Seizure disorders: Types and causes | Pacific Medical ACLS
It can be terrifying to witness anyone, a loved one or stranger, having a seizure. Approximately one in 50 adults will have a seizure in their lifetime, but two-thirds will never have another episode. While many people only experience a seizure once or twice in their life, others may have recurring seizures that impact their daily routine.
Seizure disorders affect people of all ages, ethnicities, and countries. Understanding seizure disorders is crucial because they impact the quality of life of family, friends, or patients. Healthcare professionals diagnose and manage seizures with medication, lifestyle changes, and other treatments.
People with seizure disorders can lead productive and fulfilling lives with proper treatment and management. This article will help you to understand the basics of seizure disorders, including types, causes, symptoms, diagnosis, and treatment.
What are seizure disorders?
Seizure disorders are neurological disorders affecting the brain’s electrical activity. The type of seizure disorder impacts an individual’s symptoms, treatment, and long-term prognosis.
Neurons may release electrical discharges within an epileptogenic (seizure-causing) focus. A seizure occurs following an excessive electrical discharge in the brain that disrupts the brain’s typical function.
Where do seizure disorders occur?
Seizure disorders are complex conditions that can occur in various areas of the brain. The two significant areas where seizure disorders occur are the cortex and subcortex.
The cortex, the brain’s outer layer, enables higher thinking functions like critical thinking and language in this “gray matter.” Focal seizures originate in the cortex due to imbalances in the gray matter of the cortex.
The brain’s subcortex is underneath the cortex and controls primitive functions like autonomic regulation, sleep, and emotions. Parts of the subcortex are the “white matter.” The brain’s white matter in the subcortex communicates with the cortex, so disorders of the white matter may cause generalized seizures or other types of neurologic disorders.
Nerve fibers covered in myelin, a sheath covering nerves wrapped in phospholipids and proteins, connect the sides of the brain. For those experiencing epilepsy, seizures often worsen over time. Researchers believe that this is due to increasing myelination following epilepsy seizures, which leads to more episodes. As the number of bouts grows, so does the amount of myelination, and the cycle continues.
Seizure disorders can affect the brain’s deep structures, like the brainstem, thalamus, and basal ganglia. Together, these drugs control movement, sensation, and consciousness. Generalized and absence seizures may occur due to dysfunction in these areas.
What is the difference between a seizure disorder and epilepsy?
A seizure is a singular episode of abnormal electrical activity in the brain, whereas epilepsy is a neurological disorder with recurring seizures. This article describes other types of seizure disorders.
Types of seizure disorders
Many people assume that people who experience a seizure have epilepsy. However, there are many other types of seizures. The seizure type varies depending on the part of the brain affected and the electrical discharge severity. This article explores the most common type of seizure disorders and their characteristics.
What are the types of seizures?
The earliest prominent characteristics classify seizures. The initial classification of seizures splits insignificant or categories related to onset:
Generalized
Focal
Unknown onset
Healthcare providers also classify seizures by motor or nonmotor onset. Within these categories, there are many different types of seizures.
Seizure types that are generalized-onset motor seizures are:
Tonic-clonic seizure (formerly grand mal seizure) occurs bilaterally and includes a tonic phase followed by clonic muscle contractions. This is one of the most dangerous types of seizure.
Chronic seizures that involve continuous bilateral rhythmic jerking muscle movements.
Tonic seizures with increased muscle tone lead to stiffening limbs but no jerking.
Atonic seizures simply include a loss of muscle tone which can cause a person to collapse.
Myoclonic seizures include brief jerking of a muscle or group without stiffening and affect various body parts.
Myoclonic-tonic-clonic seizures include myoclonic episodes followed by tonic (muscle stiffening) and clonic (jerking) movements.
Myoclonic-atonic seizures occur when there is myoclonic jerking and then atonia.
Epileptic spasms, formerly infantile spasms, are a type of seizure seen in young children. These spasms typically occur in clusters with brief, sudden muscle contractions or spasms involving the neck, trunk, or extremities. The child may briefly bend forward or stiffen, and it can last a few seconds but with several spasms in a short period.
