Drop Attack

David Goldemund M.D.
Updated on 26/08/2024, published on 09/12/2021

Introduction

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

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)

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

syncope is a temporary loss of consciousness caused by a sudden drop in cerebral blood flow
types of syncope:
- vasovagal syncope
  - this is the most common type of syncope, triggered by a sudden drop in blood pressure due to a reflex response from the vagus nerve
  - it can be caused by emotional stress, pain, or prolonged standing
- cardiac syncope – caused by an underlying heart condition, such as arrhythmias, structural abnormalities, or valvular disorders, which can disrupt the normal flow of blood to the brain
- orthostatic syncope – occurs when there is a sudden drop in blood pressure upon standing up or changing position, often due to dehydration, medication side effects, or autonomic nervous system dysfunction
- neurogenic syncope – caused by neurological conditions that affect the autonomic nervous system’s ability to regulate blood pressure and heart rate, such as Parkinson’s disease, multiple sclerosis, or autonomic neuropathy
- carotid sinus syncope – a rare form of syncope is triggered by pressure on the carotid sinus due to tight collars, shaving, or specific head movements, leading to a sudden drop in heart rate and blood pressure
before experiencing a syncope episode, individuals may experience one or more of the following symptoms:
- dizziness or lightheadedness
- nausea or vomiting
- sweating
- blurred vision or tunnel vision
- tinnitus
- feeling warm or flushed
- rapid or irregular heartbeat