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Biomedical subjects

J T Becker

Publications and source records attributed to J T Becker.

At least 73 records · Page 4Linked to original sources
PubMed1995

Cognitive performance after progression to AIDS: a longitudinal study from the Multicenter AIDS Cohort Study.

OBJECTIVE: To describe changes in cognitive functioning before and after development of an acquired immune deficiency syndrome (AIDS)-defining illness or CD4+ lymphocyte count < 200/mm3 in participants in the Multicenter AIDS Cohort Study. METHODS: The study population included participants who either were diagnosed with an AIDS-defining illness (n = 52) or had at least one measurement of CD4+ count < 200/mm3 (n = 57) and who had at least four neuropsychological (NP) evaluations, two or more before and two or more after the AIDS diagnosis. A group of subjects with clinical diagnosis of dementia (n = 29) was also included for comparison. The NP test battery included measures of attention, memory, constructional abilities, and psychomotor speed. Longitudinal data analysis, using the generalized estimating equation, was performed separately for each NP measure. Time was measured in months from the date of clinical AIDS or CD4+ < 200/mm3. RESULTS: Before AIDS< the dementia group showed significant decline (slope different from zero) only on measures of psychomotor speed. For all other measures, there was no evidence of decline in performance before AIDS for the other groups. After development of AIDS, the group with clinical AIDS showed significant decline on psychomotor speed but none on the other cognitive measures. The group with CD4+ < 200/mm3 did not show significant decline on any of the cognitive measures after AIDS. As expected, the dementia group showed significant decline on all measures. Sensory neuropathy was associated with a significant decline in performance on measures of psychomotor speed after AIDS. Antiretroviral therapy was not associated with any measurable changes in NP performance. CONCLUSION: These results are consistent with previous findings showing no significant decline in cognitive functions before AIDS, unless overt dementia is present, and no decline in immunosuppressed subjects who have had no AIDS-defining illness. By contrast, in subjects who have developed clinical AIDS, there is mild decline in fine motor skills but no significant change in other cognitive domains.

AIDS Dementia Complex↗
PubMed1995

Alternate forms of the Auditory-Verbal Learning Test: issues of test comparability, longitudinal reliability, and moderating demographic variables.

The present investigation examines the alternate-form and longitudinal reliability of two versions of the Auditory-Verbal Learning Test (AVLT) on a large, multiregional, healthy male sample. Subjects included 2,059 bisexual and homosexual HIV-seronegative males recruited from the Multicenter AIDS Cohort Study from centers in Baltimore, Chicago, Los Angeles, and Pittsburgh. The findings revealed no significant differences between forms upon initial or 1-year longitudinal administration, supporting the equivalence of the two versions. However, significant practice effects were noted longitudinally, arguing for the need of appropriate retest normative data. Furthermore, as age, ethnicity, and education were found to significantly affect test performance, it is recommended that normative data be interpreted according to these variables. In addition to providing normative and longitudinal data, this investigation presents information concerning the use and limitations of the alternate forms of the AVLT.

Journal Article↗
PubMed1995

[Difficulties in differential diagnosis of long-term Creutzfeldt- Jakob disease].

Creutzfeldt-Jakob disease (CJD) is characterized by a rapidly progressive dementia that often leads to death within a few months of onset. However, some cases evolve over a much longer period of time and have a clinical picture that is difficult to distinguish from other progressive dementias that occur in the adult, especially Alzheimer's disease (AD). We examine the clinical features of 3 patients with pathologically confirmed CJD whose course was slow (4-5 years) and who were initially diagnosed as having AD. Only two of them had shown signs of CJD in the terminal stages. In this study we examine the clinical characteristics of these patients, and discuss of differentiating CJD from other entities, especially from AD.

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PubMed1994

The natural history of Alzheimer's disease. Description of study cohort and accuracy of diagnosis.

