Introduction

What is TLE? 

Epilepsy is a chronic disorder of the brain that affects up to 50 million people across the world.¹ The exact cause for approximately 50% of people who have epilepsy is still unknown.¹ This can be put down to the fact that there are numerous different types of epilepsy, all of which vary in severity and origin, as well as this, the list of known causes is ever-growing. Temporal lobe epilepsy (TLE) is a type of epilepsy that originates in the temporal lobe of the brain, and it is one of the most common forms of the disorder. 

The primary symptom of epilepsy is recurrent, unprovoked seizures, which can cause a variety of different behaviours. Seizures are induced by abnormal electrical activity within the brain and can result in an inability to feel, behave, or remember correctly. Additionally, they can cause people to be unaware and unresponsive to what is going on around them.² One common kind of seizure that causes this sort of confusion are focal impaired awareness seizures. These types of seizures often involve automatisms, which are involuntary movements most commonly associated with TLE. They could be described as subconscious, predictive habits in the run-up or cool-down of a seizure. Examples of automatisms are things such as lip smacking, mumbling, or pacing. After experiencing an automatism, the individual often has no memory of what they have just done and are unresponsive whilst it is happening.³

These involuntary actions can be very distressing for those affected and can have detrimental impacts on people's quality of life. Uncontrolled seizures are very dangerous to the individual, additionally many have gotten into trouble with the law as a result of automatisms manifesting as socially abnormal behaviours. 

TLE is therefore a major public health issue, and for decades, there has been terrible stigma and misunderstanding surrounding epilepsy, stunting the development of compassionate and effective treatments. Furthermore, in low-income countries, access to adequate treatment and information on this disorder is limited. The World Health Organisation published a global report on epilepsy in 2019, highlighting the key issues faced by people diagnosed with epilepsy and calling for a worldwide movement to provide adequate treatment and care to people all over the world. 

This article will explore automatisms in the context of TLE, how this condition is diagnosed, and the main treatment options that are available. 

Risk factors of epilepsy

Multiple known factors increase the likelihood of someone developing epilepsy and seizures in their lifetime. Understanding these risk factors and raising awareness around them can aid in the successful treatment of epilepsy.

Non-epileptic seizures, if left untreated, can cause permanent brain damage, which can in turn lead to the development of epilepsy and the resultant occurrence of epileptic seizures. Therefore, it is important for clinicians to treat the cause of the seizures (such as an infection, injury or epilepsy) quickly in order for no long-term damage to be done. Common risk factors for epilepsy are listed below;

Hippocampal sclerosis (damage)

The hippocampus is an important part of your brain located in the temporal lobe. This is the most commonly associated cause of TLE⁴ due to an alteration of essential cells within the hippocampal tissue, such as glial cells and neurons, which are detrimental to the brain's ability to function normally.⁵

Genetics

People may have a genetic disposition that increases their risk of experiencing seizures and developing epilepsy. These have been successfully linked to specific genetic variations, and the mechanisms of how genetic mutations make individuals more susceptible to epilepsy are slowly being discovered in more recent research.⁶

Infection

Many infectious diseases have been seen to cause neuroinflammation and brain cell alterations that can result in seizures and epilepsy. Rabies, herpes, and pneumonia are well-known examples of infectious agents that have been documented to have these effects.⁷

Injuries as a result of brain trauma

Within the population of individuals that are currently experiencing epilepsy, around 20% of existing cases, and 5% of newly diagnosed cases are linked to a past traumatic brain injury.⁸

Brain tumours

The onset of epilepsy is one of the most prevalent warning signs for brain tumors in a previously unaffected individual. The growing mass of cancerous cells can lead to very similar seizure-inducing mechanisms that are seen in epilepsy.⁹

Lifestyle and environment

Factors such as lack of quality sleep, as well as drug and alcohol abuse, have strong associations with alterations in the temporal lobe and epilepsy. 

Types of automatisms in TLE

There are three main categories used to classify the involuntary movements called automatisms that commonly occur in TLE.

Motor automatisms

These types of automatisms involve the uncontrolled movement of any part of the individual's body. Between 40-80% of cases with TLE display oroalimentary and manual automatisms.¹⁰

• Oroalimentary - movement relating to the mouth and digestion (e.g., lip smacking, chewing, swallowing) 
• Manual - these movements tend to affect the hands (e.g., fumbling, grasping, picking at clothes)
• Ambulatory - less common lower limb movement (e.g., wandering, pacing)

Verbal automatisms

These automatisms are distinct in that they involve uncontrolled vocalisations.

• Repetitive speech (e.g., mumbling, unintelligible sounds)
• Vocalisations (e.g., grunts, cries)

Emotional and behavioural automatisms

These automatisms are distinct in that they involve uncontrolled emotional behaviours.

