Zonisamide treatment of early infantile epileptic encephalopathy

A case of early infantile epileptic encephalopathy with suppression-bursts (EIEE or Ohtahara syndrome) with an excellent response to zonisamide is reported. Tonic spasms began immediately after birth and increased in number, such that they formed a series of several dozen spasms lasting for 5 to 15 minutes. When the patient was 1 month old, a partial clonic seizure emerged predominantly on the right side of her face and extremities. It was often followed by tonic spasms and later continued after the beginning of the spasm series. Interictal electroencephalography demonstrated an atypical suppression-burst pattern and focal paroxysmal discharges. Detailed hematologic tests, magnetic resonance imaging, single-photon emission computed tomography, and auditory brainstem response did not reveal any metabolic or structural abnormalities. Oral administration of zonisamide first controlled the partial seizures and, subsequently, the tonic spasms in a dose-dependent fashion. The mode of response to zonisamide and the findings on electroencephalography indicate that EIEE may be caused by multiple independent brain lesions and that EIEE is a heterogeneous disorder. It is suggested that zonisamide may be useful in the treatment of EIEE.