Charcot-Marie-Tooth Disease(CMT)/Type 1 HMSN
Type 1 hereditary motor and sensory neuropathy (HMSN) is an inherited disorder characterised by degeneration of the posterior columns of the spinal cord, loss of anterior horn cells with degeneration of the spinocerebellar tracts, demyelination of peripheral nerves. Prevalence of 41/100 000.
Usually onset is around 5 years (first concern may be difficulty fitting shoes). Characterised by atrophy of the peroneals and intrinsic muscles with a pes cavus foot may present with pain under lateral forefoot. Pes cavus develops as muscle weakness primarily affects peroneus brevis and tibialis anterior with peroneus longus being spared plantarflexion of first ray. Mild cases are often misdiagnosed as pes cavus and not investigated further. Initial symptoms are the peroneal brevis weakness and a ‘foot slap’ with falls and tripping. Patients generally notice a feeling of weakness in the legs. Then get progressive loss of vibration sensation and proprioception. Rearfoot and first ray are usually initially flexible, later becomes fixed.
• conservative management of symptoms of pes cavus
• surgical correction of foot deformity.