ISOLATED SO-CALLED APRAXIA OF EYELID OPENING - REPORT OF 10 CASES ANDA REVIEW OF THE LITERATURE

So-called apraxia of eyelid opening (scAEO) has been described chiefly in the context of extrapyramidal disorders. We described 10 new patie nts with scAEO developing in the absence of any other CNS sign and rev iewed the 11 cases with isolated scAEO reported in the literature. Com bining our patients and those from the literature, peak age at onset w as in the 6th decade and there was a female preponderance of 2:1. The characteristic inability to initiate lid elevation was frequently asso ciated with failure to sustain lid elevation, thus suggesting that eye lid motor control may be abnormal in isolated scAEO. Antecedent events included ocular signs and symptoms consistent with diseases of eyes o r face (4 cases in our series and 2 in the literature), chronic treatm ent with flunarizine (1 case), and family history of dystonia (1 case) . Flunarizine discontinuation led to sustained remission of the eyelid disturbance. Overall, these clues suggest the involvement of the extr apyramidal system in the pathophysiology of isolated scAEO. Familial c lustering of isolated scAEO in one of our patients may be in favor of a genetic contribution. In our series, botulinum toxin administration close to the pretarsal part of the orbicularis oculi muscle significan tly improved scAEO in 8/10 cases, whereas orbital/preseptal injection had no effect. We conclude that the term 'apraxia' may not be the corr ect descriptive term even when the eyelid disturbance occurs without a ny other CNS disease.