These patients cannot feel when they are stepping on a foreign body, like a splinter, or when they are developing a callus from an ill-fitting shoe. Consequently, they are at risk of developing ulcers and infections on the feet and legs, which can lead to amputation. Similarly, these patients can get multiple fractures of the knee, ankle or foot, and develop a Charcot joint. Loss of motor function results in dorsiflexion, contractures of the toes, loss of the interosseous muscle function that leads to contraction of the digits, so-called hammer toes. These contractures occur not only in the foot but also in the hand where the loss of the musculature makes the hand appear gaunt and skeletal. The loss of muscular function is progressive. Autonomic neuropathy
The autonomic nervous system is composed of nerves serving the heart, lungs, blood vessels, bone, adipose tissue, sweat glands, gastrointestinal system and genitourinary system. Autonomic neuropathy can affect any of these organ systems. One commonly recognized autonomic dysfunction in diabetics is orthostatic hypotension, or becoming dizzy and possibly fainting when standing up due to a sudden drop in blood pressure. In the case of diabetic autonomic neuropathy, it is due to the failure of the heart and arteries to appropriately adjust heart rate and vascular tone to keep blood continually and fully flowing to the brain. This symptom is usually accompanied by a loss of respiratory sinus arrhythmia – the usual change in heart rate seen with normal breathing.
Pelvic floor muscle exercises can improve sexual dysfunction caused by neuropathy. Electric stimulation of the plantar aspect of the foot showed improved balance and sensation when performed daily. Other
Low-quality evidence supports a moderate-large beneficial effect of botulinum toxin injections. There is insufficient evidence to draw firm conclusions for the utility of the cannabinoids nabilone and nabiximols. Prognosis
The mechanisms of diabetic neuropathy are poorly understood. At present, treatment alleviates pain and can control some associated symptoms, but the process is generally progressive. As a complication, there is an increased risk of injury to the feet because of loss of sensation (see diabetic foot). Small infections can progress to ulceration and this may require amputation. Epidemiology
Globally diabetic neuropathy affects approximately 132 million people as of 2010 (1.9% of the population).Diabetes is the leading known cause of neuropathy in developed countries, and neuropathy is the most common complication and greatest source of morbidity and mortality in diabetes. It is estimated that neuropathy affects 25% of people with diabetes. Diabetic neuropathy is implicated in 50–75% of nontraumatic amputations. The main risk factor for diabetic neuropathy is hyperglycemia. In the DCCT (Diabetes Control and Complications Trial, 1995) study, the annual incidence of neuropathy was 2% per year but dropped to 0.56% with intensive treatment of Type 1 diabetics. The progression of neuropathy is dependent on the degree of glycemic control in both Type 1 and Type 2 diabetes. Duration of diabetes, age, cigarette smoking, hypertension, height, and hyperlipidemia are also risk factors for diabetic neuropathy.