Inter-rater reliability of two-point discrimination in acute stroke patients

The two-point discrimination (2PD) test is widely used in clinical practice to assess tactile acuity and central somatosensory function in stroke patients.

The aim of this study was to evaluate the reliability of 2PD test in fingers on the affected and non-affected sides in acute stroke patients.

This was a single group repeated-measures inter-rater reliability study. Thirty adults with completed ischemic stroke and left paresis participated in the study. Static 2PD sensation was assessed using a standardized Dellon discriminator. Two examiners performed measurements of 2PD sensation on both hands. Each examiner made three series of measurements at intervals of 1 minute. After 15 minutes, the study was conducted in the same order by a second examiner.

The ability for 2PD sensation was significantly reduced in all examined fingers on the affected side in comparison to the non-affected side. The difference was statistically significant (in each case, p < 0.0001). Inter-rater reliability (ICC2,1) for the first measurement at the affected site ranged from 0.95 to 0.98; at the non-affected site ranged from 0.30 to 0.82. Analysis of the average value of three measurements (ICC2,3) yielded values for the affected site ranging from 0.98 to 0.99; at the non-affected site ranged from 0.81 to 0.95.

The 2PD sensation values for all fingers were higher for the affected site in comparison to the non-affected site. Conducting three repeatable measurements ensures measurement reliability and repeatability when evaluating 2PD sensation in fingers on both sides in acute stroke patients.