Magnetic resonance spectroscopy (MRS) in five patients with treated propionic acidemia

Propionic acidemia is an inherited disorder caused by a defect of propionyl CoA carboxylase. Untreated, propionic acidemia leads to metabolic decompen sation and toxic encephalopathy. We report on the magnetic resonance imagin g (MRI) and magnetic resonance spectroscopy (MRS) findings in five children who were properly treated by protein restriction and carnitine supplementa tion, during a phase of clinically and metabolically stable conditions. The examinations were performed on a whole-body 1.5 T scanner. During the obse rvation period, from 1992 to 1996 we employed long echo time single-voxel s pectroscopy and chemical shift imaging in addition to a conventional MRI pr otocol. The two children with the longest delay before onset of therapy sho wed cerebral atrophy. AIRS yielded elevated lactate peaks in four of the ch ildren. These results indicate that MRS can detect metabolic alterations in the brains of children with propionic acidemia during metabolically stable conditions. The presence of lactate could be caused by hampered aerobic ox idation within the citrate cycle due to intracellular elevated propionic me tabolites. J. Magn. Reson. Imaging 2000;11:596-600. (C) 2000 Wiley-Liss, In c.