RESUMEN
BACKGROUND AND PURPOSE: Hyperargininemia (HA) is a rare autosomal recessive metabolic disorder and the neuroimaging features of this disease have seldom been reported. Hyperammonemic encephalopathy is uncommon in HA, and the clinical presentation of HA is distinct from other urea cycle disorders. This paper describes the brain MRI findings and a magnetic resonance spectroscopy (MRS) study of a series of Brazilian HA patients. METHODS: Brain MR images were obtained in eight male and two female patients with the classic HA phenotype. Six patients were evaluated twice. Single-voxel (1)H-MRS was also performed in six of the patients. RESULTS: Only 1 patient, with less severe neurological symptoms, had normal MRI images. A variable degree of cerebral atrophy was noted in the other patients, and 3 patients also presented mild symptoms of cerebellar atrophy. MRS indicated no metabolic abnormalities in any patient. CONCLUSIONS: We present the MRI and MRS findings of a large series of HA patients. Variable degrees of brain atrophy and mild cerebellar atrophy were observed, and these findings were not specific. No metabolic abnormality was observed using MRS in this series of patients.