Generalized-onset non-motor seizures include changes in consciousness without motor manifestations due to widespread electrical discharges in both brain hemispheres. This affects the entire brain and can be further categorized.
Generalized-onset nonmotor seizure types include:
Absence seizures are characterized by a brief loss of awareness that may present as eye blinking or staring spells.
Typical: No typical cause
Atypical: Less abrupt onset or termination or abnormal changes in tone
Myoclonic seizures are sudden, brief muscle contractions that affect different body parts with jerking movements (often bilateral).
Eyelid myoclonia includes rapid, fluttering, involuntary movements of the eyelids.
Absence seizures tend to occur in younger people and start and end suddenly.
Focal onset seizures originate in a specific area of the brain and one brain hemisphere, often in the subcortical structures. They were formerly known as partial seizures and can be widely distributed or localized. The patient’s level of awareness classifies focal onset seizures:
In focal onset aware seizures (formerly known as simple partial seizures), the person remains conscious during the seizure. During the seizure, they may experience unusual sensations, emotions, thoughts, and repetitive moments.
Focal impaired awareness seizures (formerly known as complex partial seizures) are where awareness is impaired at some point during the seizure. They involve losing consciousness or a significant alteration in awareness.
Focal onset motor seizures classify seizure types, including:
Automatisms are coordinated, repetitive motor activity
Atonic is the focal loss of muscle tone
Clonic occur with focal rhythmic jerking
Epileptic spasm is a focal extension or flexion of the upper extremities (arms) and trunk flexion
Hyperkineticoccurs with pedaling or thrashing
Myoclonic is brief, irregular focal jerking
Tonic is sustained focal stiffening on a unilateral limb or side of the body
Atonic seizures and epileptic spasms often do not have an associated awareness level.
Focal onset nonmotor seizures are classified by their earliest prominent features, such as:
Autonomic dysfunction includes sensations of hot or cold, gastrointestinal sensations, sexual arousal, and palpitations.
Behavior arrest occurs when the movement ceases, with unresponsiveness as the main feature of the seizure.
Cognitive dysfunction impairs language or other cognitive domains. It can cause positive features like déjà vu hallucinations or illusions.
Emotional dysfunction manifests emotional changes like anxiety, fear, or joy.
Sensory dysfunction causes visual, auditory, olfactory, gustatory, somatosensory, or vestibular sensations.
Other Types of focal onset seizures
Focal-onset seizures may evolve into generalized-onset tonic-clonic seizure that causes a loss of consciousness. The initial focal onset seizure may not be clinically apparent due to brevity.
Focal-to-bilateral tonic-clonic seizures occur when a focal onset seizure spreads from one hemisphere to another and activates the entire cerebrum bilaterally without losing consciousness.
Focal onset tonic seizures: Stiffening unilateral limb or one side of the body without loss of consciousness.
A focal dyscognitive seizure doesn’t involve convulsions but impairs consciousness.
Unknown-onset seizures
Seizures with an unknown origin refer to cases with an unknown cause and can be motor or nonmotor. Unknown-onset seizures are diagnosed when data about the onset is lacking but may be reclassified later.
Unknown-onset motor seizures include tonic-clonic seizures and epileptic seizures. A tonic-clonic seizure is obscure and often classified as an unknown onset seizure.
The diagnosis of unknown-onset nonmotor seizures may be given before identifying the specific disorder, such as epileptic spasms or behavior arrest seizures.
Eclampsia
During pregnancy, those who have never experienced a seizure may experience seizure activity due to eclampsia, a hypertensive disorder. Eclampsia is a serious pregnancy complication with a sudden onset of seizures or convulsions in someone with preeclampsia between 20 weeks gestation and six weeks postpartum. Preeclampsia causes elevated blood pressure and organ damage. Symptoms include headaches, blurred vision, and abdominal pain. Less than one percent of people with preeclampsia have a seizure.
