Skip to comments.Reduced Cardiac Vagal Modulation Impacts on Cognitive Performance in Chronic Fatigue Syndrome
Posted on 12/30/2012 7:18:29 AM PST by Seizethecarp
Cognitive difficulties and autonomic dysfunction have been reported separately in patients with chronic fatigue syndrome (CFS). A role for heart rate variability (HRV) in cognitive flexibility has been demonstrated in healthy individuals, but this relationship has not as yet been examined in CFS. The objective of this study was to examine the relationship between HRV and cognitive performance in patients with CFS.
Patients with CFS showed no deficits in performance accuracy, but were significantly slower than healthy controls. CFS was further characterized by low and unresponsive HRV; greater heart rate (HR) reactivity and prolonged HR-recovery after cognitive challenge. Fatigue levels, perceived effort and distress did not affect cognitive performance. HRV was consistently associated with performance indices and significantly predicted variance in cognitive outcomes.
These findings reveal for the first time an association between reduced cardiac vagal tone and cognitive impairment in CFS and confirm previous reports of diminished vagal activity.
(Excerpt) Read more at plosone.org ...
Tell me about it!
I suddenly feel sleepy ... I’ll read this later ....
Hold-outs for the “its all in the mind” (big fakers, big whiners) theory of ME/CFS will be hard-pressed to explain how “chronic sympathetic hyper-arousal...persists even during sleep,” but old prejudices die hard for some.
It took a whole study with some long, stupid name to tell that people who can’t sleep have slower reaction times?
That’s why I wouldn’t feel safe driving until my parathyroid surgery.
Maybe the government should give me millions of dollars to find out why Liberals are so stupid...
You believe this crap, Jane?
CFS isn’t about people who can’t sleep, although some folks with CFS may also have sleep disorders or develop sleep disorders.
I hope you never have to experience it.
Too small a study to be useful
Hold-outs for the its all in the mind (big fakers, big whiners) theory of ME/CFS will be hard-pressed to explain how chronic sympathetic hyper-arousal...persists even during sleep, but old prejudices die hard for some.
But... Doesn't this study show strong evidence that it *is* all in the mind? It's all that nervous system involvement, you know.
Another thing, of course, the endocrine system is forgotten about.
“Patients with CFS showed no deficits in performance accuracy, but were significantly slower than healthy controls. CFS was further characterized by low and unresponsive HRV; greater heart rate (HR) reactivity and prolonged HR-recovery after cognitive challenge. Fatigue levels, perceived effort and distress did not affect cognitive performance. HRV was consistently associated with performance indices and significantly predicted variance in cognitive outcomes”
I already have primary hyperparathyroid disease. I’ve been experiencing it since 2002.
We’ve already decided that Liberals are moronic, at least Conservatives have. I figure that since the government gives out grants to study the sex habits of a Polish frog, then yeah, I believe taxpayer money goes to Liberal orgs as payback ... :)
another thing is if you are smoking like a chimney you are unlikely to get well under any circumstances—little frustration with my sibling here
I’ve never smoked anything at all and don’t have any plans to start smoking anything.
Studying the sex habits of a Polish frog... it kinda makes me vaguely regret being a taxpayer.
“It took a whole study with some long, stupid name to tell that people who cant sleep have slower reaction times?”
The study validates the CFS diseased state of the autonomic heart-brain feedback loop that ultimately regulates blood flow to the brain. This defective mechanism is NOT a function of lack of sleep per se, although poor sleep quality contributes to background fatigue level for CFS patients, I am sure.
Here is a 1997 John’s Hopkins paper that explains better what this Australian study is confirming:
GENERAL INFORMATION BROCHURE ON NEURALLY MEDIATED HYPOTENSION AND ITS TREATMENT
Neurally Mediated Hypotension Working Group
Johns Hopkins Hospital
Revised January 1997
This document has been prepared for those who have requested further information about neurally mediated hypotension.
What is neurally mediated hypotension?
Neurally mediated hypotension is also known by the following names: the fainting reflex, neurocardiogenic syncope, vasodepressor syncope, the vaso-vagal reflex, and autonomic dysfunction. Hypotension is the formal medical term for low blood pressure, and syncope is the term for fainting. Neurally mediated hypotension occurs when there is an abnormal reflex interaction between the heart and the brain, both of which usually are structurally normal.
When does neurally mediated hypotension lead to symptoms?
Neurally mediated hypotension occurs in susceptible individuals in the following settings:
after prolonged periods of quiet upright posture (such as standing in line, standing in a shower, or even sitting up for long periods),
after being in a warm environment (such as in hot summer weather, a hot crowded room, a hot shower or bath),
immediately after exercise,
after emotionally stressful events (seeing blood or gory scenes, being scared or anxious).
some individuals get symptoms soon after eating, when blood flow has shifted to the intestinal circulation during the process of digestion.
We are all susceptible to activation of the vaso-vagal reflex that results in a lowered blood pressure (NMH), but each person’s susceptibility is affected by his or her genetic make-up, dietary factors, psychological make-up, and acute triggers such as infection and allergy. The clinical problem of NMH occurs when there is sufficiently early triggering of this reflex to cause symptoms.
How does upright posture lead to these problems?
After a normal individual stands up, blood pools in the legs through the effect of gravity. To compensate for the lower amount of blood returning to the heart immediately after standing, the body has a surge of adrenaline (epinephrine). This adrenaline surge leads to a faster heart rate and to more vigorous heart beats (a familiar feeling we all experience when we are frightened, for example). The faster heart rate and more vigorous heart contractions allow the reduced amount of blood returning to the heart to be pumped more efficiently to vital organs (especially the brain).
In individuals with neurally mediated hypotension, there is a Amiscommunication@ between the heart and the brain. Just when the heart needs to beat faster, (to pump blood to the brain and prevent fainting), the brain sends out the message that the heart rate should be slowed down, and that the blood vessels in the arms and legs should dilate. These actions take even more blood away from the central part of the circulation where it is needed. In response, individuals feel lightheaded or may faint because not enough blood is getting to the brain. Fainting is helpful, in that it restores a person to the flat position, removing the pooling effect of gravity on the blood, and allowing more blood to return to the heart. Following the lightheadedness or syncope, most individuals feel tired and their mental abilities are somewhat foggy.
Which symptoms can be caused by the neurally mediated hypotension?
Recurrent lightheadedness and fainting are common symptoms, as is an unusual difficulty with prolonged fatigue after a modest amount of physical activity. This post-exertional fatigue can last 24-72 hours, and interferes with many daily activities.
We have also observed that chronic fatigue, muscle aches (or fibromyalgia), headaches, and mental confusion can be prominent symptoms of neurally mediated hypotension even in individuals who do not faint. The mental confusion takes the form of difficulty concentrating, staying on task, paying attention, or finding the right words.
good, I was talking about my sister who has chronic fatigue and never eats anything, just chain smokes pot and cigarettes all freaking day long. I don’t know you from Adam, and have no idea what you do.
I gathered from your reference to parathyroid surgery that you probably had something going on along those lines. However, please realize that doesn’t make you somehow magically CFS-immune. And it doesn’t make CFS any less legitimate.
Perhaps I misinterpreted your comments viewing those with CFS as people who can’t sleep and summing up with, “You believe this crap, Jane?”
It probably just hit me wrong.
“But... Doesn’t this study show strong evidence that it *is* all in the mind?”
Insufficient blood flow to the brain caused by failure of the brain, heard and autonomic nervous system to regulate blood pressure when the body and/or brain are subjected to a stressor. For those with severe CFS, going from a supine to sitting or standing posture is sufficient to cause loss of blood to the brain in a relatively short time. This has nothing to do with lack of sleep as a primary cause.
I sleep little, and the sleep I do get isn’t rejuvenating. It’s almost noon here, I haven’t been awake for 3 hours and I’m already exhausted.
I do have primary hyperparathyroid disease, and I don’t have the means to get the surgery yet, so I’m going to be suffering with it for a while to come.
There’s more stupid programs that are funded by gov’t as payback for political help.
Thanks for the ping, Nully.
Please don’t minimize the varied and severe effects of CFS/CFIDS on the individual and the people who are loved by the victim.
It is NOT cut and dried, and while it certainly could explain to some extent the sleeping (or not) of a PWC, it my no means explains anything else.
With around 40 symptoms, the best the researchers can come up with is “we don’t know what causes it so we can’t find a cure.” And there are still many, in all walks of life, who still maintain it is a psychosomatic illness.
One should hope that no one you know should suffer with this.
“Another thing, of course, the endocrine system is forgotten about.”
IIUC, whenever the article discusses the sympathetic nervous system, it involves the endocrine system (part of the feedback loop that is defective in CFS):
“The sympathetic nervous system is responsible for up- and down-regulating many homeostatic mechanisms in living organisms. Fibers from the SNS innervate tissues in almost every organ system, providing at least some regulatory function to things as diverse as pupil diameter, gut motility, and urinary output. It is perhaps best known for mediating the neuronal and hormonal stress response commonly known as the fight-or-flight response. This response is also known as sympatho-adrenal response of the body, as the preganglionic sympathetic fibers that end in the adrenal medulla (but also all other sympathetic fibers) secrete acetylcholine, which activates the great secretion of adrenaline (epinephrine) and to a lesser extent noradrenaline (norepinephrine) from it. Therefore, this response that acts primarily on the cardiovascular system is mediated directly via impulses transmitted through the sympathetic nervous system and indirectly via catecholamines secreted from the adrenal medulla.”
I notice that throughout most of my worknight: when I get up from a crouch, more often than not I feel lightheaded.
“I notice that throughout most of my worknight: when I get up from a crouch, more often than not I feel lightheaded.”
When you go from sitting to standing there is a blood flow from your upper body into your legs and abdomen and away from your brain. Your autonomic nervous system detects this and hormones are near-instantly secreted in the brain that cause increase in heart rate and constriction of blood vessels to force blood out of the legs and abdomen and maintain blood pressure in the brain.
The vagus nerve handles the part of the process of increasing heart rate.
As we get older or are compromised by illness or disease, this feedback loop is not fully effective and blood loss to the brain results. In some persons the loss is very quick while in others it may take minutes or hours for the blood flow to the brain to fall and even produce feinting if the person doesn’t lie down. Lying down eliminates the symptoms.
Another name for the CFS-associated symptom in this article is orthostatic intolerance.
In my case I cannot tolerate standing still for more than a few minutes and I can only tolerate sitting for two hours at a time, even with my legs elevated. Then I must lie down for at least a half hour to restore my ability to sit for another two hours. This is how I go through me day. There is NO fully effective medical treatment for this, yet.
(Midodrine and fludrocortisone are not effective for me for those thinking of that)
Lack of sleep has nothing to do with the defect in this mechanism. I use CPAP both at night and during my four lie-down naps during the day that restore my ability to sit up.
If I try to push past about two hours of sitting up, I experience increasingly uncomfortable “pre-syncope” a pre-feinting syndrome that eventually becomes painful and results in me passing out if I don’t lie down. This has been experimentally proved on me and thousands of other CFS patients in HUTT testing (Heads Up Tilt Table). They strap you to a table (so you can’t bend your knees to pump blood to your head) Then they elevate you to 70 to 90 degrees an wait to see if you pass out in agony and measure how long it takes. My last test was 15 minutes. Although there are false positive for some folks, most healthy people can last a half-hour during HUTT testing without ever getting stressed or passing out.
Is this report available in English?
Is this report available in English?
Its about Heart Rate Variability (HRV) and mental performance of CFS patients. The heart of a CFS patient doesn’t respond either soon enough or strong enough to mental and physical stress to maintain adequate blood flow to the brain. So CFS sufferers report “brain fog” or reduced mental clarity, particularly mental speed compared to normal folks (controls in the study).
In my experience (as can be seen in my comments in this thread) the lack of blood flow to the brain in CFS is often partly due to “blood pooling” in the abdomen and legs when the person sits up (from lying down) or stands up from either sitting or lying.