Seizure – Diagnostics – Overview of Information and Clinical Research

Understanding when and how to diagnose seizures is crucial for anyone experiencing sudden changes in awareness, unusual movements, or unexplained symptoms. Proper diagnosis helps healthcare providers determine whether you’re dealing with seizures, identify the underlying cause, and create an effective treatment plan to manage your condition and improve your quality of life.

Introduction: Who Should Seek Diagnostic Testing

If you experience a sudden episode where you lose control of your movements, stare blankly into space, or have convulsions, it’s important to see a healthcare provider for proper evaluation. Seizures can happen to anyone at any age, and up to 10% of people worldwide will experience at least one seizure during their lifetime.^[1] However, having a single seizure doesn’t automatically mean you have epilepsy, which is a condition defined by recurrent unprovoked seizures.^[2]

You should seek diagnostic testing if you’ve experienced what appears to be a seizure for the first time, especially if there was no obvious trigger like a high fever, injury, or medication reaction. It’s equally important to see a specialist if you’ve had multiple episodes that might be seizures, even if they seem mild or brief. Sometimes seizures can be subtle, causing only a brief period of confusion, unusual feelings, or staring spells that might go unrecognized by both the person experiencing them and those around them.^[5]

Anyone who has had two or more unprovoked seizures should undergo diagnostic evaluation, as this pattern typically warrants a diagnosis of epilepsy and may require treatment with medication to reduce seizure risk.^[5] Even after a single seizure, your doctor may recommend testing if there are signs that you’re at increased risk for more seizures, such as abnormalities found on brain imaging or other diagnostic tests.^[5]

⚠️ Important

Not all seizures are caused by epilepsy. Seizures can be provoked by many factors including infections, abnormal blood sugar levels, medication side effects, alcohol withdrawal, or lack of sleep. Your healthcare provider will work to determine whether your seizures are provoked or unprovoked, as this is essential for proper diagnosis and treatment planning.

Children who experience seizures during a fever, known as febrile seizures, also need evaluation, particularly if it’s the first time or if the seizure lasts longer than five minutes.^[3] While febrile seizures are relatively common, affecting about 1 in 30 children between 6 months and 6 years old, they still require medical assessment to rule out other serious conditions.^[3]

Adults over 55 years old who experience their first seizure should be particularly vigilant about seeking diagnosis, as new seizure cases increase in this age group. This increase is often related to brain injuries such as stroke, brain tumors, or conditions like Alzheimer’s disease, all of which can increase seizure risk.^[5] Working closely with your physician to identify which diagnostic tests you need is an important step in evaluating your risk for further seizures and determining whether medication or other treatments are necessary to prevent future episodes.^[5]

Classic Diagnostic Methods for Identifying Seizures

When you visit a healthcare provider after experiencing a possible seizure, they will begin with a thorough review of your symptoms and medical history, along with a physical examination.^[8] This initial evaluation is crucial because many different conditions can cause symptoms similar to seizures, including fainting, movement disorders, sleep-related events, and psychological conditions.^[2] Your doctor needs to carefully distinguish between these possibilities to make an accurate diagnosis.

During your appointment, your healthcare provider will ask detailed questions about what happened before, during, and after the episode. If someone witnessed your seizure, it can be extremely helpful to bring them along, as they can describe what they observed.^[8] The doctor will want to know about any warning signs you experienced, how long the episode lasted, what movements or sensations occurred, and how you felt afterward. This information helps determine the type of seizure and where in your brain it might have started.

Neurological Examination

A neurological exam is a standard part of seizure diagnosis. During this examination, your healthcare provider evaluates your behavior, motor abilities, and how your brain functions.^[8] They check your reflexes, muscle strength, coordination, and sensory responses. This exam helps identify any signs of neurological problems that might explain your seizures or indicate an underlying brain condition.

Blood Tests

Blood tests are commonly ordered to help identify potential causes of seizures. A blood sample can reveal important information about your blood sugar levels, which when too high or too low can trigger seizures.^[8] Blood tests also check for signs of infections, examine the levels of salts and minerals in your body (called electrolytes), and can detect certain genetic conditions that might be associated with seizures.^[8] Additionally, if you’re already taking seizure medications, blood tests can measure drug levels to ensure they’re within the proper therapeutic range.

Electroencephalogram (EEG)

The electroencephalogram, or EEG, is one of the most important diagnostic tools for seizures. This test records the electrical activity of your brain through small metal discs called electrodes that are attached to your scalp.^[8] The brain’s neurons constantly send electrical signals to communicate with each other, and an EEG captures these patterns of activity. When someone has seizures, the EEG often shows abnormal electrical patterns that can help confirm the diagnosis and identify the type of seizure disorder.

