How long must a person be seizure-free to safely engage in scuba diving?

Seizure-Free Duration Required for Scuba Diving

Individuals with a history of epilepsy or seizures should be seizure-free for at least 5 years before engaging in scuba diving activities.

Risk Assessment for Seizures During Diving

Scuba diving presents unique physiological challenges that can be life-threatening if a seizure occurs underwater:

• Seizures underwater pose an immediate drowning risk
• Decompression illness can be exacerbated by seizure activity
• Nitrogen narcosis and oxygen toxicity risks are increased
• Rescue attempts for a seizing diver are extremely dangerous for both the affected diver and rescuers

Physiological Considerations

The British Thoracic Society guidelines highlight that the pulmonary circulation plays a critical role in filtering bubbles formed during decompression 1. A seizure underwater could compromise this filtering mechanism, potentially leading to:

• Pulmonary decompression illness ("the chokes")
• Systemic gas embolism if anatomical or physiological shunts are present
• Increased risk of neurological decompression illness

Evidence-Based Recommendations

The Sport Diving Medical Committee in the United Kingdom recommends that individuals with epilepsy must be:

1. Seizure-free for at least 5 years
2. Off all anti-seizure medications for 5 years 2

This recommendation is based on the understanding that:

• The risk of seizure recurrence decreases with increasing time in seizure remission
• However, the risk is never completely eliminated
• The consequences of a seizure while diving are potentially fatal

Seizure Recurrence Risk

Studies on seizure recurrence after medication discontinuation show:

• Approximately 30-50% of patients will experience seizure recurrence after stopping anti-seizure medications 3
• The highest risk period for seizure recurrence is within the first 12 months (especially the first 6 months) after medication withdrawal 4
• Even after 2 years of seizure freedom, the pooled relapse risk is 29% (95% CI 24-34%) 4

Special Considerations

Medication Status

While some research suggests that stable patients who have been seizure-free on medication for at least 4 years might consider shallow diving with appropriate precautions 2, this remains controversial and potentially dangerous. The standard recommendation remains 5 years seizure-free and off medication.

High-Risk Activities

Multiple guidelines classify scuba diving as a high-risk activity that is generally contraindicated for people with epilepsy 5. Other high-risk activities in the same category include:

• Free climbing
• Hang gliding
• Activities at significant heights without safety equipment

Practical Guidance

For individuals with a history of seizures who wish to dive:

1. Consult with a neurologist specializing in epilepsy
2. Document at least 5 years of complete seizure freedom
3. Complete medication withdrawal under medical supervision
4. Undergo medical clearance specifically for diving
5. Consider diving with a buddy who is fully informed about the medical history
6. Limit initial dives to shallow depths

Conclusion

The 5-year seizure-free recommendation represents a balance between individual autonomy and safety. While this may seem restrictive, the potential consequences of a seizure while diving justify this conservative approach. The American Heart Association recognizes that seizures occurring in water represent a medical emergency requiring immediate EMS activation 1, highlighting the serious nature of this risk.

Alternative water-based activities with lower risk profiles may be more appropriate for individuals who do not meet these criteria.