Synkinetic blepharoclonus

Abstract

Objectives: To analyze the clinical data and test results collected in a group of patients exhibiting eyelid-closure blepharoclonus (BLC) on clinical neurologic examination.

Materials and methods: Thirty-five patients were referred for neurologic evaluation for reasons other than BLC. Clinical electrophysiologic evaluations, including cranial nerve testing and electromyograms, were done according to standards. All patients had neuroimaging studies, including brain magnetic resonance imaging and head computerized tomography, or both, and many had electroencephalograms. Additional tests were done based on the patient's symptoms or reasons for referral.

Results: Eight patients had reflex BLC. Two cases were precipitated by vertical gaze; one of these patients had hereditary palmoplantar keratoderma and cataplexy, and the other patient had Ehlers-Danlos syndrome and familial BLC. Other precipitants included speech in four cases, postural changes in two cases, and light stimulation in one case. Two patients had generalized myoclonus independent of their BLC, two patients had a history of sleep myoclonus, and several patients had BLC-associated facial myoclonus. One patient had BLC-associated myoclonus of the right shoulder. Synkinetic cranial movements were detected in 11 patients (four oculofacial, three oculopterygoid, one oculolingual, two dual cases, and one case of imitation synkinesis.) Three patients had familial BLC, seven patients had congenital developmental disorders, six patients had synkinetic tremors, and six patients had restless feet. Some indication of peripheral neuropathy was evident in eight patients.

Conclusions: Eyelid-closure BLC is an underrecognized, sporadic or familial, mostly benign, chronic eyelid-movement disorder that may be associated with tremors, myoclonus, cranial synkinesis, and restless feet. Reflex mechanisms may be identified in some patients. Gaze-induced BLC seems to have the greatest clinical relevance. In the current series, there were no examples of posttraumatic BLC, multiple sclerosis, hydrocephalus, or blepharospasm conditions previously reported to be associated with BLC. No electroencephalographic abnormalities were recorded during BLC, ruling out eyelid-closure epilepsy.