Heart Rate Variability (HRV) serves as an objective correlate of distress and symptom burden in multiple sclerosis.

Background: Autonomic nervous system (ANS) dysfunction is frequently seen in people living with multiple sclerosis (MS). Heart rate variability (HRV) is an easy and objective index for evaluating ANS functioning, and it has been previously used to explore the association between ANS and the experience of symptom burden in other chronic diseases. Given ANS functioning can be influenced by physical and psychological factors, this study investigated whether emotional distress and/or the presence of ANS dysfunction is