Diagnosis

At Mayo Clinic, your epilepsy care team will take the time to listen to you, have conversations and answer questions in order to accurately diagnose your condition and tailor the best treatment options to you. This begins with a thorough evaluation to review your symptoms and medical history and coordinate all necessary tests to determine the cause of your seizures. This comprehensive evaluation may be overwhelming, but Mayo Clinic epilepsy experts will take as much time as necessary to explain, interpret and guide you through the process. Your evaluation may include:

  • Neurological examination. Your doctor may test your behavior, motor abilities, mental function and other areas to diagnose your condition and determine the type of epilepsy you may have.
  • Blood tests. Your doctor may take a blood sample to check for signs of infections, genetic conditions, autoimmune disorders or other conditions that may be associated with seizures.

Your Mayo Clinic epilepsy care team may also suggest tests to detect brain abnormalities, such as:

  • Electroencephalogram (EEG). This is the most common test used to diagnose epilepsy. In this test, electrodes are attached to your scalp with a paste-like substance. The electrodes record the electrical activity of your brain. EEG can be done in an outpatient or inpatient setting. Each Mayo Clinic location offers inpatient video-EEG epilepsy monitoring.

If you have epilepsy, it's common to have changes in your normal pattern of brain waves, even when you're not having a seizure. Your doctor may monitor you on video while conducting an EEG while you're awake or asleep, to record any seizures you may experience. Recording the seizures may help the doctor determine what kind of seizures you're having or rule out other conditions. Your doctor may give you instructions to do something that will cause seizures, such as getting little sleep prior to the test.

In the Mayo Clinic inpatient video-EEG epilepsy monitoring units, not only is the EEG recorded, but technicians monitor the patient every second of the day or night. This way, if the patient is sleeping or the seizure is subtle, technologists are still able to pick it up. Continuous 24/7 monitoring by trained, on-site technicians increases safety and can reduce the length of stay on the unit.

At Mayo Clinic Children's Center, the pediatric EEG video monitoring unit is designed so that you can stay with your child at all times. Although children are restricted to their room, they are free to move about within the room. The unit's rooms are equipped with the latest technology, including interactive computer games. Child-life specialists visit several times a day with crafts, toys, games and videos and also work with children and families to help them through procedures that may be uncomfortable or are unfamiliar.

  • Computerized tomography (CT) scan. A CT scan uses X-rays to obtain cross-sectional images of your brain. CT scans can reveal abnormalities in your brain that might be causing your seizures, such as tumors, bleeding and cysts.
  • Magnetic resonance imaging (MRI). An MRI uses powerful magnets and radio waves to create a detailed view of your brain. Your doctor may be able to detect lesions or abnormalities in your brain that could be causing your seizures.
  • Functional MRI (fMRI). A functional MRI measures the changes in blood flow that occur when specific parts of your brain are working. Doctors may use an fMRI before surgery to identify the exact locations of critical functions, such as speech and movement, so that surgeons can avoid injuring those places while operating.
  • Positron emission tomography (PET). PET scans use a small amount of low-dose radioactive material that's injected into a vein to help visualize active areas of the brain and detect abnormalities.
  • Single-photon emission computerized tomography (SPECT). This type of test is used primarily if you've had an MRI and EEG that didn't pinpoint the location in your brain where the seizures are originating.

    A SPECT test uses a small amount of low-dose radioactive material that's injected into a vein to create a detailed, 3-D map of the blood flow activity in your brain during seizures.

    Mayo Clinic scientists developed a form of a SPECT test called subtraction ictal SPECT coregistered to magnetic resonance imaging (SISCOM), which can provide even more detailed results and enable more accurate and effective surgeries.

  • Neuropsychological tests. In these tests, doctors assess your thinking, memory and speech skills. The test results help doctors determine which areas of your brain are affected.

Mayo Clinic neurologists, neurosurgeons, imaging specialists (radiologists) and mental health specialists (neuropsychologists) conduct these tests and collaborate with each other on a daily basis at team conferences to provide accurate diagnoses and treatment plans individualized for each patient. What might take months to accomplish elsewhere can typically be done in only a matter of days at Mayo Clinic.