Autonomic nervous system dysfunction in diabetics can occur apart from peripheral sensorimotor polyneuropathy and sometimes leads to complaints which may be diagnosed by electrodiagnostic methods. Moreover glycemic control of these patients may prevent such a complications.
Materials and Methods: 30 diabetic patients were compared to the same number of age and sex-matched controls regarding to electrophysiologic findings of autonomic nervous system. Symptoms referable to autonomic disorder including nightly diarrhea, dizziness, urinary incontinence, constipation, nausea, and mouth dryness were recorded in all diabetic patients. Palmar and plantar SSR and expiration to inspiration ratio (E: I) and Valsalva ratio were recorded in all diabetics and control individuals by electromyography device. In addition NCS was performed on two sensory and two motor nerves in diabetic patients.
Results: There was no relation between age of diabetics and abnormal D: I ratio, Valsalva ratio and degree of electrophysiologic autonomic impairment. Also no relation between peripheral sensorimotor polyneuropathy and electrophysiologic autonomic impairment was found. Plantar SSR was absent in 80% of diabetics with orthostatic hypotension (p~ 0.019). Palmar and plantar SSR were absent in many diabetics in comparison to control group (for palmar SSR p~ 0.00 and for plantar SSR p< 0.015). There was no relation between diabetes duration since diagnosis and electrophysiologic autonomic impairment.
Conclusion: According to the above mentioned findings diabetic autonomic neuropathy develops apart from peripheral sensorimotor polyneuropathy and probably with different mechanisms. Remarkable absence of palmar SSR in diabetics with orthostatic hypotension can be due to its sympathetic origin. Absence of any relation between diabetes duration and electrophysiologic autonomic impairment can be due to late diagnosis of type 2 diabetes or no pathophysiologic relation between chronic hyperglycemia and autonomic neuropathy.
