12th August 2024

Inherited neuropathies

Charcot-Marie-Tooth

CMT, also known as the hereditary motor sensory neuropathies (HMSN), refers to a group of disorders with inherited mutations to myelin (or rarely axonal) proteins.

• CMT1, the most common form, is characterised by distal lower limb sensory and motor loss, bony foot deformities (pes cavus, often with fractures followed by remodelling). Reflexes are typically diminished or absent. Biopsy may show characteristic ‘onion-bulb’ demyelination.
• CMT2 is a rare axonal form, characterised by sensory loss, distal weakness, atrophy, hyporeflexia and variable foot deformity. It presents in the teens to early twenties.

The mainstay of treatment is supportive, with orthotics and physiotherapy playing a large role.

Hereditary neuropathy with pressure palsies

HNPP describes a recurrent, transient, acute demyelinating mononeuropathy at sites of compression or trauma. Nerves commonly affected include radial, peroneal, median, axillary, ulnar, or brachial plexus.