Stroke-induced resolution of primary blepharospasm: evidence for the lenticular nucleus as a control candidate.

Primary blepharospasm is an adult-onset focal dystonia characterised by involuntary contractions of the orbicularis oculi, leading to bilateral spasmodic closure of the eyelids. While spasms of this muscle constitute the hallmark of disease, other motor manifestations include increased spontaneous blinking and apraxia of eyelid opening. Originally misdiagnosed as a psychiatric condition, blepharospasm is now well established as being of neurological origin although questions remain as to its pathophysiological mechanisms.We report a 66-year-old woman who had a 14-year history of primary blepharospasm which completely resolved following a left medial cerebral artery thromboembolic infarct of the lenticular nucleus. This report provides supporting evidence of the lenticular nucleus as a key structure mediating the disease which can lead to functional blindness.