Vascular Health and the Brain--the Eyes Have it.

March 14, 2012 at 4:16pm

“Vascular health has a direct effect on the brain, and you can see those developments when you look at the eye,” says Haan, from UCSF.

A new study shows the link between retinal health and the health of the brain.  

This link has already been made with OCT (optical coherence tomography) retinal scans in Multiple Sclerosis--

link to article on OCT and MS

The health of easy-to-check blood vessels in the retina reflects the health of blood vessels deep inside the head, findings that raise the possibility of a simple eye exam catching early signs of brain trouble, scientists report in the March 27 Neurology. 

The findings add to the growing number of studies focusing on blood vessels that link eye and brain health. The Neurology study was conducted as part of the Women’s Health Initiative, which tracks the health of postmenopausal women. Over 10 years, researchers led by epidemiologist and biostatistician Mary Haan of the University of California, San Francisco looked for a link between eye disease and brain performance in 511 women who were at least 65 years old. 

In the study, participants had their pupils dilated as researchers took pictures of their retinas. After careful examinations, 39 women, or 7.6 percent of the total, were found to have diseased blood vessels in the retina, a condition called retinopathy in which the vessels can become swollen, leaky or grow abnormally. Usually, retinopathy is a symptom of diabetes or high blood pressure, two disorders that if left untreated are known to affect brain functioning.

Over the decade of testing, women with retinopathy scored about 10 to 15 percent lower on questionnaires that tested brain functions such as memory, verbal fluency and writing than did women without the eye disease. What’s more, MRI scans revealed that women with retinopathy had more blood vessel damage in their brains — and also more areas of damage to brain tissue, possibly from tiny strokes. 

http://www.sciencenews.org/view/generic/id/339152/description/Retina_can_help_reveal_brain_health

Pregnancy, MS and changes to the veins

March 9, 2012 at 3:53pm

Naturally, there is lot of discussion on how the immune system is modulated while carrying a fetus...something the body sees as "other" and how this might affect MS.  And many people have mentioned hormones, especially estrogen.

But I wanted to discuss the vascular changes that happen while a woman is pregnant, because I never see this discussed, and I hope to encourage the ISNVD and other MS researchers to look into this correlation.

During pregnancy, a woman's blood volume increases by 50%.   This is to nourish the placenta and growing fetus, and also to compensate for blood loss during delivery.  If the blood vessels remained the same, with more blood volume, blood pressure would become dangerously high....so, the veins become more pliant, open and relaxed.  This is why many women develop varicose veins or hemorrhoids during preganancy.  

Venous Distension increases approximately to 150% during the course of gestation and the venous ends of capillaries become dilated.  Hormonal factors cause the veins to become more compliant. Together with the increased venous pressure that occurs later in pregnancy, these factors cause significant venous distension. Venous distendibility follows the rise in the hormones progesterone and relaxin.   Relaxin works by softening collagen and elastin in the tissues. It loosens the strong, cord-like fibers until they are super-pliable.

The hormone Relaxin is now being studied in cardiovascular disease, for its affects on the endothelium, via nitric oxide mechanisms.

The ovarian peptide hormone, relaxin, circulates during pregnancy, contributing to profound maternal vasodilation through endothelial and nitric oxide (NO)–dependent mechanisms. To conclude, relaxin is a novel regulator of BMDECs number and function, which has implications for angiogenesis and vascular remodeling in pregnancy, as well as therapeutic potential in vascular disease.

http://bloodjournal.hematologylibrary.org/content/119/2/629.abstract

Cerebral bloodflow increases during pregnancy:

Internal carotid artery blood flow volume increased during pregnancy from 318 mL/min ± 40.6 mL/min in the first trimester to 382.1 mL/min ± 50.0 mL/min during the third trimester, corresponding to CBF values of 44.4 and 51.8 mL/min(-1)/100 g(-1), respectively (P < .0001). CBF changes were associated with progressive decrease in cerebral vascular resistance and moderate increase in ICA diameter.

CONCLUSION:

Maternal CBF is gradually increasing during normal pregnancy. Vasorelaxing impact of estrogens and other factors on cerebral vessels may explain the changes in CBF during pregnancy.

http://www.ncbi.nlm.nih.gov/pubmed/20599183

 Could the hormonal relaxation of the jugular and azygos veins and increased blood volume during pregnancy account for better cerebral/spinal bloodflow?  Could this be why MS symptoms are less during pregnancy,  why pregnancy appears to "protect" women from MS?

more questions to ask, and to be answered--

Joan