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EEG & Tegretol

I was diagnosed as bipolar Dec '06 & my doc put me on Tegretol & Clonazepam. I'm scheduled for an EEG Jan 19-22 to (hopefully) find out if what I had was a seizure. I called my neuro to find out if either drug would interfere w/the EEG & his nurse assured me it wouldn't, but it would seem like it would. Anyone have any thoughts on this?


hye i just wanna asking abt some medication drugs ,because i want to know the effect of them in EEG Signal ? which of them have a huge effect on EEG signal ,couse my graduation project abt classifier between normal and abnormal dataset ,so ,i want to which of them effect of signal to make it abnormal as(spike,flat) to get clearly to classifier between normal dataset and patient take this medication ! which best ? thx :)
1. carbamazepine (Tegretol)
2. valproic acid (depakine)
3. Phenytoin (epanutin)
4. oxcarbazepine (trileptal)
5. 5hydroxytryptamin(Serotonin)

any help !!!

i agree that this medicine would interfere. my neurologist would as well as he wrote in my medical chart, "i think that this patient needs to have an electroencephalogram to rule out the possibility of temporal lobe seizures. if the EEG is abnormal, i think that she should also have an MRI scan. if the EEG is normal, i think that we should follow her carefully, take her off the Clonopin take her off the Clonopin because that might interfere with the expression of the illness..."

of course sadly, no one ever ordered any EEG's back then because i was hospitalized for anorexia and a suicide attempt. my entering the mental health milieu ended any medical explanation for my sensory/psychic+depersonalization symptoms.

I have taken both medications and I am an EEG technician and seen my EEG's personally. The medication does not effect the record at all. I was a test patient of Tegretol and have been on it a long time. Klonopin did not change anything either. You have a good question some medications do cause changes. Phenobarb is a stinker it causes fast activity (Beta) riding on waves. The medication helps the patient but subtle changes on the EEG are harder to detect. Most sz medications do not cause much problem. I have been all of them. My EEG is abn. I have a seizure disorder. I have a spike and slow wave focus at the posterior left temporal lobe. I have had 2 surgeries. I worked at UCLA. Now I am disabled because other medical problems have gotten in the way but I help doctors that need coverage. I am on disability. You can contact me anytime w/ questions. Good luck on finding out what the cause is.

hye tonialpha/ i just wanna asking abt some medication drugs ,because i want to know the effect of them in EEG Signal ? which of them have a huge effect on EEG signal ,couse my graduation project abt classifier between normal and abnormal dataset ,so ,i want to which of them effect of signal to make it abnormal as(spike,flat) to get clearly to classifier between normal dataset and patient take this medication ! which best ? thx :)
1. carbamazepine (Tegretol)
2. valproic acid (depakine)
3. Phenytoin (epanutin)
4. oxcarbazepine (trileptal)
5. 5hydroxytryptamin(Serotonin)

Thanks for the info. Seeing that you have experience in the field of reading EEG's I have a couple of questions (more like a whole bunch! since we can't get a straight answer from my son's neurologist)

Anyway pre May 2000 our then 5 yr old son was normal. Post May 2000 he developed an e.coli infection complicated by Heamolytic Uremic Syndrome (known for causing seizure conditions) and a host of complications. During acute stage of illness developed altered concisousness, irritability, confusion etc. Upon discharge condition continued along with bizzare behaviour, mood swings, tantrums, blank stares, irritability, confusion, drop in cognitive ability etc. Initially treated as behaviour problems related to his hospitalization. No change found after psychological intervention. One neurologist witnessed him walking in circles with altered conciousness. She began him on Clobazam that had little or no improvement on the symptoms and at times seemed to make them worse.

To complicate things more he was diagnosed with a diffuse brain injury from the e.coli.

A sleep EEG showed poor sleep pattern with several indicative epileptic spike patterns.

His first awake EEG was negative showing the benign "Psychomotor variant".

A subsequent followups then showed a wave pattern that indicated CPS.

He was started on Tegretol and showed a significant improvement however not full symptom control.

During another EEG the neuro commented about the slow spike wave discharges but said it was due to the TEGRETOL.

Recently we noticed an increase in his symptoms again and felt that he possibly required an increase with his meds.

He went for an EEG which was "normal". His treating Neuro then announced to us that as far as he was concerned our son had NEVER had epilepsy and everything he showed symptom wise was from "Psychiatric problems". He stated that after looking at all of the EEG's he was satisfied that all our son had was the psychomotor variant, and he wanted to discontinue his meds immediately.

So being naturally astounded by his "new" diagnosis we questioned him about the EEG Tech's conclusion on the majority of the EEG's - CPS. The EEG tech was the same for all of the testing.

Needless to say we are now getting a second opinion. After reading up on the different types of epilepsy I would almost hang my hat on Lennox-Gastaut Syndrome since his symptoms are so varied and all over the map.

Just wondering as a professional what you thought of this? Also would the tegretol cause this slow spike wave formation?

Rather long story but your input/comments are greatly appreciated.


