NCT05400174 · University of California, San Diego
Blood Pressure Effects on Cognition and Brain Blood Flow in PD
What this study is about
Parkinson's disease (PD) is the second most common neurodegenerative disorder worldwide. Besides causing symptoms that impair movement, PD also causes non-motor symptoms, such as problems thinking and orthostatic hypotension (OH), i.e., low blood pressure (BP) when standing.
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Parkinson's disease (PD) is the second most common neurodegenerative disorder worldwide. Besides causing symptoms that impair movement, PD also causes non-motor symptoms, such as problems thinking and orthostatic hypotension (OH), i.e., low blood pressure (BP) when standing. About one-third of people with PD have OH, which can cause sudden, temporary symptoms while upright, including lightheadedness, dizziness, and fainting. People with PD and OH can also experience problems thinking that happen only while upright and not while sitting - this can occur without other symptoms, such as feeling dizzy or faint. However, the level of low BP that can affect thinking remains unknown, and no guidelines exist for treating OH when it happens without symptoms. This is significant because OH could be a treatable risk factor for thinking problems in PD, but OH is often not treated if people do not report obvious symptoms. This project's goal is to determine how BP affects brain function in PD. The proposed experiments will measure BP and brain blood flow continuously in real-time using innovative wearable technology. Persons with PD with OH and without OH will undergo repeated cognitive tests while supine (lying down) and while upright. I will study the associations between BP, thinking abilities, and brain blood flow, and will compare groups with and without OH. These findings could be important because if a certain level of BP correlates with thinking abilities, then treating OH in PD may prevent thinking problems, which would improve health-related quality of life and reduce disability and healthcare costs.
Interventions
DIAGNOSTIC_TEST
Tilt table (upright position)
Different versions of cognitive assessments will be administered in the supine and upright positions.
Primary outcome measures
Delis-Kaplan Executive Function System Verbal Fluency Test score (number of words per minute). Minimum: 0; Maximum: N/A; higher is better
Time frame: up to 30 months
Participant says as many words in 1 minute as possible each of several letter or category prompts.
Oxygenated and deoxygenated hemoglobin change from baseline
Time frame: up to 30 months
Functional near-infrared spectroscopy will measure relative changes in oxygenated and deoxygenated hemoglobin variables
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Diagnosis of idiopathic Parkinson Disease using the Movement Disorders Society (MDS) Clinical Diagnostic Criteria
- Age at least 50 years old
- Hoehn \& Yahr (H\&Y) stages I-III (early to moderate-stage PD; able to walk without assistance
- Proficiency in the English language (native English speaker level)
Exclusion criteria
- Any involuntary movements (i.e., tremor or dyskinesia) \> 3 cm in amplitude (ok if movements are treated with medication), since the motion artifact could interfere with blood pressure monitor data collection
- Dementia (including PD dementia)
- History of deep brain stimulation (DBS) surgery
- Any current unstable, active medical problem, e.g. decompensated heart failure, liver failure, pneumonia, etc.
- Moderate or severe carotid artery stenosis (according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria
- History of cerebral infarction or hemorrhage
- Uncontrolled diabetes or any other systemic disease causing autonomic failure
- Syncope (fainting) within the past week
- Illiteracy (unable to read)
- Taking antihypertensive medications or alpha-adrenergic blocking medications, since these can cause hypotension (see \
- Impairment of hearing or vision that is not corrected by devices (e.g., hearing aids or glasses)
- Currently pregnant (will be confirmed by women of child-bearing potential with a urine pregnancy test)
- Any other condition, which, in the opinion of the investigator, could place the participant at increased risk.
- Please note that persons may not participate if they are taking any of the following:
- medications to treat high blood pressure (called "antihypertensives") such as clonidine (Catapres), hydralazine, verapamil, diltiazem (Cartia), or medications ending in "-olol", "-artan", or "-pril")
- diuretics (also called "water pills") such as furosemide (Lasix), bumetanide (Bumex), hydrochlorothiazide (HCTZ; Microzide), or spironolactone (Aldactone)
- medications for enlarged prostate such as prazosin (Minipress), terazosin, doxazosin (Cardura), alfuzosin (Uroxatral), or tamsulosin (Flomax) If persons are taking these medications and would like to participate in the study, they will be advised to discuss whether they may discontinue these medications for 48 hours before the study visit with their prescribing doctor.
Where
- San Diego, California
Collaborators
Beth Israel Deaconess Medical Center, Drexel University
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 27, 2026 · Source of record for eligibility and locations