Weather conditions & epilepsy

Published By Epilepsy Action Australia , 10 months ago

Have you ever noticed that your seizures happen more often in relation to the weather? Well you are not alone. In Australia, many people report that their seizures are often related to hot weather conditions. Whilst this topic has not been studied in Australia, research in the northern hemisphere, limited studies have shown:

that in spring, autumn and winter, unstable weather conditions cause an increase in seizures in almost half of the people with epilepsy they studied, and but only in 7 percent had an increase in seizures in summer[i].
an increase in seizures in winter conditions – lower ambient temperatures, higher atmospheric pressure, higher humidity, and reduced sunlight exposure[ii].
that low atmospheric pressure and high relative air humidity may also increase epileptic seizure risk[iii].
that weather-dependent seizure risk may be heightened in people with less severe epilepsy, that is, those taking a single antiepileptic drug. However, these studies had an under-representation of people with severe epilepsy.

Obviously, as with many seizure triggers, this is individual for everyone and clearly the effect of weather on seizure risk is still not fully understood.

Seizure Triggers

Most epileptic seizures occur unexpectedly and independently of known risk factors. There are many risk factors identified, and we also call them triggers. People with epilepsy report weather to be a major risk factor for epileptic seizures. [iv]

Triggers are circumstances that can bring on a seizure in some people with epilepsy. They differ from person to person, but not all people with epilepsy have seizure triggers.

And what triggers one person's seizures might not affect someone else with epilepsy in the same way.

Some commonly reported seizure triggers also include:

Missed medication
Lack of sleep
Physical fatigue and exhaustion
Stress, excitement, emotional upset
Menstruation and hormonal changes
Illness or fever
Poor diet
Medications other than prescribed seizure medications
Flickering lights or geometric patterns
Alcohol or drug use

For some people, knowing their seizure triggers, means they may be able to avoid them and lessen the risk of having a seizure.

What's the difference between triggers and causes?

Triggers for seizures are not the same as causes for epilepsy. A trigger for someone to have their first seizure may be a stressful situation, but the underlying cause for that person to start having seizures may be quite different. Causes can be genetic or because of structural damage to the brain.

Research: Temperature induced seizures

The latest epilepsy research carried out by experts in the US has looked into the issue of temperature-induced seizures, which remains a problem for many people around the world. They found that inserting a mutation into the genes of fruit flies that was similar to those found in people who experience febrile seizures led to the flies also having seizures. These experts have discovered new insights into the issue of heat-related seizures.

"What happens is the mutant neural (nerve) channels don't open and close properly. This effect is amplified at high temperature and this changes the ability of neurons to generate the appropriate electrical signals, leading to hyperactivity in the brain circuits".

"With this knowledge, the next step is to use this model to look for drugs that might reduce or eliminate heat-induced seizures."[v]

Seizures and the heat

Whilst research related to weather and seizures has been limited, and based in the northern hemisphere, there is no scientific evidence that hot weather itself causes seizures to occur in people with epilepsy. In Australia it appears most people report that the heat, or becoming overheated, tends to increase the likelihood of seizures. Becoming severely overheated can cause seizures, but an average hot day is not in itself the culprit.

How heat may cause seizures

Obviously, heat can be a major contributor to dehydration. If someone is exposed to heat for a long period of time and does not drink enough fluid, this can cause dehydration which can increase the risk of a seizure in someone with epilepsy, sometimes later in the day. When fluid loss from the body (mostly perspiration) is greater than fluid intake, it causes a change in electrolytes – a drop in sodium (salt) and glucose (sugar) levels in the body. Ultimately, this can lead to low blood sugar levels (hypoglycemia) which can also trigger seizures for some people.

Not surprisingly, on the rare occasions when a person becomes severely overheated, they risk a higher chance of having a seizure (amongst other serious health issues). So, it is important for people with epilepsy to prevent becoming over-heated in the first place, which at it's worst, can lead to heat exhaustion or heat stroke.

Sometimes though, people report seizures due to changes in weather (or environment). For instance, if a person enters a hot environment from a cold environment this could potentially trigger a seizure; however, the opposite remains true as well.

How to protect yourself from the heat

If hot weather or becoming overheated is a trigger for your seizures it does not mean that you must sit in front of the air conditioner all summer. It means that sensible preventative measures can be taken in order to ensure a happy and safe summer.

A few suggestions to help:

When inside, keep the house at a temperature that is cool enough to be comfortable. The air conditioner temperature ideally should be set at 24 degrees Celsius. Try not have it too cool as this creates a large difference between the inside and outside temperature.
Don't let the house heat up before cooling it down. Keep the air conditioner on a constant temperature all day.
Good full thickness or blackout curtains, or tinted windows are another way to keep the house cooler.
Ceiling fans and free-standing fans work as a good method to circulate the air as well, and in high humidity, sometimes are more effective in keeping you cool.
Why not plant some good shade trees or bushes in your yard?
Seek shade when going outdoors when you can. If you have to walk, do so on the shady side of the street. If you are taking the children to a park or playground, source one with good shade or plenty of trees. Try not to be in direct sunlight for lengthy periods.
Stay hydrated. Take a water bottle with you and drink regularly.
Wear light cotton clothing and avoid synthetics in the heat. Synthetic clothes make you sweat more and make you feel hotter. Cotton is the coolest type of clothing to wear and "breathes" better. It goes without saying that wearing a hat is also a good idea.
Young children and seniors have more difficult time regulating body temperature. So monitoring their time in the heat is recommended. Give the kids some down time with a food break, or instigate water play such as water pistols, sprinklers or water balloons.
Topamax (topiramate) can decrease perspiration, which is the body's natural way of staying cool. Be aware of this if you take Topamax.
If you have to spend a hot day outdoors then make sure take it easy and don't over exert yourself.

Ultimately, it is important to spend time both indoors and outdoors in the summer. We all need a bit of sunshine. Just be prepared and take appropriate measures to ensure you or your family don't get overheated or sunburnt.

If you think your seizures may be weather related

What you can do:

Keep a diary of seizures; when they occur and the circumstances in which they occur. Patterns can emerge for some people. This may take months to recognise, particularly if they are associated with weather changes.
If you think your seizures are weather related, look at adjusting your environment at home (and preferably work) so you are less likely to have a seizure. This may even mean getting an air conditioner for your bedroom.
A domestic weather station (they vary considerably in price) may be worth considering so you can record the conditions on the days you have seizures to see if there are patterns.
Take precautions in unfavourable weather conditions for you.

Many people with epilepsy find that their seizures are triggered by various things, including temperature or barometric changes, certain lights and sounds, hormones and even sleep. Regardless of the cause, if heat is a seizure trigger for you, use caution in hot weather to reduce your risk of seizures.