polyneuropathy

Polyneuropathy is a disorder in which multiple peripheral nerves are damaged simultaneously. It typically presents with symmetric, distal, length-dependent sensory symptoms such as numbness, tingling, and burning pain in the feet and hands, followed by weakness and gait disturbance as it progresses. Autonomic symptoms may occur, including dizziness, constipation or diarrhea, and urinary difficulties. The course can be acute, subacute, or chronic.

Causes are diverse and include metabolic, toxic, infectious, inflammatory, autoimmune, hereditary, and paraneoplastic factors. Diabetes mellitus is among the most common causes. Others include alcohol-related neuropathy, vitamin deficiencies (notably B12), hypothyroidism, uremia, chemotherapy or radiation, HIV, and inflammatory disorders such as CIDP or Guillain–Barré syndrome. Hereditary neuropathies (for example Charcot–Marie–Tooth disease) and paraneoplastic processes also contribute. Exposure to heavy metals and certain solvents or drugs can trigger polyneuropathy.

Diagnosis is based on history and examination, supported by nerve conduction studies and electromyography to distinguish axonal versus demyelinating patterns. Laboratory workup targets metabolic control and potential etiologies: glucose/HbA1c, vitamin B12 and folate, thyroid function, renal and liver tests, and infectious or autoimmune markers. Cerebrospinal fluid analysis may help in inflammatory cases. Genetic testing is considered when a hereditary neuropathy is suspected.

Management centers on treating the underlying cause when possible, and relieving symptoms. Glucose control for diabetic neuropathy; avoidance of neurotoxins; supplements for deficiencies. Pain control may include anticonvulsants, antidepressants, and topical agents. Rehabilitative approaches, fall prevention, and assistive devices are important. Immunotherapies are used for immune-mediated polyneuropathies such as CIDP. Prognosis depends on etiology and disease pattern; some forms stabilize or improve, others progress.