Partial Epilepsy

What is Partial Epilepsy?

Seizures happen when the brain’s electrical signals don’t function as they should, leading to a disturbance in normal communication between brain cells. Seizures, whether they happen once or several times, start from the cerebral cortex or hippocampus areas of the brain. It’s important to note that there’s a distinction between a seizure and epilepsy. A seizure is a one-time occurrence with a lower chance of happening again. On the other hand, epilepsy is a disease where two or more unexpected seizures happen more than 24 hours apart, or there’s a single seizure with a high chance that more will follow, similar to the general risk of having a second seizure within the next ten years, specifically a 60% likelihood or higher.

Epilepsy may be diagnosed when seizures have a common cause, known prognosis, and accepted treatment. Many times, the likelihood of seizure activity happening comes down to the root cause, which may or may not be known. There are, however, exceptions like when a child has a seizure due to fever. In such cases, epilepsy isn’t diagnosed because the seizure stops when the fever subsides. However, complicated fever-induced seizures can be connected with epilepsy.

The International League Against Epilepsy provided a classification in 2017 that categorizes seizures based on where the seizure starts in the brain. Seizures can be partial or generalized. If a seizure starts from a specific spot in the brain, it’s known as a focal or partial seizure. If it starts from both halves of the brain at the same time, it’s a generalized seizure. Partial seizures can be further classified into simple and complex. Simple partial seizures happen in a small area of the brain. Complex ones begin in one area and spread to another.

The key difference between simple and complex seizures is that in complex seizures, there is a loss of awareness and a recovery period afterward. Both these characteristics are also found in generalized seizures. Therefore, complex and generalized seizures can look very similar. However, they differ in that generalized seizures involve both halves of the brain, while complex seizures begin in one specific area and move to another. The terms partial epilepsy and focal epilepsy are sometimes used interchangeably.

Epilepsy is more than just having seizures – it can also negatively affect a patient’s mental health and cognition, leading to other health issues or side effects from medication. As a result, there’s a growing need for comprehensive approaches in treating epilepsy so that patients can maintain a good quality of life.

What Causes Partial Epilepsy?

Seizures can be caused by a whole bunch of different things, and these reasons can greatly vary depending on the person’s age. Over the years, we have noticed a growing connection between genetic factors and the development of partial seizures. However, figuring out the exact cause or location of seizure development can be quite tricky.

Seizures can fall under these classifications: genetic, structural, metabolic, autoimmune, infectious, or sometimes even unknown.

A common type of partial epilepsy is Mesial Temporal Lobe Epilepsy (MTLE), which is connected to a condition called hippocampal sclerosis. This is caused by a disruption in the normal transcription of mRNA leading to various issues in cell health, and ultimately resulting in permanent hardening of tissue. As this hardened tissue replaces healthy tissue, it makes patients resistant to anti-epileptic medications resulting in drug-resistant epilepsy.

Here are detailed examples of various causes:

Genetic:
– Random gene mutations with no family history of epilepsy
– Gene mutations with a family history of epilepsy
– Developmental disabilities such as Autism spectrum disorder

Structural:
– Pathologies of blood vessels
– Vascular lesions
– Stroke
– Abnormal blood vessels in the brain
– Developmental abnormalities
– Arnold Chiari malformation
– Changes after surgery
– Traumatic brain injuries
– Tumors

Infectious:
– Meningitis
– Focal encephalitis
– Tuberculosis
– HIV
– Cerebral malaria
– Subacute sclerosing panencephalitis (a rare brain disorder)
– Toxoplasmosis (a disease caused by a parasite)
– Neurocysticercosis (a parasitic infection of the brain)

Metabolic:
– Shifts in metabolism and electrolyte
– Hypoxic insults (lack of oxygen)
– Endocrine disorders
– Medications and toxins
– Alcohol intoxication
– Alcohol withdrawal
– Neonates with fetal alcohol syndrome
– Drug abuse
– Complicated seizures with high fever

Autoimmune Disorders:
– Systemic lupus erythematosus
– Sjogren syndrome
– Sarcoidosis
– Hashimoto’s Encephalopathy
– Chron disease
– Behcet disease.

Risk Factors and Frequency for Partial Epilepsy

Epilepsy is a widespread condition affecting over 68 million people worldwide, including roughly 2.2 million people in the U.S. It’s one of the most common brain disorders, with over 150,000 new cases diagnosed each year. By the time they reach 20, 1 in 100 people will have developed epilepsy. This number increases significantly with age, as 3 in 100 people are diagnosed with the condition by the time they’re 80.

