Epilepsy is characterized by unprovoked, recurring seizures that disrupt the nervous system and can cause mental and physical dysfunction. In the U.S., about 2.5 million people are affected by epilepsy and seizures. About 10% of the American population will experience at least one seizure during their lifetime. he structures of the brain include: the brainstem, consisting of the spinal cord, the medulla oblongata, the pons and the midbrain; the cerebellum; the cerebrum (one half, or hemisphere shown), and the diencephalon. Epilepsy affects all age groups. Males have a slightly higher risk than females. The incidence is highest in children with another, but lesser, peak occurring after age 60. According to one estimate, 14% of epilepsy patients are under 15 years old and about 25% are over age 64.

Every year, 25,000 – 40,000 American children have a first seizure that is unrelated to a fever. Epilepsy is decreasing in childhood but increasing in the elderly, probably because of mild strokes and cardiac arrest.

Varieties of Epilepsy

There are several forms of epilepsy. Most people will have seen someone suffer a major epileptic seizure, suddenly losing consciousness, jerking the arms and legs, etc. But there are other types of epilepsy – for example, one common form of epilepsy in children merely consists of staring blankly and losing contact with the surroundings for a few seconds.

What is a seizure?

The best available classification of seizures is that proposed by the International League Against Epilepsy (”seizure” is an alternative term for “epileptic attack”).

It starts by dividing seizures into partial seizures, where the abnormal electrical discharge originates from one specific area of the brain, and generalised seizures, where the whole brain is involved. What makes it a little confusing is that a partial seizure may occasionally go on to become generalised, if the epileptic discharge originating in one area of the brain is strong enough to then spread to the whole brain. However, even if the situation of a partial seizure progressing to become generalised, with complete loss of consciousness, convulsions, etc., the initial symptoms will be prominent, and will distinguish it from other forms of generalised epilepsy, where the whole brain is involved from the outset.

How long does a seizures last?

Depending on the type of seizure, they can last anywhere from a few seconds to several minutes. In rare cases, seizures can last many hours. For example, a tonic-clonic seizure typically lasts 1-7 minutes. Absence seizures may only last a few seconds, while complex partial seizures range from 30 seconds to 2-3 minutes. “Status Epilepticus” refers to prolonged seizures that can last for many hours, and this can be a serious medical condition. In most cases, however, seizures are fairly short and little first aid is required.

 

Partial Seizures

Partial, or focal, seizure is the more common type of epilepsy, and is generally defined as a disorder of neurons that starts on one side of the brain. The seizures are currently subcategorized as “simple” or “complex partial.”

• Simple Partial Seizures. A person with a simple partial seizure (sometimes known as Jacksonian epilepsy) does not lose consciousness, but may experience confusion, jerking movements, tingling, or odd mental and emotional events. Such events may include deja vu, mild hallucinations, or extreme responses to smell and taste. After the seizure, the patient usually has temporary weakness in certain muscles.
• Complex Partial Seizures. Slightly over half of seizures in adults are complex partial type. About 80% of these seizures originate in the temporal lobe, the part of the brain located close to the ear. Disturbances there can result in loss of judgment, involuntary or uncontrolled behavior, or even loss of consciousness. About 20% of these patients have seizures that start in the brain’s frontal lobes. Prior to the actual seizure, people sometimes experience a warning sign, known as an aura, which can be a visual or auditory hallucination, an odd odor or a feeling of warmth. They may lose consciousness briefly and appear to others as motionless with a vacant stare. Emotions can be exaggerated; some sufferers even appear to be drunk. After a few seconds, a patient may begin to perform repetitive movements, such as chewing or smacking of lips. Episodes usually last no more than 2 minutes. They may occur infrequently, or as often as every day. A throbbing headache may follow a complex partial seizure.

In some cases, simple or complex partial seizures evolve into what are known as secondarily generalized seizures. The progress may be so rapid that the partial stage is not even noticed.

While the term “partial” implies the seizures affect only small or specific brain locations, in reality, they almost always involve diffuse and even widespread areas. In the future, the term “focal seizures” will most likely replace the term “partial seizures,” and its subcategories. Until new classifications are more widely in use, this report will continue to use the term “partial seizures” and its subcategories.