Epilepsy Overview

Epilepsy is a neurological condition that leads to recurrent seizures. It occurs due to abnormal patterns of electrical activity in the brain. In most cases, the cause of epilepsy is unknown. In other cases, stroke, brain trauma, inflammation, or genetics cause epilepsy. High blood pressure and previous head injury are correlated with an increased risk of developing this condition.

The symptoms of epilepsy vary depending on the seizure type. Some seizures only affect one part of the brain while others impact the entire brain. There are many different antiseizure medications used to treat epilepsy. If these don’t control symptoms, surgery or brain stimulation devices may be used. Fortunately, most people are able to manage their epilepsy with the right treatments.

Types of Epilepsy

The International League Against Epilepsy (ILAE) developed diagnostic criteria for epilepsy. It combines different symptoms and features of epilepsy, leading to a specific diagnosis.

Broadly, seizures are classified into three groups: focal onset, generalized onset, and unknown onset. These groups are categorized based on where in the brain the seizure occurred. Sometimes healthcare providers are not able to determine this, so the type of seizure is labeled unknown.

Focal Onset

A focal onset seizure starts in one part of the brain, only affecting that one side. These are further divided into two subtypes:

• Focal aware seizures: The person does not lose their awareness during the seizure. There may be motor or non-motor symptoms.
• Focal impaired awareness: The person loses some awareness during the seizure. The symptoms may be motor or non-motor. 

Seizure subtypes of focal epilepsy include:

• Impaired awareness seizure: This seizure results in a noticeable change in your level of awareness. It may cause involuntary repetitive movements called automatisms.
• Motor seizure: This causes jerking, stiffening, or twitching of muscles and sometimes repetitive movements.
• Non-motor seizures: These seizures may cause strange sensations and/or a feeling of déjà vu (the feeling that you’ve had this exact experience before), but you will remain alert to these changes. 
• Bilateral tonic-clonic seizures: These seizures start from one region but spread and affect the entire brain. This leads to the stiffening and twitching of muscles.

Generalized Onset Seizure

A generalized onset seizure affects both sides of the brain. There are many forms of epilepsy with a generalized onset, including:

• Absence seizure: These seizures cause a person to lose consciousness and stare into space.
• Myoclonic seizure: These involve brief jerking muscle spasms.
• Atonic seizure: These seizures cause the body to go limp. It may cause you to fall, make your head nod, or cause your eyelids to droop.
• Tonic seizure: These seizures cause the stiffening of muscles.
• Tonic-clonic seizure: These seizures cause muscles to stiffen, then twitch and jerk. 

The symptoms depend on the different subtypes of seizure. Some people will have both types of seizures. This occurs within epilepsies that are caused by genetic factors.

Unknown Onset

This diagnosis is provided when your healthcare provider isn’t able to narrow down the epilepsy type.

Epilepsy Symptoms

Seizures cause different symptoms depending on the parts of the brain affected. 

Prodromal Symptoms

More than 20% of people with epilepsy experience prodromal symptoms, meaning they occur days before the onset of the seizure itself. These symptoms include:

• A “funny feeling”
• Headache
• Confusion
• Anxiety
• Irritability

Symptoms of Focal Onset Epilepsy

These seizures affect only one specific part of the brain. The symptoms of these seizures depend on their location. Typically, they include:

• Intense déjà vu
• Unexplained feelings of joy, anger, sadness, or nausea
• Auditory or visual hallucinations
• A smell, taste, or feeling that isn’t real. An example is the smell of burnt toast when there is no toast nearby.
• Movements in one particular part of the body
• Zoning out of consciousness into a dreamlike state
• Repetitive behaviors like frequent blinking, twitching, or mouth movements

Symptoms of Generalized Onset Epilepsy

These seizures affect both sides of the brain. Subtypes include distinctive symptoms:

• Absence seizures: These can cause impaired awareness, staring into space, and repetitive behaviors or muscle twitching. 
• Tonic seizures: These seizures cause muscle stiffening across the body. This can cause you to fall down or struggle to stay afloat if they are swimming. 
• Clonic seizures: These seizures cause repetitive jerking movements on both sides of your body.
• Myoclonic seizures: These seizures cause twitching movements of your upper body, arms, or legs.
• Atonic seizures: These seizures make your muscles go limp. This leads to falling. 
• Tonic-clonic seizures: Symptoms of this subtype include body stiffening, followed by repeated jerking of limbs. It may also lead to the loss of consciousness.

What Causes Epilepsy?

Neurons normally communicate through electrical signals and neurotransmitters. Glutamate causes neurons to fire while GABA tells neurons to stop. In epilepsy, the signals from these neurotransmitters aren’t balanced, which can cause the neuronal cells to misfire. This abnormal electrical activity is a telltale sign of seizures.

