Investigations
There are a number of Investigations that we may ask for during your time within the CESS pathway. These different investigations enable us to build a picture of your epilepsy and to find out what parts of the brain your seizures are coming from and what areas of the brain are responsible for what functions (like language and memory). We will review the results of the investigations in MDT meetings to decide what are the best options moving forward, whether this be resective surgery or other options.
EEG
Electrodes on the scalp records the electrical activity of the brain. By looking at which electrodes detect abnormal electrical activity during a seizure can help workout which area of the brain the seizures are coming from. It also shows how a seizure develops and spreads. This is important information when deciding whether surgery is an option or which part of the brain future investigations should be focused.
VT Or home LTM
This stands for Video Telemetry. This is the same as a EEG but your are also video recorded at the same time. By comparing the video of the seizures with the EEG helps the CESS team to work out which part of the brain is responsible for our epilepsy. This requires a hospital stay of up to 5 days. Sometimes a home LTM (Long-term electroencephalographic monitoring) may be possible. This is the same idea as a VT but done at home. The data from this is not can sometimes be not as detailed as a VT.
3T MRI
This is the same as an MRI but on a 3T scanner. This is a stronger scanner than in most hospitals, so the images are clearer and help us find any abnormalities in the brain that might be causing your epilepsy.
fMRI
This is another version of an MRI. By doing tasks during the scan it helps the CESS team work out which parts of the brain are responsible for language and memory. This information will determine what surgery might be possible.
MEG
Your brain works by means of tiny electrical signals, which are often called “brain waves” or “brain activity”. A MEG system (MEG stands for Magnetoencephalography), can measure brain activity and the scans produce an “activity map” of your brain.
PET
This scan detects how your brain uses sugar. Areas in the brain that are responsible for seizures don’t use sugar as well the rest of the brain. You are injected with a special dye and these areas are highlighted on the scanner.
sEEG/ Grids
sEEG -This is a small operation where electrodes are carefully implanted into the brain to detect the electrical activity from within the brain. Once implanted an EEG is recorded with video (like the VT) for up to a week. Then the electrodes are surgically removed. Grids - This is where strips of electrodes are placed on the surface of the brain, this is a larger operation than sEEG as it requires a flap in the skull to be made to place the grids. (Craniotomy).
One of these may be required if the EEG/VT hasn’t pinpointed accurately enough the exact area of the brain the seizures are coming from.
We may not ask for all of these investigations if we feel we have enough information to decide what options there are in your epilepsy treatment. Also some of these investigations are not done at BCH, fMRI and MEG are done at Aston University Birmingham and PET is done at St Thomas’ in London.