Drop Attack

David Goldemund M.D.
Updated on 01/02/2024, published on 09/12/2021


  • drop attack is a symptom, not a diagnostic unit
  • defined as a sudden fall while standing or walking without accompanying loss of consciousness
    • differentiate from syncope, where often prodromes and especially a brief disturbance of consciousness are present (but both may escape attention)
  • weakness may last for several minutes or hours
  • drop attacks are more common in older patients


  • sudden and transient loss of muscle tone (cataplexy, atonic seizures, etc.)
  • hypertonus and freezing with postural dysbalance (Parkinsonian syndromes)
  • cerebellar-vestibular disorders (Meniere’s disease)
  • neuromuscular disorders
  • joint disorders


  • CNS impairment
    • spinal cord ischemia
    • vertebrobasilar insufficiency, incl. subclavian steal syndrome
    • brainstem compression due to expansions or, e.g., dolichobasilaris
    • myoclonus
    • epilepsy (atonic seizures, myoclonic seizures, focal motor seizures)
    • postural stability disorders in Parkinsonian syndromes
    • cataplexy (often associated with narcolepsy)
      • a sudden and transient episode of muscle weakness accompanied by full consciousness, typically triggered by emotions such as laughing, crying, or fear
      • sometimes manifested by an isolated head drop
      • usually, a manifestation of narcolepsy sometimes develops after stroke or encephalitis
  • craniocervical junction disorders
    • Arnold-Chiari (relatively rare)
    • osteophytes compressing the brainstem
    • cervical spondylosis
  • cerebellar-vestibular disorders
    • e.g., in late-stage Meniere’s disease
  • orthopedic and neuromuscular causes
    • knee instability
    • myopathy
    • peripheral paresis
  • other
    • functional
    • syncope with unrecognized brief loss of consciousness or presyncope with atony (see DDx)
  • cryptogenic/idiopathic (up to 64% by some estimates)
    • many cryptogenic drop attacks may be considered a functional neurological disorder (FND)  (Revel, 2021)

Differential diagnosis

  • epilepsy
    • disturbance of consciousness, seizures other than those listed above
  • narcolepsy
  • cardiovascular syncope
    • a sudden, transient loss of consciousness and postural tone (brief loss of consciousness may go unnoticed)
    • many syncopal patients may have a loss of tone and fall as part of the presyncope phase ⇒ carefully exclude syncope (especially cardiovascular syncope)  [Dey, 1997]
  • fall due to tripping, slipping, etc.
  • recurrent episodes of weakness, fatigue, and sudden falling asleep during the day
  • quality of night sleep is impaired
    • patient wakes frequently
    • REM sleep is disturbed
    • recurrent episodes of sleep paralysis may occur
  • cataplexy is common

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Drop attack