Electrophysiological study of diabetic autonomic and sensorimotor polyneuropathy

Abstract

Neurological complications of Diabetes Mellitus were looked for in a group of 31 patients using clinical examination and electrophysiological tests. Clinically evident sensorimotor neuropathy was found to be prsent in 41.9% and clinical autonomic neuropathy in 15% of the patients. Electrophysiological tests showed evidence of sensorimotor neuropathy in 80% and autonomic nerve dysfunction in 35% of the same patients. Autonomic neuropathy was found to occur always in association with sensorimotor neuropathy. The electrophysiological tests were found to be convenient as they were easy, and required little cooeration from the patient. Sensory nerve tests were found to be more sensitive than motor nerve tests alone and the yield of anyone test was found to increase the more nerves one examined. Electrocardiographic tests for autonomic neuropathy ( i.e. 'beat to beat variation' of pulse rate and the 'valsalva ratio' ) were found to be of equal sensitivity, but the former was easier to carry out and is therefore recommended. The use of postural blood pressure changes to assess autonomic nerve function was found to be too insensitive for any practical use. When postural hypotension is present, other signs of neuropathy are usually grossly evident.