If a follow up appointment is needed, this will usually be booked before you leave the outpatient department.
The timing of the follow up appointment will be decided by the health care professional you have seen and may vary depending on the severity of your symptoms and investigations to be undertaken before you are seen next.
In addition to tests undertaken on the day of your clinic appointment, you may be referred for other investigations. The most common tests are:
- Electroencephalogram (EEG): electrodes are placed on your head to record the electrical activity of your brain. The electrodes are held against your scalp with a sticky paste.
- If you have epilepsy, there may be changes in your normal pattern of brain waves even between seizures but an EEG without any speciﬁc changes does not exclude epilepsy. A routine EEG can be performed at any time of day. Your doctor can also suggest that you have a “sleep deprived EEG” in which you are asked to limit your sleep before the EEG that will then be performed in the morning. During the EEG recording, you may be asked to breathe deeply for a few minutes. Sometimes ﬂashing lights are used to try to bring out epileptic activity on the EEG. The EEG may help the doctor determine what kind of epilepsy you are having or rule out other conditions.
- Ambulatory EEG: This is similar to a standard EEG, but you will leave the hospital wearing the electrodes connected to a small machine (carried like a shoulder bag) that records your brain wave activity for up to 24hours. You will then need to return to the hospital the next day to have the electrodes removed.
- Video EEG telemetry: This test is done to record your seizures or attacks on video and your electrical brain activity at the same time. You will be admitted for several days to hospital, to one of our specialised video telemetry units, either at the National Hospital for Neurology and Neurosurgery in Central London, or at the Sir William Gowers Centre in Chalfont St Peter.
- Computerized tomography (CT) scan: A CT scan uses X-rays to take images of your brain. CT scans can reveal abnormalities in your brain that might be causing your seizures, such as tumours, stroke and cysts.
- Magnetic resonance imaging (MRI): An MRI uses powerful magnets to create images of your brain that are more detailed than those obtained with a CT scan. The MRI is performed to detect lesions or abnormalities in your brain that could be causing your seizures.
- Functional MRI (fMRI): A functional MRI scan is performed in the same machine as a normal MRI but you will be asked to perform a task during the scan. The fMRI measures the changes in blood ﬂow that occur when speciﬁc parts of your brain are active during the tasks. Doctors may use an fMRI to identify the exact locations of important functions, such as speech and movement. This is particularly important if an operation is considered.
- Positron emission tomography (PET): PET scans use a small amount of low-dose radioactive material injected into a vein to help identify areas of the brain that use less sugar. Brain areas where epileptic seizures start often use less sugar between seizures and a PET can help detect such areas and is particularly helpful in the investigations for epilepsy surgery if the MRI scan is normal.
- Single-photon emission computerized tomography (SPECT): This type of test is used primarily during investigations for epilepsy surgery if you have had an MRI and EEG that were not able to pinpoint the location in your brain where the seizures are originating. Similar to the PET scan, SPECT test uses a small amount of low-dose radioactive material that is injected into a vein, this time look at the blood ﬂow activity in your brain during seizures, so called ictal SPECT. This needs to be compared to the blood ﬂow between seizures and you will therefore have another SPECT scan between seizures.
- Neuropsychological assessment: You will be given a number of tests. Most assessments include some memory, language, drawing tests and you may be given some puzzles to complete. The test results help to show which areas of your brain are affected by your epilepsy and its treatment. If there are difﬁculties, for example with memory, the neuropsychologist may be able to suggest strategies on how to cope with these.
- Genetic testing: This is usually carried out on a sample of blood. Genetic material (DNA) is extracted from the sample and sent for one or more genetic tests. The results usually take months to come back. The results are carefully examined to see whether there might be a genetic change that could cause, or contribute to, your epilepsy. It is often helpful to test samples from your parents or other family members, if that is possible.