A seizure is an abnormal burst of electrical activity in the brain. While some seizures cause no symptoms, others produce movements or changes in behavior, sensation or level of consciousness. When seizures occur repeatedly, this usually indicates a seizure disorder, or epilepsy. The Epilepsy Foundation estimates that 1 in 26 Americans will develop epilepsy at some time during their life. Some people experience early warning signs before a seizure. There are two types of warnings: prodromal symptoms and auras. Prodromal symptoms usually occur hours or even days before a seizure. Auras occur seconds to minutes before the main part of a seizure -- they are actually the initial stage of certain types of seizures.
Symptoms that occur at least 30 minutes before a seizure are called prodromal or premonitory symptoms. They generally begin gradually and often include emotional symptoms, such as irritability or mood changes. Difficulty concentrating, slowed thinking, decreased memory and sleep disturbances may also occur. Prodromal symptoms can also include physical symptoms, such as fatigue, vomiting, increased appetite, feeling unusually cold or hot, and changes in speech. Abdominal pain and headaches -- often similar to migraines -- are relatively common. Prodromal symptoms may or may not continue until the seizure begins. In a study of 100 adults with epilepsy reported in the May 2009 issue of "Seizure," one-half of the 39 participants who had prodromal symptoms indicated that they did not disappear before the seizure.
When present, an aura occurs immediately before the main part of a seizure. It usually lasts a few seconds to a few minutes until the main seizure begins. An aura occurs when the burst of electrical activity begins in one area of the brain before spreading to other areas. The type of symptoms during an aura depend on the exact location of this initial burst. Movement or numbness of a certain area of the body, difficulty speaking, abnormal smells, noticing a strange taste in the mouth, hearing a non-existent musical sound or feeling "butterflies" in the stomach are all examples of aura symptoms. Visual changes, such as blurred vision or seeing lights that aren't present, are relatively common. A sense of intense fear or unusual feelings, such as feelings of déjà vu, may also occur.
Importance of Warning Signs
When people with epilepsy experience warning signs, they are often the same from seizure to seizure. This may help predict when a seizure is on the way. Knowing that a seizure may occur can help the person find a safe place to rest during the seizure. It may even offer the possibility of preventing the seizure or stopping a seizure while still in the aura stage. Some people report that they can prevent or stop a seizure by simple maneuvers, such as rubbing a specific area of the body. Medication adjustments or activation of a device such as a vagus nerve stimulator when warning signs occur are other ways to prevent or stop seizures in some people.
If you have seizures, discuss the possibility of warning signs with your doctor. Your doctor may ask you to keep a diary to record any symptoms you note before your seizures. This may help you identify symptoms that are most likely to be useful warnings. Your doctor will provide specific information about what you should do if you notice early warning signs. Do not make any medication adjustments or device activations unless advised to do so by your doctor.
Reviewed by Mary D. Daley, M.D.
- American Academy of Neurology: Summary of Evidence-based Guideline for Patients and Their Families -- Vagus Nerve Stimulation for Treating Epilepsy
- Johns Hopkins Medicine: Epilepsy and Seizures
- Merck Manual Professional Version: Seizure Disorders
- Seizure: Prodromal Symptoms in Epileptic Patients: Clinical Characterization of the Pre-ictal Phase
- Epilepsy Foundation: About Epilepsy -- The Basics