Temporal lobe epilepsy (TLE) is a type of focal epilepsy where the seizures originate in the temporal lobe of the brain. Approximately 60 percent of all forms of epilepsy are focal in origin, with the majority originating in the temporal lobe.
The seizures are called focal seizures, or focal onset seizures. Sometimes focal seizures can evolve into a convulsive (tonic clonic) seizure which is then termed focal to bilateral seizure.
Figure 1 Temporal Lobe from: https://commons.wikimedia.org/wiki/File:Temporal_lobe_-_lateral_view.png
The temporal lobes
The temporal lobes sit at each side of the head, behind the ears. They are most commonly associated with memory function and also processing language, sound, emotions and visual recognition.
Damage to the temporal lobes can cause problems such as:
- Difficulty in understanding spoken words
- Difficulty learning and retaining new information
- Memory difficulties
- Disturbance with selective attention to what we see and hear (focus)
- Persistent talking
- Difficulty in recognising faces
- Increased or decreased interest in sexual behaviour
- Emotional disturbance
Types of TLE
TLE can be divided into two types:
- Mesial temporal lobe epilepsy (mTLE) is the most common and involves the inner structures of the temporal lobe. Seizures often begin in the region of the temporal lobe called the hippocampus or amygdala. Scarring or hardening of the hippocampus is the most frequent cause of mTLE
- Lateral temporal lobe epilepsy is when the seizures begin in the outer part of the temporal lobe.
People with TLE can have a poor response to antiseizure medication and should be considered for surgical assessment if this is the case. Surgery to remove the area causing the seizures is a possible option for many people with TLE.
Seizure types
While TLE seizures primarily have focal seizures. These can vary greatly between individuals. They are broken down into two groups:
- when awareness is retained – focal aware seizure, and
- when awareness is impaired – focal impaired awareness seizure.
Note: Any focal seizure can spread to both hemispheres of the brain and become a tonic clonic seizure. This is called a focal to bilateral tonic-clonic seizure.
Symptoms of temporal lobe seizures can include the following:
- Focal aware seizures: often referred to as “auras,” where the person is conscious (aware) and will know that something is happening and will remember the seizure afterwards. Sometimes they may not be able to move or communicate during the seizure, but they are aware of what is happening.
Symptoms can include:
- Focal sensory seizure– numbness, tingling or burning sensation in a region of the body, unusual smell or taste, dizziness, feeling hot or cold
- Focal motor seizure – jerking of a limb, twitching of the face, weakness or paralysis of a muscle group
- Focal autonomic seizure – blushing, pallor, heart-rate changes or palpitations, nausea
- Focal emotional seizure – changes in mood or emotion such as fear, panic, laughing, crying
- Focal cognitive seizure – unable to speak, speech difficulty, déjà vu, visual hallucinations, hearing sounds
- Focal behaviour arrest seizure – the person will just “freeze” and appear unable to move or talk
Remember, the person knows these seizures are happening and may not even consider them as a seizure, but merely as a warning of an impending seizure. What causes these symptoms though is seizure activity in a small region of the brain. Approximately 70% of focal aware seizures progress into a focal impaired awareness seizure.
- Focal impaired awareness seizures: this is when there is a loss of awareness for some or all of the seizure. The person’s awareness is diminished, and they may be confused, may or may not be able to hear you, and not fully understand what you say or be able to respond appropriately. Often, they lose memory for some or all the seizure.
Symptoms vary but can include;
- blank staring, disorientation or confusion, not responding appropriately, chewing or lip smacking, picking at clothes, fumbling, repetitive movements, unusual vocalisation or unable to speak, becoming unaware of surroundings, and wandering.
Sometimes these seizures are very subtle and not recognised as a seizure by onlookers, and other times they are mistaken for intoxication or psychiatric illness. This seizure type may be preceded by a focal aware seizure.
- Both these seizure types can progress into a focal to bilateral tonic clonic seizure if they seizure activity spreads to both hemispheres of the brain.
Who gets TLE?
Anyone of any age can develop TLE. Common risk factors that lead to developing TLE include:
- Brain injury
- Brain infections
- Brain abnormalities present at birth
- Brain tumours
- Genetic factors
- Unknown cause
Sometimes seizures may not happen immediately after damage to the brain. Scar tissue can develop because of the brain injury or infection and seizures may start months or years afterwards.
How is TLE treated?
Medication: Many people with TLE gain seizure control with anti-seizure medication, but about 1 in 3 may not respond well to medication and continue to have seizures.
Poorly controlled seizures can significantly affect quality of life. People commonly report problems with memory, moods – primarily anxiety and depression, social isolation and difficulties getting or maintaining work.
If you’ve tried many medications, yet continue to have seizures, talk to your doctor or about other treatment options available that may help you. You may need a referral to a comprehensive epilepsy centre to investigate further options.
Surgery: If seizures fail to respond to medication, then epilepsy surgery may be an option.
Early surgical assessment and intervention has a good success rate and also benefits through improvements in quality of life. Epilepsy surgery is only suitable for a small number of people with drug resistant epilepsy, but fortunately TLE is one type of epilepsy that is often successfully treated with surgery.
Depending on the individual circumstances, up to 7 out of 10 people can be seizure-free after epilepsy surgery.
Listen here to neurosurgeon Dr Erica Jacobsen answer questions about epilepsy surgery.
Neuromodulation: For people where epilepsy surgery is not possible, other options such as neuromodulation – vagus nerve stimulation (VNS), deep brain stimulation (DBS) – is available for consideration. This can lead to fewer and shorter seizures, and better recovery after seizures.
For more about treatment options, click here
Lifestyle choices
Your lifestyle choices can affect seizure control. Important ways you can help improve seizure control are:
- Taking medications as prescribed
- Avoiding seizure triggers when possible
- Getting enough sleep
- Managing stress
- Eat well and exercise
- Avoid or limit alcohol intake.
For more information see our Self-Management Factsheet
Online Support Networks: connect with others living with epilepsy
Seizure First Aid: How to assist someone during a seizure safely.