During an EEG, you typically sit or lie down while the electrodes are placed on your scalp using a special paste or fitted cap. The test is painless and usually takes about an hour. Sometimes doctors ask you to do certain things during the test, such as breathing deeply or looking at flashing lights, because these activities can sometimes trigger abnormal brain waves that wouldn’t otherwise be visible.^[8] In some cases, a longer EEG recording may be needed, which can be done in a hospital setting over several days to capture seizure activity that doesn’t happen frequently.

Brain Imaging Tests

Various imaging tests help doctors see the structure of your brain and identify any abnormalities that might be causing seizures. These tests create detailed pictures of your brain and can reveal issues such as tumors, areas of scarring, blood vessel problems, or brain injuries.

Magnetic Resonance Imaging, or MRI, uses powerful magnets and radio waves to create highly detailed images of your brain’s soft tissues.^[8] An MRI doesn’t use radiation and can show very small abnormalities that might not be visible with other types of scans. This test is particularly useful for finding structural problems in the brain that could be causing seizures. During an MRI, you lie inside a large tube-shaped machine for about 30 to 60 minutes. The machine can be noisy, but you’re usually given earplugs or headphones to make the experience more comfortable.

Computed Tomography, or CT scan, is another imaging test that creates pictures of your brain. A CT scan uses X-rays taken from different angles and combines them with computer processing to produce cross-sectional images.^[8] CT scans are faster than MRIs and are often used in emergency situations to quickly check for bleeding, tumors, or other serious problems. However, they don’t provide as much detail about soft tissue as an MRI does.

In some cases, specialized imaging tests may be used. SPECT imaging (Single Photon Emission Computed Tomography) can show blood flow patterns in your brain during and between seizures, helping to pinpoint exactly where seizures are starting.^[8] This information is especially valuable if surgery is being considered as a treatment option.

Additional Diagnostic Tests

Depending on your specific situation, your doctor might order additional tests. An electrocardiogram (ECG or EKG) checks your heart’s electrical activity to rule out heart rhythm problems that can sometimes cause symptoms similar to seizures.^[8] If your healthcare provider suspects your episodes might be related to psychological factors rather than abnormal brain electrical activity, they may refer you for evaluation of psychogenic nonepileptic seizures (PNES), a condition where seizure-like attacks are caused by intense emotional trauma or stress rather than epilepsy.^[7]

The combination of these various diagnostic methods helps your healthcare provider build a complete picture of what’s happening in your brain and body. This comprehensive approach is necessary because seizures can have many different causes, and the correct diagnosis guides the most appropriate treatment for your individual needs.

Diagnostics for Clinical Trial Qualification

When considering participation in a clinical trial for seizure disorders or epilepsy, patients typically need to undergo specific diagnostic tests that serve as standard criteria for enrollment. Clinical trials are research studies that test new treatments, medications, or devices, and they require precise documentation of each participant’s condition to ensure the study results are reliable and meaningful.

The diagnostic requirements for clinical trials are often more rigorous than those used in routine clinical practice. Researchers need detailed, objective evidence about the type, frequency, and severity of your seizures, as well as comprehensive information about your overall health and how your brain functions. This information ensures that the right patients are matched with the right experimental treatments and helps researchers accurately measure whether the new treatment is working.

⚠️ Important

Clinical trials have specific inclusion and exclusion criteria based on seizure type, frequency, and other medical factors. The diagnostic tests help determine whether you qualify for a particular study. If you’re interested in clinical trials, discuss with your healthcare provider which studies might be appropriate for your condition and what additional testing might be needed.

For clinical trial enrollment, extended EEG monitoring is commonly required. This might involve a video EEG, where you stay in a hospital setting for several days while your brain activity is continuously recorded and your behavior is captured on video.^[8] This allows researchers to document the exact nature of your seizures, confirm they are truly epileptic seizures rather than other types of episodes, and precisely identify which type of seizure disorder you have. Video EEG monitoring is particularly important for trials testing new anti-seizure medications or surgical approaches, as it provides the most accurate baseline information about your condition.

Brain imaging with MRI is almost always required for clinical trial qualification. The MRI images need to be recent (typically within the past year) and often must follow specific protocols that provide the level of detail researchers need.^[8] These images help researchers understand the structure of your brain, identify any abnormalities that might be causing seizures, and exclude participants who have conditions that might interfere with the study results or put them at increased risk from the experimental treatment.

Comprehensive blood tests are standard for clinical trial screening. Beyond the basic blood work used in routine diagnosis, trials often require more detailed laboratory analysis to assess your liver and kidney function, check for specific genetic markers, and ensure there are no underlying health conditions that might be affected by the experimental treatment.^[8] Some trials may also require genetic testing to identify specific gene variations that might influence how you respond to the treatment being studied.

