Epilepsy – Causes, Symptoms, Treatments

What is Epilepsy?

Epilepsy is a neurological disorder characterized by recurrent, unpredictable seizures. These seizures are caused by abnormal electrical activity in the brain. Seizures can vary widely in their presentation and severity, ranging from brief lapses of attention or muscle jerks to severe and prolonged convulsions. Epilepsy can start at any age, but it usually starts either in childhood or in people over 60. It’s often lifelong, but can sometimes improve over time.

Epilepsy is a surprisingly common neurological disorder. Globally, around 50 million people have epilepsy, making it one of the most widespread neurological diseases according to the World Health Organization (WHO). This translates to an estimated 4-10 people per 1,000 having active epilepsy at any given time.

In the United States, studies suggest 1.2% of the population, roughly 3.4 million people, have active epilepsy according to the Centers for Disease Control and Prevention (CDC).

It’s important to note that access to diagnosis and treatment can vary depending on the region. Low- and middle-income countries are estimated to have a higher number of cases, with nearly 80% of people with epilepsy living there according to the World Health Organization (WHO). In these areas, proper diagnosis and treatment rates are significantly lower.

Epilepsy is defined by two key features:

• Recurrent Seizures: The hallmark of epilepsy is having repeated seizures, which are temporary disruptions in brain function caused by abnormal electrical discharges. These can manifest in various ways depending on the seizure type and the area of the brain involved.
• Unprovoked: These seizures are unprovoked, meaning they occur without a clear immediate trigger like flashing lights, sudden withdrawal from alcohol, or a fever. A single seizure doesn’t necessarily indicate epilepsy.

Causes of Epilepsy

In a healthy brain, nerve cells (neurons) communicate with each other through electrical impulses in an orderly fashion. In epilepsy, the normal electrical activity becomes imbalanced, leading to excessive and synchronized firing of neurons. This surge disrupts the brain’s normal function, causing the symptoms we recognize as a seizure. The underlying cause of this electrical imbalance can vary.

Brain Abnormalities:

• Scarring: Brain injuries from head trauma, strokes, or infections can leave scar tissue. This scar tissue disrupts the normal electrical flow in the brain, increasing the risk of seizures.
• Brain Tumors: Both benign and malignant tumors can cause seizures by disrupting normal brain function and electrical activity.
• Developmental Malformations: Malformations in brain structure present at birth can also be a contributing factor.
• Neurological disorders: Some neurological conditions, such as Alzheimer’s disease, multiple sclerosis, or neurofibromatosis, may be associated with an increased risk of epilepsy.

Genetic Predisposition:

In some cases, there’s a genetic component that increases the risk of developing epilepsy. This can be:

• Familial Epilepsy: Certain types of epilepsy run in families, suggesting a genetic link. However, having a family member with epilepsy doesn’t guarantee you’ll develop it.
• Genetic Conditions: Some specific genetic disorders can predispose someone to epilepsy.

Other Causes:

• Infections: Brain infections such as meningitis or encephalitis can cause inflammation and scarring, leading to seizures.
• Autoimmune Disorders: In rare cases, the body’s immune system can attack healthy brain tissue, triggering seizures. Autoimmune conditions affecting the brain, such as autoimmune encephalitis or lupus, may trigger seizures and contribute to the development of epilepsy.
• Metabolic Disorders: Electrolyte imbalances or problems with blood sugar regulation can disrupt brain function and cause seizures. Certain metabolic disorders, such as phenylketonuria (PKU) or mitochondrial disorders, can increase the risk of epilepsy.
• Febrile seizures: Seizures triggered by high fever, particularly in young children, can sometimes lead to epilepsy, although this is relatively rare.
• Prenatal factors: Lack of oxygen during birth or infections in the mother during pregnancy can increase the risk of epilepsy in the child. Exposure to certain toxins, infections, or maternal health conditions during pregnancy can affect the development of the fetal brain and increase the risk of epilepsy in the child.

