Ola A. Seines

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

Article abstract–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.

Language dysfunction in early- and late-onset possible Alzheimer's disease

Disproportionate involvement of language has been claimed to be a distinguishing feature of Alzheimers disease (AD) with onset before age 65. We tested this hypothesis in a group of 133 patients with possible AD by NINCDS criteria. Sixty-one had onset of symptoms prior to age 65; the remaining 72, at 65 or later. The two groups were well matched on overall dementia severity as measured by the Mini-Mental State Exam. Using standardized tests, we did not find any significant differences in the severity of language dysfunction between the two groups, particularly after controlling for greater attention/ concentration deficits in the early-onset group. Previous reports of differences in language dysfunction between early- and late-onset AD may have been due to small sample sizes and nonstandardized testing.

HIV‐1 infection and nervous system abnormalities among a cohort of intravenous drug users

A group of 109 HIV seropositive and 51 seronegative intravenous drug users was evaluated for the presence of HIV-1-related neurologic disease using clinical, neurologic, neuropsychological, and electrophysiologic evaluations. About 80% of HIV seropositive subjects had less than two constitutional symptoms. CD4 cell counts were less than 500/mm3 among 56% of seropositive participants; three individuals were receiving zidovudine. Neurologic abnormalities were found frequently among the cohort, independently of HIV-1 serostatus; electrophysiologic abnormalities were uncommon. Participants from both serologic groups scored significantly lower on neuropsychological tests as compared with norms established for a cohort of homosexual men, and there was no clear association between HIV-1 serostatus and performance on these tests. This study suggests that HIV infection was not the dominant cause of neurologic abnormalities among the study cohort.

Normative Data for a Brief Neuropsychologic Test Battery in a Cohort of Injecting Drug Users

Recent epidemiologic studies of the cognitive performance of injecting drug users have demonstrated the need to establish appropriate test norms for this population. This report provides normative data from a group of 150 injecting drug users on a battery of standardized tests of cognitive performance stratified by age group (range 20 to 49 years) and educational level (mean 11.6, standard deviation 2.0). The analysis also includes estimation of partial correlations between neuropsychologic test scores and age and education. The analysis demonstrates that age and education are important determinants of performance for several of these tests, and provides norms that may be of use as a reference for clinical evaluation and research in drug user populations.

Rater agreement for the Rey-Osterrieth Complex Figure Test

This report assesses the intrarater and interrater reliability of quantitatively scoring the Rey-Osterrieth Complex Figure Test (RCF). The intrarater correlation coefficients were .96, .99, and .96, and the interrater correlation coefficients were .88, .97, and .96 for the Copy, Immediate Recall, and Delayed Recall, respectively. However, statistically significant mean differences in score were found between raters on the Copy, Immediate, and Delayed Recall. Though the majority of structural units within the RCF are reliably scored, several units had a greater magnitude of observed scoring differences compared to the other units after adjusting for expected differences. Overall, reliability estimates demonstrate high intrarater reliability and acceptable interrater reliability except for the potential for systematic scoring differences.

Sustained Cognitive Decline in HIV Infection: Relationship to CD4+ Cell Count, Plasma Viremia and p24 Antigenemia

To determine the clinical and virological correlates of neuropsychological test performance decline in HIV infection, we measured viral burden in blood in 272 HIV-seropositive men without dementia in the Baltimore arm of the Multicenter AIDS Cohort Study (MACS). These measures were then related to neuropsychological (NP) decline, defined as a decline relative to prior best performance of 2.0 standard deviations or more on one or more neuropsychological tests. A short battery of NP tests (Mini-Screen Battery) was administered to all 272 men. NP test performance decline was identified in 53/272 (19.5%) of participants on the Mini-Screen Battery. Follow-up NP data were available for 204 participants who had undergone the Mini-Screen. The frequency of sustained NP test performance decline was 7.8% for the Mini-Screen Battery. A lower CD4+ cell count was weakly associated with sustained NP test performance decline. After adjustment for CD4+ cell count, hemoglobin, body mass index, and presence of AIDS, none of the viral burden measures (p24 antigenemia, plasma viremia, quantitative culture) correlated with sustained NP test performance decline. We conclude that these measures of blood HIV viral burden are not markers for NP decline, but that a lower CD4+ cell count is.

Brain reserve: HIV morbidity and mortality

Yaakov Stern, The Concept of Cognitive Reserve: A Catalyst for Research. Joseph H. Lee, Understanding Cognitive Reserve through Genetics and Genetic Epidemiology. Marcus Richards, Amanda Sacker, Ian J. Deary, Lifetime Antecedents of Cognitive Reserve. Maureen Dennis, Keith Owen Yeates, H. Gerry Taylor, J. M. Fletcher, Brain Reserve Capacity, Cognitive Reserve Capacity, and Age-Based Functional Plasticity after Congenital and Acquired Brain Injury in Children. Erin D. Bigler, Traumatic Brain Injury and Cognitive Reserve. Patricia A. Boyle, Susan A. Legendre Ropacki, Robert A. Stern, Electroconvulsive Therapy and Coronary Artery Bypass Grafting Surgery: Pseudoexperimental Paradigms for Studying Cognitive Reserve. Linas A. Bieliauskas, Ami Antonucci, The Impact of Cognitive Reserve on Neuropsychological Measures. Miranda G. Dik, Dorly J.H. Deeg, Marjolein Visser, Cees Jonker, Association between Early Life Physical Activity and Late-life Cognition: Evidence for Cognitive Reserve. Robert S. Wilson, Lisa L. Barnes, David A. Bennett, Assessment of Lifetime Participation in Cognitively Stimulating Activities. Brent J. Small, Tiffany F. Hughes, David F. Hultsch, Roger A. Dixon, Lifestyle Activities and Late-Life Changes in Cognitive Performance. Nikolaos Scarmeas, Lifestyle Patterns and Cognitive Reserve. M. J. Reinhard, P. Satz, O. A. Selnes, N. Sacktor, B. A. Cohen, J. T. Becker, E. N. Miller, Brain Reserve: HIV Morbidity and Mortality. Jennifer J. Manly, Nicole Schupf, Ming-Xin Tang, Yaakov Stern, Literacy and Cognitive Decline among Ethnically Diverse Elders. James A. Mortimer, David A. Snowdon, William R. Markesbery, Brain Reserve and Risk of Dementia: Findings from the Nun Study. Yaakov Stern, Imaging Cognitive Reserve. Cheryl L. Grady, Cognitive Reserve in Healthy Aging and Alzheimer Disease: Evidence for Compensatory Reorganization of Brain Networks. David Friedman, A Neurocognitive Overview of Aging Phenomena Based on the Event-Related Brain Potential (ERP). Yevgenia Kozorovitskiy, Elizabeth Gould, Adult Neurogenesis and Regeneration in the Brain.