Trial Outcomes & Findings for Effects of Methylene Blue in Healthy Aging, Mild Cognitive Impairment and Alzheimer's Disease (NCT NCT02380573)

Results Overview

The subject draws a clock that says 1:45. Performance is rated according to the CLOX directions, and scored as "CLOX1" with scores ranging from 0-15 with a lower score indicating greater impairment. CLOX1 reflects performance in a novel and ambiguous situation. The CLOX's second step is a simple copying task. The examiner allows the patient to observe him or her drawing a clock in the circle provided on the scoring sheet. The examiner sets the hands again to "1:45", places the 12, 6, 3, and 9 first, and makes the hands into arrows. The patient is allowed to copy the examiner's clock. This clock is scored as "CLOX2" with scores ranging from 0-15 with a lower score indicating greater impairment. Participants can earn up to 15 points for each test, this is summed to give a possible score out of 30 with a higher score indicating less cognitive impairment. Scores reported are from inter-rater reliability

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

117 participants

Primary outcome timeframe

baseline, 2 weeks ± 3 days, 12 weeks ± 3 days

Results posted on

2024-09-19

Participant Flow

Participant milestones

Participant milestones
Measure	Healthy Aging MB Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease (AD) MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Alzheimer's Disease (AD) Placebo Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride
Overall Study STARTED	22	21	28	24	1	2
Overall Study COMPLETED	12	13	12	16	1	1
Overall Study NOT COMPLETED	10	8	16	8	0	1

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Effects of Methylene Blue in Healthy Aging, Mild Cognitive Impairment and Alzheimer's Disease

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Healthy Aging MB n=22 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=21 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=28 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=24 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease (AD) MB n=1 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Alzheimer's Disease (AD) Placebo n=2 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Middle Age Placebo Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Total n=98 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	0 Participants n=42 Participants
Age, Categorical Between 18 and 65 years	3 Participants n=5 Participants	4 Participants n=7 Participants	6 Participants n=5 Participants	4 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	17 Participants n=42 Participants
Age, Categorical >=65 years	19 Participants n=5 Participants	17 Participants n=7 Participants	22 Participants n=5 Participants	20 Participants n=4 Participants	1 Participants n=21 Participants	2 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	81 Participants n=42 Participants
Sex: Female, Male Female	13 Participants n=5 Participants	8 Participants n=7 Participants	17 Participants n=5 Participants	18 Participants n=4 Participants	1 Participants n=21 Participants	1 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	58 Participants n=42 Participants
Sex: Female, Male Male	9 Participants n=5 Participants	13 Participants n=7 Participants	11 Participants n=5 Participants	6 Participants n=4 Participants	0 Participants n=21 Participants	1 Participants n=8 Participants	0 Participants n=8 Participants	0 Participants n=24 Participants	40 Participants n=42 Participants
Race/Ethnicity, Customized Race/Ethnicity · White, Non-Hispanic	11 Participants n=5 Participants	11 Participants n=7 Participants	7 Participants n=5 Participants	6 Participants n=4 Participants	1 Participants n=21 Participants	2 Participants n=8 Participants	—	—	38 Participants n=42 Participants
Race/Ethnicity, Customized Race/Ethnicity · White, Hispanic	11 Participants n=5 Participants	8 Participants n=7 Participants	18 Participants n=5 Participants	16 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	—	—	53 Participants n=42 Participants
Race/Ethnicity, Customized Race/Ethnicity · Pacific Islander, Non-Hispanic	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	—	—	0 Participants n=42 Participants
Race/Ethnicity, Customized Race/Ethnicity · Pacific Islander, Hispanic	0 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	—	—	1 Participants n=42 Participants
Race/Ethnicity, Customized Race/Ethnicity · Black, Non-Hispanic	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	—	—	2 Participants n=42 Participants
Race/Ethnicity, Customized Race/Ethnicity · Black, Hispanic	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	—	—	1 Participants n=42 Participants
Race/Ethnicity, Customized Race/Ethnicity · Asian, Non-Hispanic	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	—	—	1 Participants n=42 Participants
Race/Ethnicity, Customized Race/Ethnicity · Asian, Hispanic	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	—	—	0 Participants n=42 Participants
Race/Ethnicity, Customized Race/Ethnicity · White, Not Specified	0 Participants n=5 Participants	1 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	—	—	1 Participants n=42 Participants
Race/Ethnicity, Customized Race/Ethnicity · Not Specified, Not Specified	0 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants	0 Participants n=8 Participants	—	—	1 Participants n=42 Participants
Region of Enrollment United States	22 participants n=5 Participants	21 participants n=7 Participants	28 participants n=5 Participants	24 participants n=4 Participants	1 participants n=21 Participants	2 participants n=8 Participants	—	—	98 participants n=42 Participants

