Search PubMed⌕ Search

Biomedical subjects

R K Heaton

Publications and source records attributed to R K Heaton.

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

Neuropsychological studies of asymptomatic human immunodeficiency virus-type-1 infected individuals. The HNRC Group. HIV Neurobehavioral Research Center.

The current review was conducted to address the ongoing debate regarding the presence or absence of neuropsychological impairment in asymptomatic HIV-Type 1 (HIV-1) seropositive individuals. Results were summarized from 57 studies that compared the performances of seropositive asymptomatic and seronegative individuals. Overall, the differences observed between median rates of impairment for asymptomatic (35%) and seronegative (12%) groups provided the clearest indication of deficits in asymptomatics. In addition, five variables were examined as possible contributors to inconsistencies found in the literature: mode of infection, test battery type, test battery size, sample size, and method of data analysis. Of these variables, only mode of infection and test battery size appeared to substantially influence the outcome of the studies reviewed with regard to identifying neuropsychological impairment in asymptomatics.

AIDS Dementia Complex↗
PubMed1995

Gender differences in schizophrenia.

In an assessment of gender differences in schizophrenia, 85 outpatients (53 men and 32 women) with schizophrenia were evaluated for illness history, symptom severity, IQ, neurocognitive status, cerebral volume loss, and cortical asymmetry. Social functioning was assessed using marital status, independent living skills, and employment status. Significant gender differences were found, as women were on lower doses of neuroleptic medications and more frequently met criteria for paranoid and disorganized subtypes of schizophrenia than men. Women also were better educated and more often married, living independently, and employed. No gender differences were found in present age, symptom severity, neurocognitive functioning, or clinical magnetic resonance imaging scan readings. Our findings suggest that women may experience less of the adverse interpersonal psychosocial consequences of schizophrenia than men, even when symptom and neurocognitive status is equivalent between groups. However, more extensive investigations are warranted to better understand the role of pathophysiological or social mechanisms in gender differences.

Activities of Daily Living↗
PubMed1994

HIV-associated psychosis: a study of 20 cases. San Diego HIV Neurobehavioral Research Center Group.

OBJECTIVE: Psychosis is an uncommon but serious complication of infection with HIV. This article presents the results of a study of HIV-infected individuals with psychosis. METHOD: The authors evaluated 20 HIV-infected men who had noniatrogenic new-onset psychosis without delirium, current substance abuse, or previous psychotic episodes. Clinical, neuropsychological, CSF, magnetic resonance imaging, and neuropathologic assessments were made. A comparison group consisting of 20 nonpsychotic HIV-infected men matched to the psychotic subjects with respect to age, race, years of education, and Centers for Disease Control HIV stage was also evaluated. RESULTS: The psychotic patients differed from the nonpsychotic comparison subjects in having significantly higher rates of past stimulant and sedative/hypnotic abuse or dependence and, at follow-up, a significantly higher rate of mortality. They also showed a trend toward greater global neuropsychological impairment. CONCLUSIONS: New-onset psychosis may be, at least in part, a manifestation of an HIV-associated encephalopathy.

AIDS Dementia Complex↗
PubMed1994

Neurobehavioral and neurodiagnostic aspects of late-onset psychosis.

The onset of psychotic symptoms later in life requires careful multidisciplinary evaluation, yet may pose significant diagnostic difficulties given current classification schema. Here we describe a patient with new onset of schizophrenia-like symptoms at age 61. Cognitive screening and laboratory tests were within normal limits. However, detailed neuropsychological studies suggested mild to moderate, diffuse cerebral dysfunction, and MR revealed an arachnoid cyst around the right sylvian fissure. Three annual follow-up evaluations demonstrated no additional cognitive deterioration. Neuropsychological findings are discussed along with limitations of current psychiatric nosology and cognitive screening tasks in older patients with new-onset psychosis.

Journal Article↗
PubMed1992

Epidural blood patch in the HIV-positive patient. Review of clinical experience. San Diego HIV Neurobehavioral Research Center.

To characterize the natural history of autologous epidural blood patch (EBP) in human immunodeficiency virus (HIV)-seropositive patients, records from an ongoing longitudinal study of the neuropsychological manifestations of HIV infection were retrospectively reviewed. Of 252 participants (218 HIV-seropositive, 34 HIV-seronegative) who underwent at least one diagnostic lumbar puncture, 9 (7 seropositive, 2 seronegative) required EBP for post-dural puncture headache. After EBP, 6 of the seropositive subjects underwent serial neuropsychological evaluations over periods ranging from 6 to 24 months; none of these six subjects had a decline in neurocognitive performance or other adverse neurologic or infectious sequelae. We were unable to identify morbidity attributable to EBP in the HIV-seropositive patient followed for as long as 2 yr.

