Additional CNS Disorders Flashcards
List CNS disorders to be covered
- Myasthenia Gravis
- Hydrocephalus
- Infections
- Seizures
What is Myasthenia Gravis?
- a neuromuscular junction disorder characterized by progressive muscular weakness and fatiguability on exertion
- autoimmune disease
- antibody-mediated attack on acetylcholine receptors at neuromuscular junction
Etiology and risk factors for Myasthenia Gravis
- Etiology
- cause → unknown
- possible thymus dysfunction
- Risk Factors
- average age of onset → 59
- Female:Male (2:1)
- Prior autoimmune disorder
S/S of Myasthenia Gravis
- LMN disorder
- Weakness
- worsens with continous contraction, improves with rest
- muscles of face and throat particularly
- generalized weakness throughout body
- extremities
- intercostal muscles
- Diplopia and ptosis
- Laryngeal irritation
- cause voice impairments, dysphonia
- increased risk for choking/aspriation
what is the first symptom in 50% of Myasthenia Gravis pts?
ocular related symptoms like diplopia and ptosis
what is the most pronounced symptom in Myasthenia Gravis?
Weakness
how may the course of Myasthenia gravis appear?
course varies - may progress from mild to severe
progression typically seen within 18 months of symptom onset
Exacerbating factors of Myasthenia gravis
- Fatigue
- Illlness
- Stress
- Extreme heat
- Some meds
- beta-blockers
- calcium-channel blockers
- some antibiotics
List the subtypes of Myasthenia gravis
- Ocular myasthenia
- Mild generalized myasthenia
- Severe generalized myasthenia
- Myasthenia crisis*
describe ocular myasthenia
- only affects the muscles that move the eyes and eyelids
- double vision
- blurry vision
- ptosis
what is myasthenia crisis?
not really a subtype
myasthenia gravis + respiratory failure
T/F: the vast majority of Myasthenia Gravis pts are impacted by myasthenia crisis?
FALSE
- 15-20% of myasthenia pts are affected by a myasthenia crisis at least once in their lives
- median time to first myasthenic crisis from onset of MG ranges from 8-12 months
Structures involved in myasthenia crisis
- upper airway muscles
- respiratory muscles
- both inspiratory and expiratory muscles can be affected resulting in dyspnea
- combo of upper and respiratory muscles
Precipitating factors to myasthenia crisis
- physical stressors
- environmental stressors
- aspiration pneumonia
- infection
- perimenstrual state
- pregnancy
- sleep deprivation
- surgery
- pain
- temp extremes
- tapering of immune-modulating meds
potential complications and treatments for myasthenia crisis
- Complications
- fever
- infection
- DVT
- cardiac complications
- Treatments
- IVIg
- Plasmaphoresis
Diagnostic Testing for Myasthenia Gravis
- Edrophonium test
- Blood analysis
- Ice Pack Test
- Electrodiagnostic Testing
- NCV → repetitive nerve stimulation
- Pulmonary Function Tests
Medical management of Myasthenia Gravis
- IVIg
- Plasmapheresis
- Cholinesterase inhibitors
- Corticosteroids
- Immunosuppressants
- Surgical management (secondary sequale)
- videothorascope
- Tracheostomy
T/F: dietary changes can be beneficial for MG pts?
TRUE
Examination for MG
- Cranial Nerves
- Respiratory function
- Muscle strength
- Functional mobility
cranial nerve findings in MG pts during examination
- examine for:
- diplopia
- ptosis
- progressive dysarthria or nasal speech
- difficulty in chewing and swallowing
- difficulties in facial expression
- drooping facial muscles
muscle strength findings during exam in MG pts
- proximal more involved than distal
- fatigability
- repeated muscle use results in rapid weakness
- endurance typically poor
what types of functional mobility deficits are expected in MG?
difficulty climbing stairs, rising from a chair or lifting
MG prognosis
- 25-50% of pts require inpatient rehab after myasthenic crisis
- even with moderately severe cases, with appropriate treatment, ppl can continue to work and live independently between exacerbations
- life expectancy = normal
PT goals for MG
- functional strengthening
- energy conservation techniques
- breathing exercises and strategies
- monitor changes in pt’s condition for complications, VS, respiration and swallowing