Magnetic stimulation including the triple-stimulation technique in amyotrophic lateral sclerosis.
To study the relative importance of upper motor neuron (UMN) dysfunction in the weakness of amyotrophic lateral sclerosis (ALS) and to compare the sensitivity of several transcranial magnetic stimulation (TMS) parameters as means of assessing UMN impairment in ALS, we used TMS to evaluate one upper limb of 63 patients. The triple-stimulation technique (TST) and silent period (SP) were found to be the most frequently abnormal parameters (55.6% and 47.6%, respectively), without significant difference in their diagnostic sensitivity. The SP was found to be a useful parameter in patients with suspected or possible ALS. A positive correlation was found between weakness and the TST amplitude ratio, indicating that weakness may partly be caused by UMN dysfunction. Thus, the TST provides a quantitative tool for assessing UMN conduction failure. When used in association with the SP, the TST provides a sensitive diagnostic tool for use on ALS patients.
Attarian
Shahram
S
Department of Neurology and Neuromuscular Diseases, CHU La Timone, 264 rue Saint-Pierre, 13385 Marseille, France. sattarian@ap-hm.fr
Verschueren
Annie
A
Pouget
Jean
J
D000200:Action Potentials / Q000502:physiology / Q000528:radiation effects; D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology / Q000503:physiopathology*; D004558:Electric Stimulation / Q000379:methods*; D019054:Evoked Potentials, Motor / Q000502:physiology / Q000528:radiation effects*; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D009046:Motor Neurons / Q000528:radiation effects*; D018709:Statistics, Nonparametric; D050781:Transcranial Magnetic Stimulation