[Contribution of sleep EEG to epileptology: evaluation of a year-long study]

In order to confirm, or to deny, the diagnosis of epilepsy a sleep EEG recording as a supplement to the routine EEG investigation has been performed in 229 subjects in 1980 at Saint Paul Center. In 93% of the cases, spontaneous afternoon napping, and in 7% spontaneous nocturnal sleep was studied. Sleep EEG was analysed and correlated to the clinically suspected type of epilepsy. The occurrence of focal or generalized EEG abnormalities, clearly related to the type of epilepsy, confirmed anamnestic and clinical findings in 54% of the cases and gave a more accurate diagnosis in 20% of the cases. Sleep recordings were necessary for the diagnosis of the type of epilepsy in 2% of the cases.