While similar, there are differences. Most commonly, Epilepsy is defined as a disorder of the brain in which people have a tendency to have recurrent, unprovoked seizures. “Provoked” seizures are those that are caused directly by some insult to the brain such as immediately following trauma, infection with fever, or medication reaction.
A Seizure refers to a sudden storm of electrical activity in a portion of the brain (focal), or the entire brain (generalized).
Electroencephalography (EEG)
Routine EEG: Monitoring of electrical signals in the brain with electrodes (sensors) attached to the scalp is usually first performed in a specialized outpatient clinic. These studies are interpreted, or “read,” by a trained neurologist. Clinicians can find evidence of abnormal electrical activity in the brain and figure out the type or types of seizures a patient is having, as well as the origin(s), by measuring brain waves over minutes to a couple of hours.
Prolonged EEGs: If a routine EEG is normal, diagnosing seizures may require a stay in an epilepsy monitoring unit for continuous EEG monitoring with video over several days. Prolonged video-EEG monitoring uses a video camera to capture onset and characteristics of seizures simultaneously with an EEG.
Radiologic Testing
Some seizures and epilepsies are due to irregularities within the brain tissue, such as scars, tumors or other lesions that can show up on radiologic imaging. Some of these issues can be treated with epilepsy surgery. Radiologic tests include:
Magnetic Resonance Imaging (MRI)
A brain MRI allows a physician to clearly see a patient’s internal body structures, including brain tissue, using magnetic fields and radio waves.
By revealing details of the brain’s structure in cross-sectional images called “cuts,” MRI can help the doctor locate possible seizure-producing areas in or next to the regions of structural change (called a seizure focus in patients with focal epilepsy or foci in patients with multifocal epilepsy).
Diagnostic protocols for epilepsy may involve a 3-D portion and special coronal cuts so the epilepsy specialist can evaluate the temporal lobes for signs of mesial temporal sclerosis or malformation of a part of the brain called the hippocampus.
A brain MRI may not be necessary or indicated in patients with generalized epilepsy (seizures coming from the entire brain at once rather than focal or multifocal areas).
Functional magnetic resonance imaging (fMRI) of the brain can help locate areas where speech, memory, movement or other functions take place. Doctors understand the general brain areas responsible for these activities, but fMRI can help pinpoint them more precisely.
During fMRI of the brain, the technologist will ask the patient to perform a specific task, such as naming objects, which illuminates active areas of the brain. This helps doctors focus on specific functional centers that may be affected by seizure disorders.
Positron Emission Tomography (PET)
A brain scan called an interictal fluorodeoxyglucose (FDG) PET scan can show changes in brain metabolism and chemistry, which is valuable in evaluating patients with many different conditions affecting the brain, especially epilepsy.
This is a nuclear medicine procedure. The patient wears a plastic mask that helps with positioning in the scanner machine. A technologist injects a small amount of radioactive material into a vein in the patient’s arm while, at the same time, taking a blood sample from the other arm. As the material moves through the brain, the scanner machine reveals and records changes.
Single Photon Emission Computed Tomography (SPECT)
Also called “ictal SPECT”, this procedure can detect areas of the brain with changes in cell metabolism, blood flow, or transmissions between brain cells during a seizure. These areas of altered activity can indicate seizure-causing conditions in a particular patient.
The test takes place in a monitoring unit where the doctors and the patient wait for a seizure to occur. The first part of the test occurs during a seizure (ictal), and the second is after the seizure (interictal); the doctors then compare these two studies. During each of the two stages, a health professional injects an imaging agent and the patient is transported to a specialized scanner that can visualize blood flow in the brain.
Intracranial Monitoring
Physicians use intracranial monitoring technology to observe the characteristics of a patient’s seizures and correlate these findings with the electroencephalogram, or EEG. The tests can include the following:
Depth electrodes: These are small, multi-contact probes that are inserted through small holes made in the skull and the coverings of the brain.
Strip and grid electrodes: These small platinum disks are set in a sheet of plastic and inserted underneath the covering of the brain called the dura.
Depth, strip and grid electrodes record brain wave activity in between and during seizures for planning epilepsy surgery.
Other Epilepsy Tests
Wada Test
When epilepsy surgery is indicated to address seizures, this two-part test is part of a patient’s pre-surgical work-up. The test can predict the impact of surgery on language and memory function. Information from the Wada test helps determine the type of surgery that will best treat seizures while preserving areas of the brain associated with speech, memory and thinking functions.
Neuro-psychological Assessment
Some people with epilepsy suffer from memory problems or other cognitive difficulties, such as trouble coming up with the correct word to use in a conversation. These problems may result from repeated seizures, medications, or a brain disease that is causing the seizures.
A quantitative assessment can provide insight into the severity and indicate the location of lesions that are causing the seizures. Neuropsychological assessments can gauge a patient’s cognitive (thinking) abilities as they relate to the function of different brain structures. For example, impaired memory may indicate an abnormality in the function of parts of the brain called the temporal lobe and the frontal lobe.
Sometimes it is hard to tell when a person is having a seizure. A person having a seizure may seem confused or look like they are staring at something that isn’t there. Other seizures can cause a person to fall, shake, and become unaware of what’s going on around them.
Seizures are classified into two groups.
- Generalized seizures affect both sides of the brain.
- Focal seizures affect just one area of the brain. These seizures are also called partial seizures.
It is possible that a person with epilepsy can have more than one kind of seizure.
No, not always. Seizures can occur due to other medical problems besides epilepsy. These problems include:
- A high fever.
- Low blood sugar.
- Alcohol or drug withdrawal.
Epilepsy can be caused by many different conditions that affect a patient’s brain. Some of the known causes include:
- Stroke.
- Brain tumor.
- Brain infection from parasites (malaria, neurocysticercosis), viruses (influenza, dengue, Zika), and bacteria.
- Traumatic brain injury or head injury.
- Loss of oxygen to the brain (for example, during birth).
- Some genetic disorders (such as Down syndrome).
- Other neurologic diseases (such as Alzheimer’s disease).
For 2 in 3 people, the cause of epilepsy is unknown. This type of epilepsy is called cryptogenic or idiopathic.
There are many things a provider and person with epilepsy can do to stop or lessen seizures.
The most common treatments for epilepsy are:
- Medicine. Anti-seizure drugs are medicines that limit the spread of seizures in the brain. A health care provider will change the amount of the medicine or prescribe a new drug if needed to find the best treatment plan. Medicines work for about 2 in 3 people with epilepsy.
- Surgery. When seizures come from a single area of the brain (focal seizures), surgery to remove that area may stop future seizures or make them easier to control with medicine. Epilepsy surgery is mostly used when the seizure focus is located in the temporal lobe of the brain.
- Other treatments. When medicines do not work and surgery is not possible, other treatments can help. These include vagus nerve stimulation, where an electrical device is placed, or implanted, under the skin on the upper chest to send signals to a large nerve in the neck. Another option is the ketogenic diet, a high fat, low carbohydrate diet with limited calories.
A neurologist is a doctor who specializes in the brain and nervous system. An epileptologist is a neurologist who specializes in epilepsy. When problems occur such as seizures or side effects of medicine, the primary health provider may send the patient to a neurologist or epileptologists for specialized care.
People who have seizures that are difficult to control or who need advanced care for epilepsy may be referred to an epilepsy centers. Epilepsy centers are staffed by providers who specialize in epilepsy care, such as
- Epileptologists and neurologists.
- Nurses.
- Psychologists.
- Technicians.
Many epilepsy centers work with university hospitals and researchers.