Week 6 - Neuromuscular Disorders

Question 1

Neuromuscular Junction Disorders

Answer 1

• drug/toxin induced
• Myasthenia Gravis

Question 2

What is Myasthenia Gravis?

Answer 2

• NMJ disorder
• autoimmune
• attack on the Nicotinic Acetylcholine Receptors

Question 3

What is Spinal Muscular Atrophy?

Answer 3

• Lower motor neuron disorders
• genetic, degenerative neuropathy
• selectively affects the alpha motor neurons in the anterior horn of the spinal cord and cranial nerve motor neurons
• variability in severity depending on the type
• muscle atrophy and weakness (anywhere from hypotonia to eventual death from aspirations or respiratory failure)

Question 4

What is Guillain-Barre Syndrome?

Answer 4

• Lower Motor Neuron Disorders
• acute autoimmune-mediated reaction (most commonly following a virus or bacterial infection)
• demyelination of neurons of the peripheral NS
• Motor &/or sensory symptoms

Question 5

What are the motor/sensory symptoms of Guillain-Barre Syndrome?

Answer 5

• paresthesia, weakness, absence of reflexes
• rapidly progressive ascending symmetrical symptoms

Question 6

What is Amyotrophic Lateral Sclerosis (Lou Gehrig)?

Answer 6

• NM disorder of upper MN
• genetic/unknown etiology
• rapidly progressive degenerative disease
• degeneration of motor neurons
• affects upper AND lower motor neurons

Question 7

End Stage of Amyotrophic Later Sclerosis (Lou Gehrig)

Answer 7

• paralysis, respiratory failure

Question 8

Lou Gehrig degeneration of motor neuron physiology

Answer 8

• Protein misfolding -> neuronal death -> retrograde neuronal degeneration
• Gliosis: clumps of glial cells replace neurons that have died (forms “glial scar”)

Question 9

What is Multiple Sclerosis

Answer 9

• inflammatory autoimmune disease that affects the conduction of neural impulses
• chronic degenerative disease
• demyelination of neurons within the CNS

Question 10

Multiple Sclerosis cause

Answer 10

• unknown
• links to genetics, environmental, virus

Question 11

Multiple Sclerosis symptoms

Answer 11

• exacerbations and remissions
• degeneration can be progressive in late stages
• myelin can be repaired (repairing becomes less effective with repeated attacks)
• variable severity
• loss of balance; ataxia (cerebellum)
• diplopia, loss of vision (cranial nerve)
• weakness, paralysis (motor nerve tracts)
• paresthesia (damage to sensory nerve tracts)

Question 12

What determines the symptom type in Multiple Sclerosis?

Answer 12

location of demyelination

Question 13

What determines the symptom severity in Multiple Sclerosis?

Answer 13

extent of demyelination

Question 14

Multiple Sclerosis Pathophyisiology

Answer 14

• unknown trigger
• activated T cells cross the blood brain barrier
• secrete cytokines
• more immune cells recruited
• attack oligodendrocytes
• myelin damaged and breaks down
• plaque formation
• scar tissue formation and axonal destruction

Question 15

Multiple Sclerosis diagnosis

Answer 15

• no definitive test
• MRI provides useful info
• based on history of exacerbations & remissions
• usually need multiple symptoms
• often ‘diagnosis of exclusion’

Question 16

Multiple Sclerosis Treatment

Answer 16

• disease modifying drugs (slow progression)
• pharmaceuticals to treat complications
• physio and exercise to maintain strength and mobility
• OT to support ADL, adaptive equiptment

Question 17

Multiple Sclerosis exercise considerations

Answer 17

• improve muscle weakness, bladder and bowel function, fatigue, QOL
• consider supportive equipment
• prescribe within limitations
• importance of stretching
• resist heat stress
• avoid exercise during an exacerbation

Question 18

What is Cerebellar Ataxia?

Answer 18

can be a side effect of many neurodegenerative disorders if the cerebellum is involved

Question 19

What is Cerebral Palsy?

Answer 19

• non-progressive brain condition causing paralysis
• neurodevelopment condition (pre- or Post- natal)
• muscle affected depends on what part of brain is affected
• either spastic (upper MN damage), dyskinetic (basal ganglia damage, or ataxic (cerebellum damage)
• physical and OT useful for treatment

Question 20

What is Parkinson’s disease

Answer 20

• synaptic transmission disease
• dopamine release is reduced, specifically via destruction of neurons on nigrostriatal pathway
• progressive and degenerative

Question 21

What is the average age of diagnosis for MS

Answer 21

15-50 years

Question 22

What is the average age of diagnosis for Parkinson’s?

Answer 22

56 years old

Question 23

Parkinson’s Disease Progression

Answer 23

Postural instability -> Dementia (sometimes) -> death

Question 24

Parkinson’s disease etiology

Answer 24

• unknown
• thought to be combination of environmental and genetic factors

Question 25

Parkinson’s disease pathophysiology

Answer 25

• unknown trigger
• degeneration of neurons in substantia nigra that produce/release dopamine
• less dopamine release onto neurons of striatum
• imbalance of excitatory and inhibitory NT’s released in striatum
• result: not enough voluntary initiation of movement and too much involuntary movement

Question 26

Parkinson’s disease main symptoms

Answer 26

-resting tremors
- muscle rigidity (spastic movement)
- bradykinesia (slow movement)
- postural instability (later feature)

Question 27

What are the dopaminergic neurons of the substantia nigra responsible for?

Answer 27

• allowing signals to be sent to the cerebral cortex for movement initiation
• fine tuning movements

Question 28

Parkinson’s diagnosis

Answer 28

• based on symptoms

Question 29

Parkinson’s disease treatment

Answer 29

Pharmaceuticals:
- dopamine replacement therapy (L-dopa, converted to dopamine in brain)
- drugs that inhibit dopamine breakdown in drain (produced dopamine lasts longer)
Exercise, OT, PT:
- maintain general mobility to delay
- exercise to maintain strength, balance, flexibility
- safe use of adaptive devices