INTRODUCTION

Peripheral neuropathy is a disorder of the peripheral nerves of any cause. It typically is characterized by symmetric distal sensory loss, dysesthesias such as burning, or weakness. Most peripheral nerve disorders in children are hereditary (figure 1). However, many systemic illnesses, drugs, and toxins affect the peripheral nervous system (table 1).

An overview of acquired peripheral neuropathies is presented here. Hereditary peripheral neuropathies and specific disorders that affect the peripheral nerves are discussed separately. (See appropriate topic reviews).

CLINICAL FEATURES

Most peripheral nerve disorders have a gradual and slowly progressive course. Acute presentation may occur with toxic exposure or inflammatory conditions.

Most peripheral neuropathies show bilateral, symmetric, predominantly distal involvement. The injury is related directly to axon length; thus, longer axons are affected first, resulting in symptoms that typically have an earlier presentation and are more prominent in the lower extremities. Most have combined sensory and motor involvement. However, some disorders have only motor or sensory abnormalities.

The most common motor symptom is weakness. It may present as clumsiness, difficulty with running or climbing stairs, or impaired fine motor skills such as writing, buttoning clothes, or tying shoes. Sensory symptoms may include numbness, dysesthesias such as burning pain, or ataxia.