[Effect of motor neuron density on the curve of motor neuron impoverishment in amyotrophic lateral sclerosis].
We have clinically and electromyographically examined, during a follow-up study, weakened muscles and still clinically normal muscles of 9 patients affected by amyotrophic lateral sclerosis (ALS) and of 3 patients affected by focal benign amyotrophy (FBA). MRC scores corrected with positive semiquantitative evaluations of the number of giant motor unit (MU) action potentials and with negative evaluations of the number of fasciculations and fibrillations potentials have been found to linearly correlate with the percentage of the residual MUs calculated from the mean amplitude and the spike number during maximal voluntary contraction. A main finding is that the loss of MUs slows down in the last 10 months of the disease. It follows that after a phase when the pathological process was accelerated by the toxic effect due to the abnormally high concentration of glutamate released by dead motoneurons, the residual cells because of the decreased motoneuronal density are less exposed to the possible neurotoxic damage.
Pinelli
P
P
Divisione di Scienze Biomediche, Ospedale San Paolo, Milano.
Pisano
F
F
Miscio
G
G
D000200:Action Potentials; D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000473:pathology*; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology
L'effetto densità dei motoneuroni sulla curva di depauperamento motoneuronale nella sclerosi laterale amiotrofica.