Cataplexy

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