However, when it occurs, it can be fatal to both the patient and the baby and requires immediate medical attention. Prompt diagnosis and treatment are crucial to save the lives of both.
Epilepsy
Epilepsy is the fourth most common neurological disorder. An estimated 50 million people have epilepsy worldwide1, and 3.4 million people (1.2% of the population) in the U.S. have epilepsy2.
Epilepsy is a chronic condition with recurrent seizures caused by these surges in electrical activity3. It affects people of all ages, but healthcare providers more commonly diagnose children and older adults. About 70% of people with epilepsy can control their seizures with medication, but 30% experience uncontrolled seizures1. Sudden unexpected death in epilepsy (SUDEP) is a rare but potentially fatal complication in 1 of 1,000 people with epilepsy annually.
Is there a cure for epilepsy?
There is no known cure for epilepsy, but people with epilepsy can manage the condition with medications and other treatments. People with epilepsy can often live relatively normal lives with medical management and lifestyle changes.
What causes seizure disorders?
You might wonder what causes someone to experience a seizure suddenly. What causes a person to experience seizures for the first time? While some chronic seizure disorders occur frequently, others occur only once or twice and happen suddenly.
Multiple factors cause seizures, including:
Head trauma
Birth injuries
Hereditary neurological disorders
Metabolic disorders
Idiopathic seizure disorders
Alcohol withdrawal
Tumors
Strokes
Fever
Electrolyte abnormality
Toxic ingestion
Pregnancy with eclampsia
Hyperthermia
Hypoglycemia
Environmental factors
The causes of seizure disorders are often multifaceted and complex. Medical experts may not fully understand the multifactorial underlying causes behind seizures. For example, some causes of generalized-onset seizures sometimes result from genetic disorders.
Other causes of seizure disorders include:
Brain injury
Infections
Diseases
Environmental Factors
While there is typically a clear underlying cause, there is seemingly no cause in some cases. However, knowing that seizures with an unknown cause are idiopathic is crucial.
Seizure mimics
A seizure mimic resembles a seizure but is not caused by abnormal electrical brain activity. Some conditions may cause convulsions, involuntary muscle movements, aura, or fainting that may be mistaken for a seizure.
Examples include:
Syncope
Psychogenic non-epileptic seizures known as pseudoseizures
Migraine with aura
Movement disorders
Cardiac arrhythmias
Signs and symptoms
Seizure disorders cause some life-altering signs and symptoms. These signs and symptoms include:
Convulsions or shaking
Involuntary movements of the limbs
Loss of consciousness
Confusion or drowsiness
Staring spells
Altered behavior
Sensations in the body
Auditory or visual hallucinations
Incontinence (urinary or fecal)
Seizures may cause a loss of consciousness in some individuals. Individuals who lose consciousness may experience incontinence (urine or feces), prolonged confusion, or tongue biting.
Warning signs
Aura is a change in the individual that some experience before a seizure begins. It is subjective and may be sensory, autonomic, or psychic sensations or feelings. Auras may help individuals with seizure disorders anticipate the impending seizure and take appropriate safety methods.
What is an aura?
Aura is a simple type of seizure called focal aware seizure that occur before a more severe type of focal seizure. Auras can include many sensations, such as sights, sounds, smells, and pain.
An aura can take many different forms, such as:5
Paresthesias, meaning an abnormal skin sensation with no obvious physical cause
Abdominal symptoms such as digestion, nausea, pain, flatulence, or hunger
Twitching, jerking, or repetitive motions
Epigastric sensation
Abnormal smells
Sensory perception changes like tingling, numbness, or sensation of heat or cold
Sweating or flushing
Changes in heart rate, respiratory rate, or blood pressure
A sensation of fear
Déjà vu is the feeling that one has previously encountered something while it is being experienced for the first time, even though they know it is impossible.
Jamais vu is the phenomenon of being unfamiliar with a certain circumstance that should be very familiar and is the opposite of déjà vu.
What is the after effect of seizures in adults?
