Evaluation of polyneuropathy

Last reviewed: 24 Jan 2021

Last updated: 21 Jun 2018

Polyneuropathy is a generalized disease of the peripheral nerves. Estimates on the prevalence in the general population range from 2% to 7%.[1][2][3]

Polyneuropathies are frequent neurological manifestations of systemic illnesses. For example, approximately 50% of diabetics and patients with advanced HIV develop a polyneuropathy.[4][5] Most neuropathies caused by toxins and metabolic factors are axonal. The etiologies of demyelinating polyneuropathy (e.g., Guillain-Barre syndrome, monoclonal gammopathies) are much more limited.

Clinical presentation

It most commonly presents as symmetric numbness, paresthesias, and dysesthesias in the feet and distal lower extremities (distal symmetrical polyneuropathy). In severe cases, sensory symptoms and signs fit a stocking-glove distribution. Balance and gait may be impaired. Early motor signs include atrophy of the intrinsic foot muscles and ankle weakness. The autonomic nervous system may be involved, resulting in symptoms such as early satiety, diarrhea or constipation, sexual performance problems, sweating disturbances, and orthostatic lightheadedness.

Asymmetric neuropathies or neuropathies presenting initially with upper extremity signs or symptoms should alert the practitioner to alternate neuropathy diagnoses, including entrapment neuropathies (focal neuropathies) or vasculitic neuropathies (multifocal neuropathies). The differential diagnosis of focal and multifocal neuropathies overlaps but is distinct from that of polyneuropathies.