Electrical Impedance Tomography of Epilepsy
Electrical Impedance Tomography of Epilepsy
The purpose of this study is to determine if Electrical Impedance Tomography (EIT) can
 produce reproducible and accurate images in people with epilepsy compared to existing
 standards such as MRI, CT or EEG.

 Electrical Impedance Tomography is a relatively new medical imaging method, which has the
 potential to provide novel images of brain function. It is fast, portable, safe and
 inexpensive, but currently has a relatively poor spatial resolution. It produces images of
 the internal electrical impedance of a subject with epilepsy using rings of ECG like
 electrodes on the skin, intracranial electrode mats or deep electrodes implemented surgically
 as part of clinical assessment. EIT recording will take place in parallel with the routine
 recording on the ward. Following completion of the recording, the EIT images will
 subsequently be analysed and compared to other imaging data for accuracy.
Electrical Impedance Tomography (EIT) is a novel medical imaging method in which tomographic
 images are rapidly produced using electrodes placed around the body. The principal
 applicant's group has demonstrated that EIT can rapidly image functional brain activity in
 stroke, epilepsy and normal activity in animal models and has developed instrumentation and
 image reconstruction algorithms which work well in head-shaped tanks.

 The principal aim of this research is to optimise and assess accuracy of Electrical Impedance
 Tomography (EIT) using scalp electrodes, intracranial electrode mats or deep electrodes in
 imaging epilepsy in human participants. If successful, EIT has the potential to provide a new
 portable imaging unit. It could be used with scalp electrodes and enable imaging of the onset
 and propagation of seizures in 3D. Image quality would be better with intracranial electrode
 mats or depth electrodes that are already implanted in people with severe epilepsy who are
 being evaluated for epilepsy surgery. For both electrode types, the new 3D information will
 enable better diagnosis and so targeting of drug treatment. It could also pave the way to
 suppression of seizures by deep brain electrical stimulation which could transform management
 in severe intractable epilepsy.It can offer the same benefits in imaging in epilepsy in
 neonates and infants.

 Patients diagnosed with epilepsy will be asked to participate in the epilepsy EIT study, then
 up to 32 electrodes will be applied on the subjects' scalp or the EIT systems will be linked
 to the existing EEG video recording systems and EIT will be recorded at the same time using
 some or all of the available intracranial electrodes. It may also use some scalp EEG
 electrode placed on the scalp for clinical or research purposes. Following completion of the
 recording, scalp electrodes and any paste will be removed, the EIT system will be
 disconnected from the videoEEG. Collected data will be analysed and compared to other imaging
 data.
Inclusion Criteria:

 -  Any patient with epilepsy with either active seizures or interictal EEG changes (for
 scalp electrodes group)

 -  Any patient with epilepsy with either active seizures under evaluation for epilepsy
 surgery (for intracranial electrodes group)

 -  Ability to give informed consent

 Exclusion Criteria:

 -  none