Entrapment of medial plantar nerve [tarsal tunnel syndrome] in type 2 diabetes mellitus: An electrophysiological study

Abstract 

Background

With increase in type 2 diabetes mellitus patients the complications of diabetes are being seen more frequently. Patients with diabetic neuropathy often present with distressing symptoms such as pain and burning sensation in the feet. Tarsal tunnel syndrome with electrophysiological changes may be a causative or contributing factor. The present study was designed to assess the presence and features of tarsal tunnel syndrome in diabetes mellitus patients.

Method

In this study a group of 10 normal volunteers were selected who had no neurological complaints or foot trauma. Another group of 33 patients having longstanding diabetes mellitus with complaints of pain, burning sensation and paraesthesia in the feet were selected for electrophysiological tests and median plantar nerve was studied.

Results

In the present study we observed that 15 (45%) of diabetic cases showed abnormal findings e.g., prolonged distal motor latency, decreased amplitude of M-response, low or absent sensory response suggesting tarsal tunnel syndrome.

Conclusion

This study shows that the tarsal tunnel syndrome may be present in a significant number of diabetic patients with subjective neuropathic symptoms in the feet. The tarsal tunnel syndrome should be kept in mind during the diagnostic workup and management of diabetes mellitus.

Keywords: Diabetes mellitus, Tarsal tunnel syndrome, Medial plantar nerve, Distal motor latency, Sensory nerve action potential