Lecture 2: LMN disorders: ALS/MG/DMD Flashcards
ALS has 2 types of onset they are:
- Spinal onset (2/3)
- Bulbar onset (1/3)
Does ALS affect only the cell body of a motor neuron?
- NO both motor neuron cell body and axon are damage via wallerian degeneration
What are the 3 major systems typically spared in ALS?
- Oculomotor 3,4,6
- Bowel and Bladder
- Cognition
ALS typical progression to death?
3-5 years
Characteristics of Spinal onset ALS?
- Limb onset
- Distal > proximal
- Usually asymmetrical early on
Characteristics of Bulbar onset ALS?
- Dysarthria and Dysphagia
- Stimultaneous limb symptoms
Diagnostic tests for ALS (5)
- MRI to r/o cortical/brainstem/C/s pathology
- Lumbar puncture to r/o inflammatory
- Blood tests r/o toxic, metabolic, infections, inflammatory, genetics
- NCV: normal or slow NCV
- EMG : fibrillations and + sharp waves, fasciculations, reduced interference patterns
Medical management of ALS?
- Riluzole (the only FDA approved med)
- Symptom management
- Swallowing
- Respiratory Care (mechanical ventilation/Pulmonary Functional tests)
ALS death is usually due to ? (in either form)
Respiratory Failure
Best/worst prognostic indicators for ALS?
- Young onset –> longer duration
- Early respiratory dysfunction –> poor prognosis
How to ID ALS?
- Both UMN and LMN signs with spared oculomotor, B&B, cognition
When does Myasthenia Gravis affect Women and men?
Women: 20s - 30s
men: affects in 50-60s
Is MG and autoimmune disease? What is being affected?
YES
- ACh receptors are being blocked due to post synaptic receptor loss and damage to membrane
KEY FEATURE: MG have episodic exacerbations and remissions? T or F
True –> fluctuating weakness and fatigablity w/ full body involvement w/in 1 year.
6 clinical findings for MG?
- Ptosis (droopy eyes)
- Diplopia (double vision)
- Dysarthria
- Dysphagia
- Respiratory weakness
- Limb weakness
is MG distal to proximal? or Proximal distal?
Proximal > distal
NUMBER 1 Diagnostic Test for MG?
- Tension Test –> medication: edrophonium, patients should get better voluntary movement
- immediate 30-60 second response
What is medical management for MG SYMPTOMS?
- Cholinesterase Inhibitors: increase ACh at synaptic cleft
side effects muscarinic: diarrhea, cramping, excessive secretions
nicotinic: muscle fasciculations, cholinergic crisis
Short term medical management for MG?
Plasmapheresis and IVIG
–> improvement within week 1, lasts 1-2 months
Immunosuppressive medical mgmt for MG?
- Thymectomy
- Corticosteroids
- Nonsteroidal immunosuppression
Prognosis of symptoms exacerbation for MG?
progression to maximal severity of symptoms within 2 years.
how to ID MG? THIS KEY
- Fluctuating and fatiguable weakness
- Proximal > distal weakness
- UE > LE: triceps, neck /, quads
- Bilateral asymmetric ocular muscle weakness
Neuroanatomy affected for DMD?
- Muscle body (dystrophin protein is fucked)
DMD key characteristics?
- Pseudohypertrophy (fatty infiltrate)
- Proximal > distal
- Low tone/atrophy
- NORMAL SENSATION
