Biomedical subjects

W G van Gorp

Publications and source records attributed to W G van Gorp.

28 records · Page 2Linked to original sources

PubMed1995

Cerebral metabolic change in patients with AIDS: report of a six-month follow-up using positron-emission tomography.

The authors examined change in cerebral metabolic function over time by using PET in HIV-infected individuals diagnosed with AIDS. Ten subjects with AIDS received [18F]2-fluoro-2-deoxy-D-glucose PET scans and completed a comprehensive neuropsychological battery. The scan and test battery were repeated after 6 months. Over time, the subjects showed increased relative basal ganglia metabolism as well as increased parietal lobe metabolism. There were no statistically significant changes in neuropsychological performance. These results suggest that PET may be more sensitive than traditional neuropsychological evaluation to subtle central nervous system changes in AIDS.

AIDS Dementia Complex↗

PubMed1994

Electroencephalographic coherence in acquired immune deficiency syndrome.

We studied a quantitative electroencephalographic (EEG) measure, coherence, in 28 patients with acquired immune deficiency syndrome (AIDS) and 56 uninfected volunteers. Compared with uninfected subjects, AIDS patients had increased coherence in the 6- to 10-Hz band. The largest increases in coherence were between frontal and occipital regions and between temporal and frontal regions. Coherence within contiguous regions was less affected. Eight of the 28 AIDS patients (29%) had clinically abnormal EEG findings, compared with four of the 56 uninfected control subjects (7%). Among the AIDS patients, 12 had normal neuropsychological performance, nine had mild impairment, and six had moderate impairment. Coherence was increased in each subgroup of AIDS patients, including those with normal neuropsychologic performance and/or normal clinical EEG results. AIDS patients were then classified by quantitative EEG power in frontal head regions as "abnormal" (the upper third of patients) or "normal" (the remainder). Increased coherence was found among both groups. Because the development of abnormal neuropsychological performance or a clinically abnormal EEG examination indicates relatively advanced central nervous system disease, alterations in specific coherence measures may detect subclinical effects of the human immunodeficiency virus on brain function before other changes are evident.

Acquired Immunodeficiency Syndrome↗

PubMed1994

Frequencies of MMPI-168 code types among asymptomatic and symptomatic HIV-1 seropositive gay men.

Welsh codes of Minnesota Multiphasic Personality Inventory-168 (MMPI-168) profiles were calculated for 151 HIV-1 seropositive gay men and 27 gay seronegative controls. Although 99% of seropositives' profiles were clinically elevated, the profile configurations among subjects were varied. These data document the presence of considerable emotional distress among HIV-infected individuals, yet the heterogeneity of codes encountered argues against generalizations of seropositive subjects based upon mean MMPI profiles.

Adult↗

PubMed1994

The relationship between age and cognitive impairment in HIV-1 infection: findings from the Multicenter AIDS Cohort Study and a clinical cohort.

Previous studies have identified age as a risk factor for many neurologic disorders, and a "cerebral reserve" factor has been postulated to explain these findings. This study examined whether age represents a risk factor for HIV-1-related neuropsychological dysfunction. Subjects for study 1 were primarily asymptomatic seropositive (n = 1,066) and seronegative (n = 1,004) nonelderly male community volunteers who completed neuropsychological and reaction time measures. Data analyses revealed a significant effect for age on reaction time and timed neuropsychological measures, but no interaction between age and serostatus. Study 2, employing a similar neuropsychological battery, consisted of 76 seropositive men (29 over age 55) recruited from community outpatient clinics and 47 seronegative controls. We found serostatus and age to have main effects on a number of measures, but a trend for an effect of age-serostatus interaction on only one measure.

AIDS Dementia Complex↗

PubMed1993

Neuropsychological deficits in abstinent cocaine abusers: preliminary findings after two weeks of abstinence.

Sixteen subjects hospitalized for treatment of cocaine dependence were administered a battery of neuropsychological tests within 72 h of last cocaine use and again approximately 2 weeks later. Twenty-one non-cocaine using control subjects, matched for age, gender, ethnicity and education, also received neuropsychological testing. Abstinence from mood altering substances during the 2-week study period was verified for both groups on three occasions using quantitative urine analysis. The results suggest that recent cocaine use is associated with impairment in memory, visuospatial abilities, and concentration during the acute phase of withdrawal, independent of withdrawal-related depression. Furthermore, many of these deficits appear to persist at least 2 weeks beyond cessation of cocaine use.

Adult↗

PubMed1992

Depressed mood and its relationship to neuropsychological test performance in HIV-1 seropositive individuals.

