What is epilepsy?
Epilepsy is a disorder in which the electrical activity in the brain briefly becomes irregular. This abnormal electrical activity results in events called seizures. Seizures occur suddenly and usually lasts for seconds to minutes. During a seizure, a person can experience a change in behavior, body movements, and level of awareness (consciousness). There are many types of epilepsies and more than 30 types of seizures.
Who is affected by epilepsy?
About 3 million adults and 470,000 children and adolescents have been diagnosed with epilepsy in the United States, according to the Centers for Disease Control. In addition, about 150,000 individuals are diagnosed with epilepsy each year. Anyone can develop epilepsy. However, new cases of epilepsy are most common in babies age 1 and under and in seniors over age 65 (a time when other brain problems – strokes, Alzheimer’s disease, tumors – are more common and can be a cause of seizures).
What is temporal lobe epilepsy?
Temporal lobe epilepsy is the term used when seizures occur in the temporal lobe areas of the brain. You have two temporal lobes, one of each side of your head behind your temples (by your ears). The temporal lobe is the area of the brain that processes memories and sounds, interprets vision, produces speech, understands language, controls some unconscious/automatic responses such as hunger, thirst, fight-or-flight, emotions, and sexual arousal. Most cases of temporal lobe epilepsy in adults can be further localized to the middle area of the temporal lobe (called the mesial [“middle”] temporal lobe).
What causes temporal lobe epilepsy?
Causes of temporal lobe epilepsy include:
- Unknown causes (accounts for about 25 percent of temporal lobe seizures)
- Nerve cell death, which results in scarring in the temporal lobe (called mesial temporal sclerosis or hippocampal sclerosis)
- Brain injury
- Brain infection
- Brain tumor
- Brain inflammation
- Vascular malformations in the brain
- Developmental abnormalities
- Genetic factors (family history) or genetic mutations
- Strokes, heart attack, and other conditions that lead to lack of oxygen in the brain
- Alcoholism or alcohol withdrawal
What are the symptoms of temporal lobe epilepsy?
Temporal lobe epilepsy is the type of epilepsy that accounts for the most common form of seizures called focal seizures. Focal seizures are the most common form of seizure in adults and one of the most common forms of seizures in children. There are two types of focal seizures, each of which has its own distinct signs and symptoms, as follows:
Focal aware seizures (previously called simple partial seizures without loss of awareness) means that the level of consciousness does not change during the seizure; abnormal sensations may be all that occurs. The site of this seizure is localized to a small area of the temporal lobe. These seizures last from a few seconds to 2 minutes.
Signs and symptoms of focal aware seizures include:
- Déjà vu (a feeling of familiarity), a memory, or jamais vu (a feeling of unfamiliarity)
- Sudden sense of fear or anxiety, anger, sadness, joy
- A rising sick feeling in the stomach (the feeling you get in your gut riding a roller coaster)
- Altered sense of hearing, sight, smell, taste, or touch
- Visual distortions (objects are larger or smaller than they actually are)
- Difficulty speaking or inability to speak
Focal impaired awareness seizures (previously called complex partial seizures with loss of awareness) means that the level of consciousness is impaired to some degree. The person cannot interact with the surrounding environment as they normally could. The site of this seizure is a localized area but then spreads to other areas of the temporal lobe, causing the impaired awareness.
These seizures tend to have an aura before they occur. An aura is a “warning sign” that happens before this type of seizure occurs. The aura is actually considered a seizure itself – it is a focal aware seizure – that, in this case, has progressed to a focal impaired awareness seizure.
These seizures last from 30 seconds to 2 minutes.
Signs and symptoms of focal impaired awareness seizures include:
- Repetitive behaviors and movements (called automatisms) of the hands (such as fidgeting, picking motions), eyes (excessive blinking), and mouth (lip smacking, chewing, swallowing)
- Unusual speech; altered ability to respond to others
- Brief loss of ability to speak, read, or comprehend the spoken word
Other types of seizures can involve the temporal lobe. One type, called focal-to-bilateral seizures, begin in the temporal lobe and then spreads to involve both sides of the brain.