A little background may help. FLAIR stands for FLuid Attenuation Inversion Recovery, which is basically a fancy way of saying that free unrestricted water will lose singnal at MRI on the FLAIR sequence. It is sometimes called T2-FLAIR but I will just call it FLAIR so as not have you confuse it with T2 which is a different (but related) sequence.
Think of free water like water in a cup, the H20 molecules can move freely (It's actually the hydrogen part of the water, but that's beyond this discussion), which on FLAIR imaging will lose signal and appear black.
On a T2 image, water whether in tissues (edema or within the cells) or free will be bright. This is the value of FLAIR, we can drop out all of the signal from the free water which is typically the CSF spaces in and around the brain, so we can see specifically what areas of signal are related to increased water within the tissues.
Ok, that's a bit more theory than may be needed, but here is the crux of what you are describing (assuming your description accurately reflects your scan).......
Basically there are blood vessels that run along the outside of the brain, and they have to get "into" the brain. There are holes in the brain called "Virchow-Robbin Spaces" a.k.a. perivascular spaces that allow blood vessels to run into the brain and provide blood supply to the deep brain structures. Now, these spaces can be snug around the vessel, with little room for the CSF fluid around the brain to go, or they can be pretty "loose" with space for CSF to track along the vessel as it runs into the brain to supply nutrients. When this happens, there will be a bright area that starts at the margin of the brain where it meets the CSF surrounding the brain and then track along the vessel into the brain. One T2 images this will be bright indicating water (but this does not tell us free or within tissues), but when we do the FLAIR sequence the signal will drop if it is indeed CSF tracking along a vessel into the brain. If both FLAIR and T2 were bright this would imply that there is a small brain lesion with increased water content...Just for completeness: sometimes a small marginal lacunar infarction could have a similar appearance, but often there is a high FLAIR single ring around the lesion with central low signal, although this appearance can vary.
Now to the periventricular things you are describing...First, I will tell you this is an incredibly common finding, you see it routinely and more and more commonly the older someone is...If you were 20, 30, maybe even 40 than it would be more unusual. Basically (as per our discssion above) bright on FLAIR means that there is increased water content within the tissues. There are a very large number of reasons for this appearance in this area, which include MS, Headaches, Post-Ictal (Seizure related), Lime Disease, and many many many more...However, in the EXTREME MAJORITY of cases these are changes associated with aging, where basically a tiny area of the brain for some short period of time did not recieve adequate blood flow and some of the tissues were damaged as a result, hence "Small Vessel Disease" although I would call it "Small Vessel Ischemic Disease" because this more accurately reflects the nature of the lesion as being do to inadequate blood flow within a tiny vessel affecting a very small area. Sometimes these types of lesions manifest as Mini-strokes or Transient Ischemic Attacks (TIA's)...but often there is no decernable symptoms from them, it all depends where the "lesion" occurs. There are some things that increase your risk of developing these lesions, the big 3 are Smoking, Diabetes, and Hypertension (high blood pressure).
Hope that helps, I hope you get feeling better soon, and as always please discuss your results with your doctor because scan in hand he can do much more than any internet forum can ever offer you...but at least hopefully you can be more informed to help you sort this out better with your doctor.
Thank you for getting back to me. You are so knowledgeable & explain things in technical, then layman, terms we can all understand. In my effort to not give to much info I guess I didn't give enough. I am 47, soon to be 48, I have been using an electric cigarette for the past 6-7mo, although I never smoked more then 5-10 cigarettes/day. No diabetes or hypertension. I've suffered from migraines my whole life, or as long as I can remember.
I only went to the neurologist because my constant movement/motion, has gotten out of control. Again, this is something I've had as long as I can remember, & I've been asking childhood friends if they remember how I was. Everyone thinks/thought I am just hyper. This is because I always try to make the involuntary movements look purposeful. But in the last 1-2 yrs. it has gotten to where I can't control it, don't even know I'm doing it, & everyone sees it. It has become embarrassing! I work at a Jr. High School, grades 5-8, part-time on the play yard during lunch breaks, & the other half as a teachers aide. I have kids coming up & telling me I look like I'm dancing & asking if I can stand still. Out of the mouth of babes, as the saying goes. I thought it was a precurser to Parkinson's, & kept ignoring it. You know, if I don't acknowledge it it doesn't exist. I can be still if I concentrate on it completely, but I will still have some little part, be it a toe, finger, or even my tongue, doing something while I'm "being still".
I know this has nothing to do with your interpretation of the MRI, but it might help someone. I went back to the Dr. yesterday, he told me that there was nothing on my MRI to be concerned about, he did say the same as you about HA's possibly being part of the small vessel portion. He tried to explain the other part of T2 & FLAIR, but I understand your explanation. He then looked at me kind of like an experiment, don't get me wrong not in a bad way he is very intrigued by me. All of the thyroid & other blood tests came back normal, along with the MRI, so he said there are other genetic ways of inheriting Chorea disease, but no test to check for it. I think my 14yr. son has it, & I believe my father who lived to be 93yr. had it. So, in conclusion he is sending me to UCLA or Cedar Sinai for a consult so as he said, "Maybe someone smarter then me can look at you." I've got a lot of respect for a doctor that can say that to a patient, I just wish it wasn't me. lol
I bet your wishing you didn't have that backround now huh?
Gracie - Background always helps narrow probabilities, sometimes it doesn't make an absolute diagnosis one way or the other but it can make you lean one way or another more heavily.
Although Nicotine is better for you than smoking, Nicotine is still bad for you in several ways, especially related to your vascular system (blood vessels).
Quote from Wikipedia
"Nicotine has very powerful effects on arteries throughout the body. Nicotine is a stimulant, it raises blood pressure, and is a vasoconstrictor, making it harder for the heart to pump through the constricted arteries. It causes the body to release its stores of fat and cholesterol into the blood."
Based on your age and history of smoking, this increases significantly the chance that your MRI findings are related to small vessel ischemic change. Your age and history, does not impact the likelyhood that the basal ganglia FLAIR hypodensity is a Perivascular space, they exist regardless of other history.
A few thoughts on headaches and MRI changes. The extreme vast majority of people with headaches have absolutely no findings at MRI. Findings at MRI related to headache tend to be few and focal high T2 and FLAIR signal areas, most commonly in the frontal white matter. What you are describing, does not sound typical of headache related MRI changes to me. Also MRI changes associated with headaches are transient, meaning that they will resolve over time, small vessel ischemic changes do not resolve, and usually there is progression over time with more changes. White matter changes on MRI are not specific to any one disease, there are many many things that casue them, but everything besides small vessel ischemia is rare in comparison.
Tremors are not a specific symptom, there are lots of reasons to have tremors. I did a quick search and found this link, which has a lot of great information; and it comes from a credible source.
Good luck with everything, keep us posted as you find out more.