Generalized convulsions with diffuse spike and wave bursts emerging with Graves' disease.

Thyroid hormone lowers the seizure threshold. We present the case of a female patient who developed generalized convulsions emerging with Graves' disease, and clarified the clinico-electroencephalographic characteristics. Before treatment, electroencephalography (EEG) showed 2- to 2.5-Hz diffuse spike and wave (SW) bursts, apparent during and after hyperventilation without any distinct absence seizure. Thiamazole treatment without any anticonvulsant led to a euthyroid state, convulsions resolved and EEG abnormalities normalized promptly. Clinical seizures were generalized tonic-clonic convulsions during sleep, and EEG showed diffuse SW bursts induced by hyperventilation. These characteristics suggested that epilepsy might correspond to idiopathic generalized epilepsy (IGE). IGE might be susceptible to hyperthyroidism. Cases of IGE emerging with hyperthyroidism, even if EEG paroxysms are advanced, may be improved using antithyroid pharmacotherapy alone.