Mamede de Carvalho1, Teresinha Evangelista, M L Sales-Luís. 1. Department of Neurology, Hospital de Santa Maria and EMG laboratory of Centro de Estudos Egas Moniz, Faculty of Medicine, Lisbon, Portugal. mamedemg@mail.telepac.pt
Abstract
INTRODUCTION: It is suggested that early in ALS the corticomotor threshold (CMT) is low, but increases with increasing duration of the disease. POPULATION AND METHODS: We compared CMT, central conduction time and motor-evoked response/M-wave amplitude in two populations of ALS patients: one with disease duration shorter than 6 months (Group A, 11 patients) and another who had had the disease for more than 24 months (Group B, 14 patients). These two groups were compared with a control group of 30 subjects. In all the ALS patients, abductor digiti minimi (ADM) strength was greater than MRC 3. RESULTS: M-wave amplitude was comparable in the three groups. We found no difference between the three groups in these transcranial magnetic stimulation studies and there was no correlation between disease duration time and CMT. CONCLUSION: We did not confirm a relation between CMT and disease duration. An increased CMT late in the disease progression is associated with greater lower motor neuron loss, and greater corticospinal tract degeneration with dispersion of the descending motor volley.
INTRODUCTION: It is suggested that early in ALS the corticomotor threshold (CMT) is low, but increases with increasing duration of the disease. POPULATION AND METHODS: We compared CMT, central conduction time and motor-evoked response/M-wave amplitude in two populations of ALSpatients: one with disease duration shorter than 6 months (Group A, 11 patients) and another who had had the disease for more than 24 months (Group B, 14 patients). These two groups were compared with a control group of 30 subjects. In all the ALSpatients, abductor digiti minimi (ADM) strength was greater than MRC 3. RESULTS: M-wave amplitude was comparable in the three groups. We found no difference between the three groups in these transcranial magnetic stimulation studies and there was no correlation between disease duration time and CMT. CONCLUSION: We did not confirm a relation between CMT and disease duration. An increased CMT late in the disease progression is associated with greater lower motor neuron loss, and greater corticospinal tract degeneration with dispersion of the descending motor volley.
Authors: Michael D Weiss; Eric A Macklin; Zachary Simmons; Angela S Knox; David J Greenblatt; Nazem Atassi; Michael Graves; Nicholas Parziale; Johnny S Salameh; Colin Quinn; Robert H Brown; Jane B Distad; Jaya Trivedi; Jeremy M Shefner; Richard J Barohn; Alan Pestronk; Andrea Swenson; Merit E Cudkowicz Journal: Neurology Date: 2016-02-24 Impact factor: 9.910
Authors: M R Turner; A D Osei-Lah; A Hammers; A Al-Chalabi; C E Shaw; P M Andersen; D J Brooks; P N Leigh; K R Mills Journal: J Neurol Neurosurg Psychiatry Date: 2005-09 Impact factor: 10.154
Authors: Michael D Weiss; Eric A Macklin; Courtney E McIlduff; Steve Vucic; Brian J Wainger; Matthew C Kiernan; Stephen A Goutman; Namita A Goyal; Seward B Rutkove; Shafeeq S Ladha; I-Hweii Amy Chen; Matthew B Harms; Thomas H Brannagan; David Lacomis; Sasha Zivkovic; Maxwell Ma; Leo H Wang; Zachary Simmons; Michael H Rivner; Jeremy M Shefner; Merit E Cudkowicz; Nazem Atassi Journal: Muscle Nerve Date: 2020-12-31 Impact factor: 3.217