Biomedical subjects

J A Christy

Publications and source records attributed to J A Christy.

6 recordsLinked to original sources

PubMed1992

Magnetic resonance imaging correlates of neuropsychological impairment in multiple sclerosis.

The authors examined whether specific neuropsychological abnormalities in multiple sclerosis (MS) are associated with focal lesion areas detected by MRI. Lesion area, regardless of distribution, correlated with performance on the vast majority of neuropsychological procedures. No significant difference appeared between groups with normal/mild and moderate overall cognitive impairment on any of the MRI measures. However, patients with severe cognitive impairment had greater lesion area, regardless of location, and had significant atrophy of the corpus callosum compared with the other two groups. These results suggest that severe atrophy of the corpus callosum reflects global disease and provides a relatively focal morphological marker of severe cognitive impairment in MS.

Adult↗

PubMed1992

Asymmetrical cognitive differences associated with hemiparkinsonism.

The question of whether Parkinson's disease (PD) patients who have left (LPD) or right (RPD) motor predominance also exhibit cognitive differences is controversial. We examined this issue using a neuropsychological battery designed to provide a balanced sampling of both right- and left-hemispheric functions. RPD patients were impaired relative to LPD patients on verbally mediated tasks (left hemisphere function), but there was no group difference for visuospatial tasks (right-hemispheric function). In addition, there was a significant correlation between the extent of right side motor predominance and performance on verbal tasks, but there was no relationship between left side motor symptoms and performance on visuospatial tasks. The controversy related to cognitive differences in hemiparkinsonism may be due to the balance of the assessment procedure, the severity of motor asymmetry, or both.

Journal Article↗

PubMed1990

The pattern of depressive symptoms varies with progression of Parkinson's disease.

Whether or not depressive symptoms increase in severity with progression of Parkinson's disease (PD) remains uncertain. Unlike previous studies, we examined whether the severity of specific features of depression (mood, self reproach, vegetative, and somatic symptoms) differ with respect to the progression of PD. Results indicated that symptoms related to both mood and self-reproach were present in the early stages of PD but did not increase in severity with advancing disease. Somatic features of depression were evident early and increased with disease progression, and vegetative symptoms were seen only in the later stages of PD. The different patterns of these depressive features with progression of PD may account in part for the variations seen in previous studies.

Adult↗

PubMed1990

A brief scale for the dementia of Parkinson's disease.

The lack of standardized criteria and methodologies to assess dementia in patients with Parkinson's disease has resulted in inconsistencies and controversies in the literature regarding the incidence and basis of this condition. The authors examined a large group of patients with Parkinson's disease using two standardized sets of criteria for dementia. The neuropsychological data obtained was analyzed using stepwise discriminant analysis, and a brief scale was developed. The results indicated that a regression equation derived from just three neuropsychological procedures (which take only 10 minutes to administer) provides maximum discrimination between patients originally classified as demented or non-demented according to standardized criteria. Cut-off values for the product of the regression equation were calculated to accurately and reliably classify patients using the brief scale.

Adult↗

PubMed1989

Magnetic resonance imaging in dementia of Parkinson's disease.

The possibility that dementia in Parkinson's disease is associated with specific cerebral abnormalities identifiable by magnetic resonance imaging (MRI) was examined. Sixty eight patients with Parkinson's disease and 28 age and education matched normal controls were evaluated using neuropsychological procedures that included assessment of language, memory, cognition, visuospatial skills and mood. Twenty three patients (34%) were found to have developed significant impairment in at least three of the five areas, thus meeting criteria for a dementia syndrome. Eleven patients (16%) had no intellectual impairment and thirty four patients (50%) had a mild to moderate intellectual disturbance. Patients with (n = 10) and without dementia (n = 20), matched for severity of Parkinson's disease, and normal controls (n = 10) matched for age with the two patients groups, were evaluated by MRI. MRI scans were analysed for evidence of generalised cerebral atrophy, ventricular enlargement, visualisation of the substantia nigra and severity of focal brain lesions. Results indicated that the presence of dementia in patients with Parkinson's disease was not associated with any specific pattern of MRI abnormalities.

Adult↗

PubMed1989

Neuropsychological impairments associated with severity of Parkinson's disease.

Intellectual impairment and disease severity tend to parallel one another in patients with Parkinson's disease (PD), but the pattern of development of the neuropsychological impairments contributing to the overall intellectual decline is unknown. This problem was addressed by comparing neuropsychological performance in the early and later stages of PD. Impairment of recent memory, impairment of cognition, and somatic features of depression were seen early and worsened with more advanced disease. Impairment of visuospatial skills, remote memory, language, and mood were observed only in the later stages of PD. These findings suggest that neuropsychological impairments do not develop in a uniform manner with progression of PD.

Aged↗