Intracarotid amobarbital injection produces hippocampal EEG changes in patients with temporal lobe epilepsy.

EEGs of hippocampi of both sides were analyzed during intracarotid amobarbital tests in 12 patients with temporal lobe epilepsy. The number of paroxysms occurring 1 min before the injection ipsilaterally and contralaterally was compared with that occurring 1 min after the injection. The hippocampal EEG ipsilateral to the injection showed an increase in paroxysms irrespective of the laterality of the epileptogenic side. Contralateral to the amobarbital injection an increase in paroxysms was observed in the epileptogenic hippocampus only.