Epilepsy / Seizures
Overview: Epilepsy / Seizure Disorder
A seizure occurs when a person has an episode of excessive and abnormal electrical discharges in the brain. This can result in various symptoms, including tonic (rigid) posturing, clonic (shaking) activity, staring, repetitive behaviors, or other symptoms. These symptoms may involve the whole body or only part of the body.
Epilepsy – the medical term for a seizure disorder – is diagnosed when a person has two or more seizure spells that are not provoked by reversible causes, or has one seizure and discovery of an underlying condition that put the person at high risk for having another seizure. About 3% of the US population has Epilepsy at some point in life.
Causes of Epilepsy
Single seizure spells can occasionally be caused by reversible states, such as very low blood sugar (hypoglycemia), alcohol withdrawal, certain medications which can lower the “seizure threshold,” or other causes.
Epilepsy can be due to hereditary or acquired causes.
Most hereditary or genetic causes of epilepsy result in seizures in childhood. Examples of this include Idiopathic generalized epilepsy, Generalized epilepsy with febrile seizures plus, Juvenile myoclonic epilepsy, Dravet syndrome, or neurofibromatosis. While these seizure disorders have known gene mutations associated with them, the risk of developing epilepsy depends on various inheritance patterns. In many of these conditions, the cause of the seizure relates to a “channelopathy,” or abnormality in how signals are sent or activated in neurons, the cells of the brain.
If a person has a first-degree relative with a seizure disorder, the risk to the person is less than a 1 in 20 chance of developing a seizure disorder by the age of 40.
About 2-5% of children experience seizures in the setting of fever as a young child, despite having normal neurological systems. In these children, about 90% never have another seizure after age 6.
Some childhood seizure disorders can also be due to acquired conditions, such as a stroke in early childhood, a hypoxic (low-oxygen) event around birth, or a traumatic brain injury. There can also be abnormal brain development in childhood that can predispose one to seizures, such as mesial temporal sclerosis, where the inner part of the temporal lobe develops scar tissue.
As a person ages, it is more likely that the seizures would be from an acquired condition. Examples in adulthood include: following a stroke, in the setting of a brain mass, following a traumatic brain injury, or in the setting of brain atrophy. These acquired conditions make the brain more irritated, which can lead to excessive electrical activity in the brain.
Other causes of epilepsy can be non-hereditary and without a clear cause. The medical term for this is “idiopathic.”
Symptoms of a seizure
Seizure symptoms vary widely. They can occlude an “aura” (a “hint” that the seizure is coming, such as an abnormal smell (“burnt toast” “burning tires”) or taste (“metal”). It is thought that this aura is actually the start of the seizure. Most common seizure symptoms include tightening of the muscles (“tonic” posturing), rhythmic jerking movements (“clonic” movements), or staring. With frontal lobe seizures there can be repetitive mouth movements such as lip smacking, which are called “automatisms.”
There can be less common and quite interesting seizure symptoms, such as laughing (gelastic seizures), running (cursive seizures), colorful changes in vision (occipital lobe seizures), or others.
Anytime a behavior is felt to be abnormal and stereotypical (happens multiple times in the same way), we can consider seizure.
The precise symptoms of the seizure vary depending on the location of where the seizure starts. The Neurologist can take a detailed history and use this as a clue to discover where the seizure is starting and how to treat it.
Categories of seizures
Focal seizures refer to seizures where the extra electrical activity comes from a specific localized area of the brain. This can be seen on Electroencephalogram (EEG) and these symptoms the person experiences can vary greatly based on which area of the brain is involved. Other terms for a focal seizure include localization-related seizure or partial seizure.
- Simple focal seizures involve a partial seizure where consciousness – or the ability for the person to be aware of surroundings or remember the event – is still intact. This can involve sensory seizures (where numbness or tingling spreads), motor seizures (where there is fine twitching in one part of the body that may spread slowly, called a “Jacksonian” seizure), or other symptoms.
