CT Indices Research Articles

Clinical‐pathologic correlation in Huntington's disease

To examine the premise that cognitive impairment in Huntington's disease (HD) is related to striatal degeneration, we determined those cognitive deficits most closely associated with linear CT indices of brain atrophy in HD. We systematically evaluated 60 drug-free HD patients who were judged to be in stages I (n = 34) or II (n = 26) of illness. All subjects underwent comprehensive neuropsychological assessment covering a broad spectrum of cognitive operations and standardized head CT imaging for determination of frontal horn (FH), intercaudate (CC), and outer-table (OT) distances. We grouped the cognitive test results, based on a principal-component factor analysis, to form factors 1 (complex psychomotor), 2 (verbal memory), 3 (visuospatial), and 4 (general knowledge). Factors 1 and 3 sharply discriminated between subjects in stages I and II of illness. Factors 1, 2, and 3 correlated strongly with CC/OT, an index of caudate atrophy, whereas only factor 2 correlated with FH/OT, an index of frontal atrophy. These data demonstrate that cognitive impairment is a clear-cut characteristic of early HD that is linked closely to the extent of caudate atrophy as measured by CT.

Tardive dyskinesia in schizophrenia and other disorders: Associations with ageing, cognitive dysfunction and structural brain pathology in relation to neuroleptic exposure

AbstractLittle is known of the processes which confer vulnerability to the emergence of involuntary movements (tardive dyskinesia) in only a proportion of patients receiving long‐term treatment with neuroleptic drugs. There is no consistent evidence that patients with involuntary movements have received either longer or more vigorous pharmacotherapy, and it has proved difficult to demonstrate any general relationship between increasing neuroleptic exposure and the emergence of the syndrome. Advancing age may be associated more with deleterious changes in the central nervous system within individual patients that can raise vulnerability to the emergence of involuntary movements, than with particular predisposing patterns of neuroleptic exposure. The literature in schizophrenic patients reveals that two indirect and putative indices of ‘organicity’, namely cognitive dysfunction and negative schizophrenic symptoms, together with several CT indices of structural brain pathology, show similar and robust associations with the presence of involuntary movements. In schizophrenia, predisposition to the emergence of involuntary movements during long‐term neuroleptic therapy appears intimately related with particular features of the illness, especially those associated with clinical deterioration. It is argued from clinical and animal studies that neuroleptics may hasten the appearance of dyskinetic movements in individuals with the greatest likelihood of ultimately having such movements spontaneously as cerebral deterioration proceeds.

Cerebral blood flow and brain atrophy correlated by xenon contrast ct scanning

Correlations between cerebral blood flow (CBF) measured during stable xenon contrast CT scanning and standard CT indices of brain atrophy were investigated in the patients with senile dementia of Alzheimer type, multi-infarct dementia and idiopathic Parkinson's disease. Compared to age-matched normal volunteers, significant correlations were found in patients with idiopathic Parkinson's disease between cortical and subcortical gray matter blood flow and brain atrophy estimated by the ventricular body ratio, and mild to moderate brain atrophy were correlated with stepwise CBF reductions. However, in patients with senile dementia of Alzheimer type and multi-infarct dementia, brain atrophy was not associated with stepwise CBF reductions. Overall correlations between brain atrophy and reduced CBF were weak. Mild degrees of brain atrophy are not always associated with reduced CBF.

Case report: Computed tomography of congenital clefts of the atlas

Congenital clefts of the anterior and posterior arches of the atlas were demonstrated in a cervical spine CT performed in a case of suspected trauma. Intact cortical margins and lack of adjacent soft tissue swelling are CT indices distinguishing congenital clefts from fractures.