Neuroimaging findings in glutaric aciduria type 1

To review the imaging features of glutaric aciduria type 1 (GA-1) in a group of 20 patients, the largest published series to date. To document the findings not previously reported and compare our findings with the imaging characteristics of GA-1 previously reported in the literature.

For 14 patients the original scans were examined and in the remaining 6, where the imaging was unavailable, the radiology reports were consulted. Nine patients had serial cranial US examinations, 13 had 18 CT scans performed and 14 patients had 39 MRI scans.

Widening of the sylvian fissures and of the fluid spaces anterior to the temporal lobes was seen in 93% of cases. The mesencephalic cistern was also widened in 86%. Abnormal high-signal intensity on T2-weighted (T2-W) images was seen in the basal ganglia and periventricular white matter in 64% of children. Subdural collections were found in 3 patients, all of which resolved spontaneously. Four neonates followed with serial cranial US showed bilateral multiple caudothalamic cysts. Abnormal high signal on T2-W images was seen in the dentate nucleus, substantia nigra and the pontine medial lemniscus in 79, 43 and 64%, respectively.

Widening of the sylvian fissure, mesencephalic cistern and expansion of CSF spaces anterior to the temporal lobes are cardinal signs of GA-1. If combined with abnormalities of the basal ganglia and white matter, GA-1 should be strongly suspected.