Chaojun Zheng1, Yu Zhu2, Qifeng Yu1, Dongqing Zhu3, Jun Li4, Feizhou Lyu5, Robert Weber2, Kai Qiao3, Jianyuan Jiang6. 1. Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai 200040, China. 2. Department of Physical Medicine and Rehabilitation, Upstate Medical University, State University of New York at Syracuse, Syracuse, NY 10212, USA. 3. Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China. 4. Department of Orthopedics, Shanghai Songjiang District Central Hospital, Shanghai 201600, China. 5. Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai 200040, China; Department of Orthopedics, The Fifth People's Hospital, Fudan University, Shanghai 200240, China. 6. Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai 200040, China. Electronic address: jianyuanjiang05@126.com.
Abstract
OBJECTIVE: To assess the feasibility of motor unit number index (MUNIX) in quantitatively evaluating Hirayama disease (HD) with proximal involvement and to identify the effectiveness of anterior cervical fusion (ACF) in treating atypical HD with proximal involvement. METHODS: This study included 28 atypical HD patients with proximal involvement (proximal-distal vs. distal-proximal groups: 5 vs. 23) and 41 healthy controls. All patients underwent pre- and postoperative 1-year MUNIX tests on abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps brachii (BB) and deltoid (Del). The disabilities of arm, shoulder and hand (DASH) and Medical Research Council (MRC) scales were also performed in these patients before and one year after operation. RESULTS: Preoperatively, the patients in the distal-proximal group showed reduced compound muscle action potential (CMAP), decreased MUNIX and increased motor unit size index (MUSIX) in bilateral distal muscles and symptomatic-side proximal muscles (P < 0.05), and similar abnormalities were also observed in ADM, BB and Del on the symptomatic side in the proximal-distal groups (P < 0.05). Postoperative follow-up analysis identified increased MUNIX in the symptomatic-side proximal muscles with improved motor function in the proximal-distal groups (P < 0.05), and distal-proximal group patients showed an increase in both CMAP and MUSIX in the symptomatic-side proximal muscles (P < 0.05). CONCLUSIONS: MUNIX may serve as an available supplementary test to quantitatively evaluate the motor dysfunction and treatment outcome in HD with proximal involvement. ACF procedures can effectively treat these atypical HD patients, especially for those whose symptoms started in proximal muscles.
OBJECTIVE: To assess the feasibility of motor unit number index (MUNIX) in quantitatively evaluating Hirayama disease (HD) with proximal involvement and to identify the effectiveness of anterior cervical fusion (ACF) in treating atypical HD with proximal involvement. METHODS: This study included 28 atypical HDpatients with proximal involvement (proximal-distal vs. distal-proximal groups: 5 vs. 23) and 41 healthy controls. All patients underwent pre- and postoperative 1-year MUNIX tests on abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps brachii (BB) and deltoid (Del). The disabilities of arm, shoulder and hand (DASH) and Medical Research Council (MRC) scales were also performed in these patients before and one year after operation. RESULTS: Preoperatively, the patients in the distal-proximal group showed reduced compound muscle action potential (CMAP), decreased MUNIX and increased motor unit size index (MUSIX) in bilateral distal muscles and symptomatic-side proximal muscles (P < 0.05), and similar abnormalities were also observed in ADM, BB and Del on the symptomatic side in the proximal-distal groups (P < 0.05). Postoperative follow-up analysis identified increased MUNIX in the symptomatic-side proximal muscles with improved motor function in the proximal-distal groups (P < 0.05), and distal-proximal group patients showed an increase in both CMAP and MUSIX in the symptomatic-side proximal muscles (P < 0.05). CONCLUSIONS: MUNIX may serve as an available supplementary test to quantitatively evaluate the motor dysfunction and treatment outcome in HD with proximal involvement. ACF procedures can effectively treat these atypical HDpatients, especially for those whose symptoms started in proximal muscles.
Authors: Henrik C Bäcker; Jacob Bock; Peter Turner; Michael A Johnson; John Cunningham; Patrick Chan; Richard Gerraty Journal: Eur Spine J Date: 2022-06-21 Impact factor: 3.134