PRIMARY outcome

Timeframe: baseline, 2 weeks and 12 weeks

Population: There was not sufficient data collected to be analyzed for Mild Alzheimer's disease MB or placebo, only the scale score was measured, as reported in the Wechsler Memory Scale outcome.

fMRI measurement of task blocked activation during Wechsler Memory Scale III

Outcome measures

Outcome measures
Measure	Healthy Aging MB n=12 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=13 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=12 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=16 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Mild Alzheimer's Disease Placebo Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age Placebo FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)
fMRI Measurement Baseline	2267.0 voxels Standard Deviation 2428.23	1491.23 voxels Standard Deviation 1343.81	673.31 voxels Standard Deviation 1366.69	989.19 voxels Standard Deviation 1651.97	—	—	—	—
fMRI Measurement 2 weeks	1719.00 voxels Standard Deviation 1377.02	962.69 voxels Standard Deviation 843.93	12270.59 voxels Standard Deviation 1955.60	930.25 voxels Standard Deviation 1157.55	—	—	—	—
fMRI Measurement 12 weeks	1451.83 voxels Standard Deviation 1623.84	1623.84 voxels Standard Deviation 919.08	1238.58 voxels Standard Deviation 1743.67	1334.38 voxels Standard Deviation 2341.44	—	—	—	—

PRIMARY outcome

Timeframe: baseline, 2 weeks ± 3 days, 12 weeks ± 3 days

Working memory task behavioral measures (ie. correct number of responses) Score is 0-104, with higher scores being better.

Outcome measures

Outcome measures
Measure	Healthy Aging MB n=12 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=14 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=13 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=15 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease MB n=1 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Mild Alzheimer's Disease Placebo n=1 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age Placebo FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)
Wechsler Memory Scale, Third Edition baseline	14.58 score on a scale Standard Deviation 2.35	15.43 score on a scale Standard Deviation 2.85	15.23 score on a scale Standard Deviation 2.5	13.06 score on a scale Standard Deviation 3.23	4 score on a scale Standard Deviation 0	15 score on a scale Standard Deviation 0	—	—
Wechsler Memory Scale, Third Edition 2 weeks	16 score on a scale Standard Deviation 2.3	17.29 score on a scale Standard Deviation 1.33	15.23 score on a scale Standard Deviation 2.68	15.31 score on a scale Standard Deviation 2.94	5 score on a scale Standard Deviation 0	17 score on a scale Standard Deviation 0	—	—
Wechsler Memory Scale, Third Edition 12 weeks	15.58 score on a scale Standard Deviation 2.11	15.93 score on a scale Standard Deviation 2.13	14.69 score on a scale Standard Deviation 1.55	13.2 score on a scale Standard Deviation 3.17	11 score on a scale Standard Deviation 0	13 score on a scale Standard Deviation 0	—	—

PRIMARY outcome

Timeframe: baseline, 2 weeks ± 3 days,12 weeks ± 3 days

Population: There was not sufficient data collected to be analyzed for Mild Alzheimer's disease MB or placebo, only the scale measure was obtained in the next outcome.

Functional Magnetic Resonance Imaging (fMRI) measurement of task blocked activation. Measure reflects blood flow counts, and is not a scale with a high or low score.

