MEPs and MRI Motor Band Sign as Potential Complementary Markers of Upper Motor Neuron Involvement in Amyotrophic Lateral Sclerosis

Background: Amyotrophic lateral sclerosis (ALS) is characterized by the degeneration of both upper and lower motor neurons (UMNs and LMNs). Recognizing the involvement of UMNs is challenging because of the absence of reliable biomarkers beyond clinical evaluation. Aim: To identify a reliable marker of UMN damage in a cohort of patients with ALS referring to the Motor Neuron Disease Clinic of the University Hospital of Padova. Methods: We retrospectively evaluated the clinical records of 79 patients with ALS and compared the results of various investigations, including the motor-evoked potentials (MEPs), positron emission tomography–magnetic resonance imaging (MRI) and light neurofilaments (NfLs), with the degree of UMN clinical involvement, as assessed by the Penn Upper Motor Neuron Score (PUMNS). Results: MEPs, considering the central motor conduction time (CMCT) values in both the upper and lower limbs, showed a significant correlation with the relative PUMNS subscores (p = 0.01, ρ =...