Electroencephalographic and polygraphic features of 24-hour recordings in sleeping sickness and healthy African subjects.

Electroencephalographic (EEG) and polygraphic features were analysed in six healthy control subjects and eight patients suffering from sleeping sickness meningoencephalitis in order to determine possible functional relationships. One patient was disqualified because of intermittent metabolic disease. Twenty-four h polygraphic recordings-EEG, electrooculography (EOG), electromyography (EMG), nasal and buccal air flow, chest respiratory movements-were performed continuously both on paper and on cassette tapes. Tapes were played back on paper (paper speed: 15 mm/s). Traces were analyzed for normal and pathologic features, and transient activation phases and paroxysmal hypnopompic hypersynchrony events were counted. During wakefulness, slow theta and delta waves occurred in four patients, but alpha reactivity was present. During sleep, normal features were seen. However, transient activation phases were decreased in the patients. During slow-wave sleep, four patients presented predominantly monophasic frontal delta bursts along with paroxysmal hypnopompic hypersynchrony events. In conclusion, in sleeping sickness patients, although dampened, the waking process remains responsive and slows down only during the late stage of meningoencephalitis.