A seizure is a complex neurological process resulting from a sudden, uncontrolled burst of electrical activity in the brain. Understanding the sequence of events allows medical professionals to better diagnose and treat the underlying condition. This process is typically broken down into four sequential phases, which can vary in presence and intensity from one individual to the next.
The Prodromal Phase
The prodromal phase consists of the earliest, non-specific warning signs, often occurring hours or even days before the event itself. These symptoms are vague and relate to a person’s mood or general physical state. Only about 20% of people who experience seizures report a prodrome, and it is not considered part of the actual electrical discharge in the brain.
Common manifestations include malaise, irritability, or changes in mood. Headaches, difficulty concentrating, or increased fatigue are also frequently reported during this time. Because these changes are subtle and non-specific, they are usually only recognized in hindsight or by individuals who have learned to track their unique patterns.
The Aura (Early Ictal Onset)
The aura is the first specific signal that the seizure process has begun. It happens when the abnormal electrical activity starts in a localized area of the brain but has not yet spread widely enough to impair awareness. Auras are reported by as many as 65% of people with epilepsy, and they typically last from a few seconds up to a minute.
Sensory disturbances are common, such as smelling an odor that is not present, experiencing visual distortions like flashing lights, or tasting a bitter flavor. Other symptoms include a rising sensation in the stomach, feelings of déjà vu or unfamiliarity (jamais vu), and sudden emotions like fear or panic. For those who experience an aura, it can provide a few moments to find a safe place before the seizure progresses.
The Ictal Phase (The Seizure Event)
The ictal phase is the period of active, uncontrolled electrical discharge in the brain. It begins with the first discernible symptom, which may be the aura, and ends when the abnormal electrical activity stops. The specific symptoms depend on whether the seizure remains focal (localized) or spreads to both hemispheres of the brain, becoming generalized.
Most seizures in this phase last between 30 seconds and two minutes, and any seizure lasting longer than five minutes is considered a medical emergency. If the seizure is generalized, it often involves a sudden loss of consciousness and muscle control, as seen in tonic-clonic seizures. This can manifest as the stiffening of limbs (tonic) followed by rhythmic jerking (clonic) movements.
In focal seizures, the person may exhibit automatisms, which are repetitive, non-purposeful behaviors like lip smacking, fumbling with clothes, or chewing. Other manifestations include brief staring spells, difficulty speaking, loss of bladder control, or a rapid heart rate. Regardless of the type, the ictal phase is characterized by the brain’s inability to regulate its electrical and chemical balance effectively.
The Postictal Phase
The postictal phase is the recovery period immediately following the seizure, representing the brain’s attempt to reset and return to normal functioning. The duration of this phase is highly variable, often lasting between five and thirty minutes, but it can extend for several hours or even days, depending on the seizure’s severity and type. This period is marked by temporary neurological deficits.
Common symptoms include deep sleepiness, confusion, and disorientation. Individuals often experience a headache, general body soreness, nausea, and thirst. A temporary weakness or paralysis in a limb, known as Todd’s paralysis, may occur and can take up to 48 hours to resolve completely. Memory of the seizure event and the immediate recovery period is often impaired during this time.