In North America, epilepsy is more common among racial and ethnic minorities, and those from low-income backgrounds. Men are slightly more likely to have the condition than women. As for the types of seizures that people with epilepsy might experience, around 6 to 12% of patients will have simple partial seizures, and about 36% will have complex partial seizures.

In children, the most common form of epilepsy, other than febrile convulsions (which are seizures triggered by a fever), is a type known as benign partial epilepsy with centrotemporal spikes or benign rolandic epilepsy. This kind usually presents between the ages of 5 and 10. Additionally, glioneuronal tumors that often appear in the temporal lobe can also cause focal epilepsy. These are more common in children and teenagers.

Signs and Symptoms of Partial Epilepsy

Diagnosing the type of seizure, finding the probable cause, and determining the risk of it happening again relies heavily on a detailed medical history and physical examination. Some patients when having a seizure might experience symptoms such as:

• Tingling
• Numbness
• Jerking movements
• Muscle tightening
• Staring blankly
• Rapid eye movements
• Sudden strange sensations or hallucinations, this may include:
• Smells
• Tastes
• Visuals
• Sounds or voices
• Physical touch

The symptoms a patient experiences depend on the specific parts of the brain that the seizure affects. For example, seizures affecting specific areas may present different symptoms like:

• Temporal area – smells, restlessness, difficulty swallowing
• Parietal area – issues with hearing
• Occipital area – problems with seeing
• Frontal area – loss of self-control or cognition
• Postcentral gyrus area – tingling, numbness
• Precentral gyrus area – jerking movement, muscle tightening

Sometimes, before a seizure, patients may experience a warning sign called an “aura.” These could be tastes, smells, sights, sounds, or feelings that aren’t present. In some complex cases, particularly those relating to seizures originating in the temporal lobe, individuals may experience intense feelings of déjà vu or claim to have psychic powers or spiritual encounters.

Seizures can also sometimes cause problems with the autonomic nervous system (which controls things you don’t consciously manage, like your heart rate), or affect movement or sensation. This is particularly true for seizures originating in the temporal, parietal, or occipital lobes of the brain. Some specific parts of the body, such as the mouth, thumb, and big toe, are especially sensitive to electrical discharges in the brain during a seizure, which can lead to increased sensation in these areas just as the seizure begins.

Testing for Partial Epilepsy

An electroencephalogram (EEG) is a tool doctors use, that helps to find out where seizures are starting in the brain. In some cases, it may predict how likely it is that a person’s seizures can be controlled. Once a seizure has stopped, the EEG may return to normal. To try and trigger seizure activity in a safe and supervised environment, doctors may use video EEG while exposing patients to certain stressors like sleep deprivation, flashing lights, and quick breathing. EEG recording may show spikes at a specific point in the brain, which can suggest epilepsy. One limitation of the regular EEG is that the recording might not be able to pick up seizure activity originating from deeper parts of the brain. In these cases, a more invasive procedure may be needed where the surgeon places targeted electrodes inside the brain.

In addition to an EEG, more imaging tests can help figure out what might be physically triggering the seizures. These tests might be a brain CT scan, a specific type of MRI called fluid-attenuated inversion recovery (FLAIR), as well as an interictal positron emission tomography (PET), and ictal single-photon emission computerized tomography (SPECT). Each of these tests helps to give a different picture of the brain and its activity.

Apart from a brain scan, your doctor might also conduct a heart checkup using an electrocardiogram (EKG) and a Holter monitor, which is a portable device for continuously monitoring heart rhythm.

Your doctor may also need to analyze your blood to identify any potential underlying causes for the seizures. This can involve a complete blood count, comprehensive metabolic panel, drug screen, blood alcohol level, toxin screen, and thyroid panel.

It’s often helpful to have specialists from different disciplines coming together to fully assess your condition. Thus, you may be referred to a neurologist, psychologist/psychiatrist, and a social worker as part of a thorough, team-approach evaluation.

Treatment Options for Partial Epilepsy

The first step in treating a seizure is to identify its cause and type, if possible. Some seizures, like benign focal epilepsy, typically resolve on their own and don’t require further treatment. Simple partial epilepsy, on the other hand, can be treated with a variety of medications. There isn’t one perfect medication for everyone, and finding the right one might take some trials. Common first-choice medications for partial epilepsy include carbamazepine and lamotrigine. If seizures aren’t controlled with these, other medications like valproate, topiramate, oxcarbazepine, or gabapentin can be tried.

