Eyelid movement disorders and electromyography

Mikio Hirayama and colleagues (Oct 21, p 1413)1Hirayama M Kumano T Aita T Nakagawa H Kuriyama M Improvement of apraxia of eyelid opening by wearing goggles.Lancet. 2000; 356: 1413Summary Full Text Full Text PDF PubMed Scopus (17) Google Scholar report improvement of apraxia of eyelid opening in two patients by wearing goggles. They used F Lepore and R Duvoisin's criteria2Lepore FE Duvoisin RC Apraxia of eyelid opening: an involuntary levator palpebrae inhibition.Neurology. 1985; 35: 423-427Crossref PubMed Google Scholar to diagnose eyelid apraxia of a transitory inability to open the eyelid with no evidence of continuing orbicularis oculi activity, such as lowering of the brows beneath the superior orbital margins (Charcot's eyebrow sign of blepharospasm). Yet, in our opinion, a diagnosis is almost impossible to make on the basis of the clinical picture alone, and exact diagnosis requires electromyography. We have reported three patients with eyelid opening disorders.3Aramideh M Ongerboer de Visser BW Koelman JHTM Speelman JD Motor persistence of orbicularis oculi muscle in eyelid-opening disorders.Neurology. 1995; 45: 897-902Crossref PubMed Scopus (49) Google Scholar The first patient's symptoms were similar to those of the first patient of Hirayama and colleagues. We recorded electromyographic activity from the levator palpebrae and the orbicularis oculi muscles simultaneously. On the command to open the eyelids, our patients seemed unable to inhibit the discharges in the orbicularis oculi muscle (figure). This motor persistence was mainly restricted to the pretarsal portion of the orbicularis oculi. This muscle, just above the eyelashes, gives no impression of continuing orbicularis oculi contraction during clinical observation and, therefore, does not cause Charcot's sign. Our patient responded to botulinum toxin injections into the pretarsal orbicularis oculi muscle. Such a favourable response is reported in Hirayama and colleagues' first patient and suggests some continuing involuntary activity of the orbicularis oculi muscle. Clinical criteria would suggest apraxia of eyelid opening in all three of our patients, and exact diagnosis was only possible by use of electromyography. Furthermore, involuntary spasmodic contraction of the orbicularis oculi muscle might be restricted to the pretarsal portion of this muscle, with no Charcot's sign or other evidence of continuing orbicularis oculi contraction on clinical assessment.4Aramideh M Ongerboer de Visser BW Devriese PP Bour U Speelman JD Electromyographic features of levator palpebrae superioris and orbicularis oculi muscles in blepharospasm.Brain. 1994; 117: 27-38Crossref PubMed Scopus (116) Google Scholar The underlying mechanism for difficulty in opening the eyelid, such as a dysfunction of the levator palpebrae muscle, motor persistence or spasms restricted to the pretarsal part of the orbicularis oculi muscle, or a combination of these, can be clarified only with synchronous electromyography of the levator palpebrae and orbicularis oculi muscles, or at least of different parts of the orbicularis oculi muscle at the time of opening the lids. We suggest, therefore, that diagnostic criteria should include inability to sustain lid raising in the absence of clinical and electromyography evidence of continuing orbicularis oculi activity. Hirayama and colleagues suggest that the underlying mechanism of improvement of apraxia of eyelid opening by goggles could be the proprioceptive input to the central nervous system. Yet, this assumption is unlikely because the facial muscles, especialy the orbicularis oculi, have no proprioceptive receptors. A central modification induced by afferent impulses conducted through the trigeminal system seems more likely. Eyelid movement disorders and electromyographyAuthor's reply Full-Text PDF