Cold-induced vasomotion changes in healthy individuals and patients after median or ulnar nerve repair.

This exploratory study investigated digital vasomotion during and after a standardized cold stress test in healthy subjects and patients previously treated for median or ulnar nerve injury. Twenty-five healthy individuals and 20 patients with a median or ulnar nerve injury were included. Finger perfusion was measured before and after a Cold Stress Test, using Laser Speckle Contrast Imaging. Vasomotion activity was quantified as the area under the curve of synchronized perfusion dips, and comparisons were made within and between the groups. Synchronized perfusion dips were observed in healthy participants both before and after cold provocation but were attenuated in patients with nerve injury. This suggests an impaired neural modulation of digital microvascular tone among nerve-injured patients. Among male patients with ulnar nerve injury, baseline perfusion was lower in the injured digit V than in the corresponding uninjured digit V (132 vs. 157 PU, p = 0.001), accompanied by reduced vasomotion activity (AUC 1.07 vs. 1.92, p = 0.010). In conclusion, neural mechanisms may be important in regulating vasomotion in the hand. Patients with a nerve trunk injury exhibit a different vasomotion pattern compared with healthy participants, supporting an important role of neural regulation in the alteration of digital vasomotion.