What do you use to detect deep limbic system seizures?

[hewie]

Hello,

I already have a firm diagnosis of simple partial seizures & sleep myoclonus. I was in an epilepsy monitoring unit-3 days- a couple of years ago to learn that (due to EEG strongly suspected temporal lobe seizures-EEG said focal continuous theta throughout L-temporal chain of electrodes while I was awake.  Have had auras, metallic tastes, auditory and sudden feelings of having been given intravenous IV of valium or tranquilzer of some kind, feeling momentarily paralyzed as to movement,vaguely aware of surroundings-have had times of total time lapse-unsure as I live alone-feel like they have ranged from seconds (more mild episodes)to minutes. After the stronger-longer lasting episodes I feel drained w/strong need to sleep-very heavy feeling.I recently had another stay in the EMU (same place-not CCF)with this time them saying the EEG actually looked pretty good so no change in meds which of course is good news but did not explain or change the dx for which I was referred there again (the above) more like CPE according to neurologist. BOth stays I wasn't taken off the Lamictal-2oo mgs/Neurontin 900 day- or sleep deprived. My questions are:In your opinion is it possible I'm having deep limbic system sezures? I've read scalp electrodes most often don't pick these up. I have multiple deep white matter brain lesions both white & gray matter-MS tests been neg. What are your thoughts on this? Ive lost few brief tracts of time while driving over last year while driving w/near car accidents. I don't want to have CPE but am concerned w/the increase of sx over time. Thank you!

[CCF-Neuro-M.D.-PW]

We commonly find that patients who have auras (as opposed to seizures - just the feeling without outward clinical signs of a seizure) do not have changes in their surface/scalp EEG.

This is because the epileptic focus is too deep for it to be picked up from the scalp, only when it spreads to larger and more superficial areas does it appear. A normal EEG with an aura does not mean you do not have epilepsy.

For this reason in the EMU we withdraw antiepileptic medication to try and produce a clinical seizure, and sometimes even a secondarily generalized seizure. Sleep deprivation can provoke seizures, but in teh controlled setting of the EMU is a common practise, but it has not yet been proven to induce seizures in this setting. I cannot comment on your MRI just from you description wihtout seeing it. If Your seiures are from the limbic system (usually the hippocampus is involved) a special MRI conctrating on this structure should be done.

If you feel you may  be having seizures with some loss of awareness, you shoul dnot drive until you see your neurologist and discuss driving regulations for patients with lapses of consciousness in your state.

[AECRN40]

I am a nurse on an epilepsy unit at a major medical center in Chicago.  If scalp electrodes are not picking up activity when you have a seizure then your seizure focus may be deep.  We then send the patient to have deep electrodes implanted in the brain around the suspected area or focus.  We bring these patients back to the monitoring room, wean them off their seizure meds and hope for a seizure.

[Wesley's Mom]

I wanted to ask about Children.. Do they also recommend Deep Brain Electrodes to pick up a seizure for children?? I am asking for our son , age 12. He was diagnosed with encephalitis due to a mosquito bite. MRI shows damage in basal ganglia area. We have only had one EEG that came back with any abnormality. that was three years ago, yet he continues to have seizures and migraines.The Dr.'s are leaning towards a pseudo-seizure diagnosis because of the lack of testing.It is true he has not had a seizure while hooked up to EEg monitoring and they refuse to give him any more testing. We have been through Bio-Feedback, and psychologists to no help. What are our options?? Thank you.. Mom to 6

[hewie]

Thank you for your thoughts on my question. I will now wait for the CCF neurologist's thoughts on this also. Maybe...???... this is what is needed in my case.

Thank you again =)

[AECRN40]

To me, it sounds like your son needs further EEG monitoring, not necessarily deep electrodes...we typically will bring someone in for at least overnight but more like 3days (all dependent upon what your insurance approves).  And, to answer your question, yes, we do have children who have deep electrodes...of course that is only after our epileptologists review eegs and are pretty convinced that the seizures are deep.  My other point is that deep electrodes are only part of a surgical work up....surgery is an option only after multiple anti epileptics have failed and the seizure focus is located on one side of the brain.

[acrylicsoils]

I read your post under someone else'e question?  I found what you said very interesting I had encepalitis at 14 1/2 months from a mmr vaccination and I was told by several neurologist not to have an eeg done with depth electrodes or the subdural grids because since I had already had the encephalitis it would greatly increase over a regular person the chances of getting encephalitis again and the risk for someone that hasn't had encephalitis is high so our risk would be like tripled.  I thought you comment about the abnormal eeg was interesting.  I wasn't diagnosed until 1996 with seizures first eeg was abnormal.  Then this was followed by two ambulatory eegs one in 1997 and and one in 1999 abnormal but like your son these were my only abnormal eegs except for one that was done in the hospital where they removed me from all meds and I ran a fever the whole time  I have had a bunch of what they said were normal eegs where the seizures were going on during the eeg.  I have been accused of pseudoseizures by a bunch of neurologists.  My general neurologists wanted me to go to an epileptoligist and he wanted me to see neuropsychologist for neuropsychological testing which showed deficiencies from the encephalitis and also showed no evidence of a conversion disorder (where pseudoseizures would fit) or any other psychiatric psychological disorders  he also wants to do another mri and regular eeg and he said he would like to do another long term video eeg  please email me if you have any questions about anything I wrote I was also curious have they talked about doing anything like the neuropsychological testing if not it might be worth discussing.  Why I mentioned this the dr.that did mine said he was going to suggest some other possibilities and tests if the eeg and the long term don't show any abnormalities.  Hope this helps stay in touch i'll pray for you, your son, and the rest of your family.