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Biomedical subjects

M S Keshavan

Publications and source records attributed to M S Keshavan.

At least 91 records · Page 5Linked to original sources
PubMed1994

Predictors of acute dystonia in first-episode psychotic patients.

Sixty-two first-episode psychotic patients who were neuroleptic-naive were studied to examine predictors of acute dystonia after treatment with haloperidol. Twenty-three patients developed dystonia, two of them despite being treated with biperiden. Biperiden significantly prevented dystonic reactions. Dystonia development was significantly related to younger age, severity of illness, and negative symptoms at baseline and showed a trend to be related to positive symptoms as well. No significant effect of gender or diagnosis was found. The authors suggest that young, severely ill patients in their first psychotic episode who have never been treated with neuroleptics might be at higher risk to develop dystonia.

Adolescent↗
PubMed1994

Neurological examination abnormalities in neuroleptic-naive patients with first-break schizophrenia: preliminary results.

The authors report preliminary findings from an ongoing prospective study of neuroleptic-naive patients with first-break schizophrenia. They evaluated 17 of these patients and 15 normal subjects with a structured neurological examination before the patients received any medical treatment. The patients with schizophrenia showed significantly greater neurological impairment than did the normal comparison subjects.

Adult↗
PubMed1994

Creatine kinase elevations with clozapine.

We describe a patient with marked elevations of creatine kinase following institution of clozapine treatment. The enzyme levels promptly subsided with discontinuation of clozapine. The clinical features did not meet any of the published criteria for neuroleptic malignant syndrome.

Adult↗
PubMed1993

Erythrocyte membrane phospholipids in psychotic patients.

Thin layer chromatography and laser densitometry were used to examine erythrocyte membrane phospholipid composition in 13 medication-free patients with schizophrenia or schizoaffective disorder and 11 healthy control subjects. The patient group had significantly decreased levels of phosphatidylethanolamine and a significant increase in sphingomyelin. The patient group also showed a trend toward decreased levels of phosphatidylinositol bisphosphate. Levels of phosphatidylcholine and lysophosphatidylcholine did not significantly differ between groups. There were no significant effects of age, body mass index, or gender on any of the phospholipid parameters. The observed alterations may point to abnormalities in key membrane-related functions, including signal transduction and ion transport.

Adult↗
PubMed1993

Frontal lobe metabolism and cerebral morphology in schizophrenia: 31P MRS and MRI studies.

The relation between frontal lobe membrane phospholipid metabolism as measured by 31Phosphorus magnetic resonance spectroscopy (31P MRS) and cerebral morphology as measured on magnetic resonance images (MRI) was examined in nine first episode neuroleptic naive schizophrenic patients. Total corpus callosal area was significantly correlated with phosphodiester concentration. When examined separately, this relation was confined to the rostral quartile (genu) of the corpus callosum. The pathophysiological significance of this finding is discussed in relation to neurodevelopmental hypotheses of schizophrenia.

Adult↗
PubMed1993

31P nuclear magnetic resonance spectroscopy: neurodevelopment and schizophrenia.

A number of studies have demonstrated alterations in the structure and function of the frontolimbic system in some schizophrenic patients. Recent in vivo phosphorus-31 nuclear magnetic resonance studies of the dorsal prefrontal cortex in neuroleptic-naive, first-episode schizophrenic patients and matched controls have shown evidence of alterations in membrane phospholipid and energy metabolism. The membrane alterations observed in the schizophrenic patients are compatible with either premature aging or altered timing and exaggeration of regressive events occurring during normal brain development. These molecular changes may precede onset of clinical symptoms and brain structural changes in schizophrenia and suggest fresh approaches to the pathogenesis and treatment of this illness.

Adult↗
PubMed1993

Schizophrenia in late life: elderly patients admitted to an acute care psychiatric hospital.

Although a considerable body of biological and clinical data has been accumulated on the mood disorders and organic disorders of late life, only a handful of studies have focused on aging schizophrenia patients. Using the results of a comprehensive evaluation of all elderly patients admitted over a 30-month period to a 26-bed acute care geriatric unit, we compared the demographic, social, and clinical characteristics of schizophrenia patients, patients with recurrent major depression with and without psychotic features, and patients with primary degenerative dementia of the Alzheimer's type with and without delusions. The main findings of this study are that elderly schizophrenia patients were younger, more often African-American, more often single, and poorer than the other groups. A concomitant history of substance abuse and institutionalization as an outcome were more frequent among schizophrenia patients. Like the older depressed and demented patients, schizophrenia patients were predominantly female and commonly presented with several medical disorders. The potential significance of these findings is discussed in the context of the literature on the long-term outcome of schizophrenia.

Aged↗
PubMed1992

Plasma cholinesterase isozymes and REM latency in schizophrenia.

