Spatial Working Memory in Asymptomatic HIV-Infected Subjects

Abstract

Many clinical and research findings converge to indicate that frontal lobe, basal ganglia, and related neuronal connections are primarily involved in human immunodeficiency virus (HIV) infection; frontal lobe, mainly the prefrontal cortex, has a specialized role in working memory processes. This study focused on neuropsychological evaluation of the spatial component of working memory in a sample of 34 asymptomatic HIV-infected subjects as compared with 34 age- and sex-matched seronegative control subjects. A computer-administered test assessing spatial working memory was used for the neuropsychological evaluation. The findings did not show any spatial working memory impairment during the asymptomatic phase of HIV infection.

Verbal and spatial working memory performance among HIV-infected adults

“…Other studies that have failed to find working memory impairment in HIV-infected individuals have used asymptomatic patients (Grassi et al, 1999;Law et al, 1994;Mason et al, 2000). Considering that 74% of the HIV1 participants in the present study met CDC diagnostic criteria for AIDS, this suggests that working memory deficits may be evident only in the later stages of HIV disease.…”

“…While studies have shown that HIV infection affects working memory performance, a few have failed to find HIVassociated working memory impairment (Grassi et al, 1999;Law et al, 1994;Mason et al, 2000). One reason for this discrepancy may be differences across studies with respect to the cognitive demands needed to perform the working memory tasks.…”

“…One reason for this discrepancy may be differences across studies with respect to the cognitive demands needed to perform the working memory tasks. For example, Grassi et al (1999) used a task that appears to lack the manipulation component central to working memory, and as such resembles a short-term memory task. Sahakian and colleagues (1995) also noted that HIV-associated working memory deficits were mild and were only demonstrated on difficult tasks.…”

fMRI brain activation during a delay discounting task in HIV-positive adults with and without cocaine dependence

“…Specifically, they tend to select more cards from the disadvantageous, or “risky,” decks characterized by relatively large payoffs but also large penalties. HIV is believed to cause disruption in frontostriatal circuitry (Heaton et al, 1995) and most prominently affects sustained attention, executive functioning, and memory (Brew, 2004; Chang et al, 2001; Grassi et al, 1999; Heaton et al, 1995; Martin et al, 1995; Woods et al, 2008). The co-occurrence of drug abuse in HIV patients may contribute to neurocognitive impairments mediated by prefrontal-subcortical networks, including deficits in impulsivity and working memory (Farinpour et al, 2000; Martin et al, 2004; Rippeth et al, 2004).…”

Estudo dos transtornos cognitivos decorrentes da infecção pelo HIV-1

“…Déficits neuropsicológicos típicos, como perda da atenção sustentada, flexibilidade mental, velocidade motora, memória (Miller et al, 1990) e memória de trabalho (Law et al, 1994;Grassi et al, 1999), podem ser detectados em indivíduos com HIV/AIDS quando se aplicam testes neuropsicológicos adequados (Chang, Ernest, Leonildo-Yee, Walot & Singer, 1999;Suwanwelaa et al, 2000). Estes dados não puderam ser confirmados no estudo aqui descrito, provavelmente pela necessi- Embora alguns autores (Chang et al, 1999;Suwanwelaa et al, 2000) tenham relatado que alterações cognitivas possam ser mais facilmente detectadas por meio de exames de imagens em indivíduos com lesões mínimas ou mesmo imperceptíveis, estudo mais recente (Kemppainen, 2004) revelou que os testes neuropsicológicos são ferramentas mais sensíveis na identificação destas alterações, além de acessíveis quanto aos custos de execução e à simplicidade de aplicação, diferentemente dos exames de neuroimagem.…”