CT and MR of the brain in disorders of the propionate and methylmalonate metabolism.

PURPOSE: To present the CT and MR findings in children with propionic and methylmalonic acidemia.

METHODS: Twenty-three new patients with methylmalonic and 20 with propionic acidemia were examined with CT and/or MR of the brain. In total 52 CT and 55 MR studies were done. Twenty-six previously published cases were also reviewed.

RESULTS: The findings were similar in the two syndromes. During the first month of life the examinations were either normal or showed white matter attenuation. Later during the first year moderate or even severe widening of sulci and fissures was seen, especially in infants with propionic acidemia. During therapy, these changes often resolved, especially in the patients with methylmalonic acidemia. Mild to moderate delay in myelination was also a common finding in both disorders. Basal ganglia changes, predominately in the globus pallidus, were seen in five patients with methylmalonic acidemia and in two children with propionic acidemia; in two patients these changes were transient.

CONCLUSION: Children who have methylmalonic or propionic acidemia, in addition to widening of cerebrospinal fluid spaces and some delay in myelination, also often show symmetric involvement of the basal ganglia.