The after-effects of seizures in adults vary based on the type, severity, and duration. When signs and symptoms continue after the completion of the seizure, this is considered the postictal state. Some individuals experience post-seizure effects, including disorientation, fatigue, and confusion in the postictal state. These effects can last between several minutes to many hours.
The period of time immediately following a seizure is known as the postictal phase. Common after-effects of seizures include:
Headache
Fatigue
Weakness
Confusion
Memory loss
Speech challenges
Muscle soreness or injuries following convulsions
Emotional changes like anxiety, depression, irritability, or mood swings
Changes in cognition, like new issues with problem-solving or concentration
Loss of bladder or bowel control
Temporary paralysis or weakness in one or more limbs
Diagnosing seizure disorders
Just because someone experiences a seizure does not mean they have epilepsy. Accurate diagnosis enables healthcare providers to provide accurate therapy. Evaluate patients with seizures for possible causes.
Initial nursing assessments should include evaluating for:
Fever
Stiff neck
Focal neurologic deficits
Neuromuscular irritability
Hyperreflexia
Papilledema
It can feel challenging to get to the bottom of why these seizures are happening. However, there are medical tests that can explain what is occurring, whether it’s new onset seizures or to evaluate levels of antiseizure medications for patients with a seizure disorder who experience breakthrough seizures.
Healthcare providers can provide an accurate diagnosis and management plan from medical tests like neuroimaging, laboratory testing, and electroencephalograms. There are many diagnostic tests and procedures to review.
An electroencephalogram (EEG) measures brain electrical activity through electrodes attached to the scalp. It can help identify abnormal brain activity that may be causing seizures. Detailed EEG monitoring clarifies whether the seizure onset is focal or generalized. Determining the seizure onset is crucial because, in some cases, focal seizures are manageable. Managing a focal seizure can decrease the risk of long-term complications like mood disorders and cognition.
Computed tomography (CT) scan is a non-invasive test that uses ionizing radiation for brain imaging to identify abnormalities like bleeding or swelling5.
Magnetic resonance imaging (MRI) is a non-invasive medical test that uses a magnetic field and computer-generated radiofrequency waves to produce detailed brain images that can identify structural abnormalities that may cause seizures, such as brain tumors or cysts6. MRI machines are large tube-shaped magnets that patients lie inside.
Laboratory tests, including bloodwork, help identify or rule out underlying medical conditions causing seizures, like infections or metabolic disorders.
Video EEG monitoring combines EEG and video recording to capture and analyze seizures while they occur to identify the type and origin of the seizure.
Neuropsychological testing assesses cognitive function and emotional status that identify mental or emotional deficits. This can help with diagnosis, to establish a baseline for cognitive function, and to determine strengths and weaknesses.
Treatment
First, the management goal is to eliminate any possible cause. After potential triggers have been removed from the individual’s life, managing seizure disorders includes lifestyle changes and treatment strategies. Medications and other treatments can control conditions and prevent seizures.
Seizure treatment includes:
Anticonvulsants (antiseizure medications) stabilize the brain’s electrical activity and prevent seizures. These drugs are often required indefinitely, but some episodes do not require treatment, such as alcohol withdrawal or febrile seizures. Many types of antiseizure drugs are available, so the choice of the specific drug depends on the seizure type, patient age, and complete medical history.
Surgery is not standard. However, in some situations, if more than two drugs in therapeutic doses fail to control seizures, healthcare providers may recommend surgery to control seizures. The surgery type depends on the severity and location of the seizures.
Implantable devices can be used for certain types of epilepsy, but not all patients with epilepsy are candidates for these devices. Individuals with epilepsy should participate in shared decision-making with their healthcare provider to decide if these may benefit their seizure management plan.
A Vagus nerve stimulator (VNS) is the most common type and is implanted under the skin in the chest where a wire connects to the vagus nerve in the neck. The VNS sends electrical impulses to the vagus nerve, which is transmitted to the brain and may reduce some seizures’ frequency and severity. Vagal nerve stimulation is helpful for medically intractable seizures.
Other implantable devices, such as deep brain stimulation and responsive neurostimulation, are currently in research and development.
