Browsing by Author "Radhakrishnan, VV"

Now showing 1 - 20 of 66
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    A comparative evaluation of Dot immunobinding assay (Dot-Iba) and polymerase chain reaction (PCR) for the laboratory diagnosis of tuberculous meningitis
    (DIAGNOSTIC MICROBIOLOGY AND INFECTIOUS DISEASE, 2002)
    The results of a Dot immunobinding assay (Dot Iba) for the detection of mycobacterial antigen in the cerebrospinal fluid (CSF) of 45 patients with tuberculous meningitis (TBM) were compared with the results of a polymerase chain reaction (PCR) for the detection of Mycobacterium tuberculosis. In eight patients with culture proven TBM, Dot-lba gave positive results, while PCR yielded positive results only in six patients. The overall sensitivities of Dot-lba and PCR in 37 patients with culture negative (probable) TBM were 75.67% and 40.5% respectively. Dot-lba, in contrast to PCR is a rapid and relatively easier method. More importantly, Dot-lba is suitable for the routine application for the laboratory diagnosis of TBM and therefore best suited to laboratories in the developing world. (C) 2002 Elsevier Science Inc. All rights reserved.
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    A newer approach for the laboratory diagnosis of tuberculous meningitis
    (DIAGNOSTIC MICROBIOLOGY AND INFECTIOUS DISEASE, 2001) Mathai, A; Radhakrishnan, VV; George, SM; Sarada, C
    In this prospective study, a simple method was standardized for measuring circulating mycobacterial antigen in the cerebrospinal fluid (CSF) for the laboratory diagnosis of tuberculous meningitis (TBM). The heat-inactivated CSF specimens from tuberculous and nontuberculous patients were subjected to sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) (SDS-PAGE) and they were subsequently transferred onto nitrocellulose membrane (NCM) Using a rabbit polyvalent antibody to M tuberculosis, a heat stable 82 kDa mycobacterial antigen was demonstrated in the CSFs of patients with TBM. This antigen was conspicuous by it!; absence in the CSFs of non-tuberculous subjects. Due to inactivation of CSF; specimens, there is a minimal risk of handling of infectious material in the laboratory. Besides, this newer approach is simple, inexpensive and can be readily applied in any routine clinical laboratory and it is particularly suited to developing countries. (C) 2001 Elsevier Science Inc. All rights reserved.
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    Acoustic neurinomas during pregnancy: Report of two cases and review of literature
    (ACTA NEUROCHIRURGICA, 2001)
    Though infrequent, acoustic neurinomas have been described during pregnancy and represent a therapeutic challenge for excision without producing any problem for the mother and the foetus. First Author experienced two cases of acoustic neurinomas presenting during pregnancy. One patient presented in the terminal stages of the third trimester of pregnancy and underwent caesarean section, followed by retromastoid craniectomy and excision of the rumour. Operative management of the pregnancy and tumour in the same sitting has not been reported in the literature. Second patient who presented during 2nd trimester of pregnancy, was operated on for the tumour and had a successful continuance of pregnancy. Details of the management are discussed and the relevant literature reviewed. In addition to causing aggravation of symptoms, the larger size and increased vascularity of these rumours during pregnancy, makes them more vulnerable to acute bleeding, which in turn may initiate new or exacerbate pre-existing symptoms, as noted in one of the cases presented in this report.
