Muscle and Nerve Disease Flashcards
what symptoms may muscle disease present with?
> failure to thrive in children > weakness > short of breath > poor swallow > cardiomyopathy > pain
what signs may be present in muscle disease?
> wasting
hypertrophy
normal/reduced tone and reflexes
motor weakness
what investigations could you carry out in muscle disease?
> history and examination > CK > EMG > muscle biopsy (structure, biochemistry, inflammation) > genetic testing
what is channelopathies distinguished by?
episodic periods of weakness due to constant polarisation flux of electrolytes
name some types of muscle disease
> dystrophies > channelopathies > metabolic muscle disease > inflammatory muscle disease > congenital myopathies > iatrogenic
name two muscular dystrophies associated with hypertrophy
> duchenne’s
> becker’s
what does facioscapulohumeral muscular dystrophy affect?
facial, scapula, arm and biceps leading to muscle weakness
name some muscular dystrophies
> duchennes > beckers > facioscapulohumeral > myotonic dystrophy > limb-girdle
what are channelopathies disorders of?
calcium, sodium and chlorine channels
name some channelopathies
> familial hypokalemic periodic paralysis
hyperkalemic periodic paralysis
paramyotonia congenita
myotonia congenita
name some metabolic muscle disease
> disorders of carbohydrates metabolism > disorders of lipid metabolism > mitochondrial myopathies > endocrinopathy > biochemical abnormalities
name two types of inflammatory muscle disease
> polymyositis
> dermatomyositis (affects the skin as well)
what is the effect of inflammatory muscle disease?
painful weak muscles (and sometime characteristic rash)
what investigations would you carry out for inflammatory muscle diseases?
> CK (raised)
EMG (inflammation + myopathic)
biopsy
what is the treatment for inflammatory muscle disease?
immunosuppression
what is myasthenia gravis?
> disorder of the neuromuscular junction
describe the clinical presentation of myasthenia gravis?
fatigable weakness: > limbs > eyelids > muscles of mastication > taking > SOB > diplopia this affects you as the day goes on, starting out normal and gradually weakening.
what investigations would you carry out for myasthenia gravis?
> AChR ab
Anti MuSK ab
neurophysiology (repetitive stimulation, jitter)
CT thorax
what can myasthenia gravis be associated with?
thyoma
describe acetylcholine release in myasthenia gravis
it si released in surplus at the start then is depleted throughout the day. it then gets to the point where there is not enough acetylcholine to overcome the block at the junction
what is the treatment for myasthenia gravis?
> acetylcholinesterase inhibitor (symptomatic)
immunosuppression (prednisolone, steroid saving agent)
immunoglobulin/plasma exchange
thyectomy
name some nerve root diseases
> degenerative spine disease
inflammation
infiltration
what can a lesion of an individual peripheral nerve cause?
> compression
> vasculitis (stopping blood supply to the nerve)
what is affected first in generalised peripheral neuropathy?
the longest nerves as they have the highest energy demand
what is generalised peripheral neuropathy associated with?
> metabolic conditions (diabetes, alcohol) > drugs > infection (HIV, Lymes, leprosy) > malignancy > inflammatory demyelination
name an acute inflammatory demyelinating condition associated with generalised peripheral neuropathy
guillain barre syndrome
what symptoms and signs would be seen with nerve root disease?
> myotomal wasting and weakness
reflex change
dermatomal sensory change
what signs and symptoms would be associated with individual nerve disease?
> wasting and weakness of innervated muscle
> specific sensory change
what signs and symptoms would be associated with generalised peripheral neuropathy?
> sensory and motor symptoms starting distally and moving proximally
what investigations would you carry out for nerve disease?
> blood tests (b12) > genetic analysis > nerve conduction studies > lumbar puncture > nerve biopsy
describe the signs and symptoms of motor neurons disease
> limb onset > respiratory involvement later > LMN: fasciculation's, wasting and weakness > UMN: increased tone, brisk reflexes > NO sensory involvement
what is the prognosis for motor neurons disease?
> 3-5 years from symptom onset
2-3 years form diagnosis
50% dies within 14 months of diagnosis
how is motor neuron disease diagnosed?
> unique combination of upper and lower motor neuron signs
> EMG
what is the treatment dorm motor neuron disease?
> supportive
> Riluzole (could do nothing)
