Abstracts

Rationale: Hashimoto encephalopathy (HE) is a rare cause of epilepsy in children. Patients are usually unresponsive to anticonvulsant therapy. The clinical presentation and natural history of HE in children has been poorly characterized. Methods: To better characterize the epilepsy in children with HE, a retrospective chart review of all cases of HE seen in children (less than 16 years old) seen during the last five years was performed. Special attention was paid to clinical presentation, EEG, therapy and outcome. Results: Eight patients (age 1.5 to 15 YO) carried diagnosis of HE: five were female (mean age 10 YO) and three were male (mean age 7.5 YO). Two girls (mean age 9 YO) and one boy (9 YO) had epilepsy. Seizures were preceded by behavior changes in both girls. One girl presented with myxedema before onset of seizure. Behavior changes were a late finding in the boy and alternating hemiplegic migraine occurred after the onset of the first seizure. In the three HE patients with epilepsy, seizures were either generalized tonic clonic or partial complex with status epilepticus, refractory to anticonvulsants, but exquisitely responsive to steroid therapy. EEG shows a focal or generalized encephalopathy. Hypothyroidism required treatment in the 3 HE patients with epilepsy. Conclusions: Epilepsy can be the first symptom in HE, but behavioral changes frequently precede the onset of symptoms. Status epilepticus with partial or generalized seizures may be the first manifestation.