What does nerve ultrasound contribute to the evaluation of diabetic polyneuropathy over time? A prospective follow-up observational study of people with type 2 diabetes

Abstract

Aims: Studies using peripheral nerve ultrasound have shown moderate nerve enlargement in individuals with diabetic polyneuropathy (DPN). Neither extent, course, consistency, nor clinical significance of this finding is clear.

Method: We examined 156 people with type 2 diabetes mellitus using nerve ultrasound, nerve conduction studies, and clinical scores. 59 received a follow-up examination after one year and 43 patients after two years.

Results: Increase of cross-sectional area (CSA) of the peripheral nerves in DPN was rather negligible compared to normative cut-off values. The CSA of the median nerve at the forearm and wrist and the ulnar nerve at the upper arm, forearm and wrist were significantly larger in individuals with DPN compared to those without DPN. People with DPN had significant changes in most parameters of nerve conduction studies. Ultrasound measurements over time showed a slight increase in CSA in the median nerve at the carpal tunnel and a slight decrease in the fibular nerve at the fibular head. Ultrasound pattern sum score slightly decreased in the DPN group over two years.

Conclusions: Ultrasound measurements alone may be insufficient to detect DPN. Follow up with nerve ultrasound over one or two years was short and did not show substantial changes.

Keywords: Diabetes mellitus; Diabetic polyneuropathy; Follow-up; Nerve conduction study; Nerve ultrasound.