Recruiting

Observational Study

Sponsor:

UCLA

Code:

NCT05400174

Conditions

Parkinson Disease

Orthostatic Hypotension

Dysautonomia

Eligibility Criteria

Sex: All

Age: 50+

Healthy Volunteers: Not accepted

Interventions

Tilt table (upright position)

Study Details

Brief summary:

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.

Conditions

Parkinson Disease

Orthostatic Hypotension

Dysautonomia

Study ID

NCT05400174

Start date

Dec 14, 2021

Status verified date

Aug, 2026

Completion date

Jan 15, 2027

Anticipated

Primary completion date

Dec 15, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 50+

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Diagnosis of idiopathic Parkinson Disease using the Movement Disorders Society (MDS) Clinical Diagnostic Criteria
2. Age at least 50 years old
3. Hoehn \& Yahr (H\&Y) stages I-III (early to moderate-stage PD; able to walk without assistance
4. Proficiency in the English language (native English speaker level)

Exclusion Criteria:

1. 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
2. Dementia (including PD dementia)
3. History of deep brain stimulation (DBS) surgery
4. Any current unstable, active medical problem, e.g. decompensated heart failure, liver failure, pneumonia, etc.
5. Moderate or severe carotid artery stenosis (according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria
6. History of cerebral infarction or hemorrhage
7. Uncontrolled diabetes or any other systemic disease causing autonomic failure
8. Syncope (fainting) within the past week
9. Illiteracy (unable to read)
10. Taking antihypertensive medications or alpha-adrenergic blocking medications, since these can cause hypotension (see \* below)
11. Impairment of hearing or vision that is not corrected by devices (e.g., hearing aids or glasses)
12. Currently pregnant (will be confirmed by women of child-bearing potential with a urine pregnancy test)
13. 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.

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Diagnostic

Interventions and Outcome Measures

Arms

other: Supine cognitive testing first

The cognitive testing sessions will be alternated between supine and upright positions.

This group will perform cognitive testing sessions in the following order: 1) supine, 2) upright, 3) supine, 4) upright.

other: Upright cognitive testing first

The cognitive testing sessions will be alternated between supine and upright positions.

This group will perform cognitive testing sessions in the following order: 1) upright, 2) supine, 3) upright, 4) supine.

Interventions

Tilt table (upright position)

Different versions of cognitive assessments will be administered in the supine and upright positions.

Primary outcome measure

  • 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 ]
  • Oxygenated and deoxygenated hemoglobin change from baseline [ Time Frame: up to 30 months ]

Central Contacts and Locations

Central contacts

Katherine Longardner, MD

8588225751klongardner@health.ucsd.edu

Michael Skipworth, BS

8588225751mskipworth@health.ucsd.edu

Locations

University of California San Diego

Recruiting

San Diego, California, United States, 92093

Contacts

Katherine Longardner, MD

8588225751klongardner@health.ucsd.edu

Michael Skipworth, BS

8588225751klongardner@health.ucsd.edu

Principal Investigator:

Katherine Longardner, MD

More Information

Sponsor

University of California, San Diego

Last update posted

Aug 7, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of California, San Diego on 2026-08-07.