The Graph-DCK Scale: a measure of dorsal column function after spinal cord injury

Study design Cohort/psychometric study. Objectives Assessment of dorsal column medial lemniscus (DCML) function is important for the clinical evaluation of people with spinal cord injury (SCI) because it provides useful information to guide rehabilitation and for prognosticating outcomes. For example, research suggests that damage to the DCML pathway may be associated with neuropathic pain after SCI. Tests for graphesthesia and directional cutaneous kinesthesia (DCK) are commonly used clinically to assess DCML function. However, the reliability and validity of these assessments in people with SCI have not been investigated. Moreover, there is a poor consistency between studies in the methodology of graphesthesia and DCK assessment. The purpose of this study was to determine the psychometric properties of the Graph-DCK Scale, which is a simple and potentially useful scale for assessing graphesthesia and DCK. The Graph-DCK Scale does not require expensive equipment and it takes less than 5 min to administer. Setting A university-based laboratory in Miami, FL, USA. Methods Sixty-seven people with chronic SCI and neuropathic pain were included in this study. The Graph-DCK Scale and vibration detection were measured twice in each participant, with a two- to four-week period between measurement sessions. Results The scale demonstrated an excellent internal consistency (Cronbach's alpha > 0.90) and test-retest reliability (ICC values > 0.80). Further, convergent validity was supported by moderate and significant positive correlations to vibration detection (r values > 0.40). Conclusion The Graph-DCK Scale is quick and easy to administer, and it provides a reliable and valid assessment of DCML function in people with SCI.