TY - JOUR
T1 - Transverse ultrasound assessment of median nerve deformation and displacement in the human carpal tunnel during wrist movements
AU - Wang, Yuexiang
AU - Zhao, Chunfeng
AU - Passe, Sandra M.
AU - Filius, Anika
AU - Thoreson, Andrew R.
AU - An, Kai Nan
AU - Amadio, Peter C.
N1 - Funding Information:
This study was supported by Grant AR49823 from the National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health ; the Mayo Foundation ; and Grant UL1 TR000135 from the National Center for Advancing Translational Sciences .
PY - 2014/1
Y1 - 2014/1
N2 - The symptoms of carpal tunnel syndrome, a compression neuropathy of the median nerve at the wrist, are aggravated by wrist motion, but the effect of these motions on median nerve motion are unknown. To better understand the biomechanics of the abnormal nerve, it is first necessary to understand normal nerve movement. The purpose of this study was to evaluate the deformation and displacement of the normal median nerve at the proximal carpal tunnel level on transverse ultrasound images during different wrist movements, to have a baseline for comparison with abnormal movements. Dynamic ultrasound images of both wrists of 10 asymptomatic volunteers were obtained during wrist maximal flexion, extension and ulnar deviation. To simplify the analysis, the initial and final shape and position of the median nerve were measured and analyzed. The circularity of the median nerve was significantly increased and the aspect ratio and perimeter were significantly decreased in the final image compared with the first image during wrist flexion with finger extension, wrist flexion with finger flexion and wrist ulnar deviation with finger extension (p<0.01). There were significant differences in median nerve displacement vector between finger flexion, wrist flexion with finger extension and wrist ulnar deviation with finger extension (all p's<0.001). The mean amplitudes of median nerve motion in wrist flexion with finger extension (2.36±0.79 normalized units [NU]), wrist flexion with finger flexion (2.46±0.84 NU) and wrist ulnar deviation with finger extension (2.86±0.51 NU) were higher than those in finger flexion (0.82±0.33 NU), wrist extension with finger extension (0.77±0.46 NU) and wrist extension with finger flexion (0.81±0.58 NU) (p<0.0001). In the normal carpal tunnel, wrist flexion and ulnar deviation could induce significant transverse displacement and deformation of the median nerve.
AB - The symptoms of carpal tunnel syndrome, a compression neuropathy of the median nerve at the wrist, are aggravated by wrist motion, but the effect of these motions on median nerve motion are unknown. To better understand the biomechanics of the abnormal nerve, it is first necessary to understand normal nerve movement. The purpose of this study was to evaluate the deformation and displacement of the normal median nerve at the proximal carpal tunnel level on transverse ultrasound images during different wrist movements, to have a baseline for comparison with abnormal movements. Dynamic ultrasound images of both wrists of 10 asymptomatic volunteers were obtained during wrist maximal flexion, extension and ulnar deviation. To simplify the analysis, the initial and final shape and position of the median nerve were measured and analyzed. The circularity of the median nerve was significantly increased and the aspect ratio and perimeter were significantly decreased in the final image compared with the first image during wrist flexion with finger extension, wrist flexion with finger flexion and wrist ulnar deviation with finger extension (p<0.01). There were significant differences in median nerve displacement vector between finger flexion, wrist flexion with finger extension and wrist ulnar deviation with finger extension (all p's<0.001). The mean amplitudes of median nerve motion in wrist flexion with finger extension (2.36±0.79 normalized units [NU]), wrist flexion with finger flexion (2.46±0.84 NU) and wrist ulnar deviation with finger extension (2.86±0.51 NU) were higher than those in finger flexion (0.82±0.33 NU), wrist extension with finger extension (0.77±0.46 NU) and wrist extension with finger flexion (0.81±0.58 NU) (p<0.0001). In the normal carpal tunnel, wrist flexion and ulnar deviation could induce significant transverse displacement and deformation of the median nerve.
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U2 - 10.1016/j.ultrasmedbio.2013.09.009
DO - 10.1016/j.ultrasmedbio.2013.09.009
M3 - Article
C2 - 24210862
AN - SCOPUS:84888431133
SN - 0301-5629
VL - 40
SP - 53
EP - 61
JO - Ultrasound in Medicine and Biology
JF - Ultrasound in Medicine and Biology
IS - 1
ER -