Diagnosing epilepsy

How will a doctor diagnose epilepsy?

An initial consultation with your doctor (general practitioner or GP) will involve a medical history discussion, assessment of your symptoms and a general physical exam.

During your physical exam, the doctor may evaluate your behaviour, motor abilities, memory, speech skills and overall mental function (neurological exam or neuropsychological test) to see if they can pick up any warning signals for possible epilepsy. Any definitive clues may help your doctor to determine a possible type of epilepsy as well.

Your doctor may also recommend a blood test to check for any signs of infection, check your liver and kidney function and blood glucose levels or even identify a potentially genetic condition that may be associated with your seizure symptoms.

Tests to check for any brain abnormalities may also likely be recommended. These can include:

• An EEG (Electroencephalogram): Electrodes will be attached to your scalp with a paste-like substance. The electrodes will then be used to measure and record the electrical activity in your brain. Brain wave patterns typically change in a person with epilepsy even when they’re not in the middle of experiencing a seizure. Your doctor will carefully monitor you on video – you may either be awake or asleep during the test. If the test is done during a seizure, this can help a doctor to rule out other potential conditions or determine the type of seizure being experienced.
• CT scan (Computerised tomography): X-ray images will provide your doctor with highly detailed cross-sectional visuals of the brain. Any abnormalities can easily be seen with this imagine test and as such will help your doctor make a definite diagnosis. Seizures may be caused by obvious abnormalities such as a bleed, cyst or tumour.
• MRI (Magnetic Resonance Imaging) and Functional MRI (fMRI): Another imaging test that can help to provide detailed visuals is an MRI. Powerful magnets and radio waves can be used to obtain a highly-detailed view of the brain, any abnormalities and how it is functioning. As with a CT scan, obvious abnormalities can be easily seen and determined as the cause of your seizures. A functional MRI looks at the blood flow that goes through changes as specific parts of the brain function. A fMRI can help a doctor to pinpoint exact locations of the brain’s critical functions, such as movement and speech. Often this test is used just before surgery so as to avoid causing potential injury to specific locations in the brain while operating.
• SPECT (Single-photon emission computerised tomography): If an MRI or EEG hasn’t enabled your doctor to locate or identify anything causing your seizures, he or she may recommend this test to try and pinpoint a potential cause. A small amount of low-dose radioactive material is injected into a vein, helping to create a visual (detailed 3D map) of the blood flow activity in your brain, especially during seizures. A SISCOM (Subtraction ictal SPECT) test can also be used to provide similar, detailed visuals.
• PET (Positron emission tomography): These scans can be used to help visualise specific areas of the brain in order to try and determine any abnormalities. A doctor will inject a small amount of low-dose radioactive material into a vein in order to help create this detailed visual.

Typically, tests are looking to identify seizure causes or rule out various conditions. A doctor will usually diagnose epilepsy if you have had more than one seizure with no apparent cause or reversible reason.