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    Advanced magnetic resonance imaging with histopathological correlation in papillary tumor of pineal region: Report of a case and review of literature
    (NEUROLOGY INDIA, 2010) Vaghela, V; Radhakrishnan, N; Radhakrishnan, VV; Menon, G; Kesavadas, C; Thomas, B
    Papillary tumors of the pineal region are recently described as rare mass lesions with limited literature available on their natural history and imaging features. Magnetic resonance imaging (MRI) including perfusion, diffusion, and spectroscopic features were described in an 18-year-old girl with papillary tumor of pineal region. A well-defined, T1 hyperintense and contrast-enhancing mass lesion was noted in pineal region with few cystic spaces within. Solid portion of lesion showed minimal diffusion restriction with average apparent diffusion coefficient of 0.812 x 10(-3) mm(2)/s: on MR spectroscopy elevated myo-inositol peak with reduced N-acetylaspartate and elevated choline in the tumor. On perfusion study there was significantly high relative cerebral blood volume (rCBV) (6-9 times) and relative cerebral blood flow (rCBF). Our findings agree with previous descriptions of cystic areas with T1 hyperintense appearance of this tumor but very high level of tumor perfusion, diffusion restriction, and presence of myo-inositol peak are important imaging findings and may correlate with the recent reports of high tumor recurrence in these cases.
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    Advanced MRI in Rosai-Dorfman disease: Correlation with histopathology
    (JOURNAL OF NEURORADIOLOGY, 2011) Hingwala, D; Neelima, R; Kesavadas, C; Thomas, B; Kapilamoorthy, TR; Radhakrishnan, VV
    Rosai-Dorfman disease is an idiopathic benign lymphoproliferative disorder that can, on rare occasions, cause intracranial or intraspinal lesions with non-specific features on conventional imaging. For this reason, its diagnosis is based on the classical pathological findings of histiocyte proliferation and emperipolesis. In this case report, we describe the imaging features of Rosai-Dorfman disease as visualized by newer types of MRI sequences, such as diffusion tensor imaging (DTI), susceptibility-weighted imaging (SWI) and perfusion-weighted imaging (PWI). In fact, combining the findings of conventional cross-sectional imaging with high fractional anisotropy (FA), a low apparent diffusion coefficient (ADC), mild blooming on SWI and decreased perfusion can help to make the diagnosis of Rosai-Dorfman disease. These newer tools can also be used to clarify the pathology of Rosai-Dorfman disease. (C) 2010 Elsevier Masson SAS. All rights reserved.
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    An enzyme-linked immunosorbent assay for antibodies against acid soluble skeletal muscle antigen in myasthenia gravis
    (ACTA NEUROLOGICA SCANDINAVICA, 1999)
    An enzyme-linked immunosorbent assay (ELISA) system has been developed for measuring serum antibodies against citric-acid extract of human skeletal muscles. With this assay, 80% of myasthenia patients with thymoma gave positive results. No sera from patients with neurological diseases other than myasthenia gravis (MG) gave positive results. The result of this study indicates that the ELISA system is useful as an adjunct for the diagnosis of MG particularly in the patients associated with thymoma and that the ELISA method can also be used as a prognostic marker following thymectomy in patients with MG.
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    Anaplastic ganglioglioma: case report and review of the literature
    (BRITISH JOURNAL OF NEUROSURGERY, 1998)
    A 10-year-old girl underwent radical decompression of a right temporal tumour extending to the insular cortex which proved to be a differentiated ganglioglioma. One year later, she presented with a bleeding right frontal tumour extending to the insula, the histology of which showed it to be the anaplastic variant of ganglioglioma. She underwent postoperative radiotherapy but died 6 months after the second operation. Anaplastic ganglioglioma is a rare variant of ganglioglioma and progression of the latter to anaplastic ganglioglioma is an extremely rare occurrence. The literature regarding ganglioglioma is reviewed.
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    Atypical meningioma: A clinicopathological analysis
    (NEUROLOGY INDIA, 2000) Joseph, E; Sandhyamani, S; Rao, MB; Nair, S; Radhakrishnan, VV
    In this retrospective study, 382 operated cases of meningiomas were reviewed, 32 cases (8.3%) were histopathologically classified as atypical meningioma, The anatomical locations and histological features in all the thirty-two cases were correlated with their recurrence rates and biological behaviour. The overall recurrence rate for atypical meningioma within two years was 28% as compared to 9.3% in benign meningiomas. It is being emphasized that an accurate histopathological interpretation of atypical meningioma is essential for predicting the recurrence, biological behavior as well as postoperative management modalities.
