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).
Symptoms and Causes
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.
Diagnosis and Tests
How is temporal lobe epilepsy diagnosed?
Your doctor will ask questions about your medical history and about your seizures – how long they lasted; what you felt before, during, and after the seizure; where you were and what happened before the seizure started, and if something seemed to trigger the seizure (examples of triggers include stress, lack of sleep, flashing lights, intense exercise, and loud music). The doctor might also want to talk to people who were with you during a seizure to gather their observations.
Tests that are used in diagnosing epilepsy include an MRI (magnetic resonance imaging) to look for tumors or other structural problems in the brain and an EEG (electroencephalogram), which measures electric activity in the brain. Other brain scanning tests include:
- A single photon emission computed tomography (SPECT), which shows blood flow to the brain to help locate the site of the seizure.
- An ictal SPECT, which locates the area(s) of the brain where seizures are occurring.
- A positive emission tomography (PET) scan, which looks at brain metabolism to identify where seizures start.
Blood samples are also taken to screen for genetic disorders or other health conditions that could be causing the seizures.
Management and Treatment
How is temporal lobe epilepsy treated?
Treatments for temporal lobe epilepsy includes medications, diet, surgery, laser, and electrical brain stimulator devices.
- Medications. Many medications are available to treat people who have temporal lobe seizures. Your doctors might try one or more drugs and different dosages over a period of months to find the approach that is best for you.
- Diet. Another treatment approach is a very specific change in diet. The ketogenic diet, which is a diet high in fat and very low in carbohydrates, is sometimes tried in patients in whom medications were not successful in controlling seizures.
- Surgery. Surgery is considered in patients with temporal lobe seizures only after several attempts of medication have failed or a tumor or lesion responsible for the seizures has been identified. The most common surgery for epilepsy is a temporal lobectomy, which is the removal of a portion of the temporal lobe.
- Laser ablation. In this procedure, surgeons use magnetic resonance imaging (MRI) to guide the use of a laser. The laser is directed at scar tissue in the temporal lobe region that is causing seizures. The laser uses heat to destroy the tissue that is causing the seizures.
- Electrical brain stimulators. If two or more medications have not adequately controlled seizures and surgery is not an option, another option is nerve stimulation devices. These devices work in much the same way as a heart pacemaker monitors and responds to abnormal heart rhythms. One such device, called a vagus nerve stimulator, is implanted under the skin of the chest wall and is attached to the vagus nerve in the neck. The stimulator delivers brief intermittent electrical bursts to the brain to reduce seizure development. Another type of stimulator, called a responsive neurostimulation device, monitors brain wave activity and delivers an electrical burst to stop or shorten a seizure or possibly prevent it from developing. This device is implanted in the skull under the scalp. Other neurostimulator devices are also under development.
How can I reduce the chance that I will have temporal lobe seizures?
There are no medications or treatments to prevent epilepsy. However, because some seizures develop from other health events – for example, as a result of brain injuries, heart attacks and strokes – you can take some precautions to reduce your risk of developing seizures. Don’t smoke. Get some exercise. Fasten your seat belt. Wear that helmet. Think about what you eat.
Outlook / Prognosis
What is the outlook for patients with temporal lobe epilepsy?
Most patients with epilepsy can enjoy successful and productive lives. Medication is successful in controlling seizures in about two-thirds of patients with temporal lobe epilepsy. For the other third, surgery helps about 70 percent of patients become seizure free. If surgery doesn’t work or if the patient is not a candidate for surgery, electrical brain stimulation devices can be tried.
In rare cases, epilepsy can be fatal. About one in 1,000 people with epilepsy die each year from what is called Sudden Unexpected Death in Epilepsy (SUDEP). The cause is not known, but having a lot of seizures increases the risk. It’s more common in adults than children. Another way seizures can lead to death or serious injury is by causing a person to have an accident while driving or operating heavy equipment.
When should I see a doctor?
If you’ve had a seizure or think you might have had a seizure, you should see a doctor.
If you have already been diagnosed with temporal lobe seizures, call your doctor if:
- The number and severity of the seizures increases.
- You experience new symptoms.
- You develop a blistering skin rash or other new side effects.
What should I do if I’m with somebody who is having a seizure?
Stay with the person who is having the seizure and pay attention to exactly what is happening and how long it lasts. Don’t hold the person down, but try to keep him or her away from dangerous situations and move nearby objects out of the way. Speak calmly to the person who is having the seizure, during the seizure and afterward. Don’t put anything in her or his mouth. Do what you can to keep the person comfortable, during and after the seizure.
You should call 911 if the seizure lasts longer than five minutes -- or, if you’re familiar with the person’s seizure history, if the seizure lasts significantly longer than usual. If you think it’s his or her first seizure, call 911. Also call 911 if the person has another seizure right after the first one ends, is injured during the seizure, is having trouble breathing, or asks you to get medical help.