Biomedical subjects

J T Becker

Publications and source records attributed to J T Becker.

At least 91 records · Page 5Linked to original sources

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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PubMed1992

Material-specific memory loss in probable Alzheimer's disease.

This study extends previous work analysing functional dissociations occurring in patients with Alzheimer's disease (AD) by demonstrating that material-specific memory loss is common. The pattern of neuropsychological dysfunction in 191 patients with probable AD was examined and 13% presented with material-specific memory loss. Thirteen patients had impaired immediate verbal recall, but normal non verbal recall and 12 had impaired non verbal recall and normal verbal memory. These patterns appeared to be related to a specific memory deficit and were probably not secondary to associated cognitive impairments. These data confirm earlier observations that the memory defect in AD can be material-specific, and suggest that these patterns of impairment should be viewed as a focal sparing of function.

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PubMed1991

Predictors of decline in Alzheimer's disease.

Age of onset and aphasia are frequently proposed as predictors of decline in Alzheimer's disease (AD). We compared longitudinally the neuropsychological test performance of AD patients classified as Fast Decliners (FD, N = 18) based on the rate of change of their scores on the Mini-Mental State Examination (MMS) and a group classified as Slow Decliners (SD, N = 15). There was no statistical difference in the age of onset of AD or in severity of dementia at first visit. Performance on verbal tests was the best predictor of rapid cognitive decline, even after the influence of the overall degree of dementia had been accounted for. Among the language tasks, performance on a naming test was the best predictor. The results of this study do not support age of onset as a predictor of the course of AD. On the other hand, poor performance on language tests does predict a more rapid rate of decline in AD.

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PubMed1991

Motor impersistence in Alzheimer's disease.

We studied motor impersistence syndrome (MIS) in patients with a clinical diagnosis of probable Alzheimer's Disease (AD). MIS was found in 16 (10%) of the 166 patients examined; all 16 were moderately to severely demented (Mini-Mental State scores ranging from 17 to 2). We compared the neuropsychological features between these AD patients with MIS and AD patients without MIS matched by the severity of dementia. We found no significant difference between the two groups in terms of orientation, memory, language, attention, and visuoconstructional and visuoperceptual abilities. Buccolingual and limb praxis also failed to reveal differences between the groups. Although MIS has been related to visuoconstructional disorders and apraxia, the phenomenon as it occurs in AD seems not to be related to any specific cognitive domain.

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PubMed1991

Alzheimer's disease with delusions and hallucinations: neuropsychological and electroencephalographic correlates.

We longitudinally evaluated the neuropsychological functions, rate of progression, and waking EEG findings in 17 patients with probable Alzheimer's disease (AD) with delusions and hallucinations, and compared them with those of matched AD patients without delusions and hallucinations. AD patients with delusions and hallucinations had a more rapid rate of decline, as measured by the Mini-Mental State Examination, a specific defect in receptive language, and a greater frequency of aggression and hostility. Visual EEG analysis showed that these patients had a significantly greater proportion of moderately abnormal EEGs, and spectral analysis confirmed the increased amount of delta and theta activity. These data demonstrate that AD patients with delusions and hallucinations have a greater degree of cerebral dysfunction and a relatively focal neuropsychological defect, which may indicate a localized pathologic abnormality.

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PubMed1991

Behavioral, health and psychosocial factors and risk for HIV infection among sexually active homosexual men: the Multicenter AIDS Cohort Study.

We examined whether 644 homosexual men who engaged in receptive anal intercourse were at particularly elevated risk for seroconversion if they also possessed specific behavioral, health or psychosocial vulnerability characteristics. Of 11 potential factors examined, heavy drinking, moderate to heavy drug use, and younger age were significantly related to seroconversion. These variables were also associated with an increased number of sexual partners, anonymous sex, and failure to use condoms.

Acquired Immunodeficiency Syndrome↗

PubMed1991

Normative data for a brief neuropsychological screening battery. Multicenter AIDS Cohort Study.

This study reports normative data for a group of 733 homosexual/bisexual men stratified by age (range 25 to 54 years) and by education on the following six neuropsychological tests: (1) Digit Span (WAIS-R), (2) Rey Auditory Verbal Learning Test, (3) Symbol Digit Modalities Test, (4) Controlled Oral Word Association Test, (5) Grooved Pegboard, and (6) The Trail Making Test. Analysis demonstrates that both age and education are important determinants of performance for several of these measures.

AIDS Dementia Complex↗

PubMed1990

Characteristics of the memory loss of a patient with Wernicke-Korsakoff's syndrome without alcoholism.

