Epidural Cortical Stimulation as a Treatment for Poststroke Aphasia: A Systematic Review of the Literature and Underlying Neurophysiological Mechanisms.

Nearly 15 million people suffer from stroke every year worldwide, with about 20% of the survivors retaining chronic aphasic symptoms. Spontaneous recovery is limited to 3 to 6 months. Cortical stimulation techniques have been proposed to enhance the recovery process.