Magnetic resonance imaging of the brain in glutaric acidemia type I: a review of the literature and a report of four new cases with attention to the basal ganglia and imaging technique.
OBJECTIVE
In glutaric acidemia type I (GA I), a pediatric neurometabolic disease that may be mistaken for nonaccidental trauma, expeditious detection is critical as early treatment may substantially improve psychomotor dysfunction. In this study, we examine in depth the magnetic resonance (MR) findings, with special attention to the basal ganglia, in 4 new cases and compare the findings with those described in the literature.


METHODS
MR studies of 4 children, diagnosed to have GA I via cultured fibroblast enzyme studies or urine metabolite assays, were performed on a 1.5 T system in the axial plane using spin echo T(1)-weighted, fast spin echo T(2)-weighted, and fluid-attenuated inversion recovery (FLAIR) technique. Three of 4 patients were followed with serial exams to document temporal evolution of the disease.


RESULTS
On T(2)-weighted images, abnormal increased signal intensity was seen in both the putamen and globus pallidus in all cases. However, in contradistinction to cases reported in the literature, involvement of the caudate nucleus was minimal or absent even on serial MR exams. In children 15 months and older, FLAIR improved recognition of basal ganglia and white matter abnormalities. The previously described widened cerebrospinal fluid spaces anterior to the temporal lobes, increased T(2)-weighted signal intensity in the periventricular white matter, and widened sylvian fissures characteristic of GA I were noted in all patients.


CONCLUSIONS
Abnormalities of the caudate nucleus are not a prominent presentation of these patients and the absence of this finding should not exclude a diagnosis of GA I. FLAIR scans, as an adjunct to more conventional T(1)- and T(2)-weighted sequences, can play an important role in children 15 months or older despite immature myelination in these patients.
Desai
Nilesh K
NK
Texas A&M University College of Medicine, Temple, TX, USA. ndesai@medicine.tamu.edu
Runge
Val M
VM
Crisp
Darrell E
DE
Crisp
Matthew B
MB
Naul
L Gill
LG
D001479:Basal Ganglia / Q000473:pathology*; D020739:Brain Diseases, Metabolic, Inborn / Q000175:diagnosis* / Q000201:enzymology; D001930:Brain Injuries / Q000175:diagnosis*; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005917:Globus Pallidus / Q000473:pathology*; D050770:Glutaryl-CoA Dehydrogenase; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000172:deficiency*
D044925:Oxidoreductases Acting on CH-CH Group Donors; D050770:Glutaryl-CoA Dehydrogenase