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Biomedical subjects

A R Varma

Publications and source records attributed to A R Varma.

9 recordsLinked to original sources

Evaluation of the NINCDS-ADRDA criteria in the differentiation of Alzheimer's disease and frontotemporal dementia.

OBJECTIVES: The diagnosis of Alzheimer's disease (AD) is now reliant on the use of NINCDS-ADRDA criteria. Other diseases causing dementia are being increasingly recognised--for example, frontotemporal dementia (FTD). Historically, these disorders have not been clearly demarcated from AD. This study assesses the capability of the NINCDS-ADRDA criteria to accurately distinguish AD from FTD in a series of pathologically proved cases. METHODS: The case records of 56 patients (30 with AD, 26 with FTD) who had undergone neuropsychological evaluation, brain imaging, and ultimately postmortem, were assessed in terms of whether at initial diagnosis the NINCDS-ADRDA criteria were successful in diagnosing those patients who had AD and excluding those who did not. RESULTS: (1) The overall sensitivity of the NINCDS-ADRDA criteria in diagnosing "probable" AD from 56 patients with cortical dementia (AD and FTD) was 0.93. However, the specificity was only 0.23; most patients with FTD also fulfilled NINCDS-ADRDA criteria for AD. (2) Cognitive deficits in the realms of orientation and praxis significantly increased the odds of a patient having AD compared with FTD, whereas deficits in problem solving significantly decreased the odds. Neuropsychological impairments in the domains of attention, language, perception, and memory as defined in the NINCDS-ADRDA statement did not contribute to the clinical differentiation of AD and FTD. CONCLUSION: NINCDS-ADRDA criteria fail accurately to differentiate AD from FTD. Suggestions to improve the diagnostic specificity of the current criteria are made.

Aged

A 99mTc-HMPAO single-photon emission computed tomography study of Lewy body disease.

The purpose of this study was to investigate patterns of 99mTc-HMPAO single-photon emission computed tomography (SPECT) abnormality in Lewy body disease (LBD) and to compare findings with those encountered in Alzheimer's disease (AD). The study group comprised 20 consecutive patient referrals fulfilling clinical criteria for LBD. All patients had fluctuating cognitive impairment and 'subcortical' dysfunction with or without perceptuospatial and/or linguistic impairment. Six patients had asymmetrical signs of parkinsonism (three left-sided and three right-sided), and 14 patients had symmetrical features of extrapyramidal involvement. 99mTc-HMPAO SPECT imaging was performed on LBD patients and findings compared with those of 57 patients with 'probable' AD and 11 normal age-matched controls. Within the LBD and AD groups, patterns of cortical and subcortical blood-flow abnormality were compared with patterns of cognitive and neurological breakdown. LBD was associated with bilateral posterior cortical blood flow abnormality, a pattern strikingly similar to that found in AD. Within the LBD group, cortical blood-flow abnormality was found to reflect patterns of neurological dysfunction (parkinsonism) indicative of subcortical involvement. In contrast, cortical blood-flow changes did not reflect patterns of neuropsychological impairment suggestive of cortical dysfunction. Within the AD group, cortical blood-flow changes were mirrored by the pattern of neuropsychological impairment. Findings support the notion that cortical blood-flow abnormality in LBD might reflect a combination of direct cortical pathology and cortical deafferentation secondary to subcortical Lewy body pathology. It would appear that 99mTc-HMPAO SPECT imaging is of limited value in the clinical differentiation of LBD and AD.

Aged

A volumetric MRI study of Gilles de la Tourette's syndrome.

The neuroanatomic or neuropathologic basis of Gilles de la Tourette's syndrome (GTS) remains unknown. Recent studies have suggested abnormalities of cerebral asymmetry and basal ganglia volumes. We studied 17 patients with GTS and eight normal controls using volumetric MRI techniques for measuring the caudate nucleus, amygdala, and corpus callosum. One subject with GTS was subsequently excluded because he was left handed. No absolute differences in caudate nucleus volumes between patient and control groups were evident. There was an increase in corpus callosum (CC) cross-sectional area and a loss of the normal asymmetry of the caudate nucleus in the patient group. A loss of the normal correlation between cross-sectional area of the CC and whole brain index (WBI) in the patient group also was found. The amygdala measurements had a poor interrater reliability.

