Epilepsy and SCUBA
I am surprised about the number of questions I have been asked as of late regarding whether it is safe for Epileptics to SCUBA dive or not.
Let's first look at what epilepsy is:
The Mayo Clinic defines epilepsy loosely as follows: .... Epilepsy is a neurological disorder where the nerves become disturbed. These disturbances can lead to seizures, unconsciousness, abnormal behaviors, disorientation and sensations. "Even mild seizures may require treatment because they can be dangerous during activities such as driving or swimming."
The seizures (what we are most interested in here) are caused by a Paroxysmal Depolarizing Shift. Normally brain activity is non-synchronous (neurons firing independently of each other) but in epilepsy the neurons fire in a synchronous manner. Like waves of impulses flowing through the brain. This depolarizes the ion inhibitors of the excitability neurons giving rise to uncontrolled neurological impulses which cause seizures.
The closet example I can think of is the result of pouring a soda on your PCs mother board. ZZZZAP!
As the seizure ends a new and very dangerous phase for SCUBA divers begins: The Postictal period and will commonly last 3 to 5 minuets. It can last for hours. It is characterized by confusion, disorientation and fear. In 6%-10% of patients Psychosis will occur.
Approximately 1 in 100 Americans will have epilepsy. It takes at least two seizures to base the diagnosis. Treatment, which generally includes medications or sometimes surgery, may eliminate or reduce the frequency and intensity of seizures. There are not any immediate underlying causes for epileptic seizures. Epilepsy cannot be cured, but the symptoms can be treated in about 70% of the cases.
The seizures can be brought on by many different stimuli. Stress, increased levels of O2, unpredictable light patterns and other seemingly random stimuli will be on that list. And what is more, what caused a seizure one day, may not cause it another day. And vice versa.
People with epilepsy are at an increased risk of death; this increase is between 1.6 and 4.1 fold greater than that of the general population.
So how does all this effect SCUBA divers? Significantly. One cannot predict a seizure, its strength or duration, the seriousness of the Postictal period or the variables which will initiate a seizure.
So what do your think? I think the answer is NO! Not on my boat for sure!
The vast majority of divers who lose consciousness, while underwater, drown. And that is not good. More over the meds used to treat epilepsy are CNS depressants, and these are generally contraindicated for diving. Just like alcohol and barbiturates.
Any form of unconsciousness at depth is deadly and there is NO SUCH THING as "a small seizure". Remember, drowning is not the only possibility here; over expansion and uncontrolled decent and ascents are among the realistic possibilities for the epileptic diver and any would be rescuer.
DAN recommends that the diver be off all related medication and free from seizures for 5 consecutive years. And then to have a buddy who is well trained to assist a violently seizing, disoriented diver at any moment and be able to preform all surface rescue needs including extraction from the water.
My personal comment: please don't dive. I love diving, but it is not worth putting others or myself at such risks.
