A Seizure-Like Episode in a Healthy 12-Month Old

Abstract

A 12-month old previously healthy female was admitted for observation following a seizure-like episode. Routine laboratory results, including a complete blood count, comprehensive metabolic panel, and urinalysis, were within the reference intervals (RI). A urine drug screen was negative and neurological examination was unremarkable. Other than spiking a fever overnight, the observation period was uneventful. Magnetic resonance imaging of the brain 10 days later demonstrated T2-weighted hyperintensities in the occipital parietal periventricular area, a nonspecific finding sometimes associated with metabolic disease. The patient was followed up by neurology 2 weeks later and a variety of metabolic tests were ordered. Plasma total and free carnitines, as well as an acylcarnitine profile, were consistent with ketogenesis (decreased free carnitine, increased acylcarnitine: free carnitine ratio, and increased 3-hydroxybutyrylcarnitine, respectively). A serum amino acid profile revealed mildly increased branched chain amino acids, further supporting a catabolic state. Notably, serum 2-aminoadipic acid was 55 mmol/L (RI ≤ 5 mmol/L) an increase of more than 10× the upper limit of normal. Qualitative urine organic acid analysis is shown in Fig. 1.