Seizures

Signs and Symptoms

A typical seizure lasts between 30 seconds and 2 minutes. They are classified into two major categories: partial and generalized onset. Generalized onset seizures begin with an electrical disturbance in a large region of the brain, whereas partial onset seizures begin in a smaller area. Although partial seizures begin in one small area, they can spread into a larger region of the brain. This is called secondary generalization.

A grand mal, or tonic clonic, seizure is one example of a generalized seizure. The person becomes rigid, has muscle jerks, and may have a number of other symptoms. Some generalized seizures, on the other hand, are not even noticeable to onlookers. A petit mal, or absence seizure, for example, often presents as rapid blinking or staring into space. This is often just written off as daydreaming.

Caused by excess electrical discharge in the brain (scan above), seizures are most prevalent in the very old and very young.

Someone with a simple partial seizure has symptoms depending on the location of the excess electrical discharge, the focus. These people can have a change in muscle activity, alterations in taste or smell, feelings of intense anxiety or fear, or a number of other symptoms. Following the seizure, people experience headache, amnesia for the event, fatigue, and muscle aches.

In epilepsy, an aura may precede the seizure. An aura is a set of symptoms that warn of an upcoming seizure. Common examples include the feeling of déjÀ-vu, numbness in one side of the body, and hallucinations such as imagining strange sights, smells or sounds. An aura is not present in all epileptic seizures.

Status epilepticus is continuous seizure activity for 30 minutes, or two or more sequential seizures without full recovery of consciousness between the two. This is a true medical emergency.

Diagnosis

When someone first presents with a seizure, a physician will take a history and perform a physical exam. It can be difficult for a physician to differentiate a seizure from syncope, a loss of consciousness due to lack of oxygen to the brain. Therefore, a good history from the patient and a witness is the most [Page 1530]important part of determining the etiology of a loss of consciousness. The physician may order an electrocardiogram (EKG), electroencephalogram (EEG), magnetic resonance imaging (MRI), or a computed tomography (CT) scan to further help determine the cause of the episode. The EKG and EEG test the electrical activity in the heart and brain, respectively. The MRI and CT scans are both tests that take pictures of the brain.

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