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Biomedical subjects

J T Becker

Publications and source records attributed to J T Becker.

At least 19 recordsLinked to original sources
PubMed1995

Computed tomography--but not magnetic resonance imaging--identified periventricular white-matter lesions predict symptomatic cerebrovascular disease in probable Alzheimer's disease.

OBJECTIVE: To examine the clinical consequences of periventricular white-matter lesions on computed tomography (CT) and magnetic resonance imaging (MRI) scans in probable Alzheimer's disease. DESIGN: Case series, 12-month follow-up. SETTING: Multidisciplinary behavioral neurology research clinic. PATIENTS: We longitudinally evaluated the clinical characteristics of 27 patients with probable AD for whom both CT and MRI scans had been performed at baseline. INTERVENTIONS: None. MAIN OUTCOME MEASURE: The presence of abnormal neurological signs was examined at baseline and at a 12-month examination. RESULTS: Periventricular white-matter lesions were observed with CT in 12 patients (44%) and with MRI in 21 patients (78%). Computed tomography did not detect lesions of 1 to 3 mm, as were seen on MRI scans, and CT also did not detect lesions of 4 to 10 mm when they occurred in the deep subcortical white matter and were not part of a greater confluent lesion. There was no relationship between the severity of periventricular white-matter lesions with either neuroimaging method and the presence of abnormal neurological signs. However, there was a greater frequency of periventricular white-matter lesions shown on CT scans than on MRI scans at baseline in patients in whom abnormal neurological signs (eg, abnormal gait, asymmetric deep tendon reflexes, focal motor deficits, abnormal plantar response) developed at 12-month follow-up. CONCLUSION: Although MRI may be more sensitive in detecting periventricular white-matter lesions, CT is more specific in predicting subsequent symptomatic cerebrovascular disease.

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PubMed1995

Understanding impaired analysis of faces by patients with probable Alzheimer's disease.

The purpose of this study was to analyze the facial recognition skills of patients diagnosed with Probable Alzheimer's Disease (AD). The performance of 181 AD patients was evaluated to address their ability to: analyze visual forms, to discriminate individual faces, and to recognize and name familiar famous faces. The results of the study demonstrate that the ability to analyze visual information is more vulnerable early in dementia than is the ability to discriminate individual faces. The inability to recognize familiar faces among the AD patients was related to impairments of their lexical/semantic system, rather than to a specific defect in facial discrimination. These data are fully consistent with existing models of face processing and recognition, and suggest that the recognition defect in AD is related to the naming component of face recognition, rather than the perceptual component.

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PubMed1995

Qualitative features of the memory deficit associated with HIV infection and AIDS: cross-validation of a discriminant function classification scheme.

The neuropsychological defects associated with late stage HIV infection and AIDS have been characterized as being similar to those seen in patients with dementia syndromes of subcortical etiologies. The purpose of this paper is to report on the cross-center replication of the classification of HIV-infected subjects' neuropsychological status based on a discriminant function generated from other HIV-related and unrelated cognitively impaired subjects. Of the HIV-control subjects, 42/46 (91.3%) were classified as "Normal", with only two subjects in each of two "dementia" groups: subcortical and cortical. However, similar to other HIV+ samples, a large proportion (36%) of our HIV-infected subjects were classified as "Subcortical", with 61% classified as "Normal", and one (3%) in the "Cortical" group. These data demonstrate that not only does the cognitive performance of some HIV+ subjects have distinct features relative to that of HIV-control subjects, but that the features are consistent with previous suggestions that such patients have a "Subcortical" pattern of impairment.

Acquired Immunodeficiency Syndrome↗
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

[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.

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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.

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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

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↗
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.

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PubMed1992

Hand preference, immune system disorder and cognitive function among gay/bisexual men: the Multicenter AIDS Cohort Study (MACS).

This study evaluated the self-reported patterns of handedness among a large subsample (n = 1612) of the gay/bisexual men comprising the Multicenter AIDS Cohort Study (MACS). There was a small but significant elevation in left-handedness among gay/bisexual men compared to available normative data. However, there were no differences within the cohort in measures of immune function, self-reported autoimmune disorders, asthma, or hay fever, although there was an association between handedness and allergy. Performance on neuropsychological tests also did not differ as a function of handedness.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Longitudinal analysis of a two-component model of the memory deficit in Alzheimer's disease.

The memory deficit in Alzheimer's disease (AD) has been characterized as consisting of multiple components. The purpose of this study was to confirm the utility of a two-process model, and to examine changes in the nature and extent of the neuropsychological deficits after a one-year interval. The results replicate the initial observation that the memory loss in AD can be described as consisting of a focal amnesic syndrome and a dysexecutive syndrome characterized by failure of rapid information processing and search of both episodic and semantic memory. One year after the initial observation, all dysexecutive patients and the majority of the amnesic patients had become non-focal. No patient developed a dysexecutive syndrome, but 18 patients developed amnesic syndromes. These results suggest that, like other aspects of the cognitive deficits of AD, the memory loss is multifactorial. These results have implications for understanding the pathophysiology of AD, and for designing pharmacotherapeutic intervention.

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