Lidocaine-dependent early infantile status epilepticus with highly suppressed EEG.

We report an early infantile patient characterized by intractable hyponatremia, progressive megalencephaly, and epileptic seizures with an EEG pattern that alternated between interictal low-voltage background and ictal burst activity. Repeatedly all the abnormal findings improved in a lidocaine-dependent manner. Given the pharmacologic mechanisms of lidocaine as a sodium channel blocker, we speculate that our patient had a sodium channel dysfunction.