Cognitive Dysfunction in Postural Tachycardia Syndrome

Study Overview
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Brief Summary
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A common complaint among people with Postural Tachycardia Syndrome (POTS) is brain fog or difficulty concentrating. This is very poorly understood. To better understand this cognitive dysfunction, the investigators will test people with POTS and people without POTS using various neuropsychiatric instruments. The investigators hypothesis is that people with POTS will have greater abnormalities on neuropsychiatric testing than normal controls.

Detailed Description
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Postural Tachycardia Syndrome (POTS) is a disorder that affects an estimated 500,000 people in the United States alone and is an important source of disability in young adults. It shows a strong predilection for females. POTS is a form of orthostatic intolerance characterized by an excessive increase in heart rate (>30 bpm) on assuming the upright position associated with orthostatic symptoms, but in the absence of orthostatic hypotension. Their symptoms of dizziness, nausea, tremor, chronic fatigue and exercise intolerance make even simple activities of daily living exhausting prospects. Brain fog or cognitive dysfunction is a common and almost universal complaint among persons with POTS. There is a lack of pathophysiological understanding to this cognitive dysfunction and is also a major roadblock to the development of effective therapies for people with POTS. The purpose of this study is to better define the cognitive dysfunction seen in patients with POTS. We will use a series of validated neuropsychological tools in order to characterize POTS cognitive dysfunction and compare this data to age and gender matched control subjects. Specific Aims: To assess whether POTS patients have more neuropsychological abnormalities than control subjects during seated assessments. To assess whether POTS patients have more neuropsychological abnormalities than control subjects during assessments while standing. To ascertain the phenomenology of any neuropsychological deficits distinguishing POTS patients from controls.

Official Title
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Origins of Cognitive Dysfunction in Postural Tachycardia Syndrome (POTS)

Conditions
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Postural Tachycardia Syndrome

Intervention / Treatment
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* Behavioral: Seated Measurements
* Behavioral: Standing Measurements
* Behavioral: Self-Administered Surveys


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All Ages between 18-60 years Male and female subjects are eligible Able and willing to provide informed consent POTS - additional inclusion criteria - Diagnosed with postural tachycardia syndrome by Vanderbilt Autonomic Dysfunction Center (increase in heart rate greater than or equal to 30 beats per minute with position change from supine to standing (10 minutes; chronic symptoms consistent with POTS that are worse when upright and get better with recumbence.) Control subjects - additional inclusion criteria Gender matched to POTS patients Age-matched to POTS patients (+/- 5 years of a POTS patient) Grossly matched in intelligence to POTS patients Exclusion Criteria: ALL Inability to give or withdrawal of informed consent Pregnancy (determined by patient self report) Other factors which in the investigator's opinion would prevent the subject from completing the protocol. POTS - additional exclusion criteria - Overt cause for postural tachycardia (such as acute dehydration) Normal Controls - additional exclusion criteria Previously diagnosed with Axis I psychiatric disorder Previously diagnosed learning disorder Previously diagnosed attention deficit hyperactivity disorder (ADHD) Prior psychosis past or present substance abuse History of loss of consciousness History of seizures

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Normal Controls / Healthy Volunteers<br>Age and gender matched individuals without postural orthostatic tachycardia syndrome | Behavioral: Seated Measurements<br>* The following measurements will take place in a seated position: Ruff 1 & 7 (visual search and attention processes) Trails A & B (Tests of scanning, mental flexibility and executive processes) Symbol Digit Modalities Test (SDMT)(attention and psychomotor speed) Stroop Test (naming response to certain stimuli) Verbal Fluency (COWA) Randt Wechsler Test of Adult Reading (WTAR)<br>Behavioral: Standing Measurements<br>* The following will be measured in a standing position (at least 5 minutes) Orthostatic Vital Signs Randt Paired Words Subtest Digits Forward and Backward Alternate COWA test<br>Behavioral: Self-Administered Surveys<br>* Center for Epidemiologic Studies Depression Scale (CES-D) Cognitive-Somatic Anxiety Questionnaire (CSAQ) Subjective Neurocognitive Inventory (SNI)<br>|
| Patients with Postural Tachycardia Syndrome (POTS)<br>Individuals with Postural Tachycardia Syndrome | Behavioral: Seated Measurements<br>* The following measurements will take place in a seated position: Ruff 1 & 7 (visual search and attention processes) Trails A & B (Tests of scanning, mental flexibility and executive processes) Symbol Digit Modalities Test (SDMT)(attention and psychomotor speed) Stroop Test (naming response to certain stimuli) Verbal Fluency (COWA) Randt Wechsler Test of Adult Reading (WTAR)<br>Behavioral: Standing Measurements<br>* The following will be measured in a standing position (at least 5 minutes) Orthostatic Vital Signs Randt Paired Words Subtest Digits Forward and Backward Alternate COWA test<br>Behavioral: Self-Administered Surveys<br>* Center for Epidemiologic Studies Depression Scale (CES-D) Cognitive-Somatic Anxiety Questionnaire (CSAQ) Subjective Neurocognitive Inventory (SNI)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Standing Digits Backwards Test | This is a continuous variable that will provide a measure of attention with orthostatic stress. | In the standing position for approximately 15 minutes. This is a cross-sectional study with no follow-up. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cognitive Domain Score (CDS) | The CDS will consist of 1: Seated memory (Randt Short Story subtes, Paired words subtes and Digits Forward) and standing memory (Randt short story, paired words and digits forward). 2. Seated Complex Attention (Ruff, SDMT, Trails A, Randt, Digits Backward) and standing complex attention (Randt digits backward) 3. Executive functioning only while standing (Stroop, Trails) 4. Seated and standing verbal fluency (COWA). | At seated and standing. This is a cross-sectional study without follow-up. All assessments are performed on a single day. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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postural tachycardia syndrome, brain fog, cognitive dysfunction