Peripheral Neuropathy
Peripheral neuropathy is dysfunction of one or more peripheral nerves; the common chronic form is a length-dependent distal polyneuropathy, but focal, multifocal, autonomic, demyelinating and acute patterns require different investigation and urgency.
Definition
Peripheral neuropathy is dysfunction of one or more peripheral nerves, encompassing polyneuropathy, mononeuropathy and mononeuritis multiplex. The common chronic form is a symmetrical length-dependent sensory or sensorimotor polyneuropathy, but fibre type, distribution, tempo and neurophysiology determine the differential and urgency.
First principles
Describe the pattern before naming the cause
Localise the symptoms by fibre type, distribution, symmetry, time course and associated signs. A chronic symmetrical distal sensory or sensorimotor pattern suggests a length-dependent polyneuropathy; a single named nerve suggests mononeuropathy; separate painful or weak nerves developing asynchronously suggest mononeuritis multiplex. Rapid ascending weakness, a sensory level or upper motor neurone signs point away from an uncomplicated chronic peripheral neuropathy.
This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.