Unknown Cause:

It’s important to note that in roughly half of all epilepsy cases, the specific cause remains unknown despite investigations.

Types of Seizures Associated With Epilepsy

Epilepsy is characterized by recurrent seizures, but there are many different types of seizures, each with varying symptoms. Here’s a breakdown of the two main classifications and some common types within them:

1. Focal Seizures (Previously Called Partial Seizures)

Focal seizures originate in a specific area of the brain, causing symptoms that reflect the function of the affected region. Depending on whether awareness is altered during the seizure, they are further classified as:

• Focal Aware Seizures (Simple Partial Seizures):  These seizures cause alterations in perception, such as tingling, distortions in sight, smell, or taste, or auditory hallucinations, but awareness remains intact.
• Focal Impaired Awareness Seizures (Complex Partial Seizures):  Impaired awareness is the defining characteristic. People may appear dazed or confused and may not respond normally to their surroundings.
• Focal seizures can sometimes spread to both hemispheres of the brain, triggering a generalized seizure.

2. Generalized Seizures:

Generalized seizures involve abnormal electrical activity across both hemispheres of the brain, leading to widespread changes in consciousness and motor function. Some common types include:

• Absence Seizures (Petit Mal Seizures):  These brief seizures (usually lasting 10-20 seconds) cause a sudden lapse in awareness with a blank stare. The person may blink repetitively or have slight twitching of the mouth or eyelids.
• Tonic-Clonic Seizures (Grand Mal Seizures): These are the most dramatic of the seizure types. They involve stiffening of the body (tonic phase) followed by rhythmic jerking movements (clonic phase) and often loss of consciousness. They can be accompanied by tongue biting, incontinence, and post-ictal confusion (confusion after the seizure).
• Myoclonic Seizures: These are brief, jerky movements of a muscle or muscle group, often involving the arms or legs. They may go unnoticed by others.
• Atonic Seizures (Drop Attacks):  A sudden loss of muscle tone causes the person to collapse. They typically recover within seconds without injury.

Common Epilepsy Triggers

People with epilepsy can experience seizures seemingly out of the blue, but there are often identifiable triggers that can increase the likelihood of a seizure. These triggers vary significantly from person to person. 

Epilepsy medication works by regulating the electrical activity in the brain. Skipping doses or not taking the medication as prescribed disrupts this delicate balance. When the brain chemistry isn’t properly controlled, it becomes more susceptible to the electrical surges that cause seizures.

Another common trigger is sleep deprivation. During sleep, the brain goes through various stages that help it recharge and consolidate memories. When someone is sleep deprived, these stages are disrupted, and electrical activity in the brain can become unstable. This instability can increase the risk of seizures for people with epilepsy.

Additionally, stress is another common factor to consider. The body releases hormones in response to stress. These hormones can have various effects, and in some people with epilepsy, they can lower the seizure threshold. This means it takes less provocation for the abnormal electrical activity to occur and cause a seizure. Women with epilepsy may experience more seizures around their menstrual cycle due to hormonal changes. These hormonal fluctuations can affect brain chemistry and make it more susceptible to seizures.

Although a common portrayal in mass media, photosensitivity (sensitivity to flashing lights) is only a trigger for a minority of people with epilepsy. For those who are photosensitive, exposure to flickering or strobe lights can disrupt the normal visual processing in the brain, triggering seizures.

The brain relies on glucose (sugar) for energy. When blood sugar levels drop too low (hypoglycemia), the brain becomes starved of energy. This can disrupt normal brain function and trigger seizures in some people with epilepsy.

The use of alcohol and certain recreational drugs can also interfere with the brain’s electrical activity in various ways. They can disrupt the delicate balance created by medication or directly lower the seizure threshold. This increases the risk of seizures for people with epilepsy.

Another possible trigger may come in the form of fevers and infections. These can cause inflammation in the body, including the brain. This inflammation can disrupt normal electrical activity and increase the risk of seizures for some people with epilepsy.

