The focus of this work is the evaluation of a measure of cognitive functioning- intra-individual variability (IIV) - derived from a computer-based continuous reaction time (RT) task (Cogstate) as an early marker of prodromal MS.
This study is a prospective observational clinical study, where the researchers will recruit adults with early MS (n=60) to complete a cognitive assessment and an optional gait assessment using Runscribe and G-sensor. Thirty-five \[35\] participants will also have a single 60-minute investigational MRI combined with 20 minutes of simultaneous tDCS. The MRI will repeat the protocol from the researchers' current study (ClinicalTrials.gov Identifier: NCT03564496, IRB i18-00548) using simultaneous transcranial direct current stimulation (tDCS) during the imaging acquisition.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
SCREENING
Masking
NONE
Enrollment
60
The tDCS-MRI scan will last approximately one hour. The first 20 minutes of the MRI will not include tDCS stimulation. After 20 minutes, the tDCS device will ramp up to 2.0mA and deliver 2.0mA for 20 minutes. Then the tDCS will ramp down (30 seconds) and the final 20 minutes will be without stimulation.
NYU Langone Health
New York, New York, United States
Cerebral Metabolic Rate of Oxygen (CMRO2)
CMRO2 is the amount of O2 the brain consumes per unit of time (in μmol O2/100g tissue per minute). To quantify absolute CMRO2, both TRUST MRI for quantification of venous oxygenation (Yv) and phase contrast (PC) MRI for quantification of total blows are needed. The total scan time for CMRO2 MRI is approximately 4 minutes.
Time frame: Day 1 (Visit 1 - approximately 4 minutes)
Intra-Individual Variability (IIV) as Measured by Cogstate Brief Battery (CBB)
The core Cogstate Reaction Time (RT) tasks involve a deck of cards on a green background screen and the participant answers "yes" or "no" by hitting a keyboard key ("D" or "K") across repeated trials. Each task first includes instructions and practice period before the test begins and takes approximately 3-4 minutes to complete (for a total of \~7 minutes). The representative timed RT scores are provided by the Detection task (indicating when a card is revealed; DET/simple RT), Identification task ("is the card revealed black or red?"; IDN/choice RT), and One-Back ("Is this the card that you just saw?"). Performance is characterized by near complete accuracy (i.e. all, or almost all, items are answered correctly), and validity checks are built into the scoring. IIV is calculated as intraindividual standardized deviations (ISD) in RTs across both tasks, measured in milliseconds and with log10 transformation.
Time frame: Day 1 (Visit 1)
Brief International Cognitive Assessment for MS (BICAMS) Symbol Digit Modalities Test (SDMT) Z-Score
SDMT is 90-second cognitive task in which the participant is shown a sheet containing rows of symbols. Each symbol corresponds to a specific number. The participant's task is to say out loud the number associated with each symbol. SDMT is used as a general cognitive screen to detect severe cognitive impairment. The raw score is the correct number of substitutions in 90 seconds, scores range between 0 and 110. The lower the score, the more severe the cognitive impairment. The raw score is converted to a Z-score with a central value of 0. Standard deviations below the mean indicate a worse outcome; a Z-score of -1.5 or lower suggests a significant deviation from the average performance, potentially indicating cognitive impairment.
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Time frame: Day 1 (Visit 1)
BICAMS Rey Auditory Verbal Learning Test (RAVLT) Z-Score
RAVLT is a well-recognized measure of a person's ability to encode, combine, store and recover verbal information in different stages of immediate memory. consists of presenting a list of 15 words across consecutive trials. The list is read aloud to the participant, and then the participant is immediately asked to recall as many words as one remembers. This procedure is repeated for 5 consecutive trials (Trials 1 to 5). The total score is the sum of trials 1-5 and ranges from 0-75. The lower the score, the more severe the cognitive impairment. The raw score is converted to a Z-score with a central value of 0. Standard deviations below the mean indicate a worse outcome; a Z-score of -1.5 or lower indicates impairment, meaning the individual's performance is significantly below the average of their peer group.
Time frame: Day 1 (Visit 1)
BICAMS Brief Visuospatial Memory Test Revised (BVMT-R) Z-Score
Visual/spatial memory is assessed in BICAMS using the BVMT-R. In this test, six abstract designs are presented for 10 sec. The display is removed from view and patients render the stimuli via pencil on paper manual responses. Each design receives from 0 to 2 points representing accuracy and location. There are three Learning Trials, and the score is reported as the total number of points earned over the trials. Thus, scores range from 0 to 12 per trial; total score range is 0 to 36 for all three trials. The lower the score, the more severe the cognitive impairment. The raw score is converted to a Z-score with a central value of 0. Standard deviations below the mean indicate a worse outcome; a Z-score of -1.5 or lower on the BVMT-R is generally considered indicative of cognitive impairment.
Time frame: Day 1 (Visit 1)