I am know ok with surface electrodes and source imaging in epilepsy (spikes)
Some of my patients have surface electrodes and intra cérébral electrodes
I know th coordinates of both of them.
My question is "can i use intracranial eletrodes to improve source imaging?"
I know the current and referencies are not the same (biais?)
I know intra cranial electrodes are used for index of epileptogenicyting or initiation of the seizures
But in theory we could use them too, right?
What happens if i use them as "normal" electrodes in the process of source imaging?
Minimum norm source imaging of intracranial electrodes is possible, but not easy. It requires the computation of a different forward model, using BEM or preferably FEM. OpenMEEG is supposed to support SEEG forward models, but this is not clearly documented anywhere. DUNEuro supports SEEG but requires a lot more work and computation.
What happens if i use them as "normal" electrodes in the process of source imaging?
No, this is definitely not possible. You cannot use a scalp-EEG forward model for an SEEG electrode. More generally, you shouldn't mix the EEG and SEEG in the same source estimation procedure. The two modalities give completely different types of information. I recommend you process them separately and see if the observations made with the two modalities converge or not, and in the divergent cases decide on a case by case basis which one you trust more.
SEEG source modeling will not add much information to the model, as each electrode records brain activity only in the tissues in the immediate neighborhood.
It is probably easier and safer for the moment to compare the EEG source estimation with the SEEG recordings.