You might have seen someone have a seizure before, but it’s hard to imagine what could possibly be happening inside the body to cause that kind of response. When you zoom into the brain, however, all seizures don’t look exactly the same.
“There are different types of seizures and they look differently depending on if you catch it in the beginning, the middle, or the end,” according to Padmaja Kandula, MD, neurologist at Weill Cornell Medicine and NewYork-Presbyterian.
The main categories of seizures include a generalized seizure, which affects both sides of the brain, and a focal seizure, which affects one area of the brain, according to the Centers for Disease Control and Prevention. Furthermore, these types of seizures can be broken down into subtypes.
Normally, the billions of neurons or nerve cells in the brain fire off electrical impulses individually, allowing the neurons to communicate with each other to help your body function appropriately. In a seizure, those neurons all fire off at the same time, creating abnormal electrical activity.
Often, before experiencing a seizure, someone may experience an “aura.” Auras may cause sensations of strange tastes and smells, nausea, anxiety, or a fluttering feeling, and they can serve as a warning for someone who has endured many previous seizures. However, an aura itself is actually a seizure.
“The most common seizure starts from one particular area of the brain,” says Dr. Kandula. “Seizures can present differently in their appearance depending on which portion of the brain they start from.”
Temporal lobe: This part of the brain is on the lower side of the brain, and it’s the most common place a seizure starts. Seizures in the temporal lobe can affect memory.
Occipital lobe: Seizures in this rear part of the brain may result in hallucinations and clouded thinking.
Frontal lobe: If a seizure affects this large area at the front of the brain, it may cause shaking and convulsing. While these aren’t the most common type of seizure, they tend to be the most severe. Frontal lobe seizures may result in a spike in blood pressure and heart rate, as well as loss of bladder control and a risk of biting their tongues. These seizures have a higher risk of injury and may take time to recover from.
“It’s hard to predict what seizure type an individual might have, and there’s no way of finding out one way or another—which also makes it very lifestyle-imparing for patients, too,” says Dr. Kandula.