Isolated so-called apraxia of eyelid opening: report of 10 cases and a 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 patients with scAEO developing in the absence of any other CNS sign and reviewed the 11 cases with isolated scAEO reported in the literature. Combining our patients and those from the literature, peak age at onset was in the 6th decade and there was a female preponderance of 2:1. The characteristic inability to initiate lid elevation was frequently associated with failure to sustain lid elevation, thus suggesting that eyelid motor control may be abnormal in isolated scAEO. Antecedent events included ocular signs and symptoms consistent with diseases of eyes or face (4 cases in our series and 2 in the literature), chronic treatment 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 extrapyramidal system in the pathophysiology of isolated scAEO. Familial clustering 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 significantly improved scAEO in 8/10 cases, whereas orbital/preseptal injection had no effect. We conclude that the term 'apraxia' may not be the correct descriptive term even when the eyelid disturbance occurs without any other CNS disease.