Focal Electrographic Seizures in a Patient With Autism Spectrum Disorder and Speech Delay

A 6-year-old boy with a diagnosis of autism spectrum disorder (ASD) presented to primary care for a new-patient, transfer-of-care evaluation. At the initial encounter, the patient used a maximum of 60 words and was receiving speech and language therapy (SLT) through school. Family history was positive for seizures in the father and paternal grandfather as well as ASD in an older brother. Referrals to genetics, private SLT, and an autism specialist were offered, although the latter was declined by family. The subsequent genetics evaluation resulted in discovery of a small gain on chromosome 1q42.2 and associated partial duplication of the DISC1 gene. The assay could not determine the exact clinical significance of the abnormality, but similarly sized and located abnormalities involving the DISC1 gene are reported in some patients with ASD and developmental delay. During a follow-up pediatrics appointment, the father expressed his wish for further evaluation of causes of autism spectrum disorder (ASD) and requested an electroencephalography (EEG) evaluation. The family concomitantly reported slow improvement in speech with therapy, the use of up to 200 words, and the ability to count to 10. The primary care physician reiterated that EEG and imaging studies are not indicated for an isolated ASD diagnosis with no supporting history or physical examination indications. The clinician discussed ASD-recommended therapies with the family. Neurology referral was made per parental request. The patient subsequently presented to neurology at the age of 7 years. The parents reiterated during the initial neurologic developmental history that the patient had shown some improvement with speech and language therapy in the past 18 months, knew as many as 200 to 300 words, and could put some words together into simple sentences. Gross and fine motor development were felt to be within the normal range for age. The parents also reported some scripting, and mild echolalia was noted on examination. Notably, there was no history of language regression. Apart from language delay, the neurologic examination was otherwise normal at initial evaluation. Given this clinical picture, ASD treatment options were again discussed. Despite education, parents continued to request for EEG evaluation as a workup for the etiology of the patient's ASD. Electroencephalography was ultimately ordered owing to the strong and repeated paternal request despite denial of any seizure-like episodes in the patient. EEG unexpectedly showed extremely frequent, almost constant focal electrographic seizures arising from the T3/T5 electrodes in the speech area of the left temporal lobe, prompting the initiation of oxcarbazepine maintenance therapy. Because of the noted abnormalities on EEG, magnetic resonance imaging (MRI) was obtained. Mild abnormalities were noted on MRI study including possible minimal inferior cerebellar vermian hypoplasia, mildly prominent bodies of the lateral ventricles, and nonspecific, nonenhancing punctate T2 hyperintensities in the subcortical white matter. These findings were not felt to be clinically relevant to the patient's presentation or seizure evaluation. No repeat imaging was ordered. Hindsight is always 20/20. As a clinician evaluating the patient initially, would you have pursued further workup sooner?