The cross sectional area of posterior tibial nerve (PTN) is increased in diabetic patients with distal symmetric polyneuropathy (DSPN) as compared to diabetic patients without DSPN. This study aims to evaluate whether the cross sectional area of the Posterior Tibial Nerve (PTN) as measured by ultrasound is increased in patients with distal symmetric polyneuropathy (DSPN) as compared to diabetic patients without DSPN.

Regional anesthesia is associated with a low frequency of neurologic injury that can result in permanent deficit. It is believed that patients with neuropathies might be at higher risk of injury but detailed investigation of the diabetic patient is lacking yet anesthetic practices may be altered nevertheless. This study intends to investigate the appearance and sonographic qualities, as well as electrophysiologic measures, of the posterior tibial nerve (PTN) in diabetic patients undergoing nerve conduction studies in order to compare PTN characteristics between diabetic patients with peripheral neuropathy to those without. Ultimately, we hope that ultrasound, a commonly used non-invasive tool, will be able to assist in the identification of patients at higher risk of injury from regional anesthesia

Inclusion Criteria:

• Type I diabetic patients (diagnosed more than 5 years), and type II diabetic patients scheduled for routine NCS.

Exclusion Criteria:

• Non-diabetic neuropathy caused by genetic, metabolic and inflammatory diseases as well as toxic agents and drug induced (eg. chemotherapy agents)

100 adult diabetic patients scheduled to undergo a nerve conduction study.