Temporal Lobe Epilepsy (TLE)
What is temporal lobe epilepsy?
Temporal lobe epilepsy (TLE) is epilepsy that starts in the temporal lobe area of your brain. You have two temporal lobes, one on each side of your head behind your temples (by your ears and in alignment with your eyes).
TLE is the most common localized (also called “focal”) type of epilepsy. About 60% of people with focal epilepsy have TLE.
There are two types of TLE.
- Mesial (“near the middle”) temporal lobe epilepsy (MTLE). About 80% of all temporal lobe seizures start in the mesial temporal lobe, with seizures often starting in or near a structure called the hippocampus. You have a hippocampus in each temporal lobe, which control memory and learning. MTLE is the most common form of epilepsy.
- Neocortical or lateral TLE. In this type of TLE, seizures start in the outer section of your temporal lobe. This type of TLE is very rare and mostly due to a genetic cause or lesions such as a tumor, birth defect, blood vessel abnormality or other abnormalities in the temporal lobe.
What brain functions are controlled by the temporal lobe?
Your temporal lobe processes memories and sounds, interprets vision and governs speech and language. It’s also involved in some unconscious/automatic responses such as hunger, thirst, fight-or-flight, emotions and sexual arousal.
Your right and left temporal lobes differ in their functions. One or more functions may be affected depending on the exact location where the seizure starts in your temporal lobe. Right temporal lobe epilepsy may affect such functions as learning and memorizing nonverbal information (such as music and drawings), recognizing information and determining facial expressions. Your left temporal lobe is usually the dominant lobe in most people. Left temporal lobe epilepsy may affect your ability to understand language, learn, memorize, form speech and remember verbal information.
Who does temporal lobe epilepsy affect?
Anyone, of any race or sex, can develop epilepsy. Temporal lobe epilepsy usually begins between 10 and 20 years of age, although it can start at any age.
Who is at risk for temporal lobe epilepsy?
Factors that can lead to an increased risk of developing temporal lobe epilepsy (TLE) include:
- Having a long seizure (status epilepticus) or a seizure that results from a high fever (febrile seizure). Some 66% of people who have TLE have a history of febrile seizures, which usually occur in childhood. However, most people who have febrile seizures don’t develop TLE.
- Having structural problems in your temporal lobe, such as a tumor or brain malformation.
- Having a brain injury that happened early in life, including head trauma with loss of consciousness, brain infections (such as meningitis) or birth injury to your brain.
How common is temporal lobe epilepsy?
Temporal lobe epilepsy is the most common seizure disorder, affecting about 50 million people worldwide. Temporal lobe epilepsy can account for about 40% of people with epilepsy seen in a busy epilepsy center.
Symptoms and Causes
What are the symptoms of temporal lobe epilepsy?
Symptoms depend on how your seizure begins.
You may have an aura before a temporal lobe seizure. An aura is an unusual sensation that you feel before a seizure starts. Not everyone experiences an aura. An aura is a part of a focal aware seizure, meaning you’re awake and aware while the symptoms occur. They typically last from a few seconds to two minutes.
Sensations you may feel during an aura include:
- Déjà vu (a feeling of familiarity), a memory or jamais vu (a feeling of unfamiliarity).
- A sudden sense of fear, panic or anxiety; anger, sadness or joy.
- A rising sick feeling in your stomach (the feeling you get in your gut riding a roller coaster).
- Altered sense of hearing, sight, smell, taste or touch.
Sometimes, temporal lobe seizures progress to another type of seizure, such as a focal impaired awareness seizure. During this seizure, you lose some degree of awareness for typically 30 seconds to 2 minutes.
Symptoms of focal impaired awareness seizures include:
- “Staring into space” or a blank stare.
- Repetitive behaviors and movements (called automatisms) of your hands (such as fidgeting, picking motions), eyes (excessive blinking) and mouth (lip-smacking, chewing, swallowing).
- Unusual speech; altered ability to respond and communicate with others.
- Brief loss of ability to speak, read or comprehend speech.
In rare cases, a temporal lobe seizure can develop into a generalized tonic-clonic seizure. During a generalized tonic-clonic seizure, there’s stiffening and shaking of your entire body with loss of awareness. Sometimes, there’s loss of bladder control or biting of your tongue with these seizures. This seizure affects both sides of your brain and is also called a convulsion. It used to be known as a grand mal seizure.
What causes temporal lobe epilepsy?
Causes of temporal lobe epilepsy include:
- Unknown causes (accounts for about 25% of temporal lobe seizures).
- Injury to brain cells, which results in scarring in the temporal lobe (called mesial temporal sclerosis or hippocampal sclerosis).
- Brain abnormalities present at the time of birth, including hamartomas and malformation of cortical development.
- Brain injury from such things as vehicular accidents, falls or any blow to the head.
- Brain infections, including brain abscess, meningitis, encephalitis and acquired immune deficiency syndrome (AIDS).
- Brain conditions and brain vessel abnormalities, including brain tumors, strokes, dementia and abnormal blood vessels, such as arteriovenous malformations.
- Genetic factors (family history) or genetic mutations.
What are the complications of having temporal lobe epilepsy?
Epilepsy can be life-threatening in a couple of situations:
- Sudden unexplained death in epilepsy (SUDEP). About 1 in 1,000 people with epilepsy die each year from SUDEP. The cause isn’t known, but having a lot of seizures that are unable to be controlled increases the risk. It’s more common in adults than children.
- Status epilepticus. This is a long-lasting (5 minutes up to 30 minutes) seizure or seizures that occur close together without recovery between them. It’s considered a medical emergency. Call 911 or get immediate medical care if this occurs.
Diagnosis and Tests
How is temporal lobe epilepsy diagnosed?
Your healthcare provider will ask questions about your medical history and 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). Your healthcare provider might also want to talk to people who were with you during a seizure to gather their observations. It can be helpful to have someone videotape your seizure to show your healthcare provider and to keep a diary of when your seizures occur.
What tests will be done?
Tests that are used in diagnosing temporal lobe epilepsy include:
- MRI (magnetic resonance imaging): An MRI looks for tumors or other structural problems in your brain. A common finding is scar tissue in the hippocampus (hippocampal sclerosis). This appears as shrunken tissue on the MRI.
- EEG (electroencephalogram): An EEG measures the electric activity in your brain. Certain abnormal electrical patterns are related to seizures.
- Video EEG: This is a longer version of the regular EEG. You’re admitted to the hospital for several days. Your antiseizure medications are stopped. This test captures your seizures on the EEG while the video captures your movements during the seizures. Together, the information helps identify where your seizures are starting and how they affect your functioning.
- SPECT: A single-photon emission computed tomography (SPECT) shows increased blood flow to the areas of your brain where the seizure begins.
- Ictal SPECT: An ictal SPECT locates the area(s) of your brain where seizures are occurring.
- PET scan: A positive emission tomography (PET) scan looks at brain metabolism to identify where your seizures started.
- Magnetoencephalography (MEG): This test records and evaluates your brain while it’s actively functioning, pinpointing abnormal changes in your brain.
- Stereoelectroencephalography (SEEG): This test involves placing electrodes at different depths in your brain in the area of interest to create a 3D view of the site of the seizure.
- Neuropsychological testing: Neuropsychological tests assess your verbal skills, memory function and other learning skills. This test serves as a baseline for measuring and comparing any changes before and after surgery.
Management and Treatment
How is temporal lobe epilepsy treated?
Treatments for temporal lobe epilepsy include medications, diet, surgery, laser and electrical brain stimulator devices.
Many medications are available to treat temporal lobe seizures. Your healthcare provider might try one or more medications and different dosages over months to find the approach that’s best for you. Up to two-thirds of people with temporal lobe epilepsy have their seizures controlled with medications.
Because some antiseizure medications are linked to birth defects, let your healthcare provider know if you’re pregnant or planning to become pregnant.
Another treatment approach is a very specific change in diet. The ketogenic diet is a diet high in fat and very low in carbohydrates. It’s sometimes tried if medications aren’t successful in controlling your seizures.
Surgery is considered only after several attempts of medication have failed or a tumor or lesion responsible for the seizures has been identified. If an MRI shows hippocampal sclerosis in the medial temporal lobe and EEGs show seizure activity starts in that area, surgery may cure your seizures. Temporal lobectomy (removal of your temporal lobe) is the most common type of lobectomy and the most common surgery for epilepsy.
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’s causing seizures. The laser uses heat to destroy the tissue that’s causing the seizures.
This surgery involves using 3D computerized imaging and precisely focused radiation beams to destroy the nerve cells that are misfiring and causing the seizures.
Electrical brain stimulators
If two or more medications have not adequately controlled seizures and surgery isn’t an option, another option is nerve stimulation devices. These devices work in much the same way as a heart pacemaker monitors and respond to abnormal heart rhythms. There are three types of stimulators.
- Vagus nerve stimulator: This stimulator is implanted under the skin of your chest wall and electrical lead wires are placed around the vagus nerve in your neck. Your vagus nerve starts in the lower area of your brain and travels down to the abdomen. The stimulator delivers scheduled brief intermittent electrical bursts to the brain to reduce seizure development.
- Responsive neurostimulation device: This 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 your skull under your scalp.
- Deep brain stimulation device: This surgery involves implanting an electrode into your brain and placing a stimulator device under your skin in your chest. The electrode wire, guided by MRI, is placed in an area of your brain where seizures are occurring. The stimulator device sends signals to the electrode to block signals from nerve cells that trigger a seizure.
How can I reduce the chance that I will have temporal lobe seizures?
No medications or treatments can 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.
- To lower your risk of traumatic brain injury (from blows to your head), always wear your seatbelt when driving and drive “defensively”; wear a helmet when biking; clear your floors of clutter and power cords to prevent falls and stay off ladders.
- To lower your risk of stroke, eat a healthy diet (such as the Mediterranean diet), maintain a healthy weight, exercise regularly and don’t smoke.
Outlook / Prognosis
What is the outlook if I have temporal lobe epilepsy?
The more seizures you have and the longer you have them, the greater your risk of a decreased quality of life, depression, anxiety and memory impairment.
Medication is successful in controlling seizures in about two-thirds of people with temporal lobe epilepsy. For the other third, surgery helps about 70% become seizure-free.
Medication isn’t successful in controlling seizures in about 75% of people who have mesial temporal lobe epilepsy. However, 75% of these individuals are seizure-free following surgery.
If surgery doesn’t work or if you’re not a candidate for surgery, electrical brain stimulation devices can be tried.
When should I see a doctor?
If you’ve had a seizure or think you might’ve had a seizure, you should see your healthcare provider. If you have already been diagnosed with temporal lobe seizures, call your healthcare provider or seizure specialist if:
- Your seizure lasts longer than 5 minutes.
- A second seizure immediately follows the first.
- The number and severity of your seizures increase.
- You experience new symptoms.
- You develop a blistering skin rash or other new side effects.
- Your recovery after your seizure is slower than usual or not complete.
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 them 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 their mouth. Do what you can to keep the person comfortable, during and after the seizure.
Call 911 if the seizure lasts longer than 5 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 their 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.
A note from Cleveland Clinic
If you have temporal lobe epilepsy (TLE), becoming seizure-free is the goal. Seeing your healthcare provider at the first sign of seizures leads to early diagnosis, treatment and the best outcomes. Medications control seizures in most people with TLE. If you have mesial TLE, 75% of people become seizure-free after surgery. The key to the successful management of TLE is great communication between you and your healthcare provider. Make sure you understand all the benefits and risks of all your treatment options, the complications of uncontrolled seizures and possible adverse effects of medications. Ask your healthcare provider about support groups, too.
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