What Is the Postictal Phase of a Seizure?

And What the Symptoms Following a Seizure Can Tell Us

An EEG test is performed on an epilepsy patient.
An EEG test is performed on an epilepsy patient. BSIP/UIG/Getty Images

The postictal phase refers to the period of time immediately following a seizure. The postictal phase can last for seconds, minutes, hours, and sometimes even days. It is commonly thought of as the time during which the brain recovers from a seizure.

The other phases include the prodromal phase (when emotional signs appear), the aural phase (typified by altered sensations), and the ictal phase (the actual seizure).

Symptoms of the Postictal Phase

The duration of a postictal phase can vary as can the symptoms. The types and severity of symptoms are largely dependant on the part of the brain involved and how long the seizure lasted.

Postictal symptoms can effect changes in behavior, thinking, mood, and motor function, including:

  • Fatigue
  • Headache
  • Nausea
  • Sleepiness
  • Memory loss
  • Mental confusion or fogginess
  • Feeling thirsty
  • Weakness on part of all of the body
  • A strong urge to urinate
  • Loss of bladder and/or bowel control
  • Difficulty walking
  • Speech or writing impairment

As the result of a seizure, a person may experience injuries ranging from head traumas and bruises to bone fractures and bitten tongues. There may also be an emotional component characterized by feelings of embarrassment, anxiety, frustration, or sadness.

Postictal migraines are a common complaint among people with epilepsy. One possible explanation for this is the cerebral edema (brain swelling) that can result from a seizure, causing increased intracranial pressure and pain.

In some cases, a person may only be aware of a seizure when a characteristic migraine appears.

On the flip side, postictal bliss, described as having an excessively happy feeling, has been know to occur following a seizure.

What Postictal Symptoms Tell Us About a Seizure

Postictal symptoms can sometimes help doctors determine the focus of the seizure (where the brain where the seizure activity originated).

There are a number of examples of this:

  • Postictal dysphasia, characterized by difficulty speaking, suggests that the seizure originated in that person's dominant hemisphere (the half of the brain that a person favors).
  • Postictal paralysis, a symptom characterized by the temporary weakness of a hand or limb, is associated with the side of the brain opposing the seizure focus.
  • Postictal automatisms, manifesting with repetitive actions such as lip smacking or nose rubbing. are a common sign of complex partial seizures that frequently arise in the temporal lobe.

Value of an EEG in the Postictal Phase

During the postictal phase, an electroencephalogram (EEG) will usually show a slowing of brain activity on the side of the brain where the seizure originated.

With that being said, it can sometimes be difficult to distinguish between the ictal and postictal phase as the slowing of brain activity will sometimes occur with both phases.

In addition, the brain wave changes on an EEG do not always correlate with a person's behavioral changes. This is why some doctors prefer to focus on describing a person's behavior in context with any EEG changes that occur during or after a seizure (as oppose to labeling them ictal or postictal).

While it may seem that taking an EEG after a seizure has limited value—rather like calling the weather bureau after the storm has passed—the event leaves a trail of altered brain activity which can help doctors characterize seizures for the purpose of treatment or surgery.

Sources:

Fisher, R. and Engel, J. "Definition of the postictal state: when does it start and end?" Epilepsy Behav. 2010;19(2):100-4.

Rémi, J. and Noachtar, S. "Clinical features of the postictal state: correlation with seizure variables." Epilepsy Behav. 2010;19(2):114-7.

Theodore, W. "The postictal state: effects of age and underlying brain dysfunction." Epilepsy Behav. 2010;19(2):118-20.

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