Towards development of a nonhuman primate model of carpal tunnel syndrome: Performance of a voluntary, repetitive pinching task induces median mononeuropathy in Macaca fascicularis

Abstract

This study investigated changes in median sensory nerve conduction velocity (SNCV) over several weeks of exposure to a voluntary, moderately forceful, repetitive pinching task performed for food rewards by a small sample of young adult female monkeys (Macaca fascicularis). SNCV, derived from peak latency, decreased significantly in the working hands of three of the four subjects. The overall decline in NCV was 25%-31% from baseline. There was no decrease in SNCV in the contralateral, nonworking hands. Several weeks after being removed from the task, SNCV returned to within 87%-100% of baseline. MRI showed enlargement of the affected nerves near the proximal end of the carpal tunnel, at the time of maximal SNCV slowing. This new animal model demonstrates a temporally unambiguous relationship between exposure to a moderately forceful, repetitive manual task and development of median mononeuropathy at the wrist, and recovery of SNCV following termination of task exposure. This study contributes to the pattern of evidence of a causal relationship between manual work, median mononeuropathy, and carpal tunnel syndrome in humans. In the future, this new animal model could be used to characterize dose-response relationships between risk factors and carpal tunnel syndrome. ß

Serum and tissue cytokines and chemokines increase with repetitive upper extremity tasks

“…10 In contrast to our human study, we did not find increased serum IL-6 in this study, a result consistent with findings of a repetitive pinching task in a nonhuman primate model 6 and a study examining patients with carpal tunnel syndrome. 19 However, there was no detectable serum TNFa in those two studies 6,19 results differing from ours. Species differences in cytokine response profiles, the detection system used, and inherent differences in the injury induced may account for these varying results.…”

“…For example, here, the rats flex their wrists as well as extend their elbow and shoulder, increasing the involvement of more regions than in the pinch task. 6 Prolonged, intensive cycling results in short-lived increases (immediate to 2 h postexercise) of several serum cytokines, 13,14 presumably after release from contracting muscles. 21 However, it is unlikely that muscle contractions contributed to our increased serum cytokines and chemokines because we collected serum at 18-36 h after completion of the final task session.…”

“…Recent work suggests that RMIs induce injury in several tissue types in animal models, [1][2][3][4][5][6] as well as an early inflammatory response at the tissue level. 2,3,[7][8][9] Increases in four circulating inflammatory mediators, C-reactive protein, interleukin 1 beta (IL-1b), IL-6, and tumor necrosis factor alpha (TNFa) have also been shown to increase in patients with upper extremity overuse disorders.…”

Awareness of Apt Computer Use and Hazards among University Students in Dhaka

“…To support this viewpoint, Reference [20] reported that more than 35 percent of the students using Tablet PC at home would not utilize a desk or table. And over 50 percent of the students experienced discomfort in eyes, neck, head, wrist and back.…”

Ibuprofen as a Treatment for Work-Related Musculoskeletal Disorders: Effectiveness versus Caveats

“…Those suggested maximum limits are indicated in Table 1. 4. An operant rat model of WMSD Several animal models have been developed to study WMSDs and have shown that repetitive hand activities induce sensorimotor dysfunction [27][28][29][30][31][32][33]. A model developed in our laboratory is a unique operant rat model of voluntary reaching and grasping (Figure 1; [7,34]).…”