Amyotrophic Lateral Sclerosis (ALS)


  • Uncurable motor neuron degenerative disease.
  • May present to ED as:
    • Abnormal gait (falls)
    • "Radiculopathy" (eps. cervical)
    • "Footdrop"/"Wristdrop" Saturday night palsy.
    • Bulbar "event" (e.g. slurred speech or aspiration).
  • M:F = 2:1, any age (incidence rising with age).



  • 80% present with limb weakness ("amyotrophy" = muscle fibre atrophy), NB foot drop or loss of finger dexterity.
  • 20% with bulbar symptoms, slurred speech, poor swallow, aspiration.
  • Initial flaccid, then ±spastic cramps.
  • Later cognitive and emotional fluctuations.


  • Mixed UMN and LMN signs in different body regions.
  • No sensory signs in ED

Differential Dx

Very early presentation may "mimic" others:

Investigations (in-patient)

  • EMG - Normal sensory, abnormal motor conduction.


  • If suspected, admit neurology for workup and management plan.
  • Consider, respiratory support, analgesia etc.

Content By Dr Íomhar O' Sullivan . Last review Dr ÍOS 24/05/21.