Idiopathic generalized epilepsy presenting with hemiconvulsive seizures

Unilateral seizures, or hemiconvulsive attacks, are motor seizures with tonic and/or clonic phenomena that involve only one side of the body.

We describe three adolescents who presented with hemiconvulsive seizures and were found to have 3-cps generalized spike-and-wave discharges on ictal and/or interictal EEG. All had normal neuroimaging studies. Two patients had been previously treated with carbamazepine, which led to a partial response in one patient.

All three patients, however, are now seizure free on either sodium valproate or a combination of sodium valproate and lamotrigine. We believe the electroclinical diagnosis is that of idiopathic generalized epilepsy.

Idiopathic generalized epilepsy presenting with hemiconvulsive seizures has not, to our knowledge, been previously described. However, the correct diagnosis of an idiopathic generalized seizure disorder, as opposed to a partial seizure disorder, has important treatment implications. The possible mechanism of hemiconvulsive seizures in idiopathic generalized epilepsy is discussed.