Sequence of electromyographic abnormalities in stroke syndrome.

In 20 stroke patients who were examined by repeated electromyography, fibrillation potentials and positive waves were noted as early as seven to ten days after the stroke and gradually disappeared as volitional potentials and spasticity appeared. This sequence of events occurred first in the antigravity muscles, then in their antagonists and finally in the most distal muscles. We hypothesize that the abnormal irritability is a consequence of the loss of the neurotrophic influence on the muscle fiber after the stroke.