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What is the prognosis of ALS?

Average survival is 3-5 years after the onset of first symptom
Cause of  death are respiratory failure and insufficiency
Bulbar onset MND has worst prognosis, median survival is 20 months and 5% survive 5 years after the onset
Spinal onset MND has median survival  of 29 months and 15% survive 5 years after the onset
Short survival is associated with the following
Survival in ALS is depended on clinical and laboratory values
Clinical factors that determine the prognosis
  • Increasing age 
  • Recent significant weight loss 
  • Short time from onset to diagnosis 
  • Rapid rate of strength & respiratory loss during 6 months after diagnosis 
  • Respiratory failure 
  • No gastrostomy 
Laboratory factors that determine the prognosis are 
  • Poor pulmonary function < 60% of predicted 
  • Serum chloride: Falling; relation to poor nutrition 
  • EMG 
  • Low CMAPs 
  • Decrement on RNS 
  • EMG: Marked jitter; Low fiber density