Flashcards in Quiz 3 - disorders of neuromuscular system Deck (68):
myelin in the peripheral nerves comes from.....
myelin quantity and function
heavy - somatic motor, sensory to reflexes
intermediate - touch, proprioception, joint position
light - sharp pain, autonomic motor preganglionic
none - burning, aching, temp, postganglionic autonomic
more sensory loss in peripheral or nerve root damage?
peripheral, in nerve root damage there is overlap
fasciculations, along with weakness and/or atrophy indicates damage to what?
anterior horn cell or its axons
what does weakness with a high firing rate of motor units indicate?
compensation for loss of motor neurons or axons
what are the two pediatric inherited anterior horn cell degenerative diseases and who do they affect?
Werdnig-Hoffman - infants
Kugelberg-Welander - children/young adults
ALS damage is usually to what?
both upper and lower motor neurons
who usually gets ALS
weakness in ALS
can be varied between upper and lower motor neurons in single patient
CN involvement in ALS
- tonge, face, phalanx, soft palate
- NOT eyes
longevity and death in ALS
- 3-5 years
- due to respiratory muscle weakness and superimposed infection
ALS involving only upper motor neurons is called
primary lateral sclerosis
ALS involving only lower motor neurons is called
progressive muscular atrophy
ALS involving only cranial musculature is called
progressive bulbar palsy
what drug slows down ALS?
3 categories of peripheral nerve damage
2) mononeuropathy multiplex
mononeuropathy is most often due to
PE technique for mononeuropathy
Tinel sign, tapping at place of damage for mechanical sensitivity
most common mononeuropathy
carpal tunnel syndrome
damage to the radial nerve is indicated by
nerve damage in thoracic outlet syndrome is in the distribution of the....
what is radiculopathy?
damage to nerve root
causes of radiculopathy in younger and older adults
younger - disc herniation
older - degenerative issues in discs, bones, joints
- usually symmetrical
why are legs affected first in polyneuropathy?
- longer nerves with higher energy demand
indication of larger fiber polyneuropathy
- loss of vibration and joint position sense
- can result in poor balance
most common symptoms of polyneuropathy
- dysesthesias, paresthesias
most common causes of polyneuropathy
heavy metal exposure
chemo and antivirals
diseases that can cause polyneuropathy
Guillain-Barre (AIDP) differences from typical polyneuropathy
- rapid course - ether ascending or descending
- severe weakness
- follows diarrheal or viral disease often
- lost reflexes
- high CSF protein levels
- high CSF protein levels
- asymmetric polyneuropathy
- lost reflexes
name a relatively common inherited polyneuropathy and what are the two forms?
Charcot-Marie-Tooth disease (HMSN)
type 1 - demyelinating - nerve conduction testing
type 2 - axonal
Romberg and proprioceptive nerve loss
- will often improve dramatically when touching stationary object with only one finger
most common causes of mononeuritis multiplex
- diabetes mellitus
- systemic vasculitis
diabetic inflammatory disorder of the lumbar or rarely the brachial plexus resulting in weakness of quads and loss of patellar reflex
who most commonly gets myasthenia gravis?
- young adult women
- small spike in late middle aged men with thymic tumors
first signs of myasthenia gravis
- ptosis/diplopia (ocular myasthenia)
- pharynx and soft palate (bulbar myasthenia)
Lambert Eaton PE in comparison to MG
- exercise increases rather than decreases strength in Lambert Eaton.
almost all myopathies include the following:
- proximal muscle weakness
EMG of the motor unit in myopathy
small, brief, and polyphasic action potentials
two major groups of muscle disease
- destruction of muscle fibers - progressive weakness
- functional defect - with little muscle wasting
destructive muscle diseases fall into three categories:
1) muscular dystrophies
2) metabolic myopathies
3) inflammatory myopathies
functional muscle diseases fall into two categories:
1) myotonic disorders
2) periodic paralysis
Duchenne is a type of....
inheritance of Duchenne dystrophy
Duchenne pathophysiology and disease progression
- disrupts a protein in muscle structure
- presents after child is walking because another protein in early childhood takes its place
- progressive decline in muscle strength until death in early 20s
contrast Becker to Duchenne
- same gene
- less severe
- somewhat later onset
prototypical acquired metabolic myopathy
medications that can cause metabolic myopathy
mitochondrial (Kearn-Sayer) diseases are what type of myopathy?
name 3 acquired inflammatory myopathies
- inclusion body myositis
metabolic myopathies are either.....
genetic or acquired
inflammatory myopathies are either.....
acquired or autoimmune
when do people get polymyositis?
contrast polymyositis and dermatomyositis
- purple rash
- more muscle soreness
- in children and older adults
- more commonly associated with autoimmune disorders
in polymyositis and dermatomyositis you often see elevations in....
- ESR and C-reactive protein (inflammatory markers)
presentation of inclusion body myositis
- flexors of fingers and wrists as well as proximal muscles
what are the two major myotonic disorders?
- congenital myotonia
- paramyotonia congenita
contrast congenital myotonia and paramyotonia congenita in terms of channel affected and presentation
congenital myotonia - chloride channels, improves with exercise
paramyotonia congenita - sodium channels, worsens with exercise and with cold
presentation of periodic paralysis
- weakness after large meals or following exercise
presentation of limb-girdle dystrophy
- slow progressing
- proximal limb weakness
limb-girdle dystrophy inheritance
- 15 different mutations
- recessive or dominant depending
facioscapulohumeralm muscular dystrophy presentation
- adolescence/early adulthood
- chromosome 4 hypomethylation
presentation of two types of myotonic dystrophy
type 1 (more common), distal to proximal, face involved early, numerous non-neurologic problems
type 2 (less common),
pathophysiology of type 1 myotonic dystrophy
- autosomal dominant
- trinucleotide repeat disease
- myotonic protein kinase
- starts in childhood or young adult life, sometimes even infancy
pathophysiology of type 2 myotonic dystrophy
- quadronucleotide repeats
- transcription factor
oculopharyngeal dystrophy pathophysiology
- trinucleotide repeats
- abnormal intranuclear protein for mRNA trafficking