Diabetic Neuropathies

Abstract

The diabetic neuropathies are heterogeneous, affecting different parts of the nervous system that present with diverse clinical manifestations. They may be focal or diffuse. Most common among the neuropathies are chronic sensorimotor distal symmetric polyneuropathy (DPN) and the autonomic neuropathies. DPN is a diagnosis of exclusion. The early recognition and appropriate management of neuropathy in the patient with diabetes is important for a number of reasons. 1 ) Nondiabetic neuropathies may be present in patients with diabetes. 2 ) A number of treatment options exist for symptomatic diabetic neuropathy. 3 ) Up to 50% of DPN may be asymptomatic, and patients are at risk of insensate injury to their feet. As >80% of amputations follow a foot ulcer or injury, early recognition of at-risk individuals, provision of education, and appropriate foot care may result in a reduced incidence of ulceration and consequently amputation. 4 ) Autonomic neuropathy may involve every system in the body. 5 ) Autonomic neuropathy causes substantial morbidity and increased mortality, particularly if cardiovascular autonomic neuropathy (CAN) is present. Treatment should be directed at underlying pathogenesis. Effective symptomatic treatments are available for the manifestations of DPN and autonomic neuropathy. This statement is based on two recent technical reviews (1,2), to which the reader is referred for detailed discussion and relevant references to the literature. An internationally agreed simple definition of DPN for clinical practice is “the presence of symptoms and/or signs of peripheral nerve dysfunction in people with diabetes after the exclusion of other causes” (3). However, the diagnosis cannot be made without a careful clinical examination of the lower limbs, as absence of symptoms should never be assumed to indicate an absence of signs. This definition conveys the important message that not all patients with peripheral nerve dysfunction have a neuropathy caused by diabetes. Confirmation can be established with …