Contribution of central motion conduction time to the assessment of corticospinal tract lesions and its clinical significance

Abstract

Objective: To investigate the association of central motion conduction time (CMCT) with corticospinal tract lesions and its clinical application. Methods: Patients who completed transcranial magnetic stimulation-motor evoked potentials were included from Department of Neurology, Xuanwu Hospital between June 2020 and June 2021. The differences of CMCT values between corticospinal tract sign-positive group and tendon reflex-positive group and the relevant negative groups were compared. The consistency between increased CMCT values and the positive signs of corticospinal tract damage, as well as the significance of CMCT in different neurological diseases were further evaluated. Results: A total of 271 patients were included in the study, aged 12-86 (49±16) years, with 137 males (50.55%) and 134 females (49.45%). The CMCT values［M（Q1，Q3）］from Hoffmann's sign-positive group [9.52 (8.54, 10.99) ms vs 9.03 (8.30, 9.53) ms], Babinski's sign-positive group [19.54 (16.97, 24.43) ms vs 16.85(15.63, 18.55) ms] and tendon reflex-positive group [15.38 (9.27, 19.28) ms vs 10.49(8.79, 16.60) ms] were larger than those of relevant negative groups (all P<0.01). In the Babinski sign-positive group, 78.01%(181/232) of the patients had increased CMCT, while in the Hoffmann's sign-positive group, only 26.03%(19/73) of the patients had increased CMCT, indicating that the contribution of CMCT from the lower extremities to the assessment of corticospinal tract lesions was better than that of the upper extremities. With the increase of CMCT values in lower limbs, Babinski sign positive rate increased, the difference was statistically significant(P<0.001). In nervous system diseases, the consistency between CMCT and pathological signs was 75.65% (205/271). Conclusions: The contribution of CMCT from the lower extremities to the assessment of corticospinal tract lesions is superior to that of upper limbs. The higher increase of CMCT values are more reliable for corticospinal tract damage. CMCT has a good concordance with corticospinal tract lesions in some neurological diseases, which can be used to assist clinical diagnosis.