The relation between electroencephalographic sleep parameters and plasma cholinesterase isozymes was examined in a group of 19 unmedicated schizophrenic patients. Rapid eye movement (REM) latency was found to be significantly inversely correlated with isozyme 3 (mainly acetylcholinesterase). The results are discussed in relation to cholinergic involvement in the regulation of REM sleep and in the pathophysiology of schizophrenia.

Adult↗
PubMed1992

First-episode studies in schizophrenia: criteria and characterization.

Studies of early schizophrenia offer several advantages for efforts to unravel the biology, treatment, and outcome of this disorder. A review of available first-episode studies, however, suggests marked variability in findings, frequently attributed to the presumed heterogeneity of the disorder. Another cause may be variation in definitions and criteria used. Thus, attention has turned to the study of patients experiencing their first episode of psychosis. Although this strategy will not control for the true underlying heterogeneity of the illness, it provides a valuable method for homogenizing variability due to course. For this strategy to be effective, definition and operationalization of criteria for such studies are crucial. In this article, we reviewed assessment methods used in first-episode studies in the recent literature and found marked inconsistencies. We offer a framework for definition of patient populations for studies of early schizophrenia and outline some key variables that may serve as the basis for fuller characterization of the disorder. It is important to provide data on such variables to enhance comparability among studies of early schizophrenia and to facilitate meaningful interpretation of data.

Adolescent↗
PubMed1991

Alterations in brain high-energy phosphate and membrane phospholipid metabolism in first-episode, drug-naive schizophrenics. A pilot study of the dorsal prefrontal cortex by in vivo phosphorus 31 nuclear magnetic resonance spectroscopy.

In this pilot study, membrane phospholipid and high-energy phosphate metabolism were studied in the dorsal prefrontal cortex of 11 drug-naive, first-episode schizophrenic patients and compared with those of 10 healthy control volunteers comparable in age, education, and parental education. The schizophrenic patients had significantly reduced levels of phosphomonoesters and inorganic orthophosphate and significantly increased levels of phosphodiesters and adenosine triphosphate compared with the controls. The levels of phosphocreatine and adenosine diphosphate did not differ in the two subject groups. The adenosine triphosphate and inorganic orthophosphate findings suggest functional hypoactivity of the dorsal prefrontal cortex. The phosphomonoester and phosphodiester findings are compatible with either premature aging or an exaggeration of normal programmed regressive events occurring in the neural systems sampled.

Adult↗
PubMed1991

Electroencephalographic sleep and cerebral morphology in functional psychoses: a preliminary study with computed tomography.

We investigated the association between cerebral morphology as revealed by computed tomography and sleep polysomnographic findings in patients with functional psychoses. The third ventricle-brain ratios, caudate ratios, and anterior horn ratios were significantly negatively associated with sleep maintenance and were positively correlated with rapid eye movement (REM) latency. When the effects of illness severity were covaried out, the relation between REM latency and anterior horn ratios remained significant. Disturbances in sleep in some patients with schizophrenia and schizoaffective disorders may be related to dysfunction of forebrain structures, and may be similar to those seen in dementia.

Adult↗
PubMed1991

Magnetic resonance spectroscopy in psychiatry: potential, pitfalls, and promise.

Magnetic resonance spectroscopy (MRS) is a novel noninvasive approach to measuring important metabolites in living tissue. Its application to psychiatry is just beginning. In vivo MRS with 31P provides important information on brain phospholipid metabolism and energy production. In vivo 13C and 1H MRS can reveal information about carbohydrate, protein, and amino acid metabolism. In vivo 7Li and 19F MRS can be used to study the pharmacology of lithium and fluorinated psychopharmacological agents. MRS with 23Na can yield information about electrolyte balance. The limitations of in vivo MRS include poor sensitivity, poor resolution, and the fact that only highly mobile atomic nuclei can be detected. Future clinical application of MRS will benefit from improvements in the technology of localization, use of spectroscopy contrast agents, stronger magnets, and the merging of MRS and imaging technology.

Brain↗
PubMed1991

Schizophrenia with secondary transsexualism.

We describe a patient with schizophrenia who developed transsexualism. The emergence of transsexualism and the patient's improvement paralleled those of the schizophrenic illness. The relationship between the diagnosis of the primary psychiatric illness in transsexualism has implications for prognosis and appropriate management.

Adult↗
PubMed1989

Elevated sleep and waking heart rates in anxious depressions.

Autonomic functioning, as measured by baseline heart rates during daytime (DHR) and during sleep (SLHR), was examined in 28 patients with major depressive disorder (MDD), 13 patients with panic disorder (PD), 28 patients with MDD and coexisting PD (MDD + PD), and 19 controls. DHR and SLHR in patients with PD or MDD did not differ from normals. Only the MDD + PD group showed significantly higher heart rates than controls. This pattern of results suggests a combined effect of MDD and PD, providing psychophysiological support for clinical findings of poorer prognosis in this group.

Adult↗