Epilepsy Symptoms & Causes

Epilepsy: How Seizures Affect the Body

The brain is the “control center” of the body. It manages everything from movement and balance to emotions and memory. When a seizure occurs, some or all brain functions are affected.

The brain uses electrical signals to send messages throughout the body. Signals sent from different parts of the brain control different body functions. For instance, one part of the brain controls balance. Another part controls speech. A doctor can record brain signals using a test called an EEG (electroencephalogram).

During a seizure, excessive electrical signals in the brain disrupt its normal activity. How this affects body functions depends on two main factors. First is the location of the seizure. For instance, a seizure in a part of the brain that controls movement might cause an arm or leg to jerk. Second is the type of seizure. For instance, a seizure that affects more of the brain may affect more of the body.

Seizures, absence

Absence seizures are benign, generalized seizures thought to originate subcortically. These brief episodes of unconsciousness usually last 3 to 20 seconds and can occur 100 or more times per day, causing periods of inattention. Absence seizures usually begin between ages 4 and 12. Their first sign may be deteriorating school work and behavior. The cause of these seizures is unknown.

Absence seizures occur without warning. The patient suddenly stops all purposeful activity and stares blankly ahead, as if he were daydreaming. Absence seizures may produce automatisms, such as repetitive lip smacking, or mild clonic or myoclonic movements, including mild jerking of the eyelids. The patient may drop an object that he’s holding, and muscle relaxation may cause him to drop his head or arms or to slump. After the attack, the patient resumes activity, typically unaware of the episode.