Does idiopathic carpal tunnel syndrome deteriorate proprioception of the hand? A case-control study

OBJECTIVES: This study aims to investigate the deterioration in kinesthetic kinesthesia (KKS) and visual kinesthesia (VKS) of the hand as a component of proprioception in patients with idiopathic carpal tunnel syndrome (CTS). PATIENTS AND METHODS: This study included a total of 90 hands of 60 patients (9 males, 51 females; mean age: 47.6±9.4 years; range, 28 to 60 years) who were diagnosed with CTS and 25 hands of 25 healthy individuals (8 males, 17 females; mean age: 42.6±14.4 years; range, 20 to 60 years) as the controls between January 2019 and January 2021. The KKS and VKS scores were compared between the groups. Clinical parameters such as pain levels, hand grip strength (HGS) values, and two-point discrimination (2PD) test scores were compared between the patients with and without KKS or VKS deficits. The association between the severity of electromyographic findings and KKS or VKS deficits was examined. RESULTS: The mean VKS score of the CTS group was 22.9±1.6 and the KKS score was 20.8±3.4, which was significantly lower than that of the control group (p=0.002 and p<0.001, respectively). The CTS patients performed less accurate repetitions in visually cued (60%) and kinesthetically cued (40%) positions than the control group (100% both). There were significantly more patients with VKS and KKS deficits in the moderate or severe CTS groups than in the mild CTS group (p<0.001 and p=0.007, respectively), and KKS or VKS deficits were significantly associated with the impaired HGS (p=0.042 and p=0.048, respectively) and functional status (p=0.020 and p=0.016, respectively) accompanied by the increased symptom severity (p=0.010 and p=0.002, respectively). CONCLUSION: Our study results suggest that idiopathic CTS is associated with impaired proprioception and kinesthetic sense of the hand. In addition, idiopathic CTS is related to impaired hand function and severe symptoms. Screening kinesthetic sense in patients with idiopathic CTS prior to decompression surgery or postoperative hand therapy is helpful to set realistic goals and achieve superior clinical outcomes.