Validation of a novel cone tool for pinprick sensation examination in patients with spinal cord injury

Study Design Psychometrics study. Objective The objective of this study was to introduce a novel tool for pinprick sensation examination and validate its usefulness in patients with spinal cord injury (SCI). Setting China Rehabilitation Research Center, Capital Medical University School of Rehabilitation Medicine, China. Methods A set of cone tools with different tapers (22.5 degrees, 45 degrees, 67.5 degrees, 90 degrees, 112.5 degrees, 135 degrees, 157.5 degrees, and 180 degrees) was made. The cone tool was validated first in 91 able-bodied individuals and then in 30 patients with SCI. The reliability and validity of the cone tool were analyzed by comparing the results of a pinprick sensation examination with the results of the International Standards for the Neurological Classification of SCI (ISNCSCI), the cone tool, and the thermal analyzer. Results The intraclass correlation coefficient (ICC) of the cone tool in able-bodied individuals was between 0.48 and 0.94 while that of the cone tool and the ISNCSCI tool ranged between 0.43 and 0.78. Pinprick sensation in patients with SCI can be graded into five levels using four tapers (22.5 degrees, 45 degrees, 67.5 degrees, and 90 degrees): normal, slight impairment, moderate impairment, severe impairment, and complete loss of sensation. Conclusion This easy-to-use cone tool can produce a reliable semi-quantitative pinprick test result and is useful for pinprick sensation examination in patients with SCI.