Clinical features of epilepsy with pervasive developmental disorder

To clarify the clinical features of patients with epilepsy and pervasive developmental disorder (PDD).

We examined 12 outpatients with epilepsy as well as PDD at Seiai Rehabilitation Hospital.

The patients comprised 7 males and 5 females. The initial neurological symptoms appeared between 5 months and 4 years of age. The interval between the initial neurological symptoms/developmental delay and seizure onset ranged from several months to twenty years. The seizures started at 10-19 years of age in 8 out of the 12 cases. The types of seizures were astatic-drop in 2 cases, tonic-to-astatic in one, atypical absence (decreased consciousness) and generalized tonic clonic seizures (GTCS) in 3 cases, GTCS in 4 cases, or myoclonic and psychomotor in 2 cases. The mental development distributed from normal to extremely severe retardation. Paroxysmal abnormalities on eegs were focal at the frontal area in 7 cases (58%) and other findings in 5 cases. Presumptive risk factors were prenatal in 6 cases (family history for PDD in 1 case, for epilepsy in 1, twin pregnancy in 2 cases, and other in 2 cases), perinatal in 2 patients, postnatal in 1, and unknown in 3 cases.

The seizures occurred most frequently after the onset of neurological symptoms or developmental delay. The frontal lobe dysfunction was associated with seizure onset in 58% of the cases based on the EEG findings. The risk factors were prenatal in 50% of the cases.