Comparison: Breath-Holding Spells vs Reflex Anoxic Seizures
Pathophysiology
| Feature | Breath-Holding Spells (BHS) | Reflex Anoxic Seizures (RAS) |
|---|
| Mechanism |
Autonomic dysregulation involving prolonged expiratory apnea after crying or frustration |
Cardiovascular reflex-mediated transient asystole in response to sudden pain or fright |
| Trigger |
Emotional distress (crying, frustration, anger) |
Unexpected pain (e.g. bump), fright, or minor trauma |
| Cause of unconsciousness |
Hypoxia due to breath-holding |
Transient cerebral hypoperfusion from cardiac asystole |
Age of Onset
| Feature | BHS | RAS |
|---|
| Typical Age |
6 months to 4 years |
6 months to 4 years (peak at ~18 months) |
Clinical Features
| Feature | Breath-Holding Spells (BHS) | Reflex Anoxic Seizures (RAS) |
|---|
| Preceding Cry |
Present (cyanotic type) or absent (pallid type) |
Usually no prolonged crying |
| Colour Change |
Cyanotic (most common) or pallid |
Pallor is typical |
| Loss of Consciousness |
May or may not occur |
Always occurs, typically sudden |
| Seizure-like Movements |
Sometimes – due to cerebral hypoxia |
Common – due to brain hypoperfusion |
| Duration |
Usually brief (10–30 sec) |
Brief (less than 1 minute) |
| Recovery |
Rapid and complete |
Rapid and complete |
| EEG |
Normal |
Normal unless prolonged anoxia |
| Cardiac Monitoring |
Usually not necessary |
May show bradycardia or asystole |
Investigations
| Feature | BHS | RAS |
|---|
| Workup |
Clinical diagnosis; consider iron studies |
ECG, Holter, tilt test; exclude long QT syndrome |
| Iron Status |
Iron deficiency common and treatable |
No proven benefit |
Management
| Feature | BHS | RAS |
|---|
| Acute |
Reassurance; safe positioning |
Reassurance; avoid trigger |
| Chronic |
Parental reassurance; iron therapy if deficient |
Avoid known triggers; pacemaker rarely needed |
| Medications |
Not indicated |
Not indicated |
Summary Table
| Aspect | Breath-Holding Spells | Reflex Anoxic Seizures |
|---|
| Trigger |
Emotional stimulus |
Pain/fear stimulus |
| Primary System |
Respiratory/autonomic |
Cardiovascular/autonomic |
| Colour |
Cyanosis or pallor |
Pallor |
| Onset |
Gradual (with cry) |
Sudden |
| Movements |
May occur |
Often occur |
| Recovery |
Rapid |
Rapid |
| Long-term Risk |
Benign |
Benign; pacemaker in rare cases |
Clinical Pearl
Pallid BHS and RAS may appear similar. However, in RAS there is typically no crying beforehand and the episode is immediate after impact or fright. EEG is not diagnostic unless epilepsy is suspected.
