Blink reflex in hemiplegia.

Data about the influence of hemispheric lesions on the blink reflex are conflicting. 21 hemiplegic patients and 11 control subjects were investigated. The duration, latency and electric area of electrically evoked blink reflex responses were evaluated by common electromyographic techniques. A depression of the ipsilateral and the consensual late response after stimulation of the paretic side was the most evident finding. However, also a certain increase of the early response and a depression of the late response of the paretic side independent of the side of stimulation emerged. Concerning the parameters taken into account, the evaluation of the latency period seems to be the most significant and reliable. Determination of the electric area provides additional useful data which, however, may easily lead to mistakes.