How is Epilepsy Diagnosed?

Diagnosing epilepsy involves a multi-pronged approach to pinpoint the cause of the seizures and determine the most effective treatment strategy. A doctor will gather a comprehensive medical history, including a detailed description of the seizures, including frequency, duration, and symptoms experienced before, during, and after the seizure.

Additionally the doctor will seek to understand any potential triggers, such as sleep deprivation, stress, or illness, past medical history, including head injuries, infections, or any neurological conditions and your family history of epilepsy or other neurological disorders.

A neurological examination will then be used to assess the nervous system function, including reflexes, muscle strength, coordination, and sensation. This helps identify any underlying neurological abnormalities that might be contributing to the seizures.

While no single test can definitively diagnose epilepsy, several tests can provide valuable information. The Electroencephalogram (EEG) is the most common test for epilepsy. It measures electrical activity in the brain using electrodes placed on the scalp. Abnormal electrical patterns during the EEG, even if a seizure isn’t captured, can be indicative of epilepsy.

The use of techniques like magnetic resonance imaging (MRI) or computed tomography (CT) scans can help identify potential causes of seizures, such as brain tumors, scarring, or developmental abnormalities.

In some cases, depending on the suspected cause, additional tests like blood tests or lumbar punctures (spinal taps) might be needed to rule out other conditions that can mimic seizures.

How is Epilepsy Treated?

Epilepsy, while not curable, has a range of treatment options aimed at managing and reducing the frequency of seizures.

The use of medications is the first-line treatment for most people with epilepsy. Anti-epileptic drugs (AEDs) work by altering brain chemistry to prevent the abnormal electrical discharges that cause seizures.  There are many different AEDs available, and doctors will personalize the medication regimen based on the specific type of epilepsy, seizure frequency, and other factors.

In some cases, a special diet can be helpful, particularly for children with epilepsy. The ketogenic diet, for example, is high in fat and low in carbohydrates. It forces the body to use fat for energy instead of glucose (sugar). This metabolic shift can have an anti-seizure effect for some people.

If medication or dietary changes aren’t effective, epilepsy surgery may be an option. This is typically considered for people with uncontrolled seizures arising from a well-defined area of the brain. The goal is to remove the part of the brain causing the seizures while minimizing impact on other brain functions.

Neurostimulation Devices use electrical stimulation to modulate brain activity and reduce seizure frequency. There are two main types. With vagus nerve stimulation (VNS) a pacemaker-like device implanted under the skin in the chest that sends electrical signals to the vagus nerve in the neck, which indirectly influences brain activity. The other option is deep brain stimulation (DBS). Electrodes are implanted deep within the brain near the seizure origin, delivering electrical stimulation to regulate abnormal activity.

In some cases, other therapies may be used to manage seizures,  such as cognitive behavioral therapy to help people cope with the psychological impact of epilepsy.

What Medications are Most Often Prescribed for Epilepsy?

There isn’t one single most commonly prescribed medication for epilepsy. Doctors personalize treatment based on the specific type of epilepsy and individual factors. However, several medications are frequently used as first-line therapy:

• Levetiracetam (Keppra): This broad-spectrum medication is effective for various seizure types, both partial and generalized, and is generally well-tolerated with fewer side effects compared to some older options.
• Lamotrigine (Lamictal): This medication is another popular choice for a wide range of seizure types. It may also be prescribed for certain emotional and behavioral problems that sometimes co-occur with epilepsy.
• Divalproex (Depakote): While effective for various seizure types, this medication carries a risk of more serious side effects and requires closer monitoring. Doctors typically reserve it for situations where other medications haven’t been successful.
• Carbamazepine (Tegretol): This medication works well for focal seizures but can cause drowsiness and other side effects. It may not be suitable for everyone.
• Oxcarbazepine (Trileptal): This medication is similar to carbamazepine but may be better tolerated with fewer side effects.