Is free diving (self-contained underwater diving) a risk for seizures in individuals with or without a history of seizure disorders?

Free Diving and Seizure Risk

Free diving presents a significant risk for seizures due to physiological changes that occur underwater, and should be avoided by individuals with seizure disorders and approached with caution by others due to the risk of drowning and other complications.

Mechanisms of Seizure Risk in Free Diving

Free diving (breath-hold diving) can trigger seizures through several mechanisms:

1. Hypoxia-induced seizures

   • Prolonged breath-holding leads to decreased oxygen levels in the brain
   • Cerebral hypoxia is a well-known seizure trigger
   • Risk increases with depth and duration of dive

2. Hyperventilation-related risks

   • Many free divers hyperventilate before diving to extend breath-hold time
   • This lowers CO2 levels, which can trigger seizures in susceptible individuals
   • Delayed hypoxic response can lead to "shallow water blackout" and seizures

3. Physiological stress responses

   • Immersion triggers mammalian dive reflex with significant cardiovascular changes
   • Rapid blood pressure and heart rate fluctuations can lower seizure threshold

Seizure Risk in Different Populations

For individuals with known seizure disorders:

• Free diving is absolutely contraindicated 1
• Seizures occurring in water represent a medical emergency requiring immediate EMS activation 2
• An in-water seizure is highly likely to be fatal 3

For individuals without seizure disorders:

• Still at risk for hypoxia-induced seizures during prolonged breath-holding
• Risk increases with competitive/extreme free diving attempts
• Proper training and supervision are essential

Guidelines and Recommendations

1. For those with epilepsy/seizure history:

   • Free diving should be avoided completely 1, 4
   • Even with controlled epilepsy, water activities should only be undertaken with direct supervision 5
   • Individuals with epilepsy should be seizure-free for at least 5 years before considering any form of diving 1, 6

2. For the general population:

   • Never free dive alone - always use a buddy system
   • Avoid hyperventilation before dives
   • Maintain appropriate surface intervals between dives
   • Recognize early warning signs (lightheadedness, tunnel vision)
   • Ensure proper training and gradual progression in dive depth/duration

Management of Seizures in Water

If a seizure occurs during free diving:

• Activate EMS immediately 2
• Help the person to the surface if possible
• Place in recovery position once on land/boat
• Clear the area to prevent injury 2
• Stay with the person having the seizure 2
• Do NOT restrain the person 2
• Do NOT put anything in the person's mouth 2

Conclusion

Free diving carries inherent seizure risks due to physiological changes that occur underwater. These risks are significantly elevated for those with seizure disorders, making free diving an activity that should be avoided by this population. For the general population, proper training, supervision, and adherence to safety protocols can reduce but not eliminate the risk of seizures during free diving.