Flashcards in Neuromuscular disease Deck (33):
What do we mean by neuromuscular disorders?
Conditions that affect the PNS (nerve roots etc), NMJ and muscle
key symptoms of neuromuscular disorders in general?
muscle weakness/wasting --> diplopia, dysphagia, dyspnoea
what causes foot drop?
L5 radiculopathy/ peroneal neuropathy
ddx for diplopia and ptosis
ocular nerve palsy (cranial nerve)
thyroid eye disease
is diplopia and ptosis a sign of motor neurone disease?
what is an example of anterior horn cell disease?
motor neuron disease
Does myasthenia graves and myopathies include a sensory dysfunction
what is a hallmark feature of neuropathies?
Sensory change and weakness tends to be distal. Some motor changes but later presentation.
definitive test for motor neurone disease
nerve conduction studies and EMG
what sort of signs do you see in motor neurone disease?
mixed picture of LMN and UMN signs- e.g. progressive weakness and muscle atrophy + fasiculations with hyper-reflexia.
Muscle wasting in tongue
Tone increased or decreased
Reflexes preserved until late or exaggerrated
No sensory loss!!!
Cranial nerves may be affected
what is the most common motor neurone disease?
amyotrophic lateral sclerosis (ALS)
is ALS inherited?
not usually. 90% of cases are sporadic. 10% has a familial cause
Some Ix of neuromuscular disease in general?
b) laboratory tests-blood tests, genetic tests etc
d) muscle biopsy
e) nerve biopsy
f) MRI of nerve
Some examples of focal neuropathies
Carpal tunnel syndrome
Diabetes (3rd nerve palsy)
what is the main cause of mono neuritis multiplex?
almost always ischaemia --> diabetes and vasculitis, although can be occasionally due to infection (CMV, leprosy)
What are some examples of demyelinating peripheral neuropathies
guillain- barre syndroem
What are some examples of axonal peripheral neuropathies?
Why would we do a LP for CSF analysis for neuromuscular disorder?
if you're thinking an autoimmune inflammatory cause
what does a trendelenberg gait indicate?
weakness of the gluteal muscles
what are some general causes of myopathies? Give some examples
1. Drugs- alcohol, statins, steroids
2. Endocrine- hypothyroidism, hypokalemia
3. Inflammatory- polymyositis, dermatomyositis, inclusion bodies
4. Inherited- various forms of dystrophies e.g. duchennes
5. Metabolic- McArdles, CPT (mitochondrial disorder)
6. ion channel mutations= periodic paralyses
what is a main ix for myopathies
CK levels!! if elevated, almost always indicate a myopathy
what are some other ix for myopathies?
electrophysiology and muscle biopsy
what is the pathophysiology of polymyositis?
inflammatory cell CD8 infiltrate and myophagia (phagocytes eat muscle)
what are some histological features that you see of Inclusion body myositis on muscle biopsy
1. mononuclear inflammatory infiltrate in interstitium
2. muscle fibre diameter variation
3. rimmed vacoules
4. deposition of amyloid
which, out of polymyositis or dermatomyositis do we more commonly associate with malignancy?
characterise the pathology of a dystrophy disease
muscle fibre degeneration, regeneration, fibrosis --> loss of function
what type of lymphocytes are associated with polymyositis and dermatomyositis respectively?
T and B lymphocytes respectivelt
3 types of metabolic myopathies?
1. lipid storage
2. glycogen storage
what is the main pathology of guillain barre syndrome
what is the clinical presentation of GBS?
Clinical features include progressive muscle weakness, paraesthesia, slurred speech, breathing difficulties, hyporeflexia, diplopia, dysphagia, ptosis.
Usually the muscle weakness is symmetrical, and affects the lower limbs before the upper limbs.
What is an emergency associated with GBS?
respiratory muscle failure
what are the ix we order for GBS?
First line investigation= nerve conduction studies.
Also do a LP- and look for elevated CSF protein levels
Can also do spirometry and test for serology to recent infections