Glutaric aciduria type I: ultrasonographic demonstration of early signs

Background. Glutaric aciduria type I (GA-I) is a rare inherited metabolic d isease with increased excretion of glutaric acid and its metabolites. Diagn osis is often delayed until the onset of irreversible neurological deficits . Material and methods. We reviewed the clinical and imaging (US, CT and MRI) findings in six patients with proven GA-I and with emphasis on the early U S findings. Coronal and sagittal US images of the brain were obtained throu gh the anterior fontanelle in all patients. CT was obtained in three patien ts and MRI was obtained in two. Results. Macrocephaly was found in all patients, being present in three chi ldren at birth or developing rapidly within the first weeks of life. US sho wed, in all patients, bilateral symmetrical cyst-like dilatation of the syl vian fissures. Progressive fronto-temporal atrophy developed within the fir st months. CT and MRI demonstrated fronto-temporal atrophy with lack of ope rcularisation in all cases and basal ganglia or periventricular hypodensiti es in three patients. Conclusions. In patients with macrocephaly at birth or rapidly developing w ithin the first weeks of life, US should be performed as the primary imagin g modality. Cyst-like bilateral widening of the sylvian fissures is the fir st sign of GA-I, followed by progressive fronto-temporal and ventricular en largement. These patients should be screened for GA-I in order to initiate treatment in the asymptomatic stage.