Subclinical Diabetic Thoracic Radiculopathy

Youn, Young Chul; Kwon, Oh Sang

Abstract

Thoracic radiculopathy (TR) is one of various neurologic complications of diabetes mellitus (DM), which can cause pain and motor weakness of chest or abdomen. Electromyographic study is well known to be useful for accurate diagnosis of TR. This study is conducted in order to answer following questions: To what extent does paraspinal EMG study show denervation potentials in neurologically asymptomatic DM patients? ; Is there any correlation between EMG abnormality and severity of diabetes mellitus? We performed thorough neurologic examination and review of medical records in 74 DM patients who were referred for neurologic evaluation and rountine nerve conduction studies. Among those patients, 16 were selected for EMG on lower thoracic paraspinal muscles, who had no clinical symptoms of thoracic radiculopathy and no evidence of peripheral neuropathy on routine nerve conduction studies. The EMG findings were evaluated with relation to serum fructosamine level and duration of DM. On EMG examination, ten of sixteen patients exhibited positive sharp wave in lower thoracic paraspinal muscle. Nine of those ten patients with denervation potential in thoracic paraspinal muscle showed high fructosamine level and eight had been exposed to DM for more than 5 years. It is suggested that subclinical diabetic thoracic radiculopathy is more frequent than expected arid that there is positive correlation between abnormal paraspinal EMG findings and the level of fructosamine and duration of DM. And it is also suggested that there could be selective involvement of posterior primary ramus in diabetic patients, although it needs further studies to be confirmed.