In most cases, the underlying cause of epilepsy is unclear. However, these causes may be responsible for many cases of epilepsy:

• Traumatic brain injury or stroke: Repetitive trauma or strokes damage the brain. As your brain recovers by rewiring itself, it can make a mistake that leads to epilepsy. The immune response to this injury may also lead to further damage.
• Inflammation due to infection: Normally, immune cells make antibodies to destroy the pathogen. Sometimes, this response damages healthy cells. B
• Tumors: Tumors affect the brain’s metabolism (the ability to convert glucose and oxygen to neurons and astrocytes) and divert nutrients from the brain. This starves neurons, leading to seizures.
• Genetic factors: Multiple genetic factors affect electrical signaling in the brain. Inheriting these factors may lead to the development of epilepsy.

Risk Factors

There are multiple factors that contribute to the risk of developing epilepsy. Mitigating these risk factors could reduce the risk of developing the condition. They include:

• Age: It is most common in early childhood and after the age of 85. 
• Sex: Rates of epilepsy are slightly higher in people assigned male at birth than people assigned female at birth.
• Ethnicity: Black and Hispanic Americans are more likely to develop epilepsy. They are also more likely to develop conditions like stroke, which can cause epilepsy.
• Geography: Rates of epilepsy are about three times higher in low and middle-income countries than in high-income countries. This may result from differences in access to healthcare.
• Socioeconomic status: People with low socioeconomic status have higher rates of epilepsy.
• High blood pressure: This condition damages blood vessels and puts you at risk of stroke, which can contribute to the development of epilepsy.
• Prior brain injury: Head trauma contributes to the risk of developing epilepsy later in life. It may make the brain more prone to seizure activity.

In addition, many classes of medication increase the risk of epilepsy. These include:

• Opioid medications like Oxycontin (morphine)
• Anti-cancer drugs like Busulfex (busulfan)
• Antibiotics or antimicrobials like Amoxil (penicillin)
• Immune-suppressing drugs like Prograf (tacrolimus)
• Antidepressants like Zoloft (sertraline)
• Antipsychotics like Risperdal (risperidone)
• Drugs for treating lung disease like Theobid (theophylline)
• Stimulants like Adderall/Ritalin (methylphenidate)
• Decongestants like Sudafed (pseudoephedrine)

How Is Epilepsy Diagnosed?

In addition to a medical history, a neurologist (a doctor who specializes in treating conditions of the brain and spinal cord) may perform the following tests:

• Blood tests: This can spot signs of inflammation, infectious disease, and other problems that lead to seizures. For example, low levels of sodium or high blood sugar are both associated with seizures.
• Genetic tests: Testing for epilepsy-associated genes helps diagnose genetic forms of the condition. These genes alter the brain’s electrical activity, making them misfire.
• Electroencephalography (EEG): This non-invasive exam involves placing electrodes on the scalp to measure brain activity. If there are spikes and sharp waves in the recording of one region, it suggests that it is prone to seizures. If there are abnormalities in many regions of the brain, it suggests generalized onset epilepsy.
• Magnetoencephalography (MEG): MEG is a non-invasive test that measures magnetic signals from brain cells. It helps localize focal seizures, identifying the border between healthy and seizure-prone areas.
• Computer tomography (CT) scans: CT scans combine multiple X-ray images of the brain. It identifies structural abnormalities like tumors or cysts that can cause seizures.
• Magnetic resonance imaging (MRI): MRI machines use a magnetic field and radio waves to get a detailed image of the brain. It detects lesions (areas of injury or abnormalities) that may signal focal epilepsy or other structural irregularities.
• Functional MRI (fMRI): This form of MRI measures changes in blood flow to the brain. Areas that don’t receive enough blood flow may be prone to seizures. If imaging is done during a seizure, these areas will show increased blood flow.
• Positron emission tomography (PET): A PET scan measures the brain’s metabolic activity. Areas of the brain that are prone to seizures show lower metabolic function. However, during the seizure itself, their metabolic function is increased.
• Single-photon emission computed tomography (SPECT): This measures changes in blood flow during seizure activity. A blood flow tracer is injected by a neurologist within 30 seconds of a seizure, highlighting the regions of the brain involved.
• Wada test: A drug like sodium amobarbital is injected into one of the carotid arteries (the vessels that provide blood to the brain) leading to a five-minute paralysis of one side of the brain. This lets a neurologist test memory and language in the non-paralyzed side of the brain. It verifies the source of a seizure before surgery.

Neurologists may screen for these conditions during diagnosis:

• First seizure: A first seizure does not mean a person has epilepsy. A healthcare professional will check for causes like hemorrhage or high blood sugar.
• Febrile seizure: These seizures are caused by a high fever. It occurs due to viral or bacterial infections in young children (usually younger than one-year-old).
• Non-epileptic events: This condition causes seizure symptoms without abnormal electrical activity in the brain. It may result from stress or other psychological factors.
• Status epilepticus: This is a life-threatening condition associated with epilepsy. It can cause prolonged seizures, impairment in consciousness, and death. It requires urgent treatment.

