A case of lamotrigine-induced excessive involuntary eye blinking.

A wide variety of movement disorders can be induced by the administration of antiepileptic drugs. A 44-year-old female was admitted with involuntary excessive eye blinking that manifested 5 months after beginning the administration of lamotrigine for control of complex partial and secondarily generalized seizures. The involuntary eye blinking persisted while taking lamotrigine, and disappeared 1 month after the cessation of lamotrigine. The development of atypical involuntary eye blinking in this case may have resulted from the inhibition of excitatory neurotransmitters by lamotrigine, which led to secondary dysfunction of the dopaminergic system.