Muscle disorders- the muscular dystrophies

Mind Map by , created almost 6 years ago

paeds-neurology Mind Map on Muscle disorders- the muscular dystrophies, created by v.djabatey on 01/12/2014.

Created by v.djabatey almost 6 years ago
Peripheral neuropathies
Secondary headaches- raised ICP & space-occupying lesions
Primary headaches
Circle Theorems
I Turner
Peripheral motor disorders- neuromuscular disorders
Epilepsies of childhood-pt2
Epilepsies of childhood
Classification of headache disorders
Muscle disorders- the muscular dystrophies
1 Duchenne muscular dystrophy
1.1 epidemiology
1.1.1 commonest phenotype
1.1.2 1 in 4000 male infants affected
1.2 aetiology
1.2.1 X-linked recessive inheritance
1.2.2 some have new mutations
1.2.3 deletion on Xp21 codes for dystrophin protein connects cytoskeleton of a muscle fibre to surrounding extracellular matrix via cell mb if deficient -> fibre necrosis (through abnormal intracellular signalling pathways causing) Ca2+ ion influx breakdown of Ca2+ calmodulin complex excess of free radicals
1.3 Diagnosis
1.3.1 serum creatine phosphokinase (CPK) sig raised neonatal screening by this method in some countries only e.g. Wales
1.4 presentation
1.4.1 waddling gait &/or lang delay have to mount stairs 1 by 1
1.4.2 av age of diag= 5.5 years but often symptomatic much earlier
1.4.3 Gower's sign need to turn prone to rise
1.4.4 pseudohypertrophy of calves replacement of mm by fat & fibrous tissue
1.4.5 boys slower & clumsier than peers in early school years progressive mm atrophy & weakness-> non ambulant by 10-14 years old
1.4.6 episodes of nocturnal hypoxia secondary to intercostal mm weakness
1.5 life expectancy reduced to late 20s cos
1.5.1 resp failure
1.5.2 assoc cardiomyopathy
1.6 1/3rd of kids have LD
1.7 complications
1.7.1 scoliosis
1.8 Mx
1.8.1 approp exercise maintain muscle power & mobility delays onset of scoliosis
1.8.2 passive stretching & provision of night splints prevent contractures esp @ the ankles
1.8.3 orthoses esp those allowing ambulation by leaning from side to side prolong walking
1.8.4 lengthening Achilles tendon to aid ambulation
1.8.5 maintaining good sitting posture reduce risk of scoliosis
1.8.6 scoliosis truncal brace moulded seat ultimately surgical incision of a metal spinal rod
1.8.7 overnight CPAP or NIPPV improve quality of life
1.8.8 parent self help groups
1.8.9 periodic review @ specialist regional centre
1.8.10 corticosteroids for ambulant kids w/ DMD to preserve mobility & prevent scoliosis prednisolone for 10 days each month
1.8.11 antenatal screening possibly IDing female carriers mildly raised CPK gene deletion detected on DNA analysis
2 Becker muscular dystrophy
2.1 some functional dystrophin is made
2.2 similar features to DMD
2.2.1 but disease progresses more slowly
2.3 av age of onset= 11 years
2.4 unable to walk in 20s
2.5 life expectancy- late 40s to normal
3 congenital muscular dystrophies
3.1 heterogenous group
3.1.1 most w/ recessive inheritance
3.2 present @ birth or early infancy w/
3.2.1 weakness
3.2.2 hypotonia
3.2.3 contractures
3.3 typically proximal weakness is slowly progressive
3.3.1 w/ tendency to contracture when ability to walk is lost
3.3.2 some may run a more static course
3.4 biopsy shows dysmorphic features e.g. reduction
3.4.1 in laminin- ECM proteins
3.4.2 in one of glucosyl transferases
3.5 linked to CNS abnormalities
3.5.1 may -> LD

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