Treatments

Most people receiving treatment for epilepsy reduce the severity and number of seizures they experience. Some even go into full remission. These are the most common treatments.

Medications

Antiseizure drugs work by altering the balance of excitatory and inhibitory signals in the brain. This prevents abnormal electrical activity. If a person does not respond to the first two drugs, their epilepsy is considered treatment-resistant.

These antiseizure drugs are prescribed for focal onset epilepsy:

General recommendations:

• Lamictal (lamotrigine)
• Keppra (levetiracetam)
• Trileptal (oxcarbazepine)
• Tegretol/Curatil (carbamazepine)
• Vimpat (lacosamide) 

For older adults:

• Lamictal (lamotrigine)
• Keppra (levetiracetam)
• Vimpat (lacosamide) 

For persons who may get pregnant:

• Lamictal (lamotrigine)
• Keppra (levetiracetam)

These antiseizure drugs are prescribed for generalized onset epilepsy:

For tonic-clonic seizures:

• Lamictal (lamotrigine)
• Keppra (levetiracetam)
• Depakene/Depakote (valproate)
• Topamax (topiramate)
• Zonegran (zonisamide) 

For myoclonic seizures: 

• Keppra (levetiracetam)
• Depakene/Depakote (valproate)
• Zonegran (zonisamide) 

For absence seizures:

• Zarontin (ethosuximide)
• Depakene/Depakote (valproate)
• Lamictal (lamotrigine)

These antiseizure medications share many side effects including drowsiness, dizziness, and loss of balance. In rare cases, it may lead to a hypersensitivity reaction, impaired cognition, or changes in weight. Valproate may increase the risk of birth defects for pregnant persons.

Surgery

For treatment-resistant epilepsy, surgery may be an option. There are different procedures commonly used:

• Thermal ablation: A minimally invasive procedure that uses lasers to destroy parts of the brain causing seizures
• Lobectomy or lesionectomy: Removal of a small part of the brain causing seizures
• Multiple subpial transection: Making multiple cuts in the brian to prevent further spreading of a seizure
• Corpus callosotomy: Cutting the connective fibers between the left and right side of the brain to prevent seizures from spreading
• Hemispherectomy: Removing one half of the brain as a last resort procedure

Although surgeons use brain imaging to localize seizures, they may accidentally damage healthy parts of the brain. This leads to cognitive impairment, personality changes, and sometimes physical disability.

Brain Stimulation 

Some people are not good candidates for receiving surgery, such as when multiple regions of the brain are contributing to seizures. In these cases, there are two types of brain stimulation devices available:

• Deep brain stimulation: Uses a pacemaker to continuously stimulate the brain to prevent seizures
• Responsive neurostimulation: Uses a pacemaker to stimulate the brain only when seizures are about to occur

This procedure may cause headaches, pain at the implant site, a burning or prickling sensation, an, in rare cases, hemorrhage or infection.

Ketogenic Diet

There is some evidence that a strict high-fat, low-carbohydrate diet (commonly referred to as the keto diet) treats epilepsy. However, the overall evidence supporting this intervention is still uncertain. It is always best to consult your healthcare provider before making any drastic changes to your diet. They can advise you based on your individual healthcare needs and ensure your diet doesn’t conflict with your care plan.

How To Prevent Epilepsy

Since we don’t know what causes many types of epilepsy, there are limited ways to prevent it.

• Reduce the risk of head trauma: Wearing helmets and avoiding high-impact sports reduces the risk of brain damage.
• Lower risk of stroke or cardiovascular disease: Stroke and cardiovascular disease increase the risk of getting epilepsy. Getting your blood pressure and cholesterol in check through medications and exercise can reduce the risk.
• Following vaccination schedules: Early childhood infections or diseases could lead to epilepsy.
• Prepare food safely: Cysticercosis is a common cause of epilepsy that results from ingesting a parasite. Proper food safety practices prevent it from spreading.

Comorbid Conditions

At least one-third of people with epilepsy have issues with cognition, anxiety, or depression.  Children experience stigma due to their seizures, leading to bullying, loneliness, or depression. Luckily, many of these issues are treatable through therapy, medications, and support from loved ones.

Epilepsy is associated with a rare condition called sudden unexpected death in epilepsy (SUDEP). Researchers aren’t sure what causes SUDEP but suggest it involves problems with the heart and lungs.

Living With Epilepsy

Epilepsy is a treatable condition. At first, it may reduce your mobility. Many states have laws preventing people from driving unless they’ve been seizure-free for a certain period of time. But through medications or surgery, most people get their seizure symptoms under control. As a result, many people go years without seizures after discontinuing drug treatment.