Outcome measures

Outcome measures
Measure	Healthy Aging MB n=12 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=13 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=12 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=16 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease MB n=1 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Mild Alzheimer's Disease Placebo n=1 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age Placebo FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)
fMRI During FNAME baseline	16881.03 voxels activated over a threshold Standard Deviation 8823.60	17382.29 voxels activated over a threshold Standard Deviation 6401.56	13166.23 voxels activated over a threshold Standard Deviation 4796.32	13777.75 voxels activated over a threshold Standard Deviation 8955.52	2211.00 voxels activated over a threshold Standard Deviation 0	3938.00 voxels activated over a threshold Standard Deviation 0	—	—
fMRI During FNAME 2 weeks	18146.92 voxels activated over a threshold Standard Deviation 7075.66	19748.86 voxels activated over a threshold Standard Deviation 8221.18	12935.15 voxels activated over a threshold Standard Deviation 7042.78	15617.31 voxels activated over a threshold Standard Deviation 7519.81	4939.00 voxels activated over a threshold Standard Deviation 0	4140.00 voxels activated over a threshold Standard Deviation 0	—	—
fMRI During FNAME 12 weeks	16893.83 voxels activated over a threshold Standard Deviation 6689.61	18342.57 voxels activated over a threshold Standard Deviation 8230.30	13973.56 voxels activated over a threshold Standard Deviation 10759.77	14466.56 voxels activated over a threshold Standard Deviation 9944.16	2240.00 voxels activated over a threshold Standard Deviation 0	1355.00 voxels activated over a threshold Standard Deviation 0	—	—

PRIMARY outcome

Timeframe: baseline, 2 weeks ± 3 days,12 weeks ± 3 days

Face-Name Task behavioral measures (ie. correct recalls). The FNAME is a cross-modal associative memory test which includes 16 face-name pairs and 16 face-occupation pairs, with a total of 32 pairs to remember. Scores range from 0-32, higher scores are better

Outcome measures

Outcome measures
Measure	Healthy Aging MB n=12 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=14 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=13 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=16 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease MB n=1 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Mild Alzheimer's Disease Placebo n=1 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age Placebo FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)
FNAME baseline	14.5 score on a scale Standard Deviation 4.83	14.36 score on a scale Standard Deviation 4.86	10.54 score on a scale Standard Deviation 3.71	11.19 score on a scale Standard Deviation 4.23	8 score on a scale Standard Deviation 0	6 score on a scale Standard Deviation 0	—	—
FNAME 2 weeks	16.08 score on a scale Standard Deviation 4.7	15.36 score on a scale Standard Deviation 6.1	12.54 score on a scale Standard Deviation 4.52	11.5 score on a scale Standard Deviation 4.62	2 score on a scale Standard Deviation 0	9 score on a scale Standard Deviation 0	—	—
FNAME 12 weeks	16.67 score on a scale Standard Deviation 4.16	16 score on a scale Standard Deviation 6.24	14 score on a scale Standard Deviation 3.96	12.69 score on a scale Standard Deviation 5.62	6 score on a scale Standard Deviation 0	1 score on a scale Standard Deviation 0	—	—

PRIMARY outcome

Timeframe: baseline,2 weeks ± 3 days,12 weeks ± 3 days

Population: There was no data collected to be analyzed for Mild Alzheimer's disease MB or placebo.

fMRI measurement of task blocked activation

Outcome measures

Outcome measures
Measure	Healthy Aging MB n=12 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=13 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=12 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=16 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Mild Alzheimer's Disease Placebo Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age Placebo FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)
fMRI During Psychomotor Vigilance Task baseline	271.33 # voxels beyond a threshold Standard Deviation 590.79	150.79 # voxels beyond a threshold Standard Deviation 348.98	145.00 # voxels beyond a threshold Standard Deviation 321.47	56.94 # voxels beyond a threshold Standard Deviation 220.91	—	—	—	—
fMRI During Psychomotor Vigilance Task 2 weeks	175.08 # voxels beyond a threshold Standard Deviation 370.05	129.00 # voxels beyond a threshold Standard Deviation 230.28	89.54 # voxels beyond a threshold Standard Deviation 173.65	75.31 # voxels beyond a threshold Standard Deviation 148.86	—	—	—	—
fMRI During Psychomotor Vigilance Task 12 weeks	66.25 # voxels beyond a threshold Standard Deviation 94.43	47.43 # voxels beyond a threshold Standard Deviation 105.62	156.77 # voxels beyond a threshold Standard Deviation 330.64	13.88 # voxels beyond a threshold Standard Deviation 38.76	—	—	—	—