It sounds like you have a lot of variabilities the Epileptolgist should review not a reg. Neurologist, in my opinion.

I see one a John Hopkins in the Maryland area. I would check the University settings or the Epilepsy Society in your area or the Neurolgy listings for Epileptologist.

Your son having had a brain injury of some sort caused by e. coli sounds like something to check. A wake/sleep EEG or a EEG done on telemetry sounds like a good idea, which sounds like you have done partly already.

I take Tegretol and I have never heard of this before and I have read a lot of EEGs and never heard of Tegretol doing it. I have not been in the field for 10 years so there may be some truth in it at this time but not when I was working. Barbituates cause fast waves or Beta activity to ride on waves. Most anticonvulsants do not effect the EEG unless the patient is toxic on the medication.

Normal EEG's on seizure patients are not unusual. That is why they do other studies, like wake/sleep EEG or monitor the patient in the hospital for a time period, to help w/ diagnosis if their is a question. They do MRI'S , CT's , etc.

I have heard myself of doctors thinking it is psychological but a lot of time, it is because they are puzzled on the diagnosis and it is not straight forward. Sometimes it is the patient too. Sometimes the patient has both psychological and neurological tendancies that need to be addressed. It is a big puzzle at times.

You are right on the benign psychomotor variant being diagnosed as normal.

The sleep study showing Epileptic spikes should be indicative a seizure disorder. One doctor told me a long time ago if there is one spike, the patient has a seizure disorder. He was from UCLA.

The Complex Partial Seizure (CPS) indication on the EEG is definitely indicative a seizure disorder indicating a seizure focus not a generalized focus and the patient should be on anticonvulsant or some say anti-seizure medication. I can go on but leave your eyes to rest.

THANK YOU so much for the info. You're right. Our son has many things going on and I think the neuro that we were using just couldn't get his head around everything that was going on. Heck it's been almost 8 yrs living with it and we can't get our heads around it.

Thanks again for the info you were MOST helpful......just one other thing, could a tech get CPS spikes confused with Psychomotor variants? As mentioned we had the same tech each time and with our son's first EEG the tech found it normal with the benign psychomotor variants, the 4 or 5 that followed he indicated spikes & waves consistent with CPS.....just wondering if he could have got them confused or if the neuro is just making excuses trying to get rid of a complex case....also what else would cause the slow spikes & waves noticed during one of his EEG's...any ideas?


CPS or complex partial spikes have a spread to them vs a psychomotor variant does not. ( simple explanation) A focus of a spike and slow wave is generally indicative of a seizure focus unless there are other symptoms that need to be ruled out, again a good Epileptologist is someone that will weed it out in a clear manner with other tests if need be.

Thanks a bunch. I've learned more from you in one day than our neuro over the past five. Can't thank you enough!


Benzodiazepines DO affect the EEG:

"Both the benzodiazepines and the barbiturates reduce the activity of excitable tissues...."

"Beta activity is 'fast' activity. It has a frequency of 14 and greater Hz. It is usually seen on both sides in symmetrical distribution and is most evident frontally. It is accentuated by sedative-hypnotic drugs especially the benzodiazepines..."

"Characteristical changes in the EEG after benzodiazepine medication consist in an activation of higher EEG-frequencies simultaneous to a decrease in alpha-activity.....Cortical EP-components are suppressed by benzodiazepines whereas subcortical generated potentials are not altered."

Like you, I am a purist. I too, would aim for an unadultered picture of the electrical activity in my brain. But ultimately, it is your doctor's discretion as to discontinue your Tegretol or Clonopin. These drugs do NOT effect spike and wave discharges on an EEG so if there is seizure activity to be found, it would be there regardless of taking these particular medicines.

excerpt below from site:

"Effects of Antiepileptic Medications on PET and EEG
The effects of antiepileptic medications on cerebral glucose metabolism deserve mention. Antiepileptic medications that have been studied typically decrease global cerebral glucose metabolism rather than modify its regional distribution[29-33] and, thus, cannot account for the patterns of glucose metabolism seen in our patients. However, it has also been demonstrated that although changes in the dose of antiepileptic medications do not influence the EEG spiking activity, postictal states can alter interictal spike frequency.[34] None of the patients in the present study had PET during a postictal state. Thus, the effect of antiepileptic medications on focal PET abnormalities or spiking activity on EEG is likely negligible."

good luck with your test,

After visting w/another doctor we've concluded I am not bipolar, just depressed from a combonation of many things so I am no longer on the Tegretol. I didn't realize how bad that drug was making me feel until i got off of it! I had the ambulatory EEG done & did have some abnormal spikes. So now I am having an in-patient videotaped sleep deprived EEG. I had another episode on Jan 17. This one was similar but I didn't have the amnesia. (The best way I can desribe it is like an out-of-body experience. It's as if my brain was detached from my body.) My neuro is thinking it is confusional migraines (I have a history of migraines w/the severe headache & classic symptoms) instead of seizures & wants the 2nd EEG to be sure. Anyone else had a confusional migraine diagnosis?

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