Abstracts

OBJECTIVE: to define the value and results of EEG studies in children with autism & related disorders at this hospital.
RATIONALE: To compare the incidence and type of abnormal EEGs in patients with target disorders (autism, Landau-Kleffner syndrome, language regression, pervasive developmental disorder and autistic specturm disorder) to our EEG results on all patients studied over 3 consecutive years.
METHODS: EEG & videotelemetry reports from 1999, 2000, & 2001 were reviewed, selected abnormal studies were reviewed. Only patients whose EEG requests indicated the presence of autism, etc were included. Since many EEG requests provide little or no information, some patients were surely omitted.
RESULTS: 262 studies were attempted over the 3 year period in 203 patients. 19 EEGs couldn[ssquote]t be done because of agitation. 193 EEGs and 50 videotelemetry studies were done, out of 4456 total EEGs and 540 video studies done here over 3 years. 69/103 waking EEGs were normal, 15 showed epileptiform discharges (EDs). 20/22 sedated sleep (barbiturate, chloral hydrate) EEGs were normal, 2 showed EDs. 40/68 waking and sleep EEGs were normal, 15 had EDs. Clinical or electrographic seizures were recorded in 6 patients (vs 6.1% of all outpatient EEGs), 1 of whom, with primary generalized seizures, had marked and sustained improvement with AED treatment. The incidence of abnormal EEGs and VTs was higher in very handicapped and nonverbal patients.
Videotelemetry studies (VTs) were more often abnormal than EEGs but represented a different and more selected patient group. Sleep was obtained in 9/10 ambulatory video studies and all overnight or longer studies. The commonest VT abnormality was slow or disorganized background. 16 VTs showed at least 3 EDs. Seven of these had nonepileptic staring spells plus EDs. 3/7 improved when AEDs were reduced or stopped. Three patients without EDs had events which were nonepileptic and had been presumed by parents and some physicians to be seizures. Five patients had grossly abnormal VTs, 3 with long portions of continuous spike wave discharges. Two of these patients had marked and sustained improvement with vigorous AED therapy.
Of 44 patients with EDs, 11 had a previously normal waking & sleep EEG. 54% had focal epileptiform discharges.
Many patients were taking AEDs (38%) at the time of the study. Of the 10 patients with recorded seizures or near status epilepticus VTs, 4 had no clinical history of seizures. The others were taking AEDs. Most of our patients were low functioning and could be classified as mentally retarded, 95% came from in state. Less than ten patients received steroids or ACTH.
CONCLUSIONS: The incidence of EDs in autistic & related conditions was similar to that of all EEG studies in our hospital. Sedated sleep studies had very low yield. Natural sleep recordings yielded the highest incidence of EDs. Only three patients had major sustained functional improvement after very epileptiform EEGs were found & treated. A significant number of patients had nonepileptic staring spells which were being treated with AEDs. Some of these patients improved when AEDs were decreased or stopped.
[Supported by: divisional funds]