MRI-Apparent Localized Deformation of the Median Nerve Within the Carpal Tunnel During Functional Hand Loading

Goetz, Jessica E.; Kunze, Nicole M.; Main, Erin K.; Thedens, Daniel R.; Baer, Thomas; Lawler, Ericka A.; Brown, Thomas

doi:10.1007/s10439-013-0809-3

Cited by 6 publications

(6 citation statements)

References 24 publications

(28 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All ultrasound scans at the distal wrist crease were performed with the forearm in supination to optimize acoustic coupling, which may have generated additional strain on the extrinsic finger flexors. However, previous MRI studies performed with the forearm in a prone position provided similar images and results (Goetz et al, 2013;Nadar, Dashti & Cherian, 2013). While our results infer greater localized strain and/or stress on the MN during forceful chuck gripping, we only measured travel and deformation metrics.…”

Section: Discussionsupporting

confidence: 71%

Median nerve travel and deformation in the transverse carpal tunnel increases with chuck grip force and deviated wrist position

Turcotte¹,

Kociolek²

2021

PeerJ

View full text Add to dashboard Cite

Background We assessed median nerve travel and deformation concurrently to better understand the influence of occupational risk factors on carpal tunnel dynamics, including forceful chuck gripping and deviated wrist positions. Methods Fourteen healthy right-hand dominant participants performed a chuck grip in 6 experimental conditions: two relative force levels (10% and 40% of maximum voluntary effort); three wrist positions (15° radial deviation, 0° neutral, 30° ulnar deviation). Chuck grip forces were measured with a load cell while the transverse cross-section of the carpal tunnel was imaged via ultrasound at the distal wrist crease. Images of the median nerve were analyzed in ImageJ to assess cross-sectional area, circularity, width, and height as well as travel in the anterior-posterior and medial-lateral axes. Results We found a main effect of deviated wrist position on both anterior-posterior and medial-lateral travel, with the greatest nerve travel occurring in 30° ulnar deviation. There was also a significant interaction between chuck grip force and deviated wrist position on cross-sectional area. Specifically, the area decreased with 40% vs. 10% chuck grip force when the wrist was in 30° ulnar deviation; however, there were no changes in 0° neutral and 15° radial deviation. Discussion Overall, we demonstrated that forceful chuck gripping in deviated wrist positions influenced carpal tunnel dynamics, resulting in both migratory and morphological changes to the median nerve. These changes may, in turn, increase local strain and stress with adjacent structures in the carpal tunnel. Future studies mapping contact stress between structures may further elucidate injury development of work-related carpal tunnel syndrome.

show abstract

Section: Discussionsupporting

confidence: 71%

Median nerve travel and deformation in the transverse carpal tunnel increases with chuck grip force and deviated wrist position

Turcotte¹,

Kociolek²

2021

PeerJ

View full text Add to dashboard Cite

show abstract

“…The most widely used and accepted ultrasound parameters for differential diagnosis of CTS are the cross-sectional area (CSA), swelling ratio (SR) and flattening ratio (FR) of median nerve, as well as the bowing and thickness of the transverse carpal ligament (TCL) at the carpal tunnel [ 13 ]. Recently, many researchers have made use of different medical imaging modalities to study the deformation and displacement of median nerve under various hand activities [ 14 – 23 ], and the majority of them opted to use ultrasound rather than other imaging techniques due to its capability for real-time dynamic scanning during hand activity [ 24 ]. Although evidence of deformation and greater extent of displacement of median nerve during hand activity are collected from these previous studies, many of them failed to monitor the dynamic change of median nerve in real-time.…”

Section: Introductionmentioning

confidence: 99%

Development of Kinematic Graphs of Median Nerve during Active Finger Motion: Implications of Smartphone Use

