Multifocal motor neuropathy with conduction block
Diagnosis requires progressive, focal, asymmetric limb weakness in the distribution of two nerves for more than one month and absence of sensory abnormalities. Treatment with intravenous immunoglobulin (IVIG) is recommended for all patients as it can improve weakness. Without treatment, weakness and motor symptoms will continue to progress resulting in increasing disability.
Disease typically presents before the sixth decade, with an average age of onset of 40 years (range 20-70 years); the condition very rarely presents during childhood. It has a 3:1 male predominance.
G61.82 – Multifocal motor neuropathy
230591002 – Motor neuropathy with multiple conduction block
Differential Diagnosis & Pitfalls
- Amyotrophic lateral sclerosis
- Vasculitic neuropathy (see vasculitis)
- Chronic inflammatory demyelinating polyneuropathy (CIDP)
- Progressive muscular atrophy
- Multifocal acquired demyelinating sensory and motor neuropathy
- Multifocal acquired motor axonopathy
- Hereditary neuropathy with liability to pressure palsy
- Flail arm or flail leg syndrome