What are epileptic lesions and what causes them?

On three occasions since September, my 12-year old daughter has "blacked out."  On the first occasion, she hit her head on a bar while riding on her school bus, and says she found herself on the floor a few seconds later.  In the last two instances (one in December and one in April), she says she feels somewhat dizzy, the room goes dark, light, dark, light, and then next thing she remembers is someone picking her up off the floor.  I haven't seen any of these incidents, but I am told that these episodes only last a matter of seconds, that her eyes are open the whole time, and that she doesn't stiffen or convulse.  I didn't take her to the doctor until this most recent episode because I had forgotten about the incident incident in September, as she didn't complain about it again, and in December, I thought that perhaps she hadn't eaten in awhile.

She had an EEG done, which may indicate epileptic lesions in the rolandic region.  She has also had an MRI, but we won't be able to see a neurologist until late next week.

What are epileptic lesions, and what causes them?  Could her symptoms indicate something more serious, like a brain tumor?

[CCF Neuro[P] MD, RPS]

Dear Lisa Lange:

I am sorry to hear about your daughter.  Epileptic lesions are areas of the brain that are abnormal that allow synchronous discharges of brain activity that eventually induce seizures.  These lesions can be a variety of things, neuronal migration abnormalities, atrial-venous malformations, tumors, strokes, infections, sites of hemorrhage, etc.  They can also be genetic, such as a ion-channel abnormality.  There are some that are due to immaturity of the brain.  There are many more that we are only beginning to understand, but the point is that there are many, many things that can cause seizures.  So, where events could be caused by any of these things.  That is why when a child has an event, especially if it sounds like it began in one area we do an EEG and MRI of the brain.  

If your daughter truely has rolandic area epileptoform discharges that are benign rolandic discharges (dipole, with a distinct pattern over the central/temporal region) then the outlook is very good that your daughter will grow out of the seizure activity.  However, the epileptologist will have to look at the EEG and get a good history and physical examination before concluding this.  I hope the events are benign rolandic in nature.

Sincerely,

CCF Neuro MD

[Lisa Lange]

Thank you so much for your prompt response.  Can you possibly answer two more questions?  First, what is the difference between a benign rolandic lesion and an organic rolandic lesion?  Second, what are the possible treatments for each type of lesion?

[CCF Neuro[P] MD, RPS]

Dear Lisa:

Actually, I have never heard of organic rolandic lesion.  If your son has benign rolandic epilepsy, then the outlook is very good that he will outgrow his epilepsy.  I think what someone meant when the term rolandic lesion, is when the EEG looks like benign rolandic but there is a lesion on MRI.  But, if there is a lesion, the EEG would not be classic benign rolandic and a good epileptologist should be able to tell the difference.

CCF Neuro MD

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can you please tellme something about hemiplegic migrainesi was diagnosis with this a couple years ago any info would be helpful
                                       thank you

[CCF Neuro[P] MD, RPS]

Dear marjacksi@aol:

There are two forms of hemiplegic migraine, sporadic and familial, both typically begin in childhood and cease with adulthood.  Both may be part of the same entity.  The attacks are frequently precipitated by minor head injury.  changes in consciousness ranging from confusion to coma are a feature of hemiplegic migraine, especially in childhood.  The hemiplegia may be part of the aura and last less than one hour or it may last for days or weeks.  Headache may precede the hemiparesis or be absent.  The familial hemiplegic migraine has an autosomal dominant mode of inheritance with variable penetrance.  The gene is located on chormosome 19.

I hope this helps.

CCF Neuro MD