Striatal activation during blepharospasm revealed by fMRI.

OBJECTIVE To investigate brain areas involved in the initiation and execution of eyelid spasm in patients with benign essential blepharospasm. METHODS The authors used fMRI and correlated the blood oxygenation level-dependent (BOLD) signal with epochs of frequent eyelid spasm in six patients and with epochs of voluntary eye blinks in four healthy subjects. RESULTS Spasm epochs were accompanied by activation in a subregion of the putamen in all patients, whereas voluntary blinking in healthy subjects was not. Other areas of activation common to patients and healthy subjects included frontal and parietal operculum, supplementary motor area, primary sensorimotor cortex, various visual areas, and the cerebellum. CONCLUSIONS The striatum may be involved in the initiation or execution of eyelid spasm. Future studies, possibly including electromyography (EMG) during fMRI, are needed to detect the sequence and role of other concomitantly activated areas.