Woo

White

et al. 2016

PLoS ONE

View full text Add to dashboard Cite

BackgroundCertain hand activities cause deformation and displacement of the median nerve at the carpal tunnel due to the gliding motion of tendons surrounding it. As smartphone usage escalates, this raises the public’s concern whether hand activities while using smartphones can lead to median nerve problems.ObjectiveThe aims of this study were to 1) develop kinematic graphs and 2) investigate the associated deformation and rotational information of median nerve in the carpal tunnel during hand activities.MethodsDominant wrists of 30 young adults were examined with ultrasonography by placing a transducer transversely on their wrist crease. Ultrasound video clips were recorded when the subject performing 1) thumb opposition with the wrist in neutral position, 2) thumb opposition with the wrist in ulnar deviation and 3) pinch grip with the wrist in neutral position. Six still images that were separated by 0.2-second intervals were then captured from the ultrasound video for the determination of 1) cross-sectional area (CSA), 2) flattening ratio (FR), 3) rotational displacement (RD) and 4) translational displacement (TD) of median nerve in the carpal tunnel, and these collected information of deformation, rotational and displacement of median nerve were compared between 1) two successive time points during a single hand activity and 2) different hand motions at the same time point. Finally, kinematic graphs were constructed to demonstrate the mobility of median nerve during different hand activities.ResultsPerforming different hand activities during this study led to a gradual reduction in CSA of the median nerve, with thumb opposition together with the wrist in ulnar deviation causing the greatest extent of deformation of the median nerve. Thumb opposition with the wrist in ulnar deviation also led to the largest extent of TD when compared to the other two hand activities of this study. Kinematic graphs showed that the motion pathways of median nerve during different hand activities were complex.ConclusionWe observed that the median nerve in the carpal tunnel was rotated, deformed and displaced during the hand activities that people may be performed when using a smartphone, suggesting an increased risk of carpal tunnel syndrome (CTS). In addition, the kinematic graphs of median nerve developed in the present study provide new clues for further studies on the pathophysiology of CTS, and alerting smartphone users to establish proper postural habits when using handheld electronic devices.

show abstract

“…This can be potentially important in the context of CTS, as this dorsal movement of the nerve is reciprocal to the palmar motion of the finger flexors, which, during grip, might otherwise compress the nerve against the flexor retinaculum. 33,35,38,39 Indeed, the loss of this "nerve escape" mechanism might be part of the pathophysiologic characteristics of CTS. 14,32,40,41 Ultimately, the results of this study suggest that regarding the nerve mobility improvement after the treatment of CTS, wrist movement exercises might be more helpful than finger movement exercises.…”

Section: Discussionmentioning

confidence: 99%

Carpal Tunnel Syndrome Treatment and the Subsequent Alterations in Median Nerve Transverse Mobility

Hosseini-Farid

Schrier

Starlinger

et al. 2020

J of Ultrasound Medicine

View full text Add to dashboard Cite

Objectives-The mobility (transverse movement) of the median nerve (MN) is decreased in patients with carpal tunnel syndrome and can be measured noninvasively by ultrasound. To date, there are few prognostic features to help predict the outcome of 2 commonly performed treatments: surgical carpal tunnel release and corticosteroid injection. This study aimed to assess the changes in nerve mobility after the intervention and to correlate this with treatment and the disease severity.Methods-A total of 181 patients with carpal tunnel syndrome with different electrophysiologic severities were recruited and assessed by dynamic ultrasound scanning of the MN before and after treatment. The dynamic ultrasound images were collected while the patients performed finger and wrist flexion.Results-For both injection and carpal tunnel release, the nerve displacement increased with wrist flexion, from a mean AE SD of 7.0 AE 2.4 to 7.9 AE 2.7 mm (P < .005). Patients who underwent surgery showed greater improvement (P < .005) in nerve mobility compared to those who underwent injection. We also observed that the increase in nerve mobility was predominantly in patients with more nerve damage at baseline.Conclusions-This study shows that the dynamic behavior of the MN changes in response to treatment and lays a foundation for future studies to assess the prognostic potential of nerve mobility measurement.

show abstract

MRI-Apparent Localized Deformation of the Median Nerve Within the Carpal Tunnel During Functional Hand Loading

Cited by 6 publications

References 24 publications

Median nerve travel and deformation in the transverse carpal tunnel increases with chuck grip force and deviated wrist position

Median nerve travel and deformation in the transverse carpal tunnel increases with chuck grip force and deviated wrist position

Development of Kinematic Graphs of Median Nerve during Active Finger Motion: Implications of Smartphone Use

Carpal Tunnel Syndrome Treatment and the Subsequent Alterations in Median Nerve Transverse Mobility

Contact Info

Product

Resources

About