The memory loss in alcoholic Wernicke-Korsakoff syndrome has been well characterized. However, it has been suggested that some of the neuropsychological defects seen in these patients are due to frontal lobe dysfunction resulting from chronic alcohol abuse. The present report details the nature and extent of the amnesia in a Wernicke-Korsakoff patient who did not have a history of alcoholism. In spite of her normal performance on measures of frontal lobe function, this patient showed many characteristics similar to those seen in alcoholic Wernicke-Korsakoff syndrome including a graded loss of remote memories and abnormal semantic information processing. Thus, the extent of the "core" features of this amnesic syndrome may be greater than was previously thought.

Alcohol Amnestic Disorder↗

PubMed1990

Alzheimer's disease and depression: neuropsychological impairment and progression of the illness.

The authors longitudinally evaluated the cognitive functions of patients with probable Alzheimer's disease who also met criteria for major depression and compared them with matched patients with Alzheimer's disease who were not depressed. They found no significant difference in the pattern of neuropsychological deficits between the two groups; composite scores on attention, language, memory, learning, and visuospatial functions did not differentiate the two groups at baseline or at 1-year follow-up. The results of this preliminary report suggest that depression does not modify the neuropsychological features and the rate of progression of Alzheimer's disease.

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PubMed1990

Reliability of NINCDS-ADRDA clinical criteria for the diagnosis of Alzheimer's disease.

Although the NINCDS-ADRDA Work Group has recently developed uniform clinical criteria for the diagnosis of Alzheimer's disease (AD), inter-rater reliability studies of these criteria are few. We report a study in which 2 neurologists and 2 psychiatrists independently reviewed clinical data abstracted from the records of 30 demented subjects and 10 nondemented control subjects participating in a longitudinal study of AD at the University of Pittsburgh. We recorded the clinical data on a standardized form; the subjects' identity and clinical and pathologic diagnoses were omitted. Each physician diagnosed each case according to the NINCDS-ADRDA criteria. We calculated the inter-rater agreement for all possible 2-way combinations of clinicians with the Kappa statistic, which ranged from 0.36 (fair agreement) to 0.65 (substantial agreement). We conclude that current NINCDS-ADRDA criteria enable moderate levels of agreement among clinicians in general.

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PubMed1990

Neuropsychological performance in HIV-1-infected homosexual men: The Multicenter AIDS Cohort Study (MACS)

We administered a battery of standardized neuropsychological measures to assess cognitive functions in a group of 769 HIV-1 seronegative, 727 asymptomatic HIV-1 seropositive (CDC Groups 2 and 3), and 84 symptomatic HIV-1 seropositive (CDC Group 4) homosexual/bisexual men enrolled in the Multicenter AIDS Cohort Study (MACS). Measures included tests of attention, memory, and psychomotor speed. Comparison of group means revealed significant differences in performance between HIV-1 seronegative and symptomatic HIV-1 seropositive subjects on measures of memory and on measures with strong motor and psychomotor timed components. These findings support the sensitivity of these neuropsychological instruments for detecting cognitive changes that may be related to HIV-1, and are consistent with other reports of neuropsychological abnormalities in symptomatic HIV-1-infected individuals. Asymptomatic seropositive men, on the other hand, did not differ significantly from seronegative subjects on any of the neuropsychological measures. Only 5.5% of the asymptomatic HIV-1 seropositive men showed abnormal performance on individual tests. This proportion did not differ significantly from that of seronegative controls. Further, among asymptomatic seropositive subjects, we found no statistically significant differences as a function of duration of HIV infection or level of immune system functioning. Thus, results from this study support the hypothesis that the frequency of neuropsychological abnormalities in asymptomatic HIV-1-infected homosexual men is low, and not statistically different from that of seronegative controls.

Adult↗

PubMed1990

Incidental white matter hyperintensities on magnetic resonance imaging in HIV-1 infection. Multicenter AIDS Cohort Study.

Magnetic resonance (MR) scans were performed as part of a prospective neuropsychological study within the Multicenter AIDS Cohort Study. Fifty HIV-1-seronegative men, 85 HIV-1-seropositive men without constitutional symptoms, and 14 with symptomatic HIV disease underwent MR imaging using a uniform protocol. Scans were rated by neuroradiologists blinded to all clinical details except age. The majority of MR scans were normal in all of the clinical groups and no covert mass lesions or diffuse white matter abnormalities were identified. Focal hyperintensities in the white matter were observed in 24% of the HIV-1 seronegatives, 26% of HIV-1 asymptomatic seropositives (CDC II/III), and 17% of those with ARC/AIDS. No significant associations were noted between the white matter hyperintensities and HIV-1 serostatus, neurological abnormalities, CD4 count, alcohol or drug use, hypertension, or smoking. In one individual classified with early HIV-1 dementia, MR demonstrated several hyperintensities in the deep parietal white matter, but at autopsy no microscopic abnormalities corresponding to the MR findings were identified. Our studies imply that focal white matter hyperintensities identified on MR are not specific for HIV-1 infection and are probably incidental and of no clinical significance.

