Epilepsy Testing & Diagnosis
Nurses and diagnostic specialists with expertise in epilepsy and seizure disorders use advanced diagnostic tools to continuously monitor brain activity during seizures. This specialized testing helps epilepsy specialists identify the type of seizures, where they are occurring in the brain, thereby providing information on the type of epilepsy the ability to select the best treatments.
Diagnostic Tests Offered
Electroencephalogram (EEG)
An EEG test is able to determine the type of epilepsy you have and potential underlying causes by measuring and recording the brain’s electrical activity. During the test, special sensors (electrodes) are attached to your head and a computer will records the brain’s electrical activity.
An EEG technician conducts the test, which can be done in a hospital or in a doctor’s office, and a neurologist reads the results. Over 10,000 EEG tests are performed at University Hospital each year.
Magnetic Resonance Imaging (MRI)
An MRI is a tool used for taking pictures of your brain.
For this test, you will be placed into a tube with magnets. While in there, the magnets will collect information about your brain, potentially identifying the causes of your epilepsy. This can identify tumors, strokes, a brain injury, scarring or small to large areas of brain with developmental abnormalities (cortical dysplasias).
Video EEG
Some people with epilepsy don’t respond to medical therapies and are referred to the Epilepsy Monitoring Unit (EMU) for evaluation. In the EMU, your medications are reduced or paused to safely capture and monitor seizures through continuous video-EEG. You will be closely watched by trained staff, with nurses and physicians available around the clock to ensure your safety and respond to emergencies.
This testing helps specialists determine where seizures begin in the brain and whether they come from one specific area. Some people may experience seizure-like episodes without abnormal brain activity. These episodes are diagnosed as a psychogenic nonepileptic event (PNEE), which are often linked to psychological stress. From there, you will be referred to neuropsychologists for a structured outpatient program to help manage and reduce symptoms.
Preoperative Testing
Sometimes medications are unable to help control epileptic seizures. In addition to dietary therapies, surgical treatments are another option to consider.
Before going into surgery, several tests are performed to assist with the identification and confirmation of the location of where seizures arise.
Pruebas preoperatorias disponibles
SPECT cerebral
La Single Photon Emission Computed Tomography (SPECT) genera imágenes del flujo sanguíneo hacia el cerebro.
Durante el examen, se inyecta un marcador radiactivo y su distribución en el cerebro se puede observar mediante una cámara especial. A partir de ahí, un técnico en radiología podrá determinar si el flujo sanguíneo hacia una zona del cerebro aumenta durante una convulsión o disminuye entre convulsiones.
High-Density EEG
The high-density EEG is similar to a normal EEG test where electrodes are placed on your head in order to measure and record the brain’s electrical activity.
During this test, more electrodes will be used. A high-density EEG uses up to 128 electrodes compared to 26-28 electrodes in the regular EEG.
Positron Emission Tomography
A position emission tomography (PET) scan shows blood flow and how the brain uses sugar (glucose), measuring the changes in the brain’s metabolism and chemistry.
Brain regions that cause epilepsy demonstrate impaired glucose metabolism.
Evaluación neuropsicológica
Las pruebas neuropsicológicas se utilizan antes de la cirugía para evaluar los posibles riesgos de la intervención en función de la ubicación de las convulsiones en el cerebro, y después de la cirugía para evaluar cualquier efecto adverso en el funcionamiento del lenguaje o la memoria.
Las pruebas pueden ayudar a identificar áreas del cerebro que no funcionan con normalidad.
Resonancia magnética funcional (RMf)
Una resonancia magnética funcional (RMf) captura imágenes del cerebro mientras el paciente realiza tareas específicas que implican pensar, hablar y moverse. Esto permite a los equipos de radiología y epilepsia ver qué parte del cerebro está activa.
Estimulación magnética transcraneal (EMT)
Un TMS envía pulsos magnéticos desde un dispositivo portátil a través del cráneo hasta la superficie del cerebro. Los pulsos magnéticos inducirán pequeñas corrientes que activarán o desactivarán áreas motoras, sensoriales o del lenguaje del cerebro. Esto proporciona un mapa del cerebro y muestra las áreas que el neurocirujano debe evitar para garantizar una cirugía segura.
WADA Test
The WADA test looks at speech, thinking and memory functions on one side of the brain, at a time.
A specialist will inject medication through a catheter to put one side of the brain to sleep. From there, you will be asked to identify pictures and objects while one side of the brain is asleep. Twenty minutes after the initial questions, you will be asked to recall or recognize the pictures or objects. Once the medication completely wears off, the procedure is repeated on the other side of the brain.
The test helps to predict whether surgery may affect the patient’s speech and memory functions.
Epilepsy Surgery Case Conference
The Epilepsy Surgery Case Conference is a weekly meeting where results of a presurgical evaluation are presented to a group of epilepsy specialists, including an adult and pediatric epileptologists, epilepsy surgeon, neuropsychologists and trainees.
While reviewing results, this group will reach a decision regarding next steps for treatment. This may include more testing or the referral to an epilepsy surgeon for an intercranial diagnostic procedure.