Lamotrigine is often the preferred treatment for partial seizures that also affect the entire brain (known as secondary generalization). It works by blocking certain channels in the cells that manage the electrical activity in the brain. Lamotrigine is typically chosen for patients who can’t tolerate, aren’t helped by, or can’t take a medication called valproate. It’s also used to treat a condition called Lennox-Gastaut syndrome and bipolar disorder. A severe side effect, though rare, of lamotrigine is Stevens-Johnson syndrome – a serious skin reaction that can cause a rash and large, blister-like sores, which can potentially lead to severe dehydration and other complications. If this happens, the drug must be stopped immediately and the person needs medical support.

Refractory epilepsy, sometimes known as intractable epilepsy, is a type of epilepsy where seizures continue even after trying two different seizure medications at their highest safe doses. If a person with epilepsy stops taking medication due to side effects, we don’t consider their epilepsy to be refractory. For these people, other treatments are considered.

For instance, neurostimulation treatments for refractory partial epilepsy, which use mild electrical signals to reduce seizure activity, have proven effective and are generally well-tolerated and safe. These treatments can also be beneficial for people who have had to stop taking seizure medication due to side effects.

Surgery can help some types of seizures that are caused by particular problems in the brain, like sclerosis (hardening of tissue) in the temporal lobe or surgically removable tumors.

Alongside medication and other treatments, diets high in fats, like the Atkins or ketogenic diets, have shown benefits for those experiencing refractory seizures. However, it’s important to closely monitor the levels of antiepileptic drugs in the blood during these diets, as they could be reduced and potentially worsen seizures.

Lastly, experimental treatments using the patient’s own stem cells have been promising. This involves converting these cells in a lab and putting them back into the patient, a personalized approach aiming to reduce seizures.

What else can Partial Epilepsy be?

Partial epilepsy can show up in different ways, depending on the specific area of the brain where the seizure starts. When a doctor sees someone with new seizure activity, they need to consider a number of possibilities:

• Absence seizures
• Benign childhood epilepsy
• Complex partial seizures
• Transient ischemic attacks, which are brief stroke-like symptoms
• Atypical migraine
• Neuromuscular disorders
• Hypoglycemia or, low blood sugar
• Alcohol withdrawal
• Drug intoxication
• Environmental toxins
• Panic attacks
• Thyroid diseases
• Malignancies or cancers that could be:
• Causing structural damage in the brain
• Causing changes in body’s metabolism, such as:
• Adrenal gland tumors
• Kidney tumors
• Digestive system tumors
• Thyroid gland tumors

A thorough check and different tests are needed to pinpoint the exact cause.

What to expect with Partial Epilepsy

The outlook for children with partial epilepsy is generally good, with an over 80% decrease in seizures over a seven-year period. Some seizures that happen during childhood are benign, or not harmful, and may not require treatment once the child becomes an adult.

In the past, epilepsy was seen as a lifelong diagnosis. However, current guidelines consider that epilepsy is resolved or over in patients who have been free of seizures and off medication for ten years. It’s important to note, though, that terms like “cured” or “in remission” are not used because the risk of having a seizure doesn’t drop down to the level similar to that of the general public.

Possible Complications When Diagnosed with Partial Epilepsy

Uncontrolled seizures can be dangerous and potentially lead to irregular heart rhythms and even death.

Also, medications used to manage these seizures can sometimes have side effects. These can range from common symptoms such as:

• Dizziness
• Nausea
• Vomiting
• Gum overgrowth
• Diarrhea

to more serious, yet rare, side effects like:

• Long-lasting changes to your heart rhythms noted on an EKG
• Significantly lowered white blood cell count (agranulocytosis)
• Depression
• Liver failure
• Hearing loss
• Pancreatitis (inflammation of the pancreas)

Preventing Partial Epilepsy

Patients should be informed about what may trigger their seizures, what side effects may occur from their medication, and what to expect in the course of their illness. For younger patients, their parents or guardians should also be educated. Adults who live independently should be encouraged to share this information with spouses, relatives, or friends they can rely on for support and safety.

Each patient’s safety and level of risk need to be evaluated individually, for activities such as driving, swimming, playing sports, or working in dangerous environments. Extra caution is needed in situations where seizures are not under control, such as avoiding driving, swimming, or participating in strenuous or extreme sports.

Regular check-up appointments and ongoing monitoring are essential for patients with epilepsy. These appointments help doctors assess if the medication is working effectively, monitor any potential side effects, and track the occurrence of other related health issues.