OBJECTIVE: We describe the sampling, initial evaluation, and final diagnostic classification of subjects enrolled in a natural history study of Alzheimer's disease (AD). DESIGN: Volunteer cohort study. SETTING: Multidisciplinary behavioral neurology research clinic. PATIENTS OR OTHER PARTICIPANTS: Three-hundred nineteen individuals were enrolled in the Alzheimer Research Program between March 1983 and March 1988. Of these, 204 were originally classified with AD, 102 were normal elderly control subjects, and 13 were considered special cases. MAIN OUTCOME MEASURES: Final consensus clinical diagnosis, final neuropathologic diagnosis, and death. RESULTS: Of the 204 patients enrolled in the study, re-review after as many as 5 years of follow-up resulted in a final clinical classification of 188 with probable AD. Seven patients were believed to have a significant vascular component to the dementia, three were found to have developed depression, and six were excluded on other clinical grounds. Neuropathologic examination of 50 brains indicated definite AD in 43. After removing these seven misdiagnosed patients, the final group of probable/definite AD totaled 181 individuals. Accuracy of the baseline clinical diagnosis relative to neuropathology was 86%, and when follow-up clinical data were considered, 91.4%. Detailed neuropsychological testing yielded high sensitivity (0.988) and specificity (0.983) to dementia. Analyses of survival time from study entry until death revealed that older patients were significantly more likely to die during follow-up, but neither sex, years of education, nor pattern of cognitive impairment were related to survival. CONCLUSIONS: These data provide the descriptive basis for future studies of this cohort. They indicate that longitudinal follow-up of demented cases increases accuracy of diagnosis, and that detailed cognitive testing aids in early classification.

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PubMed1994

Awareness of cognitive deficits and anosognosia in probable Alzheimer's disease.

We examined the relationship between unawareness of cognitive deficits and psychiatric and neuropsychological manifestations in 181 patients with probable Alzheimer's disease (AD). Patients unaware of their cognitive deficits were more cognitively impaired, as measured by the Mini-Mental State Examination, and had a specific defect in 'frontal/executive' functions. The presence of major depression, delusions and hallucinations was no more likely among patients who were aware of their cognitive impairment than among those who were not. These findings have important implications for the understanding of anosognosia and deficit awareness in dementia.

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PubMed1994

Visuospatial imagery in Alzheimer disease.

The purpose of the present study was to investigate the imagery ability of 8 "probable" Alzheimer disease patients using a standard task sensitive to the disruption of the imagery system. These patients were selected based on their good performance on a prerequisite clock-setting task, and with 8 matched control subjects were then required to compare the angles made by the hands on clock faces using only imagined stimuli. There were no significant differences between patients and controls in performance on the clock-imagery task. These data are consistent with models of information processing which postulate the relationships between visual imagery and a short-term memory store and include a central executive system for allocation of cognitive resources.

Aged↗
PubMed1994

Temporal trends in the incidence of HIV-1-related neurologic diseases: Multicenter AIDS Cohort Study, 1985-1992.

OBJECTIVE: To describe temporal trends in the incidence of human immunodeficiency virus (HIV)-related neurologic diseases in the Multicenter AIDS Cohort Study from 1985 to 1992. METHODS: The incidence rates of six neurologic disorders were examined: toxoplasmosis, cryptococcal meningitis, primary CNS lymphoma, progressive multifocal leukoencephalopathy, HIV dementia, and sensory neuropathy. Poisson modeling was used to test linear trends over time and the effects of progressive immunosuppression, antimicrobial prophylaxis, and antiretroviral drug therapy. RESULTS: There was an upward temporal trend in all incidence rates, except for HIV dementia. Progressive immunosuppression in the cohort explained all calendar trends except for sensory neuropathy, where an increasing temporal trend remained even after adjusting for CD4+ cell count, and for HIV dementia where a slight decline was noted, although the effects were not statistically significant. We noted a protective trend of antimicrobial prophylaxis on toxoplasmosis and cryptococcal meningitis, but, in contrast, use of antiretroviral agents was not protective against HIV dementia. Men receiving didanosine, zalcitabine, or stavudine were more likely to develop sensory neuropathy. CONCLUSION: Despite the earlier and more widespread use of antimicrobial and antiretroviral agents, neurologic conditions still occurred frequently in this cohort, with annual rates above 1.5 per 100 person-years for HIV dementia and sensory neuropathy. Sensory neuropathy seems to be increasing in incidence and HIV dementia declining slightly in this cohort. As the epidemic matures and more people with profound immunosuppression live longer, the overall incidence of HIV-related neurologic diseases can be expected to rise.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Speech motor control disorder after HIV infection.