Neuropsychological testing is frequently part of clinical trial diagnostics, especially for studies involving children or trials testing treatments that might affect memory, thinking, or behavior. These tests provide detailed measurements of cognitive function, memory, attention, and other mental abilities. The results establish a baseline that allows researchers to monitor whether the experimental treatment has any effects on these important aspects of brain function.

Documentation of seizure frequency and characteristics is essential for trial qualification. Many studies require participants to keep detailed seizure diaries for a period of weeks or months before enrollment, recording the date, time, duration, and description of each seizure. Some trials may also require participants to use seizure detection devices or smartphone apps to provide objective data about seizure frequency. This careful documentation helps ensure that all participants meet the trial’s criteria for seizure frequency and allows researchers to accurately measure whether the experimental treatment reduces seizures.

Medical history documentation for clinical trials is more extensive than for routine care. Researchers need complete records of all seizure medications you’ve tried, the doses you took, how long you took them, and why they were stopped or changed. They also need information about any other medical conditions you have, other medications you’re taking, and detailed family medical history. This information helps researchers understand whether you’re likely to be a good candidate for the experimental treatment and identify any factors that might influence your response.

The diagnostic process for clinical trial qualification takes time and effort, but it serves important purposes. It ensures participant safety by identifying anyone who might be at increased risk from the experimental treatment. It helps researchers select participants who are most likely to benefit from the treatment being studied. And it provides the detailed baseline information necessary to determine whether the new treatment actually works. If you’re interested in participating in a clinical trial, your healthcare provider can guide you through the specific diagnostic requirements for studies that might be appropriate for your condition.

Prognosis and Survival Rate

Prognosis

The outlook for people with seizures varies considerably depending on the underlying cause, the type of seizures, and how well they respond to treatment. For many people with epilepsy, the prognosis is quite positive. About 70% of people with epilepsy gain control of their seizures with medication, allowing them to live full, active lives with minimal interference from their condition.^[11] Medications work effectively for about two out of three people with epilepsy, helping to prevent or significantly reduce seizure frequency.^[10]

For individuals whose seizures are well-controlled with medication and who have had no seizures for several years, doctors may suggest trying to stop medication. Some people remain seizure-free after discontinuing treatment, while others need to continue medication throughout their lives.^[15] The remaining 30% of people with epilepsy who don’t achieve adequate seizure control with medication may be candidates for other treatments, including surgery, dietary changes, or implanted devices.^[15]

Several factors influence prognosis. The age when seizures begin plays a role, with new cases being most common in young children (particularly in their first year of life) and in people over 55 years old.^[5] People who develop epilepsy later in life often have it as a result of other conditions like stroke, brain tumors, or head injuries, which can affect their overall prognosis. The type of seizures also matters, with some types being easier to control than others. People with poorly controlled tonic-clonic seizures (the type with loss of consciousness and convulsions) face higher safety risks, especially if seizures occur without warning.^[19]

Quality of life for people with seizures can be significantly affected by factors beyond seizure frequency. Depression and anxiety commonly occur with epilepsy and can have major effects on wellbeing, but these conditions are very treatable.^[22] Lifestyle adaptations, including stress management, adequate sleep, and avoiding known seizure triggers, can improve outcomes considerably.^[21] With proper treatment and support, many people with seizures can work, drive (when seizures are controlled and medical clearance is given), and participate fully in daily activities.

Survival rate

The vast majority of people with seizures have a normal life expectancy, especially when their condition is well-managed with appropriate treatment. However, seizures do carry certain risks that need to be acknowledged and managed carefully. Seizure-related risks are highest when people have poorly controlled seizures, and good seizure control is the first step in reducing these risks.^[19]

Seizures can occasionally lead to injuries from falls or accidents during an episode. More rarely, seizures can be serious enough to contribute to or cause death, particularly when they occur in dangerous situations such as while swimming or from very prolonged seizures that don’t stop on their own.^[19] The most serious risk is Sudden Unexpected Death in Epilepsy (SUDEP), which refers to death in someone with epilepsy where no other cause can be found. While SUDEP is the most common cause of death in people with poorly controlled epilepsy, it remains relatively rare overall.^[19]

The risk of serious complications is significantly reduced when seizures are well-controlled. Taking seizure medications exactly as prescribed is one of the most important ways to reduce risks and improve outcomes.^[19] Regular follow-up with healthcare providers, making appropriate safety modifications at home and work, and educating family members about seizure first aid all contribute to better outcomes and reduced risk of complications. For the roughly 70% of people whose seizures are controlled with treatment, the prognosis is excellent, with life expectancy essentially the same as the general population.

#1 Clinical Trials Search in Europe