Temporal lobe resection: Also known as a temporal lobectomy, this commonly performed procedure involves removing the brain tissue where seizures originate. This tissue is in a portion of the brain’s temporal lobe and often results in an improvement in the number and severity of seizures.
Disconnected surgeries: Most commonly done in children, disconnected surgeries separate the area of seizure from the rest of the brain. They include functional hemispherectomy, anatomic hemispherectomy, peri-insular hemispherectomy, and corpus callosotomy.
Focal laser ablation: Minimally invasive surgery with lasers to pinpoint where the seizures are happening and eliminate the focus
Focal resection: Common epilepsy surgery that removes the brain causing seizures.
Lesionectomy: Remove a lesion in the brain causing focal seizures.
Lifestyle changes can help reduce the frequency and intensity of seizures. These changes include improving the quality and length of sleep, avoiding alcohol and other substances, managing all stress, and avoiding triggers that may provoke seizures. Triggers for some can include poor sleep, illness, alcohol, flashing lights, certain foods, menstruation, or stress. Strong smells like perfume, bleach, gasoline, glue, perfume, or smoke may trigger some seizures.
Treatment strategies like a ketogenic diet or cognitive behavioral therapy may help manage this condition.
Patient education: Learning to avoid or minimize seizure triggers can reduce the risk of complications. Patients should know to avoid situations where a loss of consciousness can cause significant harm to themselves or others. Items that patients should know to prevent include driving or swimming alone.
Coping with seizure disorders
A seizure disorder can be life-altering to the person experiencing it. There are also considerations for family, friends, and colleagues. These include:
Mental health risks: Seizures can increase the risk of depression, anxiety, or mental health issues. Psychological support can be beneficial in managing any challenges.
Social support: Individuals with seizure disorders may feel isolated. Support will provide connection and improve the quality of life through support groups, counseling, and connecting with others with seizure disorders.
Effective communication: Individuals with seizure disorders must feel free to communicate their needs, triggers, and necessary accommodations.
Lifestyle adjustments: Change sleep patterns, exercise habits, or diets to manage seizure disorders.
Safety precautions: To prevent injury, individuals with seizure disorders must avoid certain activities and have a plan for seizure management in public settings to prevent potential safety risks.
Conclusion
People with seizure disorders do not have to go through this alone. It is crucial to seek medical advice and support from your healthcare provider if you are experiencing any signs or symptoms of a seizure. People with seizure disorders have significant life changes, medication regimens, and other therapies crucial to staying healthy. This article covered all the essential ways to keep patients with seizure disorders healthy.
Works cited
World Health Organization. Epilepsy. Accessed April 15, 2023. https://www.who.int/news-room/fact-sheets/detail/epilepsy
Centers for Disease Control and Prevention. Epilepsy data and statistics. Accessed April 15, 2023. https://www.cdc.gov/epilepsy/data/index.html
Epilepsy Foundation. What is epilepsy? Published n.d. Accessed April 15, 2023. https://www.epilepsy.com/what-is-epilepsy
Centers for Disease Control and Prevention. Types of seizures. Accessed April 27, 2023. https://www.cdc.gov/epilepsy/about/types-of-seizures.htm
Merck Manual Professional Version. Seizure disorders. Published 2022. Accessed April 15, 2023. https://www.merckmanuals.com/professional/neurologic-disorders/seizure-disorders/seizure-disorders
Assid P. CT Scan vs. MRI: Differences. Verywell health. Published 2023. Accessed April 15, 2023. https://www.verywellhealth.com/ct-scan-vs-mri-6979395
Cleveland Clinic. Neuropsychological testing and assessment. Published 2020. Accessed May 8, 2023. https://my.clevelandclinic.org/health/diagnostics/4893-neuropsychological-testing-and-assessment
Written by Caitlin Goodwin on May 23, 2023
Caitlin Goodwin, DNP, RN, CNM, is a Board Certified Nurse-Midwife, Registered Nurse, and freelance writer. She has over twelve years of experience in nursing practice.