ADD-ONS / OTHER VASCULAR DISORDERS
Drop Attack
Updated on 01/02/2024, 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
Pathophysiology
- 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
Etiology
- 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)
- 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
- 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