Muscle and Nerve Diseases Flashcards
symptoms of muscle disease
weak skeletal muscle short of breath (respiratory) dysphagia cariomyopathy cramp, pain, stiffness myoglobulinuria
signs of muscle disease
muscle wasting
normal or reduced tone
motor weakness
investigations that can be done in muscle disease
creatine kinase (enzyme of muscle, elevated when muscle damage)
electromyography (EMG)
muscle biopsy
genetic testing
muscular dystrophy is genetic/acquired
genetic
pathology of muscular dystrophy is an absence or defect of what protein
dystrophin - connects cytoskeleton to extracellular matrix
which MD is X linked
Duchenne’s MD
what is a channelopathy
a disorder of an ion channel. commonly those of Ca, Na, K or Cl
familial hypokalemic periodic paralysis hyperkalemic periodic paralysis paramyotonia congenita myotonia congenita are all examples of what type of muscle disease
channelopathies
myotonia congenita only affects __ channels
Cl
paramyotonia congenita only affects __ channels
Na
what are metabolic muscle diseases
muscle cells aren’t able to metabolise fuel as well. symptoms are more caused by build up of unused metabolites than the weakness itself
types of muscle disease
metabolic
inflammatory
channelopathy
muscular dystrophy
how to treat inflammatory muscle disease
immunosuppression
myasthenia gravis is a disorder of what part of muscle
the neuromuscular junction
presentation of myasthenia gravis
FATIGUABLE WEAKNESS of limbs, eyelids, muscles of mastication, talking, breathing and eye muscles
eye symptom of myasthenia gravis
diplopia - from fatigued eye muscles
pathophysiology of myasthenia gravis
autoantibodies bind to ACh receptor
serum antibodies in myasthenia gravis
anti-acetylcholine receptor antibody (ACh-R)
muscle specific receptor tyrosine kinase (MuSK)
investigations in myaesthenia gravis
serum AChR and MuSK antibodies
CT for thymoma (15%)
neurophysiology test repetetive stimulation/jitter
symptomatic treatment of myasthenia gravis
ACh-ase inhibitor
treatment of myasthenia gravis
ACh-ase inhibitor
immunosuppression by prednisolone or azathioprine
thymectomy
immunoglobulin exchange
what surgery may be useful in ~15% of myasthenia gravis
thymectomy
what makes up peripheral nerves
sensory axons
motor axons
autonomic axons
myelin sheaths
causes of peripheral neuropathy
hereditary diabetes alcohol B12 deficiency HIV or leprosy malignancy guillain barre syndrome chronic inflammatory demyelinating polyneuropathy
symptoms of peripheral neuropathy
sensory and motor starting distally moving proximal
symptoms from nerve root damage
reflex change
sensory change in dermatome
wasting of muscles innervated by that nerve
what type of palsy is seen in MND
bulbar - difficulty chewing and talking
pathophysiology of MND
degeneration of motor neurons in the anterior horn cells and motor cranial nuclei
MND affects UMN/LMN
both - LMN signs usually predominate
presentation of MND
fasciculations, wasting, weakness, increased tone, brisk reflexes
true/false MND has sensory involvement
false - motor only
true/false MND can have cognitive decline
true - in >10%
prognosis of MND
50% die in 14 months
treatment for MND
supportive for respiration, eating, mobility and speech
palliative
riluzole can be prescribed to
what is myelopathy
injury to the spinal cord due to severe compression
what is radiculopathy
range of symptoms from a nerve root being “pinched”
pain, weakness, numbness, tingling
presentation of Guillain-Barre syndrome
weakness
pain
paraesthesiae
sensory loss starting in lower limb, reduced/absent reflexes
autonomic (reduced sweating, urinary hestitancy)
what is Guillain-Barre syndrome
autoimmune demyelinating disease of PNS
common history of Guillain-Barre syndrome
preceding infection of resp of GI tract. most commonly epstein barr virus, campylobacter, HIV and cytomegalovirus
non-compressive causes of a spinal cord lesion
infarction, haemorrhage, transverse myelitis, HIV, polio, syphilis
how does a ACh-ase inhibitor treat myaesthenia gravis
by preventing the breakdown of ACh at the neuromuscular junction