We examined the clinical characteristics of six right-handed patients who developed speech motor control disorders after human immunodeficiency virus (HIV) infection. They exhibited an ataxic dysarthria, characterized by irregular articulatory breakdowns in consonant and vowel timing; were slow in timed decision-making tasks; and had impaired procedural learning. Other aspects of the neurologic examination revealed signs of diffuse CNS involvement including action-intention tremors, ataxic gait, and release signs. None developed HIV-associated dementia during 1 year of follow-up. Motor speech control disorder appears to be related to a cerebellar dysfunction.

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↗
PubMed1994

Reliability of NINDS-AIREN clinical criteria for the diagnosis of vascular dementia.

We evaluated the reliability of clinical diagnoses using the recently standardized criteria for the diagnosis of vascular dementia (VaD) developed by the National Institute of Neurological Disorders and Stroke (NINDS) and the Association Internationale pour la Recherche et l'Enseignement en Neurosciences (AIREN). Two neurologists and two psychiatrists independently reviewed clinical data abstracted from those of 42 demented subjects participating in a longitudinal study of dementia at the University of Pittsburgh. For each patient we abstracted the clinical data on a standardized form. Each physician diagnosed each case according to the NINDS-AIREN criteria, using both clinical information and MRIs. We calculated the interrater agreement for all two-way combinations of clinicians with kappa statistics, which ranged from 0.46 (moderate agreement) to 0.72 (substantial agreement). The moderate reliability observed in this study may be attributable to patient-, clinician-, or criteria-centered sources of variance.

Aged↗
PubMed1994

Psychosocial factors associated with risky sexual behavior among HIV-seropositive gay men.

The present study examines sociodemographic characteristics, levels of psychological distress, and coping styles among HIV-seropositive (HIV+) gay men who either did or did not engage in sexual activity which placed others at risk for HIV infection. Risky sexual behavior was defined as engaging in insertive anal intercourse. Respondents were 156 HIV+ men enrolled at the Pittsburgh site of the Multicenter AIDS Cohort Study in 1989-90. HIV+ men who engaged in risky sexual behavior, while similar to remaining HIV+ men on most sociodemographic characteristics, showed lower levels of psychological distress and somewhat higher feelings of control over their lives. Risky men were less likely to employ active, behavioral strategies for day-to-day coping with the issues of HIV infection and AIDS, and were more likely to report using recreational drugs to reduce tension associated with thoughts about HIV. This profile of psychosocial characteristics associated with risky sexual activity may lead to further refinement of educational and other intervention strategies with HIV+ men. Implications for such strategies are discussed.

Adult↗
PubMed1993

Use of temporal context information in Alzheimer's disease.

Current theories of memory and memory dysfunction emphasize the importance of the use of contextual information in the storage and retrieval of specific episodes. Patients with lesions primarily in the diencephalon perform poorly on a measure of temporal recency, while those with temporal lobe amnesia are significantly better. The present study evaluated the ability of Probable AD patients to utilize information about temporal recency in the context of a recognition memory task. The performance of the AD patients was significantly impaired and resembled that of patients with Korsakoff's syndrome. The pattern of performance suggested that they were able to recognize which stimuli had been previously presented, but were unable to recall the correct temporal context. Further, there were no significant correlations between measures of temporal recency and those of frontal lobe function. These data suggest that AD patients, like other groups of patients with severe memory defects, are impaired at the use of context information in their attempts to remember recent events.

Aged↗
PubMed1993

Memory for visuospatial patterns in Alzheimer's disease.

Immediate memory for visuospatial information was assessed in patients affected by Alzheimer-type dementia but with unimpaired visuo-perceptual functions. Patients were given two tasks: one was a traditional visuospatial memory task (Corsi's block tapping test), the second explored specifically immediate memory for visuospatial patterns. The experiment was conducted in two parallel groups of patients in Italy and the United States, each with its own appropriate sample of normal control subjects. Results showed a specific deficit of visual working memory in demented patients, even in a task in which control subjects achieved error-free performance. These data are interpreted in the light of the Working Memory Model, and suggest that in dementia the functions of the Visuospatial Scratchpad, unlike the functions of the verbal subsystems, may be impaired.

Aged↗
PubMed1993

Effects of a history of heavy alcohol consumption on Alzheimer's disease.

