Early central nervous system response to HIV infection: sleep distortion and cognitive-motor decrements

Abstract

Objective: To repeat and extend findings suggesting that sleep disturbance, excessive daytime sleepiness, and degraded cognitive-motor abilities may be early markers of central nervous system (CNS) involvement in HIV infection.

Design: A controlled, cross-sectional, prospective analysis.

Setting: Clinical research center at a teaching hospital and a military health research center.

Subjects: Twenty-three HIV-positive (mean CD4+ count, 387 +/- 162 x 10(6)/l) and 13 seronegative men who were Naval personnel or participants of the University of California, San Diego HIV Neurobehavioral Research Center.

Main outcome measures: Nocturnal and daytime sleep electroencephalogram, electromyogram, and electrocardiogram. Simple and complex cognitive-motor performance assessed via computerized tasks.

Results: Comparison of sleep parameters based on HIV status, length of time infected, zidovudine use, and CD4+ count indicated that CD4+ T cells > 400 x 10(6)/l were associated with a distortion in nocturnal sleep characterized by increased stages 3 and 4 non-rapid eye movement (i.e., slow-wave) sleep in the latter portion of the night and reduced nocturnal awakenings. HIV-positive patients were no sleepier in the daytime than controls. Cognitive-motor performance revealed deficits in both accuracy and efficiency for HIV-positive patients.

Conclusion: Asymptomatic HIV-positive patients with CD4+ counts > 400 x 10(6)/l demonstrate a statistically significant increase in slow-wave sleep during the latter portion of the night and less arousability. CD4+ lymphocyte count in the early phases of HIV infection appears to differentiate between various levels of HIV disease progression with respect to certain CNS measurements of nocturnal sleep and cognitive-motor performance. Sleep structure distortion remains one of the earliest and most consistently replicable physiological signs of HIV infection. This distortion may provide a link to immune function, disease progression, and cognitive-motor disability in HIV infection.