Motor neuron diseases: comparison of single-voxel proton MR spectroscopy of the motor cortex with MR imaging of the brain.
OBJECTIVE
To evaluate single-voxel proton magnetic resonance (MR) spectroscopy in detection of abnormality of the upper motor neuron in patients with motor neuron diseases.


METHODS
In 43 of 50 patients with motor neuron disease and 14 of 14 control subjects, matching sets of MR spectra were obtained in the left and right motor cortex. The ratio of N-acetylaspartate (NAA) to creatine (Cr) was derived from peak area measurements. Mean ratios were calculated for control subjects and several patient groups, including patients with amyotrophic lateral sclerosis (ALS) or primary lateral sclerosis (PLS). MR images were evaluated for corticospinal tract hyperintensity and central sulcus dilatation.


RESULTS
Mean NAA/Cr values were significantly different between control subjects and the ALS or PLS groups (P < .05). With an optimal cutoff of 2.5, NAA/Cr values were abnormal in 15 (79%) of 19 patients with ALS, 12 (67%) of 18 patients with PLS, and one (7%) of 14 control subjects. Corticospinal tract hyperintensity, central sulcus enlargement, or both were found in 43% of the ALS group, 24% of the PLS group, and 7% of the control group.


CONCLUSIONS
NAA/Cr values determined at single-voxel proton MR spectroscopy are more sensitive than are standard findings at MR imaging in the detection of upper motor neuron disease.
Chan
S
S
Department of Radiology, Neurological Institute of New York, Columbia University, NY 10032, USA.
Shungu
D C
DC
Douglas-Akinwande
A
A
Lange
D J
DJ
Rowland
L P
LP
D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001921:Brain / Q000473:pathology*; D003401:Creatine / Q000378:metabolism*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology*; D016472:Motor Neuron Disease / Q000175:diagnosis*; D009046:Motor Neurons / Q000473:pathology*; D011712:Pyramidal Tracts / Q000473:pathology; D012680:Sensitivity and Specificity
D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine