Broken_Shell Posted June 22, 2009 Report Share Posted June 22, 2009 Hello,I am wondering if anyone can share thoughts or experiences... I often feel light-headed and like there is not enough blood going to my head, but my peripheral BP meaures in a normal range. Do others frequently experience this as well? Any ideas what causes it or how to help it? Thank you kindly.~ Broken_Shell Quote Link to comment Share on other sites More sharing options...
potsgirl Posted June 22, 2009 Report Share Posted June 22, 2009 I've also had this experience, too many times to count. Usually, however, my BP runs low, so I'm not sure about that connection. Be sure that you're not dehydrated. So many times we can get nasty headaches. lightheadedness, and fatigue due to the fact that we're under-hydrated. Some medications can also contribute to these symptoms, and also make us need to drink lots of H20. I try for 10-12 glasses of water a day. Perhaps that might help?Hope you're feeling well soon!Jana Quote Link to comment Share on other sites More sharing options...
carinara Posted June 22, 2009 Report Share Posted June 22, 2009 Hi Broken Shell,i experience this every day even though my BP is always on the higher side. When i meassure my BP in during the day (which i don't do very often anymore) its usually never under 160/100, when iam under stress the numbers are even higher. The only time i meassure my BP now is before i go to sleep. Thats when my numbers are normal or a little low. I get lightheaded very easy. Almost every time i get up i feel as if i have not enough blood in my head. This also happened during my TTT and other tests while standing up even though my BP was on the high side. My POTS doctors didnt seem to think that thats unusual with POTS. carinara Quote Link to comment Share on other sites More sharing options...
summer Posted June 22, 2009 Report Share Posted June 22, 2009 Hi Broken Shell,This is a ongoing problem of mine. I often feel light-headed, spacey and foggy as though I am not getting enough blood flow to my brain. My BP is sometimes low, but often not. Even when it is low (90's systolic) my doctors will tell me that it is not low enough to cause this feeling of hypoperfusion. I have really looked into finding an explanation for this because I knew it was not my imagination, and I was NOT anxious when I was experiencing this feeling despite what some tried to tell me. From what I understand, in POTS, the over-stimulation of the sympathetic nervous system causes constriction in the vessels of the brain, so that enough blood can not get to the cells, even though the BP is in a normal range. So the hypoperfusion is very real due to the narrowing of the cerebral blood vessels. This over-stimulation can be caused by anything that stimulates the SNS like standing, mild dehydration, a hot bath, stress, activity. In POTS, our sympathetic nervous system doesn't seem to know when to shut off, like it does in healthy people. Does this make sense?So don't let anybody try to tell you this is not real because your BP is not low enough. As Carinara pointed out, you can feel this way even with a high BP, and truely be experiencing hypoperfusion.Summer Quote Link to comment Share on other sites More sharing options...
ramakentesh Posted June 23, 2009 Report Share Posted June 23, 2009 Yeah even with postural hypertension patients with POTs were found to have either total reduced blood flow to the brain when orthostatic through the carotid arteries. I had this tested when i had my tilt table test. The theory is as Summer stated - impaired reuptake of norepinephrine due to a faulty transporter, or supersensitivity to NE results in increased transduction of the alpha receptors by norepinephrine causing excessive peripheral and carotid/cerebral vasoconstriction - chocking the brain of blood and oxygen. Others suggest that the hypertension is a response to this cerebral vasoconstriction caused by other means, to try and increase blood flow to the brain. Therefore, they believe that eventually the hypertension will become hypotension. Also in Low Flow POTS where both vasoconstriction and reduced blood flow are implicated, patients may exhibit reduced blood flow to the brain without a drop in BP. Inthis case the sympo-excitation is caused by elevated angiotensin II rather than by impaired norepinephrine clearance, but the results are similar to some extent. Finally parasympathetic withdrawl may result in dizziness through the vagal nerve without a reduction in BP. For me I have postural hypertension usually. Quote Link to comment Share on other sites More sharing options...
Broken_Shell Posted June 23, 2009 Author Report Share Posted June 23, 2009 Yeah even with postural hypertension patients with POTs were found to have either total reduced blood flow to the brain when orthostatic through the carotid arteries. I had this tested when i had my tilt table test. The theory is as Summer stated - impaired reuptake of norepinephrine due to a faulty transporter, or supersensitivity to NE results in increased transduction of the alpha receptors by norepinephrine causing excessive peripheral and carotid/cerebral vasoconstriction - chocking the brain of blood and oxygen. Others suggest that the hypertension is a response to this cerebral vasoconstriction caused by other means, to try and increase blood flow to the brain. Therefore, they believe that eventually the hypertension will become hypotension. Also in Low Flow POTS where both vasoconstriction and reduced blood flow are implicated, patients may exhibit reduced blood flow to the brain without a drop in BP. Inthis case the sympo-excitation is caused by elevated angiotensin II rather than by impaired norepinephrine clearance, but the results are similar to some extent. Finally parasympathetic withdrawl may result in dizziness through the vagal nerve without a reduction in BP. For me I have postural hypertension usually.Thank you for your thoughts. Are there currently centers or tests in the US to evaluate which of these mechanisms is causing the symptoms? I know that you are in Australia and perhaps have more extensive testing available than we do here. By the way, I love reading your replies... I really miss the medical education that I had to leave and it helps keep my brain thinking.~ Broken_Shell Quote Link to comment Share on other sites More sharing options...
Broken_Shell Posted June 23, 2009 Author Report Share Posted June 23, 2009 One more thing... those of you whose doctors "believe" in light-headedness and cerebral hypoperfussion with normal peripheral blood pressure, have they offered you any treatment that has helped? Specifically, have you been helped by midodrine or florinef? Thank you again for your replies!~ Broken_Shell Quote Link to comment Share on other sites More sharing options...
jjb Posted June 23, 2009 Report Share Posted June 23, 2009 Years ago I was DXed with ortho hypotension and would get the usual feelings of light headedness and presyncope and so forth.So anytime I'd get these symptoms I had assumed it was my BP dropping.Well, this past April I did a ttt. I got he usual light headed feelings along w/ nausea. BUT my BP was fine. It the tachy that was causing the symptoms.Hello,I am wondering if anyone can share thoughts or experiences... I often feel light-headed and like there is not enough blood going to my head, but my peripheral BP meaures in a normal range. Do others frequently experience this as well? Any ideas what causes it or how to help it? Thank you kindly.~ Broken_Shell Quote Link to comment Share on other sites More sharing options...
carinara Posted June 23, 2009 Report Share Posted June 23, 2009 All the POTS specialists i have seen so far told me that the lightheadness in POTS occurs because of the blood pooling in other parts of the body whilest upright. Reading about the possibility of constriction in the vessels of the brain just concerns me now. That sounds very dangerous. Can somebody let me know if that is dangerous for us in terms of for example getting a stroke? Thanks a lot, carinara Quote Link to comment Share on other sites More sharing options...
flop Posted June 23, 2009 Report Share Posted June 23, 2009 Hi Carinara,I think that a lot of us get symptoms such as feeling light-headed and brain-fogged from our brains not getting as much blood flow as they would like. However what we experience is quite different from a stroke. When we lie down our brain gets the blood that it needs (soem people describe fainting as the body's "failsafe" mechanism to get enough blood to our brains, when we have stood up for too long our bodies will let us know to sit/lie down or they "force" us to lie down!).There are 2 different types of stroke: haemorrhagic and embolic. In a haemorrhagic stroke a blood vessel ruptures and the person bleeds into the brain (people with aneurysms in their brains and people with high blood pressure are at higher risk of haemorrhagic stroke than average). In an embolic stroke a piece of atherosclerotic plaque (fatty build-up in the lining of the arteries) breaks off from the wall of a blood vessel and travels up the arteries to the brain where it blocks off the blood supply causing an infarction (people with high cholesterol, diabetes and high blood pressure are at higher risk of embolic stroke than average). The same health checks apply to us as to other people - to minimise your risk of stroke you should get your PCP to check that your cholesterol and blood sugar are kept in the normal range, eat a healthy diet and exercise (I realise that exercise is very difficult for many of us!).Flop Quote Link to comment Share on other sites More sharing options...
ajw4790 Posted June 23, 2009 Report Share Posted June 23, 2009 Hi,I wanted to add that I think that many (most drs) who understand dysautonomia do recognize cerebral hypoperfusion as a symptom or a process that occurs. As far as cerebral hypoperfusion occuring with a regular BP measurement is not uncommon. You do not have to be hypotensive to get it. It is more due to blood pooling distally and having less blood circulating at that pressure, and taking into account the TPR etc. By the time the blood starts to get back to the brain there is not enough ummpph behind the blood to make sure that it goes optimally against gravity and to the brain. Also, the amount of O2 in blood by this time has to be considered.As far as treatment, normally decrease blood pooling and increase fluid volume, via Midodrine and Florinef, salt and water loading, compression, and exercise to increase muscle pump to assist blood flow return to brain etc...Hope that answers some of your question!? Quote Link to comment Share on other sites More sharing options...
ramakentesh Posted June 24, 2009 Report Share Posted June 24, 2009 It the tachy that was causing the symptoms.Well the tachy would either be to compensate for thoratic hypovolumia, and thus helping, or it could be from impaired norepinephrine reuptake and thus overactivation of beta receptors in the heart. Neither of these mechanisms would result in the symptoms, both would be a consequence of the overall problem. As far as cerebral hypoperfusion occuring with a regular BP measurement is not uncommon. You do not have to be hypotensive to get it. It is more due to blood pooling distally and having less blood circulating at that pressure, and taking into account the TPR etc. By the time the blood starts to get back to the brain there is not enough ummpph behind the blood to make sure that it goes optimally against gravity and to the brain. Also, the amount of O2 in blood by this time has to be considered.In some cases, but there are also clearly cases where reduced cerebral bloodflow occurs BEFORE the consequences of reduced venous return become apparent. Hypocapnic cerebral vasoconstriction occurs in some forms of POTS, impaired cerebral vasoregulation has been found consistently in some forms of POTS (although other studies have found the opposite) and the vasoconstrictive states that occur in Low Flow and NET deficiency occur as a result of vasoconstriction impairing blood flow to the brain through the carotids. There is also postural anemia being investigated, and a whole host of other mechanisms. Quote Link to comment Share on other sites More sharing options...
ramakentesh Posted June 24, 2009 Report Share Posted June 24, 2009 The key to determining this could be peripheral resistance - if it is increased when symptomatic it may suggest that increased alpha stimulation is the cause of your symptoms and that excessive vasoconstriction is at play. It could also be a compensatory mechanism Quote Link to comment Share on other sites More sharing options...
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