Vibrotactile sense 5 years after carpal tunnel release in people with diabetes: A prospective study with matched controls.

Aim: To compare vibrotactile sense, 5 years after carpal tunnel release in people with and without diabetes.

Methods: Out of 35 people with diabetes and carpal tunnel syndrome, age- and gender-matched with 31 people without diabetes but with idiopathic carpal tunnel syndrome, 27 and 30 people, respectively, participated in this prolonged follow-up. Vibration perception threshold of the index and little finger (median and ulnar nerve, respectively), 5 years after surgery, was measured at seven different frequencies (8, 16, 32, 64, 125, 250 and 500 Hz).

Results: Significant improvement of vibration perception threshold from 1 to 5 years after carpal tunnel release was found at 64 Hz for people with diabetes, while improvement for people without diabetes was demonstrated at several frequencies (64-250 Hz). However, both groups demonstrated a significant decrease in vibration perception threshold for the low frequencies (8-16 Hz). At 5 years, people with diabetes had significantly impaired vibration perception threshold at the index finger for high frequencies (125-500 Hz), and for nearly all frequencies (16 Hz, 64-500 Hz) at the little finger, compared to people without diabetes.

Conclusion: After carpal tunnel release, significant mid-term improvement of vibrotactile sense appears limited for people with diabetes, compared to a continuous improvement for people without diabetes. In addition, a decline in low-frequency vibrotactile sense occurs for the median as well as the ulnar nerve innervated fingers. Clinical Trial Registration NCT01201109.