Sensorimotor testing for the early identification of individuals at risk of developing carpal tunnel syndrome

Abstract

Carpal tunnel syndrome (CTS) is one of the most common injuries responsible for lost time claims to the Workplace Safety and Insurance Board (WSIB). The main purpose of this study was to determine whether measurable sensorimotor changes exist in asymptomatic individuals who are at risk for CTS such that sensory impairment and/or functional tests may be used in the early detection and intervention to reduce the impact of CTS on individuals, industry and the health care system. Participants were recruited into three strata: (1) individuals diagnosed with mild CTS, (2) asymptomatic individuals who were deemed to be at risk of developing CTS due to exposure to etiological risk factors and (3) asymptomatic individuals who were deemed to be at minimal risk of developing CTS based on non-exposure to risk factors. The main outcome measures included two-point discrimination ability, pressure acuity, vibration sense, Purdue Pegboard Test performance and tracking error and tracking variance on a manual tracking task performed at two different speeds. Seven individuals with CTS, fourteen individuals at risk of developing CTS and nine control individuals with minimal risk participated. The CTS group was significantly different from the at-risk and control groups on the main and work sections of the DASH questionnaire, and the symptom severity scale and functional status scale of the Boston Carpal Tunnel Questionnaire. The only outcome measure that showed a significant difference between the at-risk and the minimal risk group was the assembly task of the Purdue Pegboard Test (p = 0.044), however other measures including median nerve conduction latencies, and manual tracking abilities showed promise that with further recruitment, a significant difference may be seen. The sensory impairment tests did not demonstrate degradation in sensory function in individuals at risk of developing CTS, however analysis of sensory nerve conduction latencies and some aspects of fine motor skills testing did show some promise in their ability to detect individuals at risk of developing CTS. A future prospective study that follows individuals at risk of developing CTS may determine that it is possible to implement a screening tool for the early identification and treatment of CTS.