By Barry Rueger
Published: Next Avenue
Aoril 9, 2025
1313 words
Read on-line.
One sunny day in mid-October I realized that I was in the hospital. I didn’t know why, and I didn’t know how long I had been there, but I was definitely in the emergency ward at Vancouver General Hospital.
By the end of the day I had learned that my wife, Susan, had found me on the dining room floor in my dressing gown, that she had called the paramedics and that through the examinations and the ambulance journey, my eyes had been open and I was answering questions.
A week later, my new neurologist, Oscar Benavente, M.D., told me that I had probably suffered a seizure. The “probably” was because the event had happened days earlier, and he hadn’t been there to see it.
According to the Cleveland Clinic, there’s a one in 10 chance you will have a seizure at some point in your life. The likelihood increases depending on underlying medical conditions, a family history of seizures or if you are over 50. Children can also experience seizures.
A seizure is, at its simplest, a surge of electrical activity in your brain that causes affected brain cells to quick-fire random signals to other surrounding cells. Your seizure can be a one-off event, or if it is caused by epilepsy, may be one in a continuing series. Your doctor might be able to say why your seizure happened, or it may remain a mystery. And those electrical signals can cause all kinds of symptoms.
Types of Seizures
In the broadest of terms, you’ll want to know if you are suffering from epileptic seizures, meaning you’re prone to having repetitive attacks, or if your seizure is likely an isolated episode. How your doctor will determine this is through observation over a long period of time. In my case this meant that for the following six months I was prohibited from driving, and was monitored for further seizures.
Seizures are first categorized by type of onset. Your doctor will ask whether your seizure began on one side of your brain (a focal-onset seizure) or on both sides (a generalized-onset seizure). If you can’t tell, it may initially be classed as an unknown-onset seizure. The neurologist will try to answer this and other questions by booking a variety of tests including a CT brain scan (computed tomography, using X-rays to scan the brain), an MRI (magnetic resonance imaging, using magnets), and possibly an EEG (electroencephalogram), a test that measures electrical activity in the brain.
Those three broad categorizations are useful, but seizures fall into dozens of different categories and combinations depending on your specific symptoms — and whether anyone was on hand to note what was happening. Most seizures last only a minute or two, so there’s every chance that it will be over before anyone else could notice how you behaved, or what parts of your body were moving in which fashion.
No Longer Called Grand-Mal
Most people associate a seizure with (what used to be called ) a grand-mal seizure, where an unconscious person’s limbs shake and jerk. These seizures — now termed “tonic-clonic seizures” —are just one of a variety of generalized-onset motor seizures. These seizures include both clonic behaviors — rhythmic jerking — and tonic stiffening, where parts of your body become rigid. Generalized-onset seizures can also include spasms, or loss of muscle tone or combinations of behaviors.
There are also generalized-onset non-motor seizures, (formerly petit-mal seizures) which still originate on both sides of the brain, but include absence seizures, where a patient “blanks out” for a few seconds but without any lasting symptoms.
Focal-onset seizures begin in only one area of the brain and can be categorized by the patient’s level of awareness. If awareness is impaired during any part of the seizure, the seizure is classified as a focal impaired-awareness seizure. As with generalized-onset seizures, jerking and stiffening of parts of the body are common events although often only one limb or one side of the body will be involved. It is common for an initially focal seizure to spread to other parts of the brain, creating a focal to bilateral tonic-clonic seizure.
If clinicians are unsure about a seizure, they may choose to describe it as an unknown-onset seizure. After further testing and scans they may be able to reclassify it as either general- or focal-onset seizure. This is important for choosing the correct approach to treatment.
Possible Causes
Just as there is a long list of seizure types, the possible causes of a seizure can vary widely, and it’s not always possible to be certain of the cause. Merck & Company’s MSD Manual lists risk factors such as head trauma, neurological disorders, family history, alcohol or drug use (or withdrawal) or not following prescribed anti-seizure drug schedules. More factors can include a high fever or heat stroke; brain infections from malaria, HIV, rabies or a variety of other bacterial or viral conditions. High or low levels of glucose or sodium can be a cause, as can kidney or liver failure.
Various cardiac problems may cause inadequate oxygen supply to the brain, as can near-drowning or carbon monoxide poisoning. Damages to the structure of the brain, such as strokes or tumors, can trigger a seizure, as can fluid accumulation, and poisoning from lead or strychnine also will cause a seizure.
In other words, just as a doctor may not ever determine exactly what type of seizure a person had, the patient also may never know what caused it.