Proton spectroscopy and imaging at 3T in ataxia-telangiectasia.
OBJECTIVE
Ataxia-telangiectasia (A-T) is an autosomal recessive disorder with characteristic neurodegeneration of the cerebellum. We used MR spectroscopy to test the hypothesis that cerebellar metabolism in A-T patients would be abnormal relative to healthy controls.


METHODS
Twelve adults with A-T and 12 healthy control subjects underwent MR imaging and long-echo time (1)H-MR spectroscopy at 3T. Voxels were acquired in the region of the dentate nucleus of the cerebellum and in parietooccipital white matter, and ratios for N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) were calculated.


RESULTS
All of the A-T patients showed marked cerebellar atrophy of the vermis and hemispheres. Two patients showed multiple small foci of hypointensity on T2*-weighted images throughout their brain suggestive of capillary telangiectasia. A further 2 patients had single low-signal-intensity foci. One patient had a tumor, thought to be meningioma radiologically, that was not suspected clinically. No group differences were found in the cerebral spectra, but analysis of the cerebellum revealed significantly lower NAA/Cho and higher Cho/Cr ratios in the A-T patients compared with the controls. There was no difference between groups for the NAA/Cr ratio.


CONCLUSIONS
The findings suggest increased Cho signal intensity in the cerebellum of adult A-T patients. If this finding is shown through the course of the disease, it may assist in the differentiation of early A-T from other forms of ataxia and provide a marker for monitoring treatment efficacy.
Wallis
L I
LI
Academic Unit of Radiology, The University of Sheffield, Sheffield, United Kingdom. l.wallis@sheffield.ac.uk
Griffiths
P D
PD
Ritchie
S J
SJ
Romanowski
C A J
CA
Darwent
G
G
Wilkinson
I D
ID
D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001260:Ataxia Telangiectasia / Q000175:diagnosis*; D002531:Cerebellum / Q000473:pathology*; D002794:Choline / Q000378:metabolism*; D003401:Creatine / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D012016:Reference Values
D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline