Temporal Lobe Epilepsy (TLE)

What is temporal lobe epilepsy?

Temporal lobe epilepsy (TLE) is a type of epilepsy where seizures begin in the temporal lobe. Seizures are the result of abnormal electrical activity in your brain. You have two temporal lobes, one on each side of your brain. These are located behind your temple and extend from your eye to your ear.

Your temporal lobe is the part of your brain that helps you to make sense of the world around you. It manages:

• Memories
• Sounds
• Vision
• Speech and language

It’s also involved in some unconscious or automatic responses, such as hunger, thirst, fight-or-flight response, emotions and sexual arousal.

Temporal lobe epilepsy is the most common type of focal epilepsy. Seizures are the main symptom of TLE. A healthcare provider can help you manage them and other issues that this condition can cause.

Left vs. right temporal lobe epilepsy

The left and right temporal lobes share many of the same functions, like memory, sounds, vision and speech. The location of where a seizure starts may affect these functions.

The left temporal lobe is usually the dominant lobe in most people, especially if you’re right-handed. People who have left temporal lobe epilepsy, over time, may have difficulty with naming objects, knowing what words to use and changing moods.

People with right temporal lobe epilepsy typically have fewer long-term memory changes, but they may still notice changes in their ability to memorize nonverbal information (particularly visual information), as well as changes in their mood.

What are the types of temporal lobe epilepsy?

There are two types of TLE:

• Mesial temporal lobe epilepsy (MTLE). “Mesial” means middle. Seizures start in or near a structure called the hippocampus. You have a hippocampus in the middle of each temporal lobe. MTLE is the most common type.
• Neocortical or lateral temporal lobe epilepsy. Seizures start in the outer section of your temporal lobe.

What are the symptoms of temporal lobe epilepsy?

Temporal lobe epilepsy symptoms can include an epileptic aura (an unusual sensation you feel before a seizure) and the seizure itself.

Symptoms of epileptic auras may 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 (like the feeling you get in your gut when riding a roller coaster)
• Stronger senses (hearing, sight, smell, taste or touch)

Not everyone experiences an aura. An aura is also described as a focal-aware seizure, meaning you’re awake and aware while the symptoms occur. They typically last from a few seconds to two minutes.

Other seizure symptoms can follow the aura. You may experience signs and symptoms including:

• Loss of consciousness
• A blank stare
• Dilated pupils
• Repetitive non-purposeful behaviors and movements (automatisms) of your hands (fidgeting, picking motions), eyes (excessive blinking) and mouth (lip-smacking, chewing, swallowing)
• Confusion
• Brief loss of ability to speak or understand language (aphasia)
• Stiffening and jerking of your body

What causes temporal lobe epilepsy?

Neurons (nerve cells) miscommunicating in your temporal lobe cause temporal lobe epilepsy. Neurons send electrical signals to different parts of your brain. When a seizure happens, neurons uncontrollably fire off signals instead of directing them to where they need to go.

Some of the most common causes of temporal lobe epilepsy include:

• Hippocampal sclerosis (neuron and glial cell loss in the hippocampus)
• Focal cortical dysplasia (abnormal collection of neurons)
• Brain tumors
• Traumatic brain injury
• Infections (brain abscess, meningitis, encephalitis)
• Vascular conditions (strokes, arteriovenous malformations)
• Genetic variants
• Unknown causes

What are the risk factors for temporal lobe epilepsy?

TLE can affect anyone at any age. You may be more at risk of this condition if you:

• Had a febrile seizure in childhood
• Had a seizure that lasted longer than five minutes or back-to-back seizures without regaining awareness in between each one (status epilepticus)
• Have a condition like a birth defect or a tumor
• Had a traumatic brain injury or brain infection early in life
• Have a family history of temporal lobe epilepsy

Two out of three people who have TLE experienced febrile seizures as an infant. Many of these were complex (prolonged seizures). However, it’s rare to develop TLE after having a febrile seizure.

What are the complications of temporal lobe epilepsy?

There’s a risk of irreversible neurocognitive decline with TLE. Neurocognitive decline means it becomes harder for you to learn, remember, make decisions or focus.

The more seizures you have and the longer you have them, the greater your risk of:

• Depression
• Anxiety
• Memory loss
• Sudden unexplained death in epilepsy (SUDEP)

A healthcare provider can help you treat TLE to prevent complications.

How is temporal lobe epilepsy diagnosed?

A healthcare provider will diagnose temporal lobe epilepsy after reviewing your symptoms, getting a seizure history, performing a neurological examination and ordering tests. Your provider will learn more about your seizure history and ask you questions about what happened before and after the seizure. Your provider will also review your medical history.

You may not remember what happens when you have a seizure. If you aren’t sure, ask someone who was with you when you had a seizure to come with you to your appointment. They can tell your provider what they noticed.

Testing helps your provider see what’s going on inside of your brain. Tests may include:

• MRI
• EEG or video-EEG monitoring
• SPECT
• PET
• MEG
• Neuropsychological testing

How is temporal lobe epilepsy treated?

Treatment for temporal lobe epilepsy may include:

• Antiseizure medications
• Epilepsy surgery
• Neurostimulation

Your provider may also recommend that you change some of the foods you eat to help you manage seizures in addition to other treatments. For example, they may recommend the ketogenic diet. This is a meal plan high in fat and low in carbohydrates.

Medications to treat temporal lobe epilepsy

Many antiseizure medications are available to treat temporal lobe seizures, including:

• Brivaracetam
• Cenobamate
• Carbamazepine
• Gabapentin
• Lamotrigine
• Lacosamide
• Levetiracetam
• Oxcarbazepine
• Pregabalin
• Rufinamide
• Topiramate
• Valproate
• Zonisamide

Your healthcare provider might try one or more medications and different dosages to find what works best for you.

Some antiseizure medications may cause birth defects, so be sure to tell your provider if you’re pregnant or if you plan to become pregnant.

Temporal lobe epilepsy surgery

Your healthcare provider may consider surgery if antiseizure medications aren’t successful or if a tumor causes epilepsy symptoms.

A temporal lobectomy (removal of part of your temporal lobe) is the most common type of surgery. As your temporal lobe has a lot of responsibilities, your neurosurgeon will carefully plan the procedure to avoid complications that may affect brain function.

Two less invasive procedures are stereotactic radiosurgery and laser ablation. These techniques use lasers or radiation to destroy nerve cells or tissue in the section of your temporal lobe where seizures start.

Temporal lobe epilepsy neurostimulation

Neurostimulation devices may be an option if medications aren’t successful or surgery isn’t a safe option. Neurostimulation uses an implanted device to deliver an electrical impulse to your temporal lobe. This treatment gradually reduces seizures over time. Common types of devices for neuromodulation used in TLE may include:

• Vagus nerve stimulation
• Responsive neurostimulation
• Deep brain stimulation

What’s the outlook for temporal lobe epilepsy?

Your outlook varies based on:

• How many seizures you have
• How long you’ve had seizures
• Your general health
• Whether irreversible complications started

Many people find success in managing seizures with medications. Some people report being seizure-free after surgery. Your healthcare provider can give you the most accurate information about what this looks like, as it’s very different for each person.

When should I see a healthcare provider?

If you’ve had a seizure or think you might’ve had a seizure, you should see a healthcare provider.

If you have a temporal lobe epilepsy diagnosis, call your provider if:

• Your seizure lasts longer than five minutes.
• A second seizure immediately follows the first.
• The number and severity of your seizures increase.
• You experience new symptoms or side effects.
• Your recovery after your seizure is slower than usual or not complete.

What questions should I ask my healthcare provider?

If you have TLE, you may want to ask your provider:

• What type of treatment do you recommend?
• Are there side effects of treatment?
• Is this antiseizure medication safe if I want to start a family?
• Am I a candidate for epilepsy surgery?