Chaojun Zheng1, Cong Nie1, Yu Zhu2, Qing Yu3, Dongqing Zhu4, Feizhou Lu1,5, Robert Weber2, Jianyuan Jiang1. 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, U.S.A. 3. Department of Obstetrics and Gynecology, The Rushan Peoples Hospital, Shandong, China. 4. Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China. 5. Department of Orthopedics, The Fifth People's Hospital, Fudan University, Shanghai, China.
Abstract
PURPOSE: Distal-type cervical spondylotic amyotrophy (CSA) is an uncommon syndrome associated with cervical spondylosis. The pathogenic mechanism of distal-type CSA is still unclear. The aim of the current study was to analyze central motor conduction time (CMCT) in the cases with distal-type CSA and to investigate the role of cervical cord compressive injury in the distal-type CSA. METHODS: Both 28 cases with distal-type CSA and 21 healthy subjects accepted CMCT measures, motor unit number estimation, handgrip strength examination, and magnetic resonance imaging evaluation. RESULTS: In this study, nine (9/28, 32.1%) cases with CSA presented with prolonged CMCT, and both reduced number of motor units and decreased handgrip strength were found in these 9 cases (P < 0.05). Magnetic resonance imaging evaluation showed that 7 of these 9 patients presented with proximal cervical cord compression with or even without distal selective compression consistent with segmental atrophy. A negative relationship between CMCT and both number of motor units and handgrip strength was found on the symptomatic side (P < 0.05), and there was a positive correlation between CMCT and amplitude of single motor unit potentials on the less symptomatic side (P < 0.05). CONCLUSIONS: Corticospinal tract damage caused by proximal spinal cord compression may induce distal motor unit loss to worsen in some cases with distal-type CSA, which may contribute to the dysfunction of the distal upper limb in some cases with distal-type CSA. Therefore, treatment and rehabilitation efforts should account for both distal selective compression and proximal cord compression in distal-type CSA.
PURPOSE: Distal-type cervical spondylotic amyotrophy (CSA) is an uncommon syndrome associated with cervical spondylosis. The pathogenic mechanism of distal-type CSA is still unclear. The aim of the current study was to analyze central motor conduction time (CMCT) in the cases with distal-type CSA and to investigate the role of cervical cord compressive injury in the distal-type CSA. METHODS: Both 28 cases with distal-type CSA and 21 healthy subjects accepted CMCT measures, motor unit number estimation, handgrip strength examination, and magnetic resonance imaging evaluation. RESULTS: In this study, nine (9/28, 32.1%) cases with CSA presented with prolonged CMCT, and both reduced number of motor units and decreased handgrip strength were found in these 9 cases (P < 0.05). Magnetic resonance imaging evaluation showed that 7 of these 9 patients presented with proximal cervical cord compression with or even without distal selective compression consistent with segmental atrophy. A negative relationship between CMCT and both number of motor units and handgrip strength was found on the symptomatic side (P < 0.05), and there was a positive correlation between CMCT and amplitude of single motor unit potentials on the less symptomatic side (P < 0.05). CONCLUSIONS:Corticospinal tract damage caused by proximal spinal cord compression may induce distal motor unit loss to worsen in some cases with distal-type CSA, which may contribute to the dysfunction of the distal upper limb in some cases with distal-type CSA. Therefore, treatment and rehabilitation efforts should account for both distal selective compression and proximal cord compression in distal-type CSA.