Spontaneous eye blinking, a measure of dopaminergic function, in children with acquired immunodeficiency syndrome

H. Vreugdenhil, P. Brouwers, P. Wolters, D. Bakker and H. Moss
HIV and AIDS Malignancy Branch, National Cancer Institute, Bethesda, Md., USA.

OBJECTIVE: To investigate possible alterations in dopaminergic function in children with acquired immunodeficiency syndrome by evaluating spontaneous eye blink rate, a putative measure of central dopaminergic function. DESIGN: Evaluation of previously videotaped test sessions of a consecutive case series of 50 children (mean age, 5.2 years; range, 2-12 years) with acquired immunodeficiency syndrome. SETTING: Government medical research center. RESULTS: Intrarater reliability was high, expected co-variation of blink rate with age and concurrent mental activity were confirmed, and obtained rates were similar to published data. Higher blink rates, suggestive of increased dopaminergic function, were associated with more severe cortical atrophy (P < .05) and white matter abnormality (P < .05) on computed tomographic brain scans. The presence or severity of basal ganglia calcifications did not seem to influence blink rate. In addition, higher blink rates were associated with higher ratings of depressed affect (P < .05) and lower ratings of hyperactive behaviors (P < .05) during other test activities. CONCLUSIONS: The higher blink rates in human immunodeficiency virus-infected children with more severe cortical abnormalities suggest increased central dopamine activity compared with that in children without cortical computed tomographic brain scan abnormalities. Thus, as a result of structural brain abnormalities, neurotransmitter levels in children with acquired immunodeficiency syndrome may vary and this may be reflected in their socioemotional functioning.