Detection of subclinical motor dysfunctions in early symptomatic HIV infection with topographical EEG

Motor dysfunctions are amongst the earliest and most common signs of brain impairment caused by human immunodeficiency virus (HIV) infection. Topographical EEG was recorded in patients both with asymptomatic and early symptomatic infection (without acquired immunodeficiency syndrome (AIDS) defining illness), as well as in seronegative controls under resting and motor activation conditions. While patients' motor performance did not differ from control values, the EEG showed a consistent increase in rhythmic activity in Theta, Alpha and Beta frequency bands in Symptomatics. This amplitude increase was evident in different topographical regions during resting states as compared with motor activation, findings which suggest concurrent involvement of several motor areas possibly due to a functional impairment in subcortical integratory mechanisms. Comparing motor task and baseline both patient groups showed less consistent patterns of task-related EEG amplitude reduction than found in the control group. Here topographical EEG in connection with motor activation procedures was found to be more sensitive than behavioral measures of motor performance and offers a technique to assess treatment effects before the development of motor abnormalities in patients with HIV infection.