Last reviewed 04/2020

Cataplexy is loss of muscular tone caused by strong emotion.

Patients may complain that a surprise or hearing a joke results in loss of strength.

There is a spectrum of severity:

  • mild:
    • jaw drop
    • neck sagging
    • buckling knees

  • severe:
    • collapse - may last several minutes

Cataplexy is a characteristic, but not essential, feature of narcolepsy:

  • if may be the presenting symptom in 4% of narcoleptics
  • 60-90% of patients with narcolepsy have cataplexy