- Complex focal seizures involve a partial seizure where consciousness is lost, or the patient “passes out.” This is the most common type of seizure in adults. In this case, there often is stiffening and/or shaking activity of part of the body while the person is unconscious. In this case, the person will not remember the seizure.
- Secondary generalized seizures involve a focal seizure (as above) where the extra electrical activity spreads to a larger part of the brain, eventually involving both hemispheres of the brain. This results in the whole body having seizure activity.
Generalized seizures are seizures that involve the whole brain. In contrast to the focal seizures, there is no consistent area of the brain that starts the seizure.
- Tonic-clonic (grand mal) seizures involve a pattern in which the person first has stiffening of all of the extremities (called “tonic” posturing) followed by rhythmic shaking activity of the extremities (called “clonic” activity).
- Clonic seizures involve only the rhythmic shaking or twitching of the body.
- Tonic seizures involve only the rigid stiffening of the body.
- Atonic seizures involve the sudden loss of tone in the muscles. This results in a person losing their posture and can result in “drop attacks,” where a person suddenly falls.
- Myoclonic seizures involve jerks of the body, but in this case the jerks are brief and not rhythmic.
- Absence seizures involve a brief loss of consciousness. There is no clear stiffening or jerking of the body. It may appear as if the person is suddenly briefly “staring.” These are also called “petit mal” seizures.
Psychogenic (stress) seizures
Significant stress or anxiety in some people can result in them having seizure-like spells. These are not actually due to excessive electrical activity in the brain and therefore are not truly “seizures” and are treated differently. Various terms are used for this diagnosis, including “pseudo-seizures” or “Psychogenic Non-Epileptiform Spells.”
These spells may be precipitated by clear stressors, have no response to seizure medications, be of a longer duration, involve pelvic thrusting, have more vocalizations, have shaking of both sides of the body without losing consciousness, or have side to side head movements. However, it is challenging to differentiate stress seizures and epilepsy, so it is of the utmost importance that a Neurologist be involved and use EEG monitoring of the brain wave.
Psychogenic seizures are not treated with anti-seizure medications. Instead, the underlying mental health of the patient should be optimized, which may include medications or therapy.
About 2-5% of young children may have seizure activity in the setting of fever. This usual begins between 3 months to 5 years of age and tends to run in families. When the child has a high fever, they have a generalized tonic-clonic seizure, despite having normal brain structure.
One third of children who have febrile seizures have more than one, but 90% of children have no more seizures after age 6.
In addition to a detailed history from the person and observers, further diagnostic testing is often used in seizure disorders.
Neuroimaging including MRI of the brain to evaluate for any structural problems with the brain is often done. There are special seizure-protocols for MRI that focus on areas of the brain that are more likely to start seizures. In some cases, functional MRI (where the metabolism of different areas of the brain is compared) or volumetric MRI (where detailed measurements of the volume of areas of the brain) are used.
Electroencephalogram (EEG) is the most helpful test for making sure that seizure is the correct diagnosis, as well as seeing if the seizure is focal or generalized. This test involves placing small electrodes on the scalp with wires to measure electrical activity. Up to 50% of people with Epilepsy have some abnormalities on this test even between seizure spells, but this test is particularly helpful if it can be done during a seizure spell. Sometimes measures such as light stimulation, sleep deprivation, or hyperventilation are used to try to provoke a seizure while EEG is in place. The pattern on EEG can also help with selection of an effective seizure medication. In special circumstances, more advanced EEG monitoring is considered, such as with implanted deeper electrodes.
Depending on the history, other testing such as lumbar puncture for cerebrospinal fluid testing or blood antibody testing for autoimmune markers of diseases associated with seizures may be completed.