Adolescent

HMPAO SPECT in non-epileptic seizures: preliminary results.

The diagnosis of non-epileptic seizures (NES) is problematic. Although diagnosis can be achieved by videotelemetry, these facilities are expensive and not widely available. HMPAO SPECT studies show focal hypoperfusion interictally in focal epilepsy. SPECT has not been studied in any detail in NES previously. Two groups (10 patients each) were studied, one with NES and one with complex partial seizures and localisation related epilepsy. SPECT scans were normal in 7 of 10 (70%) NES patients, while showing clear focal hypoperfusion in 8 of 10 patients (80%) with epilepsy. In the NES group, 1 patient showed hypoperfusion indistinguishable from that seen in epilepsy, while 2 patients in the epilepsy group showed only equivocal focal hypoperfusion. The remaining 2 patients in the NES group showed bifrontal and equivocal focal hypoperfusion. A normal HMPAO SPECT study supports the diagnosis of NES in patients with seizures of uncertain aetiology.

Adolescent

Congenital afibrinogenaemia.

A case of congenital afibrinogenaemia in a young female child is described. She had haemorrhagic tendency since birth in the form of markedly prolonged umbilical bleeding and easy bruising afterwards. Two of her brothers had bleeding tendencies, one died shortly after birth due to uncontrollable umbilical bleeding and other died at the age of 12 years from internal haemorrhage. The family study indicates the mode of inheritance to be probably autosomal recessive. The principal laboratory findings are complete non-coagulability of blood, grossly abnormal coagulation tests, zero ESR value, failure to detect fibrinogen by heat coagulation or chemical precipitation tests and biuret reaction and correction of thrombin time after fibrinogen infusion.

Afibrinogenemia

A case of subacute effusive constrictive pericarditis with a probable amoebic aetiology.

A 48 year old man with amoebic pericarditis did not improve after pericardiocentesis. Facilities for echocardiography and haemodynamic studies were not available. Cardiac compression was suspected and at emergency pericardiectomy subacute effusive constrictive amoebic pericarditis was found. The patient recovered. This is believed to be the first report of a case of subacute effusive constrictive pericarditis caused by amoebiasis.

Amebiasis

Diagnostic significance of pleural fluid eosinophilia during initial thoracocentesis.

A prospective study of pleural fluid eosinophilia (PFE) during initial thoracocentesis in 162 patients of pleural effusion was undertaken to determine its value in establishing an etiological diagnosis. Eighteen of the 162 cases showed pleural fluid eosinophilia (PFE), twelve could not be labelled with any definitive etiology even after extensive investigations, four belonged to the para-pneumonic group and resolved with treatment. Of the 32 patients with malignancy, PFE was seen in a single case of pleural mesothelioma. None of the patients with tuberculosis, empyema, systemic lupus erythematosus or amoebiasis had PFE. These findings suggest that PFE seen at initial thoracocentesis favours a benign diagnosis, with a rare chance of malignancy. Tuberculosis is unlikely in such patients.

Biopsy, Needle

Multimodality evoked potentials in aortoarteritis.

Brainstem auditory evoked potentials (BAEPs) have been used to detect early and even asymptomatic brain ischemia. There is a need to detect subclinical brain and/or spinal cord ischemia in patients with aortoarteritis so that ischemic deficits can be prevented by early intervention. We studied multimodality (Visual evoked potentials--VEPs, Somatosensory evoked potentials--SEPs and BAEPs) evoked potentials (EPs) in 10 neurologically asymptomatic subjects with aortoarteritis. EP latencies were normal in all the patients studied. The possible value of EP latencies in detection of early brain and/or spinal cord ischemia in patients with aortoarteritis is discussed.

Adolescent