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    Atypical MRI appearance of desmoplastic infantile ganglioglioma
    (PEDIATRIC RADIOLOGY, 2005)
    We report the atypical MRI features and histopathological findings of a desmoplastic infantile ganglioglioma in an 8-year-old girl. The mass was predominantly solid with a large, solid, non-enhancing exophytic component. The adjacent brain showed cortical necrosis and white-matter gliosis, suggesting earlier hypoxia.
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    Cerebellar hemisphere, an uncommon location for pleomorphic xanthoastrocytoma and lipidized glioblastoma multiformis
    (NEUROLOGY INDIA, 2003)
    Lipidized glioblastoma multiformis (LGB) and pleomorphic xanthoastrocytoma (PXA) are often supratentorial in location and occur in the second to fourth decade. This report presents two young patients, one having LGB and the other having PXA in the cerebellum. Histological differentiation between LGB and PXA is discussed.
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    Chordoid meningioma: A report of two cases
    (NEUROLOGY INDIA, 2003)
    Chordoid meningioma is an uncommon histopathological variant of meningioma. We report 2 cases of chordoid meningioma occurring in adult patients.
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    Circulating tumour necrosis factor alpha & soluble TNF receptors in patients with Guillain-Barre syndrome
    (INDIAN JOURNAL OF MEDICAL RESEARCH, 2003)
    Background & objectives: Tumour necrosis factor-alpha (TNF-alpha) is regarded as one of the immune factors that can induce demyelination of peripheral nerves in patients with Guillian-Barre syndrome (GBS). This present study was undertaken to find out the role of TNF-alpha and soluble TNF receptors in the pathogenesis of GBS; and to study the effect of intravenous immunoglobulin (ivlg) therapy on the serum TNF-a and soluble TNF receptors in patients with GBS.Methods: Thirty six patients with GBS in progressive stages of motor weakness were included in this study. The serum TNF-alpha and soluble TNF receptors (TNF-RI, TNF-RII) were measured in the serum samples of these patients before and after ivIg therapy by a sandwich ELISA.Results: Of the 36 patients with GBS, 26 (72.2%) showed elevated serum TNF-alpha levels prior to ivIg therapy. Following a complete course of ivIg therapy there was a progressive decrease in the serum TNF-alpha concentrations in these 26 patients. On the other hand, the soluble TNF receptors, particularly TNF-RII showed an increase in the serum of GBS patients following ivIg therapy.Interpretation & conclusion: The results indicate that ivIg reduces the serum TNF-alpha. concentrations in the GBS patients having elevated levels prior to ivlg therapy. Elevated serum levels of soluble TNF receptors following ivIg therapy may play a protective role by inhibiting the demyelinating effect of TNF-alpha in the peripheral nerves of patients with GBS.
