56 Charcot–Marie–Tooth disease (peroneal muscular atrophy)
Salient features
Examination
• Wasting of muscles of calves and thighs that stops abruptly, usually in the lower third of the thigh, and is described as ‘stork’ or ‘spindle’ legs, ‘fat bottle’ calves and ‘inverted champagne bottles’ (Fig. 56.1)
• Pes cavus (high arched foot) or pes planus (flat foot), clawing of toes, contractures of the Achilles tendon
• Weakness of dorsiflexion, foot drop
• Absent ankle jerks, plantars are downgoing or equivocal
• Mild sensory impairment or no sensory loss. Some patients have decreased responses to pain in the stocking distribution.
• Feel for lateral popliteal nerve thickening (seen in some cases only)
Note: There are two distinctive clinical features of this disease:
1 The muscular atrophy begins in the distal portions of the affected muscles in the lower and upper limbs, unlike the global atrophy of motor neuron disease or muscular dystrophy. The atrophy then creeps upwards, involving all muscles.
2 Second, the degree of disability is minimal in spite of marked deformity.