Neuropsychological and psychiatric evaluations were made of 39 subjects with possible Alzheimer's disease and a history of excessive alcohol consumption (AD + ETOH), who had been abstinent or had drunk minimally for at least three months before evaluation, and 225 patients with probable Alzheimer's disease (PAD) of comparable age, years of education, and baseline global impairment. At baseline, there were no significant differences between the groups in terms of age of onset of dementia, neuropsychological test scores, or current behavioural or psychiatric symptoms. One year later, no differences in rates of decline between 20 abstinent AD + ETOH patients and 88 PAD subjects could be shown. Thus, past heavy alcohol consumption does not appear to modify the presentation of dementia of the Alzheimer's type, nor does it modify progression over a one-year interval.

Aged↗
PubMed1993

Dementia in AIDS patients: incidence and risk factors. Multicenter AIDS Cohort Study.

We determined incidence and future projections of dementia after AIDS onset in 492 homosexual men with AIDS in the Baltimore/Los Angeles sites of the Multicenter AIDS Cohort Study, 64 of whom developed dementia. We studied various risk factors for dementia, including demographic and clinical features, medical history, markers of immune status before AIDS, and zidovudine use. During the first 2 years after AIDS, HIV dementia developed at an annual rate of 7%. Overall, 15% of the cohort followed through death developed dementia. The median survival after dementia was 6.0 months. Using a proportional hazards model, risk factors for more rapid development of dementia were lower hemoglobin (relative hazard, 0.59 per additional 2 g/dl; p = 0.0005) and body mass index (relative hazard, 0.64 per additional 5 kg/m2; p = 0.05) 1 to 6 months before AIDS, more constitutional symptoms 7 to 12 months before AIDS (relative hazard, 1.68 per additional symptom, p = 0.005), and older age at AIDS onset (relative hazard, 1.60 per decade older; p = 0.009). In a multivariate model, pre-AIDS hemoglobin remained the most significant predictor of dementia. There were no significant risks defined from demographic characteristics, specific AIDS-defining illnesses, zidovudine use before AIDS, or CD4+ lymphocyte count before AIDS. We project that 12 months after the first AIDS diagnosis, 7.1% of survivors will have dementia. The observed association between anemia, low weight, constitutional symptoms, and dementia suggests a role for cytokines inducing both systemic and neurologic disease.

AIDS Dementia Complex↗
PubMed1993

Low education as a possible risk factor for cognitive abnormalities in HIV-1: findings from the multicenter AIDS Cohort Study (MACS).

The present study reports new and unexpected results of cognitive abnormalities among human immunodeficiency virus type 1 (HIV-1) asymptomatic subjects in the Multicenter AIDS Cohort Study. The major purpose of our analyses is to estimate the separate and combined effects of serostatus and education level on the prevalence of cognitive abnormality. Cognitive "abnormality" was defined as performance that deviated > or = 2 SDs below the mean of the total seronegative group on at least one of the five neuropsychological screening tests (Grooved Pegboard, Verbal Fluency, Digit Span, Symbol Digit Modalities, Rey Auditory Verbal Learning). The predicted prevalence of cognitive abnormality was 38% in seropositive individuals with no more than 12 years of education, compared with < 17% in the other education-serostatus groups. This interaction between education level and serostatus remained after controlling for the possible confounding effects of age, ethnicity, CD4 level, depression, prior drug history, and learning disability using logistic regression. To account for these findings, we suggest that low education might reflect an indirect index of lower reserve capacity (i.e., a risk factor) that lowers the threshold for neuropsychological abnormalities in cases of early HIV-1 infection.

AIDS Dementia Complex↗
PubMed1992

Neuropsychiatric correlates of cerebral white-matter radiolucencies in probable Alzheimer's disease.

We evaluated the neuropsychological functions, rate of disease progression, and psychiatric characteristics of 22 patients with probable Alzheimer's disease in whom periventricular white-matter radiolucencies (PWMRs) were seen on the computed tomographic scan of the brain and compared them with 22 matched patients with Alzheimer's disease without PWMRs. Executive/attention, lexical/semantic, memory/learning, and visuospatial functions did not differ between the two groups at baseline or at the 1-year follow-up examination. The frequency of major depression, delusions, and hallucinations did not differ between the groups. However, patients with PWMRs had significantly higher Hachinski Rating scores at both visits and were more likely to develop cerebrovascular disease during follow-up than were controls with Alzheimer's disease. These preliminary results suggest that the presence of PWMRs is not associated with specific cognitive and psychiatric features or with an altered rate of progression of Alzheimer's disease but does predict the development of clinically significant cerebrovascular disease.

Aged↗