Diabetic Autonomic Neuropathy

Diabetes is probably the commonest cause of autonomic neuropathy, and causes functional changes in many systems including the cardiovascular, urogenital and gastrointestinal systems. Fainting, postural hypotension, gastroparesis, atonic bladder, and erectile dysfunction may all be associated with autonomic dysfunction in diabetes, and there may also be defective sweating and pupillary reflexes. All of these may depend on damage to the small fibres in peripheral autonomic nerves, but it is increasingly clear that there are many disturbances in synaptic transmission and end-organ responses as well. Indeed many of the studies of ‘autonomic neuropathy’ depend on the measurements made of the function of effector organs rather than of the autonomic nerves themselves. Provocation tests which investigate endorgan activity during reflex manoeuvres, such as the Valsalva manoeuvre, postural tilting or cystometry, may allow the investigator to observe changes in reflex functions that are generally interpreted as being due to a disorder of the nerves themselves. Similarly changes in gastrointestinal transit times and tests of _______________________________