synonyms: HMSN, CMT, Hereditary Sensorimotor Neuropathy, HNPP, hereditary neuropathy with predisposition for pressure palsy,
Charcot-Marie-Tooth Etiology / Epidemiology / Natural History
- Most-common inherited demyelinating neuropathy
- Caused by chromosome 17 abnormalites which encode for peripheral myelin protein 22 (PMP-22). Which leads to dysfunciton in the compact myelin sheath laid down by Schwann cells.
- CMT is a duplication of the PMP-22 gene.
- HNPP = hereditary neuropathy with predisposition for pressure pasly = a CMT related disorder caused by deletion of PMP-22 gene.
Charcot-Marie-Tooth Clinical Evaluation
- Progressive wasthing and weakness in the distal leg, peroneal innervated muscles
- High arched feet and hammer toes
- Often have positive family history
- HNPP symptoms are simlar to CTS, ulnar neuropathy, or peroneal nerve palsy often without high arched feet.
Charcot-Marie-Tooth Xray / Diagnositc Tests
- EMG/NCV: nerve conduction slowing (20m/s), may show reinnervation in distal muscles. May be demyelinating or axonal.
- Consider genetic confirmation.
Charcot-Marie-Tooth Classification / Treatment
Charcot-Marie-Tooth Associated Injuries / Differential Diagnosis
Charcot-Marie-Tooth Follow-up Care
Charcot-Marie-Tooth Review References