2. Types of Hereditary motor and sensory
neuropathy(HMSN)
• 1-CMT(Hypertrophic demyelinating)
• 2-CMT(Axonal)
• 3-Dejerine-sotta’s disease(AR)
• 4-Refsum’s disease(AR)
• 5-Spastic paraplegia
• 6-With optic atrophy
• 7-With Retinitis pigmentosa
3. Introduction
• One of most common inherited Neurological
disorders
• Compromises a group of disorders that affect
peripheral nerves
• Gradual progression of disease
• Occurs in adolescent or early childhood
5. • Mutations in genes that produce proteins
involved in the structure and function of
peripheral nerve axon or the myelin sheath
6. Types
• CMT – 1 AD Duplication of gene on
chromosome 17
• CMT – 2 Abnormalities in the axon of
peripheral nerve cell
• CMT – 3 Severe demyelinating neuropathy
• CMT – 4 AR Demyelinating motor and sensory
neuropathies
• CMT – X X linked dominant disease / point
mutation in connexin-32 gene on X
chromosome
8. Clinical features
• Weakness in feet and lower leg muscles
• Deformities – frequent tripping and falling
• Loss of muscle bulk in lower leg – ‘inverted
champagne bottle appearance’ / stork leg
appearance(distal muscle wasting)
• Bony abnormalities – long standing cases –
PES CAVUS(high arch foot) , forefoot cavus
deformity(denervation of lumbricals)
9.
10.
11. Other features
• Spine – thoracic scoliosis
• Diminished or absent DTR
• Diminished vibration and proprioception sense
• Sensory gait ataxia
• Essential tremors
• SNHL
• Palpable peripheral nerves, diaphragmatic
weakness, vocal cord involvement
12. DIAGNOSTIC WORKUP
• Patient’s history
• Family history
• Symptoms
• Neurological findings
• Radiological evidences
• Electrodiagnostic tests
13. Treatment options
• Deformity correction
Plantar fascia release,
metatarsal osteotomy, calcaneal osteotomy ,
triple arthrodesis
• Rebalancing of deforming muscle forces
EDL transfer , posterior tibial
tendon transfer, Achillus tension lengthening,
peroneus longus to peroneus brevis tendon
transfer