Paroxysmal EEG abnormalities and epilepsy in pervasive developmental disorders: follow-up study until adolescence and beyond

SPECT findings in autism spectrum disorders and medically refractory seizures

A high rate of seizures and electroencephalogram abnormalities has been noted in individuals with autism spectrum disorders (ASDs). Common underlying neurodevelopmental abnormalities may exist in the brains of individuals with both ASDs and epilepsy. Single-photon emission computed tomography (SPECT) studies of the brain have provided sensitive brain function findings. Such studies often reveal not only localized areas of hyperperfusion, which could be related to the seizure-onset zone, but also localized areas of hypoperfusion that may correlate with the focal reductions in function observed in the prefrontal lobes, cingulate gyrus, superior temporal gyrus, and mesial temporal lobes of many individuals with both ASDs and epilepsy. The focal neuronal dysfunction revealed by SPECT could be caused by aberrant neuronal connectivity. This article is part of a Special Issue entitled "Autism and Epilepsy".

Effect of levetiracetam on behavioral problems in pervasive developmental disorder children with epilepsy

AIMS

We investigated the relationship between behavioral problems, location of electroencephalogram (EEG) paroxysmal abnormalities (PA), and treatment with levetiracetam in children with pervasive developmental disorder (PDD) and epilepsy.

METHODS

Twelve PDD children with epilepsy were included in the study. All patients had EEG PA (frontal spikes, 8; rolandic, 3; generalized, 1). After a 3-month baseline period, patients were given levetiracetam with an initial dose of 10 mg/kg/day for the first week, followed by increments of 5 mg/kg/day every week. Levetiracetam dosage was then adjusted up to a maximum of 60 mg/kg/day. EEG recordings were performed every 3 months, focusing on PA frequency. We counted the frequency of seizures and EEG PA, and scored instances of panic/aggressive behaviors.

RESULTS

Eight (66.7%) of the 12 patients were considered to be responders to clinical seizures and EEG findings (≥50% reduction in both seizures and PA frequency). Six (75%) of these eight patients were considered to be responders for behavioral problems (≥50% reduction in panic/aggressive behavior). These six patients had frontal EEG paroxysms, whereas the remaining two patients without behavioral responses had rolandic EEG paroxysms. Patients with frontal PA showed a significantly higher correlation between EEG/clinical seizures and behavioral improvements (p < 0.05).

CONCLUSION

The present data indicated the usefulness of LEV in reducing behavioral problems related to the reduction of seizures and frontal spikes in PDD for some but not all of the patients. Thus, levetiracetam represents an important addition to treatment for PDD children with epilepsy presenting with frontal EEG paroxysms.

Can EEG characteristics predict development of epilepsy in autistic children?

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.