Stroke
Conditions
Brief summary
The overall objective of this study is to evaluate the use of diffuse correlation spectroscopy to non-invasively measure dynamic cerebral autoregulation in subjects with vascular risk factors. Optical cerebral blood flow measurements will be correlated with changes in arterial blood pressure to assess how CBF is maintained in response to changes in ABP, and will be compared to transcranial doppler reference measurements.
Interventions
DEVICEThigh Cuff
Sponsors
University of Pennsylvania
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age greater than or equal to 50 years * Positive history of at least one of the following vascular disk factors: hypertension, diabetes, hyperlipidemia, coronary artery disease, atrial fibrillation, prior myocardial infarct, transient ischemic attack, or history of smoking
Exclusion criteria
* Vascular risk factor subjects: 1. Pregnant women 2. Prisoners 3. Prior neurosurgical procedure or traumatic brain injury, including hemicraniectomy or other skull defect 4. Prior history of ischemic or hemorrhagic stroke 5. Prior lower extremity amputation 6. Peripheral vascular disease
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| dCA Measurement During Acute Changes in Mean Arterial Pressure, TCD | 1.5 hours | Rate of Regulation, measured using transcranial doppler. Rate of regulation (ROR) is calculated as follows: ROR = (change in relative cerebrovascular resistance / change in time) / maximum fractional decrease in blood pressure due to thigh cuff deflation. |
| dCA Measurement During Acute Changes in Mean Arterial Pressure, Optical | 1.5 hours | Rate of Regulation, measured using diffuse correlation spectroscopy. Rate of regulation (ROR) is calculated as follows: ROR = (change in relative cerebrovascular resistance / change in time) / maximum fractional decrease in blood pressure due to thigh cuff deflation. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Linear Relationship Between Rate of Regulation Measured Using TCD and Optics | 1.5 hours | Linear relationship between Rate of Regulation measured using TCD and Optics, expressed as slope of linear fit |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Intervention We will measure dCA with both TCD and DCS during acute changes in mean arterial pressure using thigh cuff deflation techniques in vascular risk factor subjects. Measurements will be compared between TCD and DCS in order to validate DCS as a tool to measure dCA in this population. | 21 |
| Total | 21 |
Baseline characteristics
| Characteristic | Intervention | — |
|---|---|---|
| Age, Continuous | 31 years | — |
| Race and Ethnicity Not Collected | — | — Participants |
| Sex: Female, Male Female | 9 Participants | — |
| Sex: Female, Male Male | 12 Participants | — |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 21 |
| other Total, other adverse events | 0 / 21 |
| serious Total, serious adverse events | 0 / 21 |
Outcome results
Primary
dCA Measurement During Acute Changes in Mean Arterial Pressure, Optical
Rate of Regulation, measured using diffuse correlation spectroscopy. Rate of regulation (ROR) is calculated as follows: ROR = (change in relative cerebrovascular resistance / change in time) / maximum fractional decrease in blood pressure due to thigh cuff deflation.
Time frame: 1.5 hours
Population: 21 subjects in the study, but hemodynamic monitoring was only possible in 18. 1 subject did not tolerate, and data acquisition was unsuccessful in 2. In 3 subjects, the pressure algorithm to isolate CBF was unsuccessful. In 4 subjects, BP did not decrease following cuff deflation due to technical issues leaving 11 subjects in the final analysis
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Intervention | dCA Measurement During Acute Changes in Mean Arterial Pressure, Optical | 0.278 per second |
Primary
dCA Measurement During Acute Changes in Mean Arterial Pressure, TCD
Rate of Regulation, measured using transcranial doppler. Rate of regulation (ROR) is calculated as follows: ROR = (change in relative cerebrovascular resistance / change in time) / maximum fractional decrease in blood pressure due to thigh cuff deflation.
Time frame: 1.5 hours
Population: 21 subjects consented, hemodynamic monitoring possible in 18. 1 subject did not tolerate,data acquisition was unsuccessful in 2. In 3 subjects, the pressure algorithm to isolate cerebral blood flow(CBF) was unsuccessful. In 4 subjects, BP did not decrease following cuff deflation due to technical issues leaving 11 subjects in the final analysis
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Intervention | dCA Measurement During Acute Changes in Mean Arterial Pressure, TCD | 0.262 per second |
Other Pre-specified
Linear Relationship Between Rate of Regulation Measured Using TCD and Optics
Linear relationship between Rate of Regulation measured using TCD and Optics, expressed as slope of linear fit
Time frame: 1.5 hours
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Intervention | Linear Relationship Between Rate of Regulation Measured Using TCD and Optics | 0.96 slope |