Brain Fog in CFS and POTS


Up ] Mechanisms of Vasovagal Syncope ] Local Vasoconstriction and Sympathoexcitation in Postural Tachycardia Syndrome ] [ Brain Fog in CFS and POTS ] Vascular Dysfunction in the Chronic Fatigue Syndrome ] Hyperpnea in Postural Tachycardia ]






    Welcome to the Brainfog in CFS/POTS Study website. Researchers at the Center for Hypotension at New York Medical College in Valhalla NY have received funding from the CFIDS Association  to study the cause and treatment of cognitive impairment in teenagers and young adults with CFS. Our most recent data indicate that cognitive loss is related to orthostasis.

    The Principal Investigator is Dr. Marvin S. Medow

    What comprises the study population? 
    What is the hypothesis and importance of the study?
    What are the symptoms and findings in patients?
    What is the goal of the study?
    What your own doctor can do to help diagnose POTS.
    How do I know if I’m eligible to be in this study? 
    Who pays for the exams, testing, and travel? 
    How can I get a questionnaire  for this study? 
    If I decide to participate what does the study entail?


    What comprises the study population? 

    We are seeking participants who have Chronic Fatigue Syndrome (CFS) and healthy volunteers, ages 15-29 years of age to participate in a New York Medical College IRB-approved (L-10,523), funded research protocol. People with CFS have many different symptoms, among them are disabling fatigue and the inability to concentrate; so-called brain fog


    What is the hypothesis and importance

    CFS-associated neurocognitive impairment , affects concentration and causes working memory deficits, and impaired speed in information processing . Although a pathophysiological cause for neurocognitive impairment in CFS/POTS has not been found, impaired cerebral perfusion could play a role in neurocognitive dysfunction in CFS/POTS. Evidence for the role of cerebral perfusion is unclear as some studies support this  while other studies fail to support the hypotheses of global or regional deficits of perfusion in patients with CFS. Data from our prior studies, however, lend support to the impaired perfusion hypothesis. These studies used transcranial Doppler ultrasound (TCD) to demonstrate reduced cerebral blood flow   and cognitive loss in CFS/POTS patients compared to healthy control subjects during 70o upright tilt and incremental tilt but not while supine.

    The purpose of the proposed study is to test the hypothesis that impaired upright cognition occurs in many CFS patients and can be improved by loading the baroreflex with sub-pressor dose phenylephrine to prevent hyperpnea, by normalizing CO2 with exogenous CO2 to prevent hypocapnia, or by administration of acetazolamide to directly improve cerebral blood flow.


    What are the symptoms of CFS with POTS
    Fainting is uncommon. Symptoms of CFS/POTS and chronic orthostatic intolerance including dizziness, fatigue, nausea and abdominal pain, headache, pallor, and neurocognitive loss (difficulty thinking), shakiness and exercise intolerance which overlap with the case definition of CFS. Most of the time these symptoms are postural, present mostly when upright or standing and relieved by lying down.


    What is the goal of the study

    The overall objectives of this proposal are to determine whether impaired upright cognition in CFIDS patients can be improved by increasing CBF.


    Specific Objectives are:


    1)      Neurocognition will be measured supine and during upright tilt using a parametric N-back task in CFIDS subjects, as will cerebrovascular circulation, CO2, respirations, BP, cardiac output, EKG and regional changes in blood flow/volume. Results form CFIDS subjects will be compared to those from age/sex-matched controls.


    2)      The results obtained from the cardiovascular, respiratory, cerebrovascular and neurocognitive responses to orthostasis will address the goal of providing “Markers and/or strategies for objective identification of CFIDS subtypes that will advance diagnosis and therapy.”


    3)    We will evaluate the response to phenylephrine, controlled re-breathing of CO2 and acetazolamide on neurocognition and cardio-respiratory parameters will achieve an additional goal of providing “Effective therapeutic approaches to symptom management or underlying pathophysiology, including exploration of existing and off-label medications, orphan or novel drug families.”   



    What can your own doctor do

    Your doctor can rule out other illnesses such as infectious and inflammatory conditions which can produce similar symptoms. For example, most blood tests will be performed by your own physician. However, the tests we will be performing are not ordinarily available to your doctor. They are, however, all approved ways of measuring how blood vessels work. POTS can be treated by a combination of lifestyle adjustments and medication which your doctor can administer. The tests performed during the study may help us determine what treatment is best for you. We will provide you and your doctor with test results and treatment information.


    How do I know if I’m eligible to be in this study? 

    Even though the study focuses on CFS patients with brain fog, all CFS patients should enroll. At this time we cannot predict who has circulatory or brain dysfunction or if POTS is the only form of orthostatic intolerance in young persons with CFS. Therefore all patients who fulfill the criteria for CFS (using the 1994 Centers for Disease Control definition) and are between 15 and 29 years old can enroll.

    The diagnosis of CFS should be made by a doctor, either your own physician or through contact with our center.

    Exclusion:The criteria for initial exclusion are adapted from the CDC  and include: 1) an active medical condition that may explain the diagnosis; 2) a previous medical condition with undocumented resolution; 3) a past or current major psychiatric disorder; 4) a history of alcohol or substance abuse within 2 years before the onset of the chronic fatigue.

    Inclusion: The criteria for initial inclusion are adapted from the CDC:15 and 29 years old adolescents who have persistent or relapsing chronic fatigue of new or definite onset; and the concurrent occurrence of four or more of the following symptoms that have persisted or recurred during at least 6 consecutive months and have not predated the fatigue:
    1) impairment in memory or concentration severe enough to cause substantial reduction of previous levels of educational, social or personal activities. In adolescents this may be most notable by a decline in academic performance and school attendance;
    2) muscle pain or multi joint pain;
    3) headaches of a new type, pattern, or severity;
    4) unrefreshing sleep; and
    5) post-exertional malaise lasting more than 24

    Sore throat and swollen glands are unreliable criteria during adolescence .



    Who pays for the exams, or testing?

    There is no charge to you for any of the the testing or testing medication. We will pay each participant who $300 as a token of appreciation for their time.



    How can I get a screening application for this study? 

    You can click on the Screening icon, and download and print out the application and mail it to us. The mailing address is on the last page of the form. Alternatively you can email the application to or to or you can also fax us the application at 914-593-8888. Or, you can call us at 914-593-8888, leave your name and address on the voicemail and we’ll mail you an application. 



    Who pays for the exams, or testing?

    The diagnosis of CFS will be made by your doctor.  There are no charges associated with participation in this study.


    How can I get a questionnaire for this study? 

    You can click on the Questionnaire icon, and download and print out the application and mail it to us. The mailing address is on the last page of the form. Alternatively you can email the application to or you can also fax us the application at 914-593-8890. Or, you can call us at 914-593-8888, leave your name and address on the voicemail and we’ll mail you an application. 


    What happens if I’m eligible to be in the study and decide to participate? 

    If you would like to take part in this study, our study coordinator will contact you to go over the questionnaire materials and to arrange a date for the study.  At that time we will also review the informed consent process and answer any questions that you might have.  You and your parents (if applicable) should understand the study, and its risks and benefits.  You can click on the Informed Consent icon to read more about the study.

    If you have further questions about the study, please feel free to call 914-593-8888 or email





Mechanisms of Vasovagal Syncope
Local Vasoconstriction and Sympathoexcitation in Postural Tachycardia Syndrome
Brain Fog in CFS and POTS
Vascular Dysfunction in the Chronic Fatigue Syndrome
Hyperpnea in Postural Tachycardia