H-reflex Studies in Patients with Subclinical Diabetic Polyneuropathy

ABSTRACT

BACKGROUND: The H-reflex has been used to assess the proximal nerve conduction in radiculopathy or peripheral neuropathy. The purpose of this study was to evaluate the clinical usefulness of the H-reflex in the diagnosis of subclinical diabetic polyneuropathy. METHOD: Thirty-four diabetic patients (17 women and 17 men) who had neither motor nor sensory symptoms were selected (mean age 57.6 +/- 12.9 years). The duration of diabetes varied from 0.5 to 24 years (mean 6.2 +/- 5.1 years). None of the patients had any known cause of peripheral neuropathy other than diabetes. Twenty-seven healthy subjects (16 women and 11 men) were evaluated as an age-matched control group. H-reflex studies were performed using Braddom and Johnson's methods. The presence and latencies of the H-reflexes were examined in both legs. RESULTS: Twenty-four of the 34 patients (70.6%) had abnormal H-reflex responses (absent H-reflex in 17, prolonged latency in 7). However, only three out of the 27 control subjects (11.1%) had abnormal H-reflex responses (absent H-reflex in 1, prolonged latency in 2). CONCLUSIONS: Abnormalities in H-reflex studies have often been seen in diabetic subjects without overt neurological symptoms. This study suggests that the H-reflex study may be a useful screening tool in the diagnosis of subclinical diabetic polyneuropathy.