Proton MR spectroscopic imaging in ataxia-telangiectasia.
OBJECTIVE
Ataxia-telangiectasia (A-T) is a recessively inherited neurodegenerative disorder with prominent progressive ataxia and cerebellar degeneration, as well as manifest abnormalities of tone, posture, and movement suggesting extrapyramidal dysfunction. In this study, we tested the hypothesis that regional metabolite levels, as measured by proton magnetic resonance spectroscopic imaging, would be abnormal in patients with A-T in the posterior fossa and basal ganglia, reflecting the underlying neurodegenerative processes in these regions.


METHODS
Spectroscopic images of N-acetyl aspartate (NAA), choline (Cho), and creatine (Cr) were obtained in 8 patients with A-T and 8 age-matched controls. Normalized metabolite levels were compared between A-T patients and control subjects in various regions of interest, including the cerebellum, brainstem, and basal ganglia.


RESULTS
A-T patients were distinguished from controls by the profound loss of all metabolites in the cerebellar vermis (NAA, p < 0.01; Cr and Cho, p < 0.05) and a trend for decreased metabolites within the cerebellar hemispheres. No abnormalities were detected in the basal ganglia.


CONCLUSIONS
Proton MR spectroscopic features in A-T closely correlate with the morphologic neuroimaging findings of posterior fossa atrophy. Although symptoms suggesting extrapyramidal dysfunction are part of the A-T phenotype, these are not associated with altered metabolite levels in the basal ganglia.
Lin
D D M
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Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. ddmlin@jhmi.edu
Crawford
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TO
Lederman
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HM
Barker
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PB
D000293:Adolescent; D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001260:Ataxia Telangiectasia / Q000175:diagnosis* / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000473:pathology; D001931:Brain Mapping; D016022:Case-Control Studies; D002648:Child; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009460:Neurologic Examination / Q000379:methods; D011522:Protons
D011522:Protons; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline