Chaojun Zheng1, Zhenhao Chen1, Yu Zhu2, Feizhou Lyu1,3, Xiaosheng Ma1, Robert Weber2, Dong Tian4, Jianyuan Jiang1, Xinlei Xia1. 1. Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China. 2. Department of Physical Medicine and Rehabilitation, Upstate Medical University, State University of New York at Syracuse, Syracuse, New York, USA. 3. Department of Orthopedics, The Fifth People's Hospital, Fudan University, Shanghai, China. 4. Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China.
Abstract
INTRODUCTION: We investigated the feasibility of motor unit number index (MUNIX) in quantitatively assessing motor root lesions and tracking different treatment outcomes in lumbosacral radiculopathy (LR). METHODS: Bilateral MUNIX was recorded from the abductor hallucis, extensor digitorum brevis, and tibialis anterior in 44 normal controls and 108 patients with LR, and this was repeated approximately 12 months after treatment in 60 patients with LR. RESULTS: More abnormalities were observed when side-to-side differences of MUNIX measurements were used to evaluate LR (P < .05). Motor unit number index measurements worsened without progression of muscle weakness after conservative treatment, and MUNIX measurements improved with or without increased muscle strength after surgical treatment (P < .05). DISCUSSION: Motor unit number index may identify a specific L5 or S1 motor root lesion even before muscle weakness occurs, especially when side-to-side differences are used. Changes in MUNIX were larger than those in motor function measures after treatments for LR.
INTRODUCTION: We investigated the feasibility of motor unit number index (MUNIX) in quantitatively assessing motor root lesions and tracking different treatment outcomes in lumbosacral radiculopathy (LR). METHODS: Bilateral MUNIX was recorded from the abductor hallucis, extensor digitorum brevis, and tibialis anterior in 44 normal controls and 108 patients with LR, and this was repeated approximately 12 months after treatment in 60 patients with LR. RESULTS: More abnormalities were observed when side-to-side differences of MUNIX measurements were used to evaluate LR (P < .05). Motor unit number index measurements worsened without progression of muscle weakness after conservative treatment, and MUNIX measurements improved with or without increased muscle strength after surgical treatment (P < .05). DISCUSSION: Motor unit number index may identify a specific L5 or S1 motor root lesion even before muscle weakness occurs, especially when side-to-side differences are used. Changes in MUNIX were larger than those in motor function measures after treatments for LR.
Keywords:
lumbosacral radiculopathies; motor root lesions; motor unit number index; quantitative assessment; side-to-side differences; treatment outcome