death. Survival meant that the patient was discharged from hospital having made a complete recovery, or with disability. Results: Twenty-five (20%) children recovered completely, 70 (57%) survived with disability, and 28 (23%) died. Employing univariate analysis nine variables correlated with survival with disability outcome: presence of tonic motor posturing, cranial nerve palsy, focal neurological deficit, hypertonia, moderate to severe hydrocephalus, cerebral infarction on cranial CT, and requiring shunt surgery, and absence of extracranial tuberculosis and no antituberculous-related hepatotoxicity; two variables correlated with fatal outcome: presence of deep coma (Glasgow coma scale score < 6), and absence of extrapyramidal movements. When logistic regression was applied only the presence of hypertonia ( P = 0.012, d.f. = 1, OR 0.12, 95% CI 0.02-0.62) correlated with survival with disability outcome, and presence of deep coma (P = 0.030, d.f. = 1, OR 0.35, 95% CI 0.14-0.90) with fatal outcome. Conclusion: In children with TBM, the presence of hypertonia at admission is an independent predictor of neurological sequelae in survivors, and deep coma is an independent predictor of mortality.

Background: In patients with multiple sclerosis (MS), transcranial magnetic stimulation (TMS) has shown significant prolongation of central motor conduction time (CMCT). Abnormal CMCT may reflect sub-clinical involvement of motor pathways and correlate with clinical motor disability. Objective: To determine the diagnostic yield of TMS in MS and the possible correlation of TMS abnormalities with clinical disability. Materials and Methods: Thirty patients with clinically definite MS presenting in acute relapse or with progressive disease course and 30 healthy controls were evaluated. TMS parameters evaluated included threshold intensity, motor evoked potentials (MEP) amplitudes and latencies and CMCT. Reassessment studies were done after three months. Statistical analysis: Student t-test, Mann-Whitney U test and Spearman's rank correlation test were used to assess the relationships. Results: Patients with MS had significantly higher threshold intensities, prolonged CMCT and reduced MEP amplitudes as compared to controls. Abnormalities in at least one parameter were observed in 86.7% of patients. When inter-side asymmetries in MEP latency and/or in CMCT were considered, the diagnostic yield increased to 96.7%. The diagnostic yield was 74.7% for visual evoked potentials, 13.3% for brainstem auditory evoked response and 10% for cerebrospinal fluid oligoclonal band. One MS patient without pyramidal or cerebellar dysfunction had prolonged CMCT. CMCT abnormalities correlated significantly with the degree of pyramidal signs, limb ataxia, intention tremor, dysdiadokokinesia and overall cerebellar score. In patients who had clinical improvement, follow-up studies showed improvement in CMCT parameters. Conclusion: TMS is a highly sensitive technique to evaluate cortico-spinal conduction abnormalities in MS that may have no clinical correlate and in monitoring the course of the disease. The effects of cerebellar dysfunction on TMS results need further evaluation.

Background: Studies have shown the detrimental effect of increased temperature on brain injury. Fever is common after intracerebral hemorrhage (ICH). The term 'central fever' ? is often used when no cause is identified. Aim: The aim of the study was to determine the correlation of fever with third ventricular shift in 61 patients with ICH and hypothesize about the mechanism of fever. Setting: Neurointensive Care Unit Design: Prospective observational study. Materials and Methods: From August 1999 to April 2000, data from 61 patients with ICH were prospectively collected including maximum temperature (Tmax) and fever (T >37.5° C) at 24, 48, 72 and 96 hours, ICH volume, and third ventricular shift. Outcome measures included discharge mortality, 3-month National Institute of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS), and Barthel Index (BI). Statistical Analysis: Spearman correlation coefficient, Mann-Whitney test, and logistic regression were used to assess relationships. Results: Fifty-six per cent of patients had fever in the first 24 hours and 53% for at least two consecutive days. There was a correlation between ICH volume and Tmax at 24 hours ( P =0.04) and 72 hours ( P =0.03) and fever at 24 hours ( P =0.039) and 72 hours ( P =0.036). Tmax at 72 hours correlated with third ventricular shift ( P =0.01). Those with shift were more likely to have fever within the first 72 hours ( P =0.049) and worse outcome. Fever at 72 hours was associated with a higher discharge mortality ( P =0.046) and trend of a worse 3-month NIHSS score ( P =0.06). Conclusion: Fever is common after ICH and correlates with ICH volume and third ventricular shift suggesting a role of hypothalamic compression in "central fever." There was a trend towards a worse outcome with fever.

Aims : The aim of this study was to evaluate the capability of intraoperative ultrasonography (IOUSG) in identifying malignant intraparenchymal tumors during surgical intervention. Settings and Design : Forty patients with intrinsic malignant tumors were evaluated by using IOUSG. Materials and Methods : A real-time ultrasound scanner with a 3- or 5-MHz transducer was used for this study in all cases. The tip of the ultrasound probe was placed on the intact cranial dura mater and then moved in the sagittal and coronal planes. Results : Nineteen of forty patients had lesions that were primary malignant glial tumors. Five of them had previous surgery and radiotherapy. The remaining twenty-one had metastatic tumors. All lesions were well localized and malignant characteristics were well defined by IOUSG. Radiation-induced changes in five lesions in the surrounding brain and tumor parenchyma were described. Conclusion : In conclusion, IOUSG is not only helpful in localizing lesions but it can also be used in determining the malignant characteristics of lesions.

The authors report a case of an intracranial aneurysm associated with von Recklinghausen's neurofibromatosis. A 34-year-old woman presented with a history of headaches, unconsciousness and neck rigidity. Widespread cutaneous neurofibromas were found. Investigations revealed an aneurysm of the anterior communicating artery. The authors discuss this case and review the relevant literature.

