Proton MR spectroscopy of the cerebellum and pons in patients with degenerative ataxia.
OBJECTIVE
To investigate whether proton magnetic resonance (MR) spectroscopy is a useful complement to MR imaging in patients with degenerative ataxia.


METHODS
Brain MR imaging and single-voxel proton MR spectroscopy of the right cerebellar hemisphere and pons were performed in 30 patients with sporadic (n = 16) or inherited (n = 14) degenerative ataxia and in 20 healthy control subjects. Several indexes of brainstem and cerebellar atrophy were measured on MR images, as well as the N-acetylaspartate/creatine (NAA/Cr), choline/Cr (Cho/Cr), and myo-inositol/Cr (mI/Cr) ratios in the MR spectra. Differences between patients and subjects were evaluated with the Kruskal-Wallis and Mann-Whitney tests, whereas correlation of clinical, MR imaging, and spectroscopic data was assessed with nonparametric Spearman rank correlation.


RESULTS
Measurements of brainstem and cerebellar atrophy obtained from MR images revealed patients had olivopontocerebellar atrophy (OPCA) (n = 11), spinal atrophy (SA) (n = 8), or corticocerebellar atrophy (CCA) (n = 4). Seven patients did not fulfill the criteria for any group and were considered undefined. In patients with OPCA, the pontine and cerebellar NAA/Cr and Cho/Cr ratios were significantly decreased when compared with those of the control subjects. Pontine and cerebellar NAA/Cr ratios were also significantly reduced in patients with SA and CCA. Five patients with undefined ataxia had a substantial decrease of pontine or cerebellar NAA/Cr ratio when compared with that of the control subjects. In patients with OPCA, the pontine NAA/Cr ratio (but not the atrophy measurements) showed a correlation (P =.04) with disability.


CONCLUSIONS
MR spectroscopy is a useful complement to MR imaging in patients with degenerative ataxia.
Mascalchi
Mario
M
Section of Diagnostic Radiology, Department of Clinical Physiopathology, University of Florence, Viale Morgagni 85, 50134 Florence, Italy.
Cosottini
Mirco
M
Lolli
Francesco
F
Salvi
Fabrizio
F
Tessa
Carlo
C
Macucci
Marco
M
Tosetti
Michela
M
Plasmati
Rosaria
R
Ferlini
Alessandra
A
Tassinari
Carlo Alberto
CA
Villari
Natale
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001259:Ataxia / Q000378:metabolism / Q000473:pathology*; D016022:Case-Control Studies; D002524:Cerebellar Ataxia / Q000378:metabolism / Q000473:pathology*; D002794:Choline / Q000378:metabolism; D003404:Creatinine / Q000378:metabolism; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007294:Inositol / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D011149:Pons / Q000378:metabolism / Q000473:pathology*; D011522:Protons; D018709:Statistics, Nonparametric
D011522:Protons; D001224:Aspartic Acid; D007294:Inositol; C000179:N-acetylaspartate; D003404:Creatinine; D002794:Choline