The relationship between depression and neuropsychological test performance in HIV-1 seropositive individuals is unclear. The present study was conducted to determine whether different patterns of neuropsychological test performance would be present in depressed vs. nondepressed individuals infected by the Human Immunodeficiency Virus (HIV-1). It was hypothesized that subjects evidencing depressed mood would demonstrate greater difficulty on measures of neuropsychological function. The subjects were 54 mostly symptomatic HIV-1 seropositive homosexual/bisexual males aged 20 to 60. A neuropsychological test battery together with the Beck Depression Inventory (BDI) was administered to all subjects. Stepwise multiple regression analysis revealed a significant relationship only between scores on the BDI and the Grooved Pegboard test and Trial 6 of the RAVLT. Subjects were then dichotomized using the BDI into high-BDI (M = 28.9) and low-BDI (M = 6.3) groups. Analysis of variance failed to reveal significant group differences between the depressed vs. the non-depressed groups on the neuropsychological measures despite their marked separation on the BDI. Similarly, examination of individual neuropsychological outliers again failed to demonstrate an increased number of outliers in the high- and low-BDI groups. These results suggest that the presence of clinically significant levels of depression in a non-elderly HIV-1 seropositive sample does not necessarily lead to significant neuropsychological dysfunction.

Adult↗

PubMed1992

Multidimensional risk assessment versus age as criterion for retirement of airline pilots.

OBJECTIVE: To determine whether airline pilots over the age of 60 pose a hazard to aviation safety and whether risk assessment could replace age-based retirement. DATA SOURCES: A computer-assisted literature search (MEDLINE), expert consultation, and government reports. STUDY SELECTION: Original studies on flight performance and pilot age; sudden incapacitation, neuropsychological testing, and/or medication use in pilots; and/or non-invasive testing for predicting sudden death or stroke in asymptomatic subjects. DATA EXTRACTION: Pertinent results and methods data were abstracted from the 49 included studies. DATA SYNTHESIS: No study on aircraft accidents or pilot performance has shown an increased accident risk for over-60-year-old pilots. Normal age-related cognitive changes probably have minimal impact on aviation safety up to age 70, given above average health, education, and experience in airline pilots. Cognitive tests have not been validated for predicting flight performance safety, but they can detect early stages of cognitive disease. Cardiovascular incapacitation risk increases with age, but risk factor profiles and non-invasive tests could identify pilots with non-acceptable risk. CONCLUSIONS: An improved medical certification test could identify those pathologic conditions that might occur more frequently in older subjects. If pilots also underwent adequate performance testing, a gradual increase of the retirement age to approximately age 70 would seem justified. In the future, a longitudinal database should be established to validate medical tests for their ability to predict a pilot's accident risk. Using individual pilots as their own controls might be more sensitive than using population-based norm values. Progress in this field would advance medical assessment for other groups such as air traffic controllers or automobile drivers.

Accidents, Aviation↗

PubMed1992

Cerebral metabolic dysfunction in AIDS: findings in a sample with and without dementia.

Positron-emission tomography was coupled with neurological and neuropsychological evaluation to study regional cerebral activity and neurologic status in two groups. Seventeen patients with full-blown AIDS and 14 seronegative control subjects were studied using [18F]2-fluoro-2-deoxy-D-glucose in a resting state. The AIDS group had relative regional hypermetabolism in the basal ganglia and thalamus; stepwise multiple-regression analyses revealed a significant relationship for the AIDS group between temporal lobe metabolism and severity of dementia on the AIDS Dementia Complex Rating Scale. These results suggest that the basal ganglia, thalamus, and temporal lobes are differentially affected in AIDS.

AIDS Dementia Complex↗

PubMed1991

Metacognition in HIV-1 seropositive asymptomatic individuals: self-ratings versus objective neuropsychological performance. Multicenter AIDS Cohort Study (MACS).

This study examined the relationship between actual and self-reported neuropsychological deficits, depression, and HIV-1 serostatus. The subjects, who consisted of 479 individuals, 256 who were HIV seronegative (SN) and 233 who were HIV-1 seropositive though still asymptomatic (ASP), were administered a standardized neuropsychological screening battery consisting of measures of attention, motor speed, psychomotor speed, verbal memory, verbal fluency, and depression. To assess subjects' subjective sense of their cognitive status, the Cognitive Failures Questionnaire (CFQ), a 25-item self-report questionnaire, was also administered. The results of MANOVA failed to reveal group differences between the SN and ASP groups on the measures of neuropsychological function. Similarly, the ASP and SN groups did not differ on the number or severity of reported cognitive failures. However, a positive correlation was found between CFQ scores and level of depression. These results do not support the hypothesis that ASP individuals are aware of cognitive decline prior to detection using standard neuropsychologic screening instruments. The data do suggest that the presence of depressed mood, independent of serostatus or actual neuropsychological impairment, is associated with increased cognitive complaints.

Adult↗

PubMed1990

Incidence of the WAIS-R Fuld profile in HIV-1 infection.

The incidence of a WAIS-R subtest "marker" sensitive to cholinergic dysfunction was assessed in a sample 116 homosexual males infected with HIV (Acquired Immunodeficiency Syndrome [AIDS] N = 40; AIDS Related Complex [ARC], N = 76). The incidence of positive profiles was low in the overall sample (11/116, 9%), and significantly lower than incidence rates reported for known cholinergic deficient groups (Alzheimer's disease; scopolamine). However, significantly more AIDS patients (8/40, 20%) than ARC patients (3/76, 4%) demonstrated positive profiles. These results suggest that, as a group, persons with ARC or AIDS do not show an increased incidence of the Fuld profile associated with cholinergic disruption, and offer continued support for diagnostic specificity of the Fuld formula for Alzheimer's disease.

AIDS Dementia Complex↗