USE OF AMPLITUDE INTEGRATED ELECTROENCEPHALOGRAPHY (AEEG) IN PATIENTS WITH INBORN ERRORS OF METABOLISM - A REVIEW OF 29 CASES

Background: Amplitude integrated EEG (aEEG) has been established in neonatal care as tool to monitor encephalopathy after asphyxia and seizures due to various aetiologies. Patterns representing seizures and different degrees of encephalopathy have been defined. Patients with inborn errors of metabolism often present with encephalopathy/ seizures but published knowledge regarding aEEG use in metabolic patients remains limited as disease frequencies are low.
Aims: Review aEEG tracings of patients with inborn errors of metabolism to evaluate the potential role of this technique in evaluation/treatment of this patient group.
Methods: Through an international collaboration, 29 aEEG tracings of patients with inborn errors of metabolism were collected and reviewed.
Results: Diagnoses were: disorders of energy metabolism (n=10), disorders of amino or organic acid metabolism and urea cycle defects (n=14), peroxisomal disorders (n=5). Encephalopathic changes were seen in 18/29 patients (62%); ictal discharges were noted in 19/29 patients (66%). In all diagnostic groups, with the exception of peroxisomal disorders, both encephalopathic changes and seizures usually coincided; in peroxisomal disorders, seizures were seen without encephalopathic background patterns. 4/29 patients (14%) showed unusual upward shifts of the lower aEEG margins Five patients, some clinically symptomatic, had normal aEEGs. Background patterns changed in 8/29 (28%) tracings during the recording. Details of individual recordings will be presented.
Conclusions: The majority of patients with metabolic disorders had abnormal aEEG tracings, some with marked and/or unusual changes. As aEEG monitoring allows for ongoing assessment of patients, it may aid in evaluation, monitoring of treatment responses and counseling in this patient group.