PRIMARY outcome

Timeframe: baseline, change from baseline at 2 weeks ± 3 days, change from baseline at 12 weeks ± 3 days

Psychomotor vigilance task (PVT) behavioral measures (ie. reaction time). The primary outcome measures of PVT performance, lapses, are defined as reaction times exceeding 500 msec or failure to react. The PVT lapses are believed to represent perceptual, processing, or executive failures in the central nervous system (CNS) Lower scores are better, as they indicate quicker reaction times.

Outcome measures

Outcome measures
Measure	Healthy Aging MB n=12 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=13 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=12 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=16 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease MB n=1 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Mild Alzheimer's Disease Placebo n=1 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age Placebo FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)
Psychomotor Vigilance Task 2 weeks	390.1 milliseconds Standard Deviation 48.85	371.86 milliseconds Standard Deviation 47.56	402.3 milliseconds Standard Deviation 66.15	456.03 milliseconds Standard Deviation 132.94	629 milliseconds Standard Deviation 0	618.83 milliseconds Standard Deviation 0	—	—
Psychomotor Vigilance Task baseline	399.9 milliseconds Standard Deviation 58.5	382.7 milliseconds Standard Deviation 39.6	408.1 milliseconds Standard Deviation 99	482.4 milliseconds Standard Deviation 134.5	744.8 milliseconds Standard Deviation 0	631.04 milliseconds Standard Deviation 0	—	—
Psychomotor Vigilance Task 12 weeks	397.5 milliseconds Standard Deviation 62.9	365.33 milliseconds Standard Deviation 43.53	390.7 milliseconds Standard Deviation 80.72	455.3 milliseconds Standard Deviation 131.5	524.7 milliseconds Standard Deviation 0	695.05 milliseconds Standard Deviation 0	—	—

PRIMARY outcome

Timeframe: baseline, then 12 weeks ± 3 days

Population: Not all participants came back for all three visits.

The patient is read two stories, out loud, by the test administrator. After each story is read, the patient is then asked to tell the story back to the administrator, as well as possible. Scores range from 0-75, with higher scores indicating better outcome.

Outcome measures

Outcome measures
Measure	Healthy Aging MB n=20 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=19 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=21 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=21 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease MB n=1 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Mild Alzheimer's Disease Placebo n=1 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age Placebo FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)
Wechsler Memory Scale III, Logical Memory Subset baseline	47 score on a scale Standard Deviation 9.5	43.5 score on a scale Standard Deviation 9.5	32.4 score on a scale Standard Deviation 9.66	37.48 score on a scale Standard Deviation 9.8	25 score on a scale Standard Deviation 0	5 score on a scale Standard Deviation 0	—	—
Wechsler Memory Scale III, Logical Memory Subset 12 weeks	48 score on a scale Standard Deviation 10.1	41.1 score on a scale Standard Deviation 9.1	33.5 score on a scale Standard Deviation 7.9	37.06 score on a scale Standard Deviation 7.7	21 score on a scale Standard Deviation 0	5 score on a scale Standard Deviation 0	—	—

PRIMARY outcome

Timeframe: baseline, 2 weeks ± 3 days,12 weeks ± 3 days

Population: Not all participants returned for all three visits.

Short screening tool for providing an overall measure of cognitive impairment in clinical, research and community settings. The MMSE contains 11 questions with scores ranging from 1-5 depending on how many responses are required for each question. One point is assigned for each correct answer. The total score can range from 0-30 with a higher score indicating better cognitive skills.