Adult↗
PubMed1992

Negative symptomatology in schizophrenic outpatients.

This study examines the prevalence of negative symptoms, and assesses the convergence of negative and depressive symptoms in 60 chronically ill schizophrenic outpatients. Negative symptoms were assessed with the Scale for the Assessment of Negative Symptoms and the negative symptom cluster of the Brief Psychiatric Rating Scale (BPRS). Depressive symptoms were assessed with the depression subscale of the Brief Symptom Inventory and the depressive symptom cluster of the BPRS. A majority of patients in this group of relatively stable, schizophrenic outpatients demonstrated mild to moderate degrees of both negative and depressive symptoms. Correlations were not significant between negative symptom and depressive symptom measures, which suggests that the symptom constructs are relatively independent. Comparisons between a subgroup with prominent negative symptoms (N = 18) and a subgroup with minimal negative symptoms (N = 32) also revealed no significant group differences in variables that characterize clinical course (i.e., age of onset and frequency and duration of hospitalization) or in the severity of depressive symptoms. This lack of any significant differences on the clinical course variables may be partially explained by the heterogeneity of negative symptoms. The constellation of negative symptoms may differ not only in etiology but also in their temporal relationships to other aspects of the patient's clinical course. Longitudinal studies will be needed to track the long-term outcome of negative and depressive symptoms.

Adolescent↗
PubMed1992

Incidence of AIDS dementia in a two-year follow-up of AIDS and ARC patients on an initial phase II AZT placebo-controlled study: San Diego cohort.

In a prospective study to determine the incidence of clinical dementia in patients with AIDS and ARC, 29 men and 3 women, 19 with ARC and 13 with AIDS, were examined neurologically and neuropsychologically every 6 months for 2 years during a placebo-controlled zidovudine (AZT) licensing trial. Most received two MRI brain scans. Although no patient was clinically demented at baseline, 9 (28%) developed dementia during the 2 years. Progression to dementia was associated with neuropsychological deterioration and with worsening on MRI during a preceding 6-month period, but not with baseline treatment group assignment. The results suggest that patients at CDC Stage IV who do not receive antiretroviral treatment earlier in their illness may develop clinical dementia at an annual rate of about 14%.

AIDS Dementia Complex↗
PubMed1992

Neuropsychological impairment in chronic cocaine abusers.

Twenty chronic cocaine abusers were compared with age and education matched controls using standardized neuropsychological assessment procedures to determine whether the cocaine abusers were impaired. Fifty percent of the cocaine abusers in contrast to 15% of the controls scored in the impaired range on the summary index of the Neuropsychological Screening Exam. The cocaine abusers also performed more poorly on the Halstead Category Test, the Symbol Digit Modalities Test, the WAIS-R Arithmetic Test, and a test of verbal memory (forgetting). In the cocaine abuser sample, neuropsychological performance was related to the amount and recency of cocaine use, suggesting a direct role of cocaine on cognitive functioning.

Adult↗
PubMed1991

Magnetic resonance imaging abnormalities in lenticular nuclei and cerebral cortex in schizophrenia.

Neuropathologic and brain imaging studies have produced evidence of brain abnormalities in schizophrenic patients, often within the cerebrum's limbic lobe, and, less frequently, within basal ganglia. In the present study we used magnetic resonance imaging morphometric techniques to estimate volumes of specific cerebral structures in schizophrenic patients and age- and sex-matched normal controls. Estimates of the volume of mesial temporal lobe structures were reduced and estimates of the volume of the lenticular nucleus were increased in the schizophrenic patients. There was also evidence of reduced cranial volume in some schizophrenics. The magnitude of the lenticular abnormality, but not the temporal lobe abnormality, was associated with age at first psychiatric contact; earlier onset was associated with larger lenticular nuclei. The possible relevance of these results to neurodevelopmental hypotheses about the pathogenesis of schizophrenia is discussed.

Adolescent↗
PubMed1991

Deficit syndrome in older schizophrenic patients.

