Had the same symptoms,,,de ja vue then an odd sensation I cannot discribe....after a complete mri, eeg and something else I can't recall..all was well in my nogan...but I was put on Keppra and the nasty feeling is finally gone...probably some kind of cluster headache without the pain....
I started getting the same symptoms in July. I've been documented when they occur what happens. The headache that accompanies it is now no longer occurring, and the deja vu has now lessoned to just a memory of something, but I still get the smell. I know the smell doesn't exist, but my brain senses it. I can always sense when it's about to occur as well.
When I spoke to my doctor she ordered a CT scan but there was nothing abnormal. She thinks it's a migraine without the migraine, since I don't get the headache anymore.
I am having very similar symptoms and they are sooo scary.
I do have allergy issues and started the sensation when I was about 10 or so, they stopped. Then when I had my child, I experience it again...shortly after the birth. When I began to go through perimenopause (and have since gone through it) I began to have issues again, but it is almost always when my face it really swollen from my allergies. I take Zoloft...and sometimes have increased my dose which eliminates the issue. It usually happens when I really tired too.
My Dr. assures me that this is not a seizure, and it related to brain chemistry...which seems to be so, since it seems to only occur when my hormones change - I began to take premarin a month ago, and have been feeling MUCH better overall, but just recently had another epidsode. Not matter how often it happens, it is always so scary!