Objective tests for upper motor neuron involvement in amyotrophic lateral sclerosis (ALS).
OBJECTIVE
To develop objective markers for upper motor neuron (UMN) involvement in ALS, the value of single-voxel MR spectroscopy (MRS) and transcranial magnetic stimulation (TMS) was studied.


METHODS
Test results of 164 ALS patients who had MRS only (n = 91), TMS only (n = 13), or both (n = 60) were analyzed; also, 11 autopsy examinations were evaluated.


RESULTS
Abnormal test results consistent with UMN involvement were found in 134 patients with clinical UMN signs: 86% on MRS, 77% on TMS, and 70% on MRS and TMS together. Among 30 patients with solely LMN signs (progressive muscular atrophy), UMN results were found in 63% on MRS, 63% on TMS, and 46% on both tests together. There was a significant association of the degree of abnormal N-acetyl aspartate/creatine ratios with UMN signs (p = 0.01). The sensitivity to detect UMN involvement was 0.86 for MRS (specificity 0.37) and 0.77 for TMS (specificity 0.38). At autopsy, all 11 patients had pathologic UMN abnormalities, including 4 with normal MRS and 1 with normal TMS in life.


CONCLUSIONS
MRS is highly sensitive, somewhat more than TMS, and shows good correlation with clinical UMN signs. Combining MRS and TMS results in the same patient with further refinement may help in the early diagnosis of ALS.
Kaufmann
P
P
Eleanor and Lou Gehrig MDA/ALS Research Center, Neurologic Institute, Department of Neurology, Columbia University, New York 10032, USA. pk88@columbia.edu
Pullman
S L
SL
Shungu
D C
DC
Chan
S
S
Hays
A P
AP
Del Bene
M L
ML
Dover
M A
MA
Vukic
M
M
Rowland
L P
LP
Mitsumoto
H
H
D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D005500:Follow-Up Studies; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008280:Magnetics; D009046:Motor Neurons / Q000502:physiology*; D009128:Muscle Spasticity / Q000175:diagnosis; D009460:Neurologic Examination / Q000379:methods*; D011237:Predictive Value of Tests; D011712:Pyramidal Tracts / Q000473:pathology; D012021:Reflex, Abnormal; D001405:Reflex, Babinski; D012026:Reflex, Stretch; D012189:Retrospective Studies