Seizures

Seizures: Sudden "malfunction" in the brain's electrical system

Seizures are a sudden, uncontrolled surge of electrical activity in the brain that temporarily disrupts its normal functioning. They can manifest as abrupt movements, changes in consciousness, sensations, or behavior. It is important to understand that seizures are a symptom, not a disease. Epilepsy is a disorder characterized by a tendency toward recurrent, unprovoked seizure attacks. A single seizure does not mean the person has epilepsy.

What happens in the brain during a seizure?

Neurons (nerve cells) in our brain communicate with each other via electrical and chemical signals. This activity is orderly and balanced. A seizure occurs when a large group of neurons suddenly begins generating excessive, synchronized electrical discharges. It is akin to an "electrical storm" or "short circuit" in the brain. How the seizure appears depends on which brain region is involved in this abnormal activity.

Types of seizure attacks

Seizures are divided into two major groups:

• Focal (partial) seizures: Abnormal activity starts in a specific brain area. Symptoms depend on the function of that area. The person may remain conscious, experiencing strange smells, twitching of one hand, or sudden fear.
• Generalized seizures: Abnormal activity immediately involves both cerebral hemispheres. They are always accompanied by loss of consciousness. The most well‑known type is the tonic‑clonic seizure, but there are others, such as absence seizures ("blanking out").

Causes of seizures

Causes can be varied and depend on age.

• Provoked seizures: Occur in response to temporary stress on the brain.
  • Febrile seizures: The most common cause in children, triggered by high fever.
  • Metabolic disturbances: Sudden drop in blood sugar or sodium levels.
  • Head injuries, infections (meningitis), stroke.
• Unprovoked seizures: Occur without an obvious cause and may be a sign of epilepsy.

It is important to distinguish seizures from fainting, which has a different mechanism.