—MC inherited
neurological disorder
—1886 described
together
—Professor Jean Martin
Charcot and his student Pierre Marie – Peroneal Muscular Atrophy
—Howard Henry Tooth –
Peroneal Progressive Muscular Atrophy. Attributed it correctly to neuropathy.
—1912 Hoffman
described peroneal muscular atrophy with thickened nerve; Hoffman’s disease.
—Hereditary Sensory
and Motor Neuropathy type I, II and III (Dejerine-Sotta’s disease)
Classification
—Type 1
—Demyelinating;
—further subdivided A
(MC, 70%), B & C.
—Autosomal dominant
—Type 2
—Axonal degeneration;
—Autosomal dominant or
recessive
—Type C
—Intermediate between
axonal degeneration and demyelinating
—Autosomal dominant
—Clinical Features
—Incidence of all
types of CMT varies from 1 in 5000 to 1 in 2500
—Presents with
—Progressive weakness and atrophy of distal muscles
—Depressed DTRs
—Slowed nerve conduction velocities
—Family h/o similar disease
—Varied age of onset
—Most commonly onset at the 2nd
decade of life
—CMT Type 2 onset 3rd decade of life
—Normal motor
milestone
—Incidence equal in
both sexes, severity more in boys with CMTX
—
—Physical signs
•Diminished to absent DTRs
—Ankle jerk lost before knee jerk
—Sensory loss
—2/3rd
of the patients
—More common in CMT 1
than CMT 2
—Muscular weakness
—Varied involvement of
muscle
—MC muscles involved
are tibialis anterior and peroneus brevis. May involve all the muscles of the
calf
—Most severe form –
generalized muscle weakness → inability to walk
—Atrophy of calf
muscles → stork leg appearance
—
—Gait changes
—Early stages – slight
foot drop seen only in swing phase
—Progressively develop
complete plantigrade foot with hyperflexion of knee then hip and elevation of
hemipelvis
—Steppage gait
—Foot deformity
—Pes cavus, pes
cavovarus or claw toe
—Hands show atrophy of
intrinsic muscles
—Progressive scoliosis
of spine seen in adolescent and teens
—Sensorineural
deafness maybe seen in CMTX.
—Investigations
—Blood tests – known
mutations
—EMG-NCV
—Demyelinating:
decrease in velocity with amplitude same as normal
—Axonal degeneration:
same velocity with decrease amplitude
—EMG shows
fibrillation due to denervation
—Nerve Biopsy
—Sural nerve is used
—Demyelinating – Onion
Bulb appearance
—Type 2 – Axonal
degeneration
—Muscle biopsy –
atrophic muscles
—MRI Spine
—Diffuse enlargement
of cauda equina, nerve roots and ganglia
—Sonography
—Enlargement of median
nerve
—Medical management
—No medical treatment
to slow or stop the disease
—71% of the patients
present with severe neuropathic pain requiring medications
—Orthopaedic manifestations
—Foot
—MC manifestation is
pes cavovarus
—Atrophy due to
denervation of the intrinsic muscles → contractures → elevation of the medial
longitudinal arch because of the contracture of plantar fascia
—Plantar flexion of
the first ray and forefoot equinus → varus of the hind foot
—Claw toes – absent
intrinsic muscles
—
—Radiographs
—Meary’s angle
—Angle between the
longitudinal axis of talus and the 1st metatarsal
—Normal 0-5°
—Coleman’s block test
—Patient made to stand
on a block of wood with the 1st metatarsal head
falling off the block
—Supple hind foot
varus – corrects
—Fixed varus – does
not correct
—Surgical management
—Olney divided
surgical management into two components
—Deformity correction
—Soft tissue release
—Plantar fascia
release
—Capsulotomies
—Bony fusions or
osteotomies
—1st
metatarsal osteotomy
—Calcaneal osteotomy
—Triple arthrodesis
—
—Rebalancing of muscle
forces
—Tendon transfers
—Dorsiflexion weakness
– EDL or posterior tibial transfer
—Overpowering peroneus
longus – transfer to
peroneus brevis
—Hindfoot equinus – tendoachilles lengthening
—
—Claw toes
—Paralyses and
contracture of intrinsic muscles
—Toe extensors
recruited to dorsiflex ankle
—Jones transfer of the
long extensors to the metatarsal to help ankle dorsiflexion
—Fusion of IP joint of
great toe and PIP joint of the other toes
—Hip
—Dysplasia of hip
—Subtle weakness of
the proximal musculature → progressive dysplasia of hip
—Asymptomatic till
adolescent
—Treatment similar to
idiopathic adolescent dysplasia of hip
—Spine
—Scoliosis seen in 37%
—Similar to idiopathic
scoliosis with increased kyphosis
—Highest risk in girls
& CMT 1
—May present with hyperkyphosis without scoliosis
—Treatment
—Orthosis
—Posterior spinal
fusion – failure of orthotic management and with progressive curves
—Hand
—Onset of hand
symptoms occur in 1st to 3rd decade of life; 8
years after the appearance of lower limb symptoms
—Present with
intrinsic muscle weakness with clawing of ring and small digits occur.
—Involvement of ulnar
and median nerve innervated forearm and intrinsic muscles
—Sparing of radial
nerve innervated muscles
—Functional problems:
—Loss of opposition
—Loss of side to side
pinch
—Clawing of fingers
—Management
—Electrodiagnostic studies done to
determine the best muscle for tendon transfer
—Transfers without
pulley or if required with static pulley preferred to tendon or tendon loop
pulley
—Opponensplasty – extensor carpi ulnaris or extensor indicisproprius
—Side to side pinch –
extensor pollicis brevis, abductor pollicislongus or extensor indicis to 1st
dorsal interosseous or adductor pollicis
—Muscle transfer done
in flexion of MCP joints to compensate extrinsic extensors
—
—Delayed till age when
patient can understand the limitations and aftercare
—The disease and
deformity can be progressive
—Transfer requires
protection from excessive abuse
—Dejerine-Sottas
Disease
(Hypertrophic Interstitial Neuritis)
(Hypertrophic Interstitial Neuritis)
—Severe,
infantile-onset demyelinating polyneuropathy
—Related to same gene
as CMT 1A
—Enlarged peripheral
nerves – proliferation of perineural and endoneural tissues
—Classical onion bulb
appearance
—Presenting complaint
—Disability of gait
under 3 years of age
—Floppy muscles,
thickened nerves.
—Severe cases present
with respiratory failure at birth.
—Similar findings as
CMT with increased severity and earlier age of onset.
—No treatment
—Steroids can be given
in severe cases.
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