Common and Less Common Peripheral Nerve Disorders Associated with Diabetes

Abstract

Diabetes can be associated with a number of peripheral nerve disorders. The commonest is slowly-progressive axonal distal symmetrical sensori-motor neuropathy. Sensory loss and positive sensory symptoms are its main manifestations. Lumbosacral radiculoplexus neuropathy (LSRPN) is a distinct entity, accompanied by severe lumbar, hip, leg pain and weight loss, with subsequent weakness. Although typically unilateral, bilaterality is described, with spontaneous recovery usual over several months. The upper limb counterpart, cervical radiculoplexus neuropathy is rare. Acute painful neuropathies, including "diabetic neuropathic cachexia", are infrequent. Accompanying weight loss is usual and burning pains in the extremities are severe. Insulin-triggered acute painful neuropathy is well-described although infrequent and still poorly-understood. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) represents an immune-mediated treatable disorder, usually causing prominent diffuse motor weakness, which was described as more common in diabetics. More recent epidemiological data have however been conflicting and it is possible that CIDP is no more frequent in diabetics than in the general population. Diagnosis is made by electrophysiology and cerebrospinal fluid analysis. A painless diabetic motor neuropathy, thought to be caused by ischaemic injury and microvasculitis, has recently been postulated as separate from LSRPN and CIDP. Other focal and multifocal neuropathies that can occur in diabetics are cranial or truncal. Entrapment neuropathies are more often of median and ulnar nerves, and may in some cases benefit from decompression. Finally, autonomic neuropathies are well-described in diabetes and can be diverse in presentation with cardiovascular, gastrointestinal, urogenital and sudomotor manifestations. Their management can be difficult with debilitating symptoms despite treatment.

Ultrasound evaluation in transthyretin‐related amyloid neuropathy

“…This is probably a preferential site of nerve damage in TTR mutations, and further data confirming this observation could provide information for an etiologic hypothesis (possibly amyloid deposit in entrapment site). On the other hand, we cannot simply exclude vulnerability of nerves at entrapment sites caused by neuropathy, as happens, for instance, in diabetic neuropathy . Furthermore, an increased CSA at entrapment sites (including the ulnar nerve at the elbow) without evidence of neurophysiological abnormalities was also found in patients with chemotherapy‐induced axonal neuropathy …”

New Insights Into the Management of Chronic Inflammatory Demyelinating Polyradiculoneuropathy

“…Indeed, the long-held concept that CIDP occurs more frequently in patients with diabetes mellitus is currently under challenge [7,8] as is the direct link between CIDP and various other systemic diseases.…”

Independent Risk Factors for Positive and Negative Symptoms in Patients with Diabetic Polyneuropathy

“…In the present study, we adjusted the duration of diabetes and HbA 1c levels; as a result, possible insulin neuritis caused the negative symptoms of DPN. 15 In a previous study, obese patients showed a lower conduction velocity in the peripheral nerves, suggesting that excessive compression of the peripheral nerves by the surrounding fat tissues causes entrapment neuropathy. 16 This mechanism will increase the degeneration of sensory fibers by diabetes, resulting in clinically evident negative symptoms.…”