Previous studies have reported that a proportion of younger schizophrenic patients have the "deficit syndrome," with persistent "negative" symptoms not secondary to factors other than the disease process (e.g., depression). Yet, there is scant information on the deficit syndrome in older schizophrenic patients. We studied 46 schizophrenic patients over age 45. Seventeen met the criteria for the deficit syndrome as described by Carpenter et al. (1988), 20 were considered definite nondeficit patients, and 9 could not be classified. The deficit schizophrenic patients had a significantly higher total score on the Scale for the Assessment of Negative Symptoms but similar scores on scales for positive symptoms, depressive symptoms, and overall psychopathology as compared with nondeficit patients. The deficit patients also had a nonsignificantly greater impairment on the Halstead-Reitan Battery. One notable difference between our results and those of Carpenter et al. was in the prevalence of deficit syndrome. We found the prevalence (37%) to be significantly higher than that reported in younger patients (15%). Pending confirmation using larger sample sizes, the increased frequency of the deficit syndrome in our study could possibly be attributed to aging or a longer duration of illness in our subjects.

Aged↗
PubMed1990

Human immunodeficiency virus-type 1 (HIV-1) and the brain.

Infection with human immunodeficiency virus Type-1 (HIV-1), the causative agent of AIDS, can be associated with central nervous system as well as immune system disease. Advanced AIDS can be complicated by a dementia. Short of frank dementia, many AIDS patients manifest neuropsychological (NP) impairment including disturbance in speeded information processing, abstraction, learning, and recall. Data conflict on whether medically asymptomatic HIV-1 carriers have subtle NP deficits. Variations in tests chosen, criterion specification, and sample selection may all be contributing to disparate results. Longitudinal research is needed, and this should examine representative samples of HIV-1 seropositive individuals for whom approximate date of seroconversion is known and in whom sources of comorbidity (e.g., drug abuse, concurrent infections, CNS injuries) can be specified.

AIDS Dementia Complex↗
PubMed1990

White matter dementia in chronic toluene abuse.

We studied 14 chronic toluene abusers with a comprehensive neuropsychological evaluation and cerebral magnetic resonance imaging (MRI). There were 10 men and 4 women, and the mean age was 29 years. Using a blinded global assessment of neuropsychological functioning, we found 3 patients to be normal, 3 in a borderline range, and 8 impaired. Independent analyses of white matter changes on MRI disclosed that the degree of white matter abnormality was strongly correlated (p less than 0.01) with neuropsychological impairment. Dementia in toluene abuse appears to be related to severity of cerebral white matter involvement.

Adult↗
PubMed1989

A comparison of dementia in Alzheimer's disease and multiple sclerosis.

We compared results of comprehensive neuropsychological testing in 42 patients with clinically diagnosed Alzheimer's disease (AD) and in an equal number of patients with clinically definite chronic-progressive multiple sclerosis. Age, sex, and education were controlled using demographically corrected T scores based on a large normal sample. Both groups showed significant impairment on the test battery, but the degree of dementia was more severe in the patients with AD. A deviation score analysis, controlling for overall level of cognitive impairment, revealed significant differences between the groups. Alzheimer's disease was associated with relatively greater impairment of learning, memory, and verbal skills, whereas the MS group showed greater relative impairment of attention, incidental memory, and psychomotor functions. These data suggest that both the degree and pattern of mental impairement differ in patients with AD and patients with multiple sclerosis. Our results support a distinction between "gray matter" and "white matter" dementia, and may help clarify the issue of "cortical" vs "subcortical" dementia by demonstrating neuropsychological differences based on secure neuropathologic distinctions.

Aged↗
PubMed1989

Cognitive loss in multiple sclerosis. Case reports and review of the literature.

Neuropsychological and neuroradiologic evidence of cerebral lesions is described for 12 patients with multiple sclerosis in whom cognitive disability was far greater than any other neurologic disability. Cognitive dysfunction resulted in significant functional impairment at work or home in three fourths (9 of 12) of the patients described here, despite mild physical disability (mean Kurtzke Expanded Disability Status Scale score, 3.2). A unique feature of the neurologic examination in these patients was the presence of prominent frontal release signs (gait apraxia and placing response) in the lower extremities. Two new scales, a Cognitive Function Scale and a Frontal Release Scale, were adapted for the investigation of these patients. The extensive literature relating to cognitive dysfunction in multiple sclerosis is reviewed and discussed with regard to its clinical relevance.

Adult↗