• Laughing (gelastic seizures)
• Crying (dacrystic seizures)
• Fear, aggression, or other emotional expressions

Diagnosing TLE and automatisms 

Seizure types

A seizure is a transient disruption to normal brain activity, caused by a sudden surge of uncontrolled electrical signals in the brain. Epilepsy itself is a chronic condition characterised by two or more seizures a year that are unprovoked, meaning there is no clear alternative medical cause for the seizures other than the characteristic of dysfunctional brain activity.¹¹

If there are signs of illness, such as an infection, physical brain trauma, or psychological issues, it is likely a non-epileptic seizure. Non-epileptic seizures are not initially responsive to anti-epileptic seizure medications. Therefore, it is important for clinicians to get a full medical history before deciding upon a treatment pathway. Epileptic and non-epileptic seizures manifest in notably different ways:

Automatisms also carry distinctive characteristics, whether they are associated with epilepsy or not. In epilepsy, automatisms are often repetitive and consistent throughout seizures; they can become valuable predictors of the onset of a seizure. Whereas in non-epileptic seizures, they are varied, more pronounced, and usually don’t follow any conceivable pattern. Therefore, automatisms are a helpful, observable way in which clinicians diagnose seizure types. 

Imaging techniques

The main way in which TLE is diagnosed is through an electroencephalogram (EEG). These use sensors attached to the scalp to measure electrical activity within the brain. This is the most standard test performed on anyone with suspected TLE.⁴ Abnormal activity picked up on an EEG is usually a good indication that an individual is suffering from epilepsy. 

Neuroimaging can also be useful in determining other potential risk factors for TLE, such as hippocampal sclerosis, tumours, or issues with blood vessels supplying oxygen to the brain.⁴ Computerised tomography scans can be used in this way; however, magnetic resonance imaging is preferred as it creates a much more detailed picture. How useful these images are in diagnosis is somewhat determined by the interpreter's experience and skillfulness.⁴

Automatism mimics

There are a number of behavioural and psychological conditions that cause automatisms much like those experienced in TLE. Examples include the sudden, brief tics caused by tourette’s syndrome, tremors caused by parkinson's disease, or sleep disorders which can cause unconscious walking or talking. Furthermore, psychological conditions such as obsessive-compulsive disorder (OCD), schizophrenia, or major depressive disorder can all cause repetitive behaviours that can be mistaken for automatisms, such as obsessive hand washing (observed in OCD) or hand flapping (a common autistic movement). 

In order for clinicians to distinguish automatisms associated with TLE and those not, they must observe a few key features. Firstly, abnormal activity on an EEG scan is essential, as well as ensuring that the automatisms that are occurring fit with the TLE automatism characteristics, as defined in the table above. 

Treatment options

Antiepileptic drugs (AEDs)

When TLE has been successfully diagnosed, the first course of action is to start treatment with AEDs. There are a lot of AEDs available on the market, and as a result, up to 70% of people newly diagnosed with epilepsy have access to medication that successfully prevents seizures.¹¹ These medications work by blocking the abnormal brain activity that causes seizures, but may cause unwanted side effects like nausea.

Refractory epilepsy, however, is resistant to AEDs, and can affect between 20-40% of sufferers.¹² In these cases, alternative treatment such as surgery may be required. The risk of someone having refractory epilepsy can be increased by comorbidity, such as those who suffer from depression alongside epilepsy.¹¹

Surgical intervention

If other pharmaceutical methods fail to control TLE, surgery to remove the dysfunctional part of the brain may be an option. This is usually only considered after trialling multiple AEDs, and if imaging identifies that there is only a small section of the brain causing TLE. The surgery for TLE is called a temporal lobectomy, and involves removal of some of the temporal lobe of the brain.¹¹ This is an invasive procedure, and can end up not preventing seizures, or leading to unwanted side effects such as memory problems, issues with eyesight, speech, and mood. However, rigorous testing and preparations done before surgery will help minimise these risks.

Lifestyle modifications

In order to manage TLE, it is essential that affected individuals prioritise their sleep, ensure they adhere to their medication schedules, and try to successfully manage stress.¹¹ These lifestyle modifications have all been linked to improvements in epilepsy symptoms. 

Another key modification that has been used to treat epilepsy since the 1920s is the ketogenic diet. A high fat, low carbohydrate meal planhas shown long-term promise in providing a non-invasive, drug-free treatment option for TLE.¹³ This is a good option for children with epilepsy and people with refractory epilepsy or those who do not react well to AEDs. 

As TLE can be caused by infectious agents or injury, it is important that public health authorities improve public awareness and help prevent such things from occurring. Small changes such as wearing a helmet when cycling, always wearing a seatbelt, and generally prioritising health and safety can be good steps towards reducing the risk of trauma-induced epilepsy. Furthermore, infection prevention measures, such as vaccinations against known seizure-inducing diseases can have similar beneficial effects.

Summary

TLE is a chronic neurological disorder that affects millions of people worldwide. It manifests in seizure behaviours, often involving automatisms. These are involuntary movements that can affect all parts of the body, such as the mouth or hands, and be very distressing for those affected. TLE and associated automatisms are usually treated with AEDs, but in drug-resistant cases, surgery to remove the dysfunctional part of the brain can be successful. 

Early recognition and intervention are key to successfully treating epilepsy. Misdiagnosis and mistreatment can be distressing and mentally draining on patients, and cause low mood and potential bodily harm if seizures are not controlled quickly. Cognitive decline and memory impairment can also occur if TLE is left unmanaged.