Predominant patterns of median nerve displacement and deformation during individual finger motion in early carpal tunnel syndrome.
Idiopathic carpal tunnel syndrome (CTS) is a common neuropathy, yet the pathologic changes do not explain the fleeting dynamic symptoms. Dynamic nerve-tendon interaction may be a contributing factor. Based on dynamic ultrasonographic examination of the carpal tunnel, we quantified nerve-tendon movement in thumb, index finger and middle finger flexion in normal subjects and those with mild-idiopathic CTS. Predominant motion patterns were identified. The nerve consistently moves volar-ulnarly. In thumb and index finger flexion, the associated tendons move similarly, whereas the tendon moves dorsoradially in middle finger flexion. Nerve displacement and deformation increased from thumb to index finger to middle finger flexion. Predomination motion patterns may be applied in computational simulations to prescribe specific motions to the tendons and to observe resultant nerve pressures. By identification of the greatest pressure-inducing motions, CTS treatment may be better developed. Symptomatic subjects displayed reduced nerve movement and deformation relative to controls, elucidating the physiologic changes that occur during mild CTS.
Department of Mechanical Engineering, National University of Singapore, Singapore. Electronic address: Kyrin.jo.liong@nus.edu.sg.
Kyrin
K
Liong
Department of Hand & Reconstructive Microsurgery, National University Hospital, Singapore.
Amitabha
A
Lahiri
Division of Plastic, Reconstructive & Aesthetic Surgery, National University Hospital, Singapore.
Shujin
S
Lee
Department of Obstetrics & Gynecology, National University Hospital, Singapore.
Dawn
D
Chia
Department of Obstetrics & Gynecology, National University Hospital, Singapore; Department of Obstetrics & Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Arijit
A
Biswas
Department of Mechanical Engineering, National University of Singapore, Singapore.
Heow Pueh
HP
Lee
D000328:Adult; D002349:Carpal Tunnel Syndrome / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D005385:Fingers / Q000000981:diagnostic imaging / Q000294:innervation / Q000502:physiology*; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008875:Middle Aged; D009038:Motion; D016059:Range of Motion, Articular / Q000502:physiology; D012720:Severity of Illness Index; D014463:Ultrasonography
Carpal tunnel syndrome; Deformation; Displacement; Dynamic nerve-tendon interaction; Median nerve