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    Clinical, electrophysiologic, and histopathologic profile, and outcome in idiopathic inflammatory myositis: An analysis of 68 cases
    (ANNALS OF INDIAN ACADEMY OF NEUROLOGY, 2010) Ramesha, KN; Kuruvilla, A; Sarma, PS; Radhakrishnan, VV
    Objectives: To study the electroclinical and histopathologic profile of idiopathic inflammatory myositis (IIM) with reference to prognosis and survival rate. Materials and Methods: Diagnosis of IIM was based on the Bohan and Peter criteria. Patients who improved and those whose condition worsened or who expired due to IIM per se at last follow-up were classified to have favorable and poor outcomes, respectively. Fishers exact test was used for univariate analysis of prognostic factors. Results: The study cohort consisted of consecutive 68 patients with IIM. The mean age at diagnosis was 36.5 years and females constituted 71%. Of these patients, 62% had definite IIM, 49% had polymyositis, 20% had dermatomyositis, and 29% had overlap syndrome. The mean follow-up period was 5.4 years. Prednisolone alone was used in 55 (80%), and azathioprine (1-3 mg/kg/day) alone in 12 (17.6%) as the initial treatment. Relapse of IIM with drug withdrawal was seen in 15 patients (22%); 70% had favorable outcome and 16% had expired. The treatment delay of %6 months (P = 0.001), absence of cardiac or lung involvement (P < 0.001), and positive biopsy (P = 0.033) were predictive of a favorable prognosis in the univariate analysis. In multivariate analysis, only the duration of illness of %6 months (P = 0.008) and the absence of cardiac or lung involvement (P = 0.001) predicted the favorable outcome at last follow-up. Cumulative survival rate was 95% at 1 year, 86% at the 5th year, and 80% at the 10th year. Conclusions: Approximately, two-thirds of the patients showed good electroclinical and histopathologic correlations and an equal number improved with treatment. The treatment delay (>= 6 months), presence of cardiac or pulmonary involvements, and negative muscle biopsy are bad prognostic factors.
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    Clinical, electrophysiologic, and histopathologic profile, and outcome in idiopathic inflammatory myositis: An analysis of 68 cases.
    (Annals of Indian Academy of Neurology, 2010)
    OBJECTIVES: To study the electroclinical and histopathologic profile of idiopathic inflammatory myositis (IIM) with reference to prognosis and survival rate.MATERIALS AND METHODS: Diagnosis of IIM was based on the Bohan and Peter criteria. Patients who improved and those whose condition worsened or who expired due to IIM per se at last follow-up were classified to have favorable and poor outcomes, respectively. Fisher's exact test was used for univariate analysis of prognostic factors.RESULTS: The study cohort consisted of consecutive 68 patients with IIM. The mean age at diagnosis was 36.5 years and females constituted 71%. Of these patients, 62% had definite IIM, 49% had polymyositis, 20% had dermatomyositis, and 29% had overlap syndrome. The mean follow-up period was 5.4 years. Prednisolone alone was used in 55 (80%), and azathioprine (1-3 mg/kg/day) alone in 12 (17.6%) as the initial treatment. Relapse of IIM with drug withdrawal was seen in 15 patients (22%); 70% had favorable outcome and 16% had expired. The treatment delay of ?6 months (P = 0.001), absence of cardiac or lung involvement (P < 0.001), and positive biopsy (P = 0.033) were predictive of a favorable prognosis in the univariate analysis. In multivariate analysis, only the duration of illness of ?6 months (P = 0.008) and the absence of cardiac or lung involvement (P = 0.001) predicted the favorable outcome at last follow-up. Cumulative survival rate was 95% at 1 year, 86% at the 5th year, and 80% at the 10th year.CONCLUSIONS: Approximately, two-thirds of the patients showed good electroclinical and histopathologic correlations and an equal number improved with treatment. The treatment delay (?6 months), presence of cardiac or pulmonary involvements, and negative muscle biopsy are bad prognostic factors.
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    Corpora amylacea (CoA) in refractory mesial temporal lobe epilepsy: Clinico-pathological correlations
    (EPILEPSIA, 2005) Ashalatha, R; Cherian, PJ; Radhakrishnan, VV; Radhakrishnan, K; Sarma, PS
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    Corpora amylacea in refractory mesial temporal lobe epilepsy: Clinicopathological correlations
    (EPILEPSIA, 2006) Radhakrishnan, A; Joseph, C; Radhakrishnan, VV; Radhakrishnan, K; Sharma, PS
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    Craniospinal and spinal enterogenous cysts - Report of three cases
    (CLINICAL NEUROLOGY AND NEUROSURGERY, 1996)
    We report three cases of enterogenous cyst, one craniospinal and two spinal manifesting with features of spinal cord compression. In one the cyst was intramedullary in location and in the other two it was intradural, extramedullary. The unusual clinical presentation, location and magnetic resonance imaging (MRI) characteristics are discussed. None of the three patients had any vertebral anomaly or other congenital malformation. All patients had excellent outcome following surgery.
