Amyotrophic Lateral Sclerosis Flashcards
What is ALS? Pathophysiology?
“Creeping Paralysis”
- Progressive degeneration & loss of motor neurons (MN) in spinal cord & brainstem (LMN) and motor cortex (UMN)
- 60% of individuals die within 3 years of onset - usually of respiratory failure
- SYNDROME rather than single disease
Who is more at risk for aquiring ALS?
a) 45 YO female
b) 22 YO female
c) 57 YO male
d) 35 YO male
C) 57 YO male
- more common in males
- risk peaks between 50-75 YO, median age of onset is 55 YO
What are the risks of ALS?
- Age (50-75 YO)
- Family history
What are potential causes of ALS?
- oxidative stress
- mitochondrial dysfunction
- defective glutamate metabolism
- protein aggregation in cell body and proximal axon
- impaired axonal transport
- dysregulated endosomal trafficking
What is impacted early on in ALS?
bad wording but couldnt think of anything else :(
Motor neurons
- affected earliest & most severely
What are some diagnostic tests for ALS?
No specific diagnostic test for ALS, diagnosis reached after observing clinical signs associated with ALS and ruling out other pathologies with tests/imaging
* disease progression MUST be seen for diagnosis of ALS (other mimic syndromes dont progress as fast
What are the EL Escorial Criteria?
- Evidence of LMN degeneration by clinical/elecrophysiological exam
- Evidence of UMN degeneration by clinical exam
- Progressive spread of symptoms/signs within a region or to other regions
What is the general clinical course of ALS?
- gradual, over months
- asymmetrical
- first symptoms often UMN & LMN signs in 1 limb that spreads
- initial weakness usually in isolated muscles - distally
- normal sensation
- normal oculomotor, bowel & bladder functions
What are the UMN and LMN symptoms that occur in the beginning?
UMN: spasticity, hyperreflexia, clonus
LMN: atrophy, weakness, fasciculations
What are the types of onset that could occur?
- Bulbar- onset (20-30% of pts)
- cervical onset (AKA limb onset - 65-80%)
- lumbar onset (AKA limb onset - 65-80%)
- Respiratory onset (5% of pts)
What would someone with Bulbar onset present with?
- Dysarthria &/or dysphagia
- LMN: bulbar palsy -> weakness of facial muscles & tongue, fasciculation (brief small contractions) of tongue, decrease palatal mov’t & atrophy
- UMN: pseudobulbar palsy - brisk jaw jerk, emotional lability (pathological laughing or crying), tongue spasticity
- more frequent in women and in late-onset disease
What would someone with cervical onset present with?
bilateral or unilateral UE symptoms
- proximal weakness (e.g., shoulder abduction)
- distal weakness (e.g., pincer grip)
- UMN (hyperreflexia) &/or LMN signs (e.g., atrophy, fasciculations)
What would someone with Lumbar onset present with?
- LMN signs in legs (e.g., foot drop, proximal weakness manifested as difficulty ascending/descending stairs)
- UMN signs often follow (e.g., hyperreflexia, clonus)
- Degeneration of ant horn cells in lumbar enlargement
What would someone with Respiratory onset present with?
- Dyspnea - attacks can cause anxiety
- respiratory muscle weakness
- chronic nocturnal hypoventilation
➜ leads to disordered sleep & daytime fatigue
➜ can occur months/years before repsiratory failure
➜ significantly decreases quality of life - thick mucous secretions from decrease fluid intake, & decrease coughing pressure
- pneumonia common
What symptoms might an individual present with regardless of disease phenotype?
- Dysphagia
- Dysarthria
- Respiratory muscle weakness (accessory muscles for breathing, paradoxic breathing)
- pain (MSK pain in later stages due to atrophy & altered tone around joints, muscle contractures & joint stiffness)
- cognitive impairment
- Affect social life
- quality of life -> pts friends, family, caregivers show greater depression & anxiety than general population
