Abstract
The study assessed motor unit loss in muscles paralyzed by spinal cord injury (SCI) using a novel compound muscle action potential (CMAP) scan examination. The CMAP scan of the first dorsal interosseous (FDI) muscle was applied in tetraplegia (n = 13) and neurologically intact (n=13) subjects. MScanFit was used for estimating motor unit numbers in each subject. The D50 value of the CMAP scan was also calculated. We observed a significant decrease in both CMAP amplitude and motor unit number estimation (MUNE) in paralyzed FDI muscles, as compared with neurologically intact muscles. Across all subjects, the CMAP (negative peak) amplitude was 8.01 ± 3.97 mV for the paralyzed muscles and 16.75 ± 3.55 mV for the neurologically intact muscles (p < 0.001). The CMAP scan resulted in a MUNE of 59 ± 37 for the paralyzed muscles, much lower than 108 ± 21 for the neurologically intact muscles (p < 0.001). No significant difference in D50 was observed between the two groups (p= 0.2). For the SCI subjects, there was no significant correlation between MUNE and CMAP amplitude, or any of the clinical assessments including pinch force, grip force, the Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) score, and SCI duration (p > 0.05). The findings provide an evidence of motor unit loss in the FDI muscles of individuals with tetraplegia, which may contribute to weakness and other hand function deterioration. The CMAP scan offers several practical benefits compared with the traditional MUNE techniques because it is noninvasive, automated and can be performed within several minutes.
Highlights
Spinal cord injury (SCI) has a detrimental effect on both shortterm and long-term health-related quality of life because damage to the spinal cord interrupts the sensory and motor pathways, resulting in varying degrees of paralysis, loss of sensation, and autonomic dysfunction
compound muscle action potential (CMAP) scan of the first dorsal interosseous (FDI) muscle was successfully recorded from each spinal cord injury (SCI) or healthy control subject
This study presents a novel examination of affected FDI muscle after SCI based on CMAP scan recording, which offers several practical benefits compared with the traditional motor unit number estimation (MUNE) techniques
Summary
Spinal cord injury (SCI) has a detrimental effect on both shortterm and long-term health-related quality of life because damage to the spinal cord interrupts the sensory and motor pathways, resulting in varying degrees of paralysis, loss of sensation, and autonomic dysfunction. Using different electromyography (EMG) techniques (e.g., concentric needle EMG, single fiber EMG, macro-EMG and conventional surface EMG), investigators have reported the presence of electrophysiological abnormalities from impaired muscles. These include fibrillation and positive sharp waves [1] [2], long lasting involuntary muscle activity [3] [4], increased motor unit action potential (MUAP) size and waveform complexity [5]-[7], disorganization of motor unit control properties [8]-10], and abnormal jitters [11] [12]. The compound muscle action potential (CMAP) measurement and motor unit number estimation (MUNE) have revealed varying degrees of motor unit loss after SCI
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
