Polyneuropathies are frequent neurological manifestations of systemic illnesses. For example, approximately 50% of diabetics and patients with advanced HIV develop a polyneuropathy. Most neuropathies caused by toxins and metabolic factors are axonal. The aetiologies of demyelinating polyneuropathy (e.g., Guillain-Barre syndrome, monoclonal gammopathies) are much more limited.
It most commonly presents as symmetric numbness, paraesthesias, and dysaesthesias 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, diarrhoea 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.
Associate Clinical Professor of Neurology
University of California
JWR declares that he has no competing interests.
Neurology and Neurological Sciences
YS is an author of a reference cited in this monograph.
Chief of Service
Neurosciences/Head and Neck Directorate
Imperial Healthcare Trust
Charing Cross Hospital
RS declares that he has no competing interests.
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