Can EEG characteristics predict development of epilepsy in autistic children?

Abstract

Background: The high occurrence of epilepsy in children with autism spectrum disorders (ASD) is a clear indication that ASD has a neurobiological basis. The current understanding of the association between epilepsy and ASD is still limited, but from a clinical point of view, this association should not be overlooked.

Aims: We investigated the electroencephalogram (EEG) paroxysmal abnormality in children with ASD and the incidence of later development of epilepsy.

Methods: Participants were recruited from University of Yamanashi hospital and 5 satellite hospitals between April 1, 2001 and March 31, 2005. EEG recordings and clinical evaluations were performed every 6 months for at least 6 years, focusing on paroxysmal abnormality. We scored the occurrence and the location of spikes and evaluated the relation with later development of epilepsy.

Results: The prospective study included 21 patients with ASD (12 males and 9 females) between the ages of 3 and 6 years. EEG paroxysmal abnormalities were present in 11/21 patients (52.4%). In addition, six of 21 patients (28.6%) had epilepsy at some point in their lives. The presence of frontal paroxysms was significantly associated with later development of epilepsy compared with centrotemporal paroxysmus (p < 0.003). The type of seizure diagnosed was mainly partial; in particular, partial with secondary generalization in 4/6 (66.7%).

Conclusion: The presence of frontal paroxysms may indicate a higher risk of epilepsy in ASD.