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    Detection of heat stable mycobacterial antigen in cerebrospinal fluid by dot-immunobinding assay
    (NEUROLOGY INDIA, 2003)
    Background: Isolation of Mycobacterium tuberculosis in cerebrospinal fluid (CSF) specimen in patients with tuberculous meningitis (TBM) is infrequent and carries low sensitivity. Thus development of an alternative laboratory diagnostic test is essential for the early diagnosis and treatment of TBM. Objective: A simple, rapid Dot immunobinding assay (Dot-Iba), for the laboratory diagnosis of TBM is devised. This method minimizes the risk of handling infectious material in the laboratory. Method: The Dot-Iba was standardized with heat-inactivated M tuberculosis antigen (PPD). The heat-inactivated CSF from TBM and non-TBM patients was similarly assayed and it can detect antigen upto 1ng/ml in CSF Result: A positive result was obtained in all the five culture positive patients with TBM and in 20/25 probable TBM. A negative result was obtained in 38/40 CSF from disease control group. The overall sensitivity and specificity of Dot-Iba was 83.3% and 95% respectively. Conclusion: Dot-Iba can be used as an adjunct for the laboratory diagnosis of TBM, particularly in culture negative TBM patients and also in those clinical situations where no laboratory tests are available to distinguish between TBM and partially treated pyogenic meningitis.
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    Diagnostic utility of polymerase chain reaction and immunohistochemical techniques for the laboratory diagnosis of intracranial tuberculoma
    (CLINICAL NEUROPATHOLOGY, 2001)
    In an attempt to establish a tuberculous etiology, polymerase chain reaction (PCR) and immunohistochemical (IHC) methods were undertaken in formalin-fixed paraffin sections of ten surgical specimens of intracranial tuberculoma. The control group included an equal number of intracranial fungal granuloma. Both PCR and IHC methods did not yield false-positive results in fungal granuloma. PCR was found to be less sensitive (60%) than IHC method (80%) in this study. IHC method definitely possesses several operational advantages over PCR and is more suited to laboratories in developing countries for establishing a tuberculous etiology particularly in those patients in whom the conventional bacteriological methods did not confirm the diagnosis of tuberculoma.
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    Electro-clinical characteristics and postoperative outcome of medically refractory tumoral temporal lobe epilepsy
    (NEUROLOGY INDIA, 2005)
    Background: Very few studies have specifically addressed surgical treatment and outcome of patients with tumor-related temporal lobe epilepsy (TLE). Aim: To define the postoperative seizure outcome and the factors that influenced the outcome of patients with tumor-related TLE. Materials and Methods: We selected patients whose surgical pathology revealed a temporal lobe neoplasm and who had completed >= 1 year of postoperative follow-up. We reviewed the clinical, EEG, radiological and pathological data, and the seizure outcome of these patients and assessed the factors that influenced the outcome. Results: Out of the 409 patients who underwent surgery for refractory TLE during the 8-year study period, there were 34 (8.3%) patients with temporal lobe neoplasms. The median age at surgery was 20 years and the median duration of epilepsy prior to surgery was 9.0 years. MRI revealed tumor in the mesial location in 21 (61.8%) patients. Interictal and ictal epileptiform EEG abnormalities were localized to the side of th lesion in the majority. Mesial temporal lobe structures were included in the resection, if they were involved by the tumor; otherwise, lesionectomy alone was performed. During a median follow-up of 4 years, 27 (79%) patients were completely seizure-free. The only factor that predicted long-term seizure-free outcome was being seizure-free during the first two postoperative years. Conclusions: Our results emphasize the fact that in patients with tumoral TLE, when the seizures are medically refractory, surgery offers potential for cure of epilepsy in the majority.