Ambulatory (home) EEG
Modern advances have allowed medical professionals to do EEG monitoring while the person goes about his or her daily activities, rather than having to stay in a hospital or clinic. With this test, electrodes are applied to the scalp and wrapped, or placed against the scalp with a head-cap. Then a digital system records the brain waves while the person does their typical daily activities for 1 to 3 days. This can be a helpful tool for diagnosis, while also being convenient for the patient.
There are a wide variety of seizure medications that can be effective at preventing seizures. The goal is to use as few seizure medications as are effective, but at times up to 3 or 4 seizure medications may be combined. Newer seizure medications have much fewer side effects and do not result in the person being sleepy or confused, like older seizure medications did. Examples include lacosamide, zonisamide, levetiracetam, or oxcarbazepine.
Seizure medications work on the chemical channels in the brain cells – such as sodium, GABA, calcium, or glutamate.
Some seizure medications require routine testing of electrolytes or drug levels, but this is not true with all.
It is of the utmost importance that seizure medications be taken reliably on a set schedule, as missing medications can result in breakthrough seizures. People often benefit from putting their medication in a pill organizer.
Other medications are used to stop – or abort – seizure activity. These include medications like lorazepam or diazepam. There are options for intranasal, oral, or rectal forms of these medications. The Neurologist will instruct when this should be given, but typically these are used if a seizure is lasting nearly 5 minutes.
High in fat and lacking in carbohydrates (sugars), a ketogenic diet can help control seizures, even when medications do not work. A Neurologist would prescribe this diet, and the person would be followed closely by a dietitian. Often, routine lab testing is used to make sure that the diet is being effective and not harming the body.
Vagus Nerve Stimulation (VNS)
In people with seizures that are not adequately controlled on multiple medications, VNS is considered. This involves a surgical procedure to implant a stimulator to the vagus nerve and a batter and signal generator under the skin in the chest. This device sends intermittent stimulation to the vagus nerve, which can help prevent seizures. The signal intensity and frequency can be adjusted by the Neurologist. Additionally, a magnet can be placed over the generator in the setting of a seizure to help stop that seizure. This can be effective and does not have the systemic side effects that additional medications may have.
A neurostimulator can be placed near the area of the brain causing seizures. This can detect early seizure activity and provide additional stimulation to stop the seizure. A common brand is Neuropace. This is invasive and should involve a team of experts, including an Epileptologist and experienced Neurosurgeon.
If a person’s seizures are not controlled on multiple maximized medications and the seizure can be localized to a specific part of the brain using EEG, the person can be considered for surgery to remove the specific region of the brain that starts the seizures. The most common region of the brain to have resected for seizure control is a portion of the temporal lobe. Prior to surgery, the team will take great care to ensure that the area of the brain to be removed is not “eloquent,” or does not have critical functioning for the patient such as involving language skills.
Driving and Seizure Disorder
States have laws restricting aspects of driving for people who have had a seizure, for fear that the person could have a seizure while driving and this could result in injury. Often there is a period of time that the person must be without seizure prior to driving and some states require input from the Neurologist to the state. The specific laws vary widely between states. The Epilepsy Society maintains an online database of driver information by state: https://www.epilepsy.com/driving-laws
Seizure Precautions / Safety
A person who has seizures should make certain adjustments in life to ensure safety. This includes things like not operating heavy machinery, not working at heights, not swimming unsupervised, and taking a shower instead of a bath.
Despite these reasonable adjustments, people with epilepsy can typically maintain employment and a sense of meaningful life.
Advice for family members of patients with seizure disorders
Family members or close friends should be educated on how to partner in the care of a person with epilepsy. If they witness a seizure, they should help lie the person on the ground or a soft surface and should place the person on their side to avoid choking or swallowing of any fluids. They should not put anything in the seizure person’s mouth. They should ensure that the person has a lowest risk of injury possible during the spell. The bystander should note which part of the body has what type of seizure activity, and should record precisely how long the seizure lasts. Family members or close friends can also be educated in how to administer abortive medications to stop the seizure and when to use these.