AIDS-Related Complex↗

PubMed1989

Vestibular responses in Wernicke's encephalopathy.

Two patients with Wernicke's encephalopathy were evaluated with quantitative vestibulo-ocular reflex and ocular motor testing. Vestibulo-ocular reflex testing included caloric irrigation, earth vertical axis rotational sinusoids, and rotational impulses. Both patients demonstrated hypoactive vestibular responses to both caloric and rotational stimuli at the time of presentation. One patient had unbeating nystagmus that diminished with upgaze, downgaze, or convergence. Following treatment with thiamine, both patients' vestibular responses improved but remained abnormal, with a short vestibulo-ocular reflex time constant and increased low-frequency rotational phase lead. Impairment of the velocity storage element attributable to damage to the vestibular nucleus and nucleus prepositus hypoglossi may account for this permanent effect on the vestibulo-ocular reflex.

Female↗

PubMed1988

Neuropsychological function in Alzheimer's disease. Pattern of impairment and rates of progression.

Although patients with Alzheimer's disease (AD) generally have impairments in multiple areas of cognitive function, there are those patients who appear to have neuropsychological deficits more prominent in one domain than in other domains. We examined the neuropsychological status of 86 patients with probable AD and 92 elderly control subjects and identified the patterns of impairments in the patients with AD. Independent deficits of visuoconstructional and lexical/semantic abilities were identified in a subset of patients by a principal components analysis. Individual patients were identified who were predominantly impaired in one, but not the other, neuropsychological domain. There were no striking relationships between the demographic characteristics of the patients and their pattern of deficits at the initial evaluation. There were no significant differences in age at onset or rate of progression of dementia among patients with different patterns of cognitive dysfunction. A review of the results of this and other studies suggests that the language impairment in AD may be associated with two distinct neuropsychological abnormalities: a lexical/semantic impairment that is unrelated to onset or progression of symptoms, and a syntactic impairment that may be associated with earlier onset and more rapid progression of dementia.

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PubMed1988

Working memory and secondary memory deficits in Alzheimer's disease.

The memory loss associated with Alzheimer's Disease (AD) may have multiple cognitive components. Working Memory appears to be impaired due to failures of a Central Executive System. Secondary Memory, on the other hand, is affected due to poor encoding or mediational processes. An analysis of the performance of 71 AD patients on tests related to these neuropsychological constructs revealed that they could indeed be dissociated. In fact, individual patients were identified with significantly different, and unique, patterns of impairment which were consistent with the two-component model. These data, therefore, lend preliminary support for the notion of multiple cognitive impairments being responsible for the memory loss in AD.

Adult↗

PubMed1987

Learning deficit in Parkinson's disease. Comparison with Alzheimer's disease and normal aging.

The learning ability of 12 patients with Parkinson's disease (PD) was studied using a verbal paired-associate learning task, and was compared with that of ten patients with Alzheimer's Disease (AD) and 12 controls (NC). Overall, the PD patients performed significantly better than the AD patients but significantly worse than the NC subjects. Their performance was not related to their overall level of cognitive functioning as measured by the Mattis' Dementia Rating Scale, but was unequally distributed suggesting that the PD population actually consisted of more than one subgroup. A low error group performed like controls, while a high error group had a learning impairment comparable to that of AD patients. It is concluded that PD patients may have three patterns of neuropsychologic performance: some are unimpaired, some have "focal" abnormalities, and some have a generalized impairment of cognitive function.

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PubMed1987

Normal rates of forgetting of verbal and non-verbal material in Alzheimer's disease.

Recent work has suggested that patients with damage to temporal lobe structures, such as patients with Alzheimer's Disease (AD), lose information from memory at an abnormally rapid rate. In contrast, data from other studies suggest that the rate of forgetting in AD is normal. In the present study, 62 patients with mild to moderate AD and 64 elderly controls were tested for their immediate and delayed recall of a short verbal passage and a modified Rey complex figure. The results suggest that although AD patients recalled less than controls, they did not forget at a faster rate during the 30 minute retention interval, supporting the finding that these memory impaired patients do not have an abnormal rate of forgetting. The data also suggest that poor initial encoding of the stimuli may be the cause of the AD patients' impaired recall.

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