Abstract
Introduction:
Two-point discrimination (2PD) is an integral part of every neurovascular examination of the hand. However, sparse studies have compared static versus dynamic 2PD. We developed a standardized and reproducible approach to compare both modalities, aiming to evaluate which is more reliable in detecting nerve recovery following cold-induced paresthesia.

Methods:

An experimental cross-sectional study performed at King Abdulaziz University Hospital was done in two phases. Cold exposure, using ice packs, was utilized to induce paresthesia in both index and little fingertips. Phase one included 33 participants and aimed to identify the timing of onset of paresthesia following cold exposure. Phase 2 included 100 participants and aimed to compare static vs dynamic 2PD in detecting onset of paresthesia and recovery. Fine touch was also tested in both phases.

Results:

The study was performed on healthy individuals between 15-35 years of age. P-values of <0.05 were considered significant. Static 2PD and fine touch showed significant changes from baseline following 4 minutes of cold exposure. Thus, 4 minutes of cold exposure was used in phase two to induce paresthesia. Phase two showed that all three tests were significantly changed from baseline. Recovery showed significant differences between all three tests. Static and dynamic 2PD recovered to baseline after 3 minutes, while fine touch failed to return to normal after 10 minutes of rest.

Conclusion:

This study demonstrates that dynamic 2PD is more resistant to cold-induced paresthesia compared to static 2PD, which demonstrated a change from baseline with cold exposure. There were no significant differences in their ability to detect sensory recovery. Fine touch was most affected by cold exposure, showing the greatest change and slowest recovery. Notably, both static and dynamic 2PD proved to be more accurate than fine touch in detecting sensory recovery from cold-induced paresthesia.

Key words: Two-point discrimination; fine touch; sensibility; nerve regeneration.