Degenerative Disorder of the CNS Flashcards
In regards to ALS
What is amyotrophy?
What is lateral?
What is sclerosis?
- Amyotrophy: Muscle atrophy
- Lateral: involving lateral (and anterior) corticospinal tracts
- Sclerosis: glial cell proliferation and hardening
What does ALS stand for?
Amyotrophic Lateral Sclerosis
T/F: ALS is most physically devastating of the neurodegenerative diseases
True
What is the etiology of ALS?
- Sporadic (90%)
- Familial (10%)
T/F: Currently, there is only one gene for ALS
False
- Over 30
When ALS is developed due to familial cause it is a (Autosomal Dominant or Autosomal recessive) disorder. Also it is associated with (Early or Late) onset.
- Autosomal Dominant
- Early Onset
What are the known risk factors of ALS?
- Males > Female
- Age: 50’s
- Race: white, non-hispanic
- Geographical area: Europe, North America, New Zealand
What are some possible risk factors for ALS?
- History of vigorous physical activity
- Chronic environmental exposure (lead, mercury, pesticides or solvents)
- Lifestyle factors (cigarette smoking, alcohol, diet)
Clear mechanism not established
T/F: Bulbar onset of ALS is more common in males
False- Females
What is the pathogenesis of ALS in regards to:
UMN?
LMN?
- Destruction of Upper Motor Neurons in the cerebral cortex affecting the corticospinal and corticobulbar tract
- Destruction of Lower Motor Neurons, the alpha motor neurons in the anterior horn of spinal cord and cranial nerve nuclei in brainstem
In regards to the pathogenesis of ALS, what are some possible causes of destruction of UMN & LMN?
- Excitotoxicity (excess glutamate)
- Oxidative damage (free radicals)
What other areas can be impacted by neuronal loss in ALS?
- Frontotemporal cortex
- Thalamus
- Substantia Nigra
- Spinocerebellar tracts
- Dorsal columns
In ALS what are the lower motor neuron symptoms?
- Asymmetric, usually distal weakness
- Extensors weaker than flexors
- Cervical extensor weakness (Head droop)
- Bulbar signs
- Hyporeflexia
- Hypotonicity
- Atrophy
- Muscle cramps
- Fasciculations
In ALS what are the Upper Motor Neuron symptoms?
- Spasticity
- Hyperreflexia/Clonus
- Pathological reflexes (Babinski, Hoffman)
- Muscle weakness (UE extensors & LE flexors)
- Pseudobulbar palsy
As ALS progresses (LMN or UMN) sign may decrease.
UMN
In ALS what are the Bulbar symptoms?
- Pseudobulbar Palsy (spastic & UMN = corticobulbar tract)
- Bulbar palsy (flaccid & LMN = cell body in CN nuclei)
What is the Bulbar presentation in ALS?
- Dysarthria
- Dysphagia
- Sialorrhea
- Pseudobulbar affect (UMN)
In ALS what are the preserved areas?
- Eye movements
- Bowel & bladder
- Sensory system
- Cognition (50%)
ALS has a variable presentation what are some early signs?
- Insidious asymmetrical weakness of distal aspect of one limb
- Cramping with volitional movement (early morning stiffness)
- Muscle fasciculations (spontaneous twitching of muscle fiber)
ALS has a variable presentation what are some late manifestations?
- Respiratory complications (respiratory failure)
- Oral motor complications (chewing, tongue mobility, swallowing) at risk for aspiration
How is ALS diagnosed?
- Clinical presentation
- EMG (Fibrillations, Fasciculation, Low amplitude polyphasic potentials)
- Muscle biopsy (Denervation atrophy)
- Muscle enzyme (CPK levels elevated)
- Normal CSF & no changes on myelogram
What is the definitive diagnostic criteria for ALS?
- UMN + LMN signs in 3 or more regions
- Exclude structural lesions
What is the time frame for obtaining an ALS diagnosis?
- May take 15-21 months from first presenting symptoms to definitive diagnosis
- EMG changes may not be seen for 6-12 months
T/F: there is no known cure for ALS
True