Cocaine abuse, generalized myasthenia, complete external ophthalmoplegia, and pseudotonic pupil.

We present the case of a 29-year-old woman with generalized myasthenia. Myasthenia with complete external ophthalmoplegia was unmasked by cocaine abuse. It was associated with changes of the pupillary motility, including light-near dissociation and positive 0.1% pilocarpine test. Treatment with acetylcholinesterase inhibitors improved the patient's condition rapidly, and led to complete normalization of extraocular movements and pupillary function. To our knowledge, this is the fourth case of cocaine-related myasthenia, and the first case of myasthenia with pseudotonic pupil.