Atrial myxomas are the most common primary tumors of the heart. Neurologic involvement usually occurs as a stroke with ischemic episodes. Following excision of cardiac myxomas, delayed neurologic events owing to aneurysms are rare and have not been reported from India. We report an operated case of left atrial myxoma. The patient initially presented with a stroke and 6 months after the surgery, developed multiple intracerebral hemorrhages due to the rupture of fusiform cerebral aneurysms, without recurrence of the cardiac tumor.

Central pontine myelinolysis is a demyelinating affection of central pons diagnosed on the basis of characteristic MRI finding in an appropriate clinical setting. The condition has been described as universally fatal; however, recent reports of recovery have been documented. We report a case of central pontine and extra pontine myelinolysis, which presented with parkinsonian features apart from bulbar symptoms and made a remarkable recovery. A short review of the literature follows.

The case of a previously healthy 24-year-old man diagnosed with extradural thoracic granulocytic sarcoma with no evidence of bone marrow or other hematological involvement is described. The tumor was removed totally by microsurgery. The histopathological examination was consistent with granulocytic sarcoma. Granulocytic sarcomas are most commonly found in the context of an acute myelogenous leukemia or in chronic myelogenous leukemia. They rarely have been reported in otherwise healthy patients without any evidence of systemic disease. A review of the literature revealed only 14 more nonleukaemic cases with granulocytic sarcoma causing thoracic spinal cord compression.

We report a case of cervical intramedullary cystic schwannoma associated with segmental syrinx in a young adult without evidence of neurofibromatosis. The relevant literature is reviewed.

Hyperammonemic encephalopathy with normal liver function is an uncommon serious adverse effect of valproate therapy. We retrospectively analyzed the case records of 5 patients of epilepsy on valproate with hyperammonemic encephalopathy. Of the 5 patients, 3 were on monotherapy. The mean valproate dose was 1250 mg/day and the duration of therapy ranged between 4 and 90 days. Alteration in the sensorium was the presenting clinical feature. The risk factors included high initial dose (2), long-term valproate therapy (1), and long-term valproate therapy with concomitant topiramate (1). There was good correlation between the fall in serum ammonia levels and clinical improvement. Hyperammonemic encephalopathy should be suspected in patients on valproate with altered sensorium. Response to treatment is rewarding.

The Protein Surplus Myopathies (PSM) are characterized by accumulation of protein aggregates, identifiable ultrastructurally, resulting due to mutations of the encoding genes. Desmin-related myopathies (DRM) are a form of PSM characterized by mutations of the desmin gene resulting in the formation of protein aggregates comprising mutant protein desmin and disturbance of the regular desmin intermediate network in the muscle fibers. We describe a rare case of DRM in a 23-year-old man who presented with complaints of difficulty in climbing stairs and running since the age of 5 years. EMG studies revealed a myopathic pattern. Muscle biopsy showed the features of muscular dystrophy with bluish rimmed vacuoles and sarcoplasmic inclusions, which were immunoreactive to desmin. Ultrastructural examination showed sarcoplasmic bodies and granulofilamentous inclusions. Although rare, the possibility of DRM/desminopathy should be considered in the presence of bluish rimmed vacuoles on light microscopy and characteristic ultrastructural inclusions. To the best of our knowledge this is the first case of DRM/desminopathy reported from India.

Neuro-cysticercosis (NCC) and Japanese encephalitis (JE) are common in tropical countries. Two cases of NCC with coexistent JE are presented, which share same socio-demographic and ecologic factors and have the same intermediate host (pig). Patients were on treatment for NCC and presented in comatose state. Sudden clinical deterioration of a patient with NCC should warrant a search for coexistent JE. We report findings of magnetic resonance spectroscopy and diffusion-weighted imaging of the JE.

Early myoclonic encephalopathy (EME) is a rare malignant epileptic syndrome. The erratic myoclonus with or without focal motor seizures, time of onset before 3 months of age, and suppression-burst (SB) pattern in EEG are accepted as the diagnostic criteria for EME. We report a 40-day-old infant with the diagnosis of non-ketotic hyperglycinemia (NKHG). The infant developed myoclonic and focal tonic seizures on the first day of life. His first sleep EEG recorded after onset of seizure was normal. Because of the diagnosis of NKHG and early developed myoclonic seizure, we thought the infant might be EME, and repeated sleep EEG on admission in which asymmetrical SB pattern was seen. We concluded that the absence of SB pattern in the first EEG recording does not exclude the diagnosis of EME, but repetition of EEG is necessary to demonstrate the presence of SB pattern to meet the diagnostic criteria for EME.

We present our experience of treating two cases of rheumatoid arthritis involving the craniovertebral junction and having marked basilar invagination by an alternative treatment method. In both the cases, the facets were osteoporotic and were not suitable for screw implantation. The patients were 66 and 72 years of age and both patients were females. Both the patients presented with complaints of progressively increasing spastic quadriparesis. Surgery involved attempts to reduce the basilar invagination and restore the height of the 'collapsed' lateral mass by manual distraction of the facets of the atlas and axis and forced impaction of titanium spacers in the joint in addition to bone graft harvested from the iliac crest. The procedure also provided stabilization of the region. No other fixation procedure involving wires, screws, plate and rods was carried out simultaneously. Following surgery both the patients showed symptomatic improvement and partial restoration of craniovertebral alignments. Follow-up is of 2 and 24 months. Distraction of the facets of atlas and axis and impaction of metal implant and bone graft in the facet joint can assist in reduction of basilar invagination and fixation of the region in selected cases of rheumatoid arthritis involving the craniovertebral junction.