Neuropsychological examination of cognitive impairment in human immunodeficiency virus type-1 (HIV-1) infection

Introduction. In addition to its ability to infect immune system cells, the human immunodeficiency virus type-1 (HIV-1), possesses neurotropism, that is, the virus is able to enter the central nervous system, even in patients without opportunistic brain neoplasia or infection. Development. To date, two different neurologic syndromes have been recognized; one of them being mild in nature (HIV-1 associated minor cognitive/motor disorder), the other being severe (HIV-1- associated dementia complex). These syndromes are known to cause impairment in different cognitive domains, as well as psychiatric and motor complaints. Here we review the different neuropsychologic tests, experiment computerized procedures (reaction time) and examination of the different types of ocular movements, which have been used from 1981 until now, with particular emphasis on the most commonly used neuropsychologic test batteries. Our results suggest that both neuropsychologic test batteries and reaction time procedures and ocular movement examination show that, as expected, the cognitive impairment is more commonly found in HIV-1-associated dementia complex patients as compared with those with HIV-1- associated minor cognitive/motor disorder. In the latter syndrome, cognitive impairment severity correlates well to disease stage, defined according to criteria by the Centers for Disease Control. However, there continues to be an important controversy as to the occurrence of cognitive deficit in the earliest HIV-1 infection stages (medically asymptomatic stage), probably due to lack of sensibility and specificity of neuropsychologic tests and other procedures used to detect cognitive impairment in earliest stages. Conclusion. There is a need for improving specificity and sensibility of neuropsychologic measurements currently used to detect cognitive impairment in HIV-1 infected patients in medically asymptomatic stage.