Outcome measures

Outcome measures
Measure	Healthy Aging MB n=22 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=21 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=28 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=24 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease MB n=1 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Mild Alzheimer's Disease Placebo n=2 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age Placebo FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)
Mini-Mental State Exam (MMSE) baseline	29 score on a scale Standard Deviation 1.05	29.32 score on a scale Standard Deviation .95	27.76 score on a scale Standard Deviation 1.9	27.52 score on a scale Standard Deviation 1.86	21 score on a scale Standard Deviation 0	21 score on a scale Standard Deviation 0	—	—
Mini-Mental State Exam (MMSE) 3 weeks	29.7 score on a scale Standard Deviation .66	29.6 score on a scale Standard Deviation .61	28.3 score on a scale Standard Deviation 1.15	27.7 score on a scale Standard Deviation 2.4	26 score on a scale Standard Deviation 0	20 score on a scale Standard Deviation 0	—	—
Mini-Mental State Exam (MMSE) 12 weeks	29.9 score on a scale Standard Deviation .58	29.3 score on a scale Standard Deviation 1.11	28.5 score on a scale Standard Deviation 1.4	28.25 score on a scale Standard Deviation 1.1	24 score on a scale Standard Deviation 0	24 score on a scale Standard Deviation 0	—	—

PRIMARY outcome

Timeframe: baseline, 2 weeks ± 3 days, 12 weeks ± 3 days

Population: It was determined after the study began that recruiting middle aged subjects would not be worthwhile.

The subject draws a clock that says 1:45. Performance is rated according to the CLOX directions, and scored as "CLOX1" with scores ranging from 0-15 with a lower score indicating greater impairment. CLOX1 reflects performance in a novel and ambiguous situation. The CLOX's second step is a simple copying task. The examiner allows the patient to observe him or her drawing a clock in the circle provided on the scoring sheet. The examiner sets the hands again to "1:45", places the 12, 6, 3, and 9 first, and makes the hands into arrows. The patient is allowed to copy the examiner's clock. This clock is scored as "CLOX2" with scores ranging from 0-15 with a lower score indicating greater impairment. Participants can earn up to 15 points for each test, this is summed to give a possible score out of 30 with a higher score indicating less cognitive impairment. Scores reported are from inter-rater reliability

Outcome measures

Outcome measures
Measure	Healthy Aging MB n=22 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=21 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=28 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=24 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease MB n=1 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Mild Alzheimer's Disease Placebo n=2 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age Placebo FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)
CLOX: An Executive Clock Drawing Test 2 weeks	.6 score on a scale Standard Deviation .75	.68 score on a scale Standard Deviation 1	0.571 score on a scale Standard Deviation 0.978	-0.857 score on a scale Standard Deviation 1.77	2 score on a scale Standard Deviation 0	7 score on a scale Standard Deviation 0	—	—
CLOX: An Executive Clock Drawing Test baseline	.89 score on a scale Standard Deviation .96	1 score on a scale Standard Deviation 1.33	1.86 score on a scale Standard Deviation 1.85	1.52 score on a scale Standard Deviation 1.72	1 score on a scale Standard Deviation 0	1 score on a scale Standard Deviation 0	—	—
CLOX: An Executive Clock Drawing Test 12 weeks	.67 score on a scale Standard Deviation .63	.69 score on a scale Standard Deviation 1.6	1 score on a scale Standard Deviation 1.13	.86 score on a scale Standard Deviation 1.54	3 score on a scale Standard Deviation 0	4 score on a scale Standard Deviation 0	—	—

SECONDARY outcome

Timeframe: baseline, 2 weeks ± 3 days, 12 weeks ± 3 days

Resting measurements will be used to assess response and CBF using fMRI. Scores are baseline, percent change between baseline and 2 weeks, baseline and 12 weeks

