Vacchiano Veria, Morabito Francesca, Bonan Luigi, Teodorani Luca, Faini Claudia, Rizzo Giovanni, Liguori Rocco
UOC Clinica Neurologica, IRCCS Istituto delle Scienze Neurologiche di Bologna, 40139 Bologna, Italy.
Centro Clinico NeMO, IRCCS Istituto delle Scienze Neurologiche di Bologna, 40139 Bologna, Italy.
J Clin Med. 2024 Nov 15;13(22):6881. doi: 10.3390/jcm13226881.
Motor unit number estimation (MUNE) methods are crucial for estimating lower motor neuron loss in motor neuron diseases. The MScanFit MUNE (MScanFit) is a novel method that estimates MUNE values from compound motor action potential (CMAP) scans, demonstrating high sensitivity and reproducibility in detecting motor unit loss in amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). In this study, we aimed to characterize the pattern of motor unit loss in the hand intrinsic muscles of SMA patients compared to ALS patients and healthy controls (HC) using MScanFit MUNE. Patients diagnosed with ALS, adult SMA patients, and HC were prospectively enrolled. MScanFit examinations were performed on the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles. To focus on the different patterns of motor neuron degeneration in the intrinsic hand muscles, the ratio of CMAP amplitude of APB to ADM (CMAP ratio) and the ratio of MUNE values of APB to those of the ADM muscle (MUNE ratio) were calculated. The study included 46 ALS patients, 16 SMA patients, and 23 HC. MScanFit MUNE revealed distinct patterns of motor unit degeneration in SMA patients, notably more severe in the ADM than in the APB muscle, indicating a "reverse" split-hand phenomenon. Both CMAP and MUNE ratios demonstrated high diagnostic accuracy in distinguishing ALS from SMA, with the MUNE ratio performing better. MScanFit MUNE is a valuable tool for exploring distinct patterns of motor neuron degeneration in patients with different types of motor neuron diseases.
运动单位数量估计（MUNE）方法对于评估运动神经元疾病中下位运动神经元的损失至关重要。MScanFit MUNE（MScanFit）是一种从复合运动动作电位（CMAP）扫描中估计MUNE值的新方法，在检测肌萎缩侧索硬化症（ALS）和脊髓性肌萎缩症（SMA）中的运动单位损失方面具有高灵敏度和可重复性。在本研究中，我们旨在使用MScanFit MUNE来描述SMA患者与ALS患者及健康对照（HC）相比，手部固有肌中运动单位损失的模式。前瞻性纳入了诊断为ALS的患者、成年SMA患者和HC。对拇短展肌（APB）和小指展肌（ADM）进行了MScanFit检查。为了关注手部固有肌中运动神经元变性的不同模式，计算了APB与ADM的CMAP波幅比值（CMAP比值）以及APB与ADM肌肉的MUNE值比值（MUNE比值）。该研究纳入了46例ALS患者、16例SMA患者和23名HC。MScanFit MUNE揭示了SMA患者运动单位变性的不同模式，特别是ADM比APB肌肉更严重，表明存在“反向”裂手现象。CMAP和MUNE比值在区分ALS和SMA方面均显示出高诊断准确性，其中MUNE比值表现更佳。MScanFit MUNE是探索不同类型运动神经元疾病患者运动神经元变性不同模式的有价值工具。
