Phases of Seizures
Discover the signs, symptoms, and progression of a seizure.
A seizure is an electrical disturbance that interferes with normal brain function – they occur when abnormal electric signals from the brain change the way the body functions. A focal seizure starts in a single location in one hemisphere (or side) of the brain, whereas a generalized seizure starts in both hemispheres simultaneously.
In addition to these categorizations, there are four distinct phases of seizures: prodromal, early ictal (the “aura”), ictal, and post-ictal.
Please note: different forms of epilepsy affect people differently, and not every seizure has the same symptoms or even the same progression. Because of this, individual experiences with seizures may vary, meaning some people will not experience all of the phases or symptoms described below.
The prodromal phase is a subjective feeling or sensation that can occur several hours or even days before the actual seizure. The most common symptoms of a prodrome include confusion, anxiety, irritability, headache, tremor, and anger or other mood disturbances (Besag & Vasey, 2018).
About 20% of individuals with epilepsy experience this phase (Besag & Vasey, 2018), which may serve as a warning sign of seizure onset for those who experience it. Unlike an aura, though, this phase is not part of the seizure.
For many people with epilepsy, the earliest sign of seizure activity is an aura. Although it has traditionally been thought of as a warning of an on-coming seizure, an aura is actually the earliest sign of seizure activity and the beginning of the ictal phase. (Besag & Vasey, 2018).
The ictal phase includes the time between the beginning (aura, if present) and the end of the seizure.
Like the prodrome, not everyone with epilepsy has auras. For those who do, the specific symptoms vary depending on seizure type, severity, and affected brain region. Some common symptoms include:
An aura can remain localized or progress to other areas of the brain with the person’s awareness becoming impaired to varying degrees. The aura can also spread to both hemispheres of the brain, becoming a secondarily generalized seizure within seconds to minutes after onset (Falco-Walter et al., 2018).
The ictal phase manifests in different ways for every person with epilepsy. They may experience a variety of symptoms, including but not limited to:
The recovery period following a seizure is called the post-ictal phase. Some people recover immediately, while others may require minutes (or days) to feel like they’re back at their baseline. The length of the post-ictal phase depends directly on the seizure type, severity, and region of the brain affected. Typical symptoms include:
Reviewed by CURE Scientific Advisory Council Members Daniel Lowenstein, MD and Jaideep Kapur, MD/PhD on Thursday, January 16, 2020.
Besag, F.M.C. and Vasey, M.J. (2018) Prodrome in epilepsy. Epilepsy & Behav. 83: 219-233
Falco-Walter, J.J., Scheffer, I.E., and Fisher, R.S. (2018) The new definition and classification of seizures and epilepsy. Epilepsy Res. 139: 73-79.