Drop attack

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farman Khan, MD, MRCP [2]

Overview

Drop attacks are sudden spontaneous falls while standing or walking, followed by a very swift recovery, within seconds or minutes. Drop attacks are typically seen in elderly patients, and the most common cause is carotid sinus hypersensitivity, resulting in either short periods of reversible asystole, or in marked drop in blood pressure in response to carotid sinus stimulation.

Causes

Causes of drop attacks include:

1. Vascular - transient ischemic attack, cerebrovascular accident, dissection, occlusion and hemorrhage
   • Intracranial hemorrhage
   • Posterior circulation infarction, emboli and vasospasm
   • Bilateral anterior circulation occlusion
   • Migraine - develops over 1 hour, with associated paresthesia, Hypertonia arterialis
   • Basilar artery insufficiency - older patient with no loss of consciousness, transient loss of lower extremity tone
2. Epilepsy/paroxysmal:
   • Neurally mediated syncope - 75% of all causes
   • Myoclonic seizure
   • Myoclonic-astatic seizure
   • Petit mal syndrome
   • Lennox-Gastaut syndrome - atonic seizure, myoclonic seizure and generalized tonic-clonic seizure typically occurring in neurologically abnormal patients
   • Juvenile Myoclonic Epilepsy - fall with myoclonus
   • Laugh or cough triggered epilepsy
   • Cataplexy associated with narcolepsy
   • Periodic paralysis
   • Complex partial seizure
   • Breath-holding spells - associated pallor/cyanosis, emotion related
   • Pure autonomic failure (Riley-Day Syndrome, long standing diabetes mellitus)
   • Episodic ataxia
   • Panayiotopoulos syndrome
3. Degenerative disease:
   • Postural instability with Parkinsons
4. Structural:
   • Chronic odontoid instability
   • Spinal cord trauma with transient paraplegia
   • Brainstem mass
5. Metabolic:
   • Hypoglycemia
   • Hypocalcemia
   • Hypomagnesemia
   • Toxins, drugs - cocaine, sedatives, antihistamine and tricyclic antidepressants
6. Cardiac:
   • Prolonged QT
   • Tachycardia
   • Bradycardia
   • Sick sinus syndrome
   • arhythmia
   • Hypertrophic cardiomyopathy
   • Aortic stenosis
   • Hypovolemia
7. Psychologic:
   • Malingering
   • Conversion disorder
   • Panic attack
   • Anxiety

Common Causes

• Seizure
• Transient ischemic attack
• Cerebrovascular accident
• Basilar artery insufficiency
• Hypoglycemia
• Hypotension
• Cataplexy associated with narcolepsy
• Cardiac arrhythmia
• Sick sinus syndrome
• Migraine
• Aortic stenosis
• Conversion disorder

Causes by Organ System

Cardiovascular	Cardiac arrest, bradycardia, prolonged QT, sick sinus syndrome, Stokes-Adams attacks, tachycardia, ventricular tachycardia, aortic stenosis
Chemical / poisoning	No underlying causes
Dermatologic	No underlying causes
Drug Side Effect	Sedatives, antihistamine, tricyclic antidepressants
Ear Nose Throat	No underlying causes
Endocrine	Hypoglycemia
Environmental	No underlying causes
Gastroenterologic	No underlying causes
Genetic	No underlying causes
Hematologic	No underlying causes
Iatrogenic	No underlying causes
Infectious Disease	No underlying causes
Musculoskeletal / Ortho	No underlying causes
Neurologic	Astatic seizure , Episodic ataxia , Juvenile myoclonic epilepsy , Migraine , Myoclonic seizure , Panayiotopoulos syndrome Parkinsons , Pure autonomic failure , Seizure , Vertebrobasilar artery insufficiency , Paraplegia, Brain stem mass
Nutritional / Metabolic	Hypoglycemia, hypocalcemia, hypomagnesemia
Obstetric/Gynecologic	No underlying causes
Oncologic	No underlying causes
Opthalmologic	No underlying causes
Overdose / Toxicity	Cocaine
Psychiatric	Malingering, conversion disorder, panic attack, anxiety
Pulmonary	Sleep apnea
Renal / Electrolyte	No underlying causes
Rheum / Immune / Allergy	Anaphylaxis
Sexual	No underlying causes
Trauma	No underlying causes
Urologic	No underlying causes
Dental	No underlying causes
Miscellaneous	No underlying causes

Causes in alphabetical order

• Anaphylaxis
• Antihistamines
• Aortic stenosis
• Astatic seizure
• Bradycardia
• Brain stem mass
• Breath-holding spells
• Cardiac arrest
• Cardiac syncope
• Cardiac tamponade
• Cocaine
• Conversion disorder
• Episodic ataxia
• Gout

• Hypocalcemia
• Hypoglycemia
• Hypokalemic periodic paralysis
• Hypomagnesemia
• Juvenile myoclonic epilepsy
• Lennox-Gastaut Syndrome - drop attacks
• Malingering
• Migraine
• Myoclonic seizure
• Panayiotopoulos syndrome
• Parkinson's disease
• Paraplegia
• Panic attack
• Panic disorder

• Prolonged QT
• Pure autonomic failure
• Sedatives
• Seizures
• Sick sinus syndrome
• Sleep apnea
• Spinal cord trauma
• Stokes-Adams attacks
• Superior canal dehiscence syndrome
• Tachycardia
• Trypanophobia
• Ventricular tachycardia
• Vertebrobasilar artery insufficiency

Diagnosis

• Important in the presence of an inciting event (Neuroleptic malignant syndrome, breatholding, postural), any loss of consciousness and presence of post-ictal period
• Initial tests:

1. Glucose
2. EKG
3. Pregnancy test
4. Urine toxicology test
5. CT head
6. Electrolytes
7. Later consider EEG, echocardiogram, MRI and tilt test