Outcome measures

Outcome measures
Measure	Healthy Aging MB n=12 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=13 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=12 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=16 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease MB n=1 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Mild Alzheimer's Disease Placebo n=1 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age Placebo FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)
Cerebral Blood Flow Measures % change, baseline vs 2 weeks	36.1 percentage of change Standard Deviation 22.9	35.97 percentage of change Standard Deviation 27.3	31.97 percentage of change Standard Deviation 16	31.55 percentage of change Standard Deviation 14.84	35.85 percentage of change Standard Deviation 0	23.93 percentage of change Standard Deviation 0	—	—
Cerebral Blood Flow Measures baseline	34.65 percentage of change Standard Deviation 15.62	37.9 percentage of change Standard Deviation 49	31.97 percentage of change Standard Deviation 16	35.2 percentage of change Standard Deviation 35	95.13 percentage of change Standard Deviation 0	4.02 percentage of change Standard Deviation 0	—	—
Cerebral Blood Flow Measures % change, baseline vs 12 weeks	40.89 percentage of change Standard Deviation 29	42.13 percentage of change Standard Deviation 32.6	57.07 percentage of change Standard Deviation 64.1	35.2 percentage of change Standard Deviation 14.85	-1.91 percentage of change Standard Deviation 0	48.57 percentage of change Standard Deviation 0	—	—

OTHER_PRE_SPECIFIED outcome

Timeframe: baseline, 2 weeks ± 3 days, 12 weeks ± 3 days

Functional magnetic resonance imaging (fMRI) measurements will be obtained while the subject rests in the scanner, with their eyes closed. The default mode network (DMN) will be identified from the resting state data using temporal concatenation independent components analysis. Dual regression will then be applied to identify the individual subject's DMN maps, followed by the counting of significant voxels above threshold within the DMN masks. This will be repeated on weeks 2 and 12. the voxel is a 3-dimensional unit that embeds the signals in brain scans. As the MRI machine scans through each dimension of the brain millimeter by millimeter, voxels are formed to enclose the signals created by protons-magnet interactions.

Outcome measures

Outcome measures
Measure	Healthy Aging MB n=12 Participants Methylene Blue (USP grade, 282mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Healthy Aging Placebo n=13 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) MB n=12 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) Methylene Blue Phenazopyridine hydrochloride	Mild Cognitive Impairment (MCI) Placebo n=16 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks) FD\&C Blue # 2 Phenazopyridine hydrochloride	Mild Alzheimer's Disease MB n=1 Participants Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Mild Alzheimer's Disease Placebo n=1 Participants Drug: FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age MB Methylene Blue (USP grade, 282 mg oral, daily, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)	Healthy Middle Age Placebo FD\&C Blue # 2 (USP grade, 282 mg oral, 2 weeks, 12 weeks) Phenazopyridine hydrochloride (97.5 mg oral, 2 weeks, 12 weeks)
Functional Connectivity Measures baseline	4703.08 Voxels Standard Deviation 735.81	4314.29 Voxels Standard Deviation 943.58	4811.23 Voxels Standard Deviation 834.89	4980 Voxels Standard Deviation 1809.93	3819 Voxels Standard Deviation 0	2990 Voxels Standard Deviation 0	—	—
Functional Connectivity Measures 2 weeks	4778.42 Voxels Standard Deviation 563.19	4066.14 Voxels Standard Deviation 1392.99	5053.38 Voxels Standard Deviation 956.65	4504.81 Voxels Standard Deviation 1671.78	5672 Voxels Standard Deviation 0	3566 Voxels Standard Deviation 0	—	—
Functional Connectivity Measures 12 weeks	4862.75 Voxels Standard Deviation 730.38	4197.64 Voxels Standard Deviation 1662.41	5124.92 Voxels Standard Deviation 984.09	4804.81 Voxels Standard Deviation 1128.53	4541 Voxels Standard Deviation 0	2006 Voxels Standard Deviation 0	—	—

OTHER_PRE_SPECIFIED outcome

Timeframe: baseline, change from baseline at 2 weeks ± 3 days, change from baseline at 12 weeks ± 3 days

Cerebral blood flow measurements will be acquired during a brief (3-5 minutes) inhalation of medical-grade 5% CO2 in air. Cerebral blood flow measurements will be obtained using Arterial Spin Labeling (ASL) during a brief (3-5 minutes) inhalation of medical-grade 5% CO2 in air. Mean regional CBF (rCBF) in gray matter is quantified as ml/100g/min of tissue. The percent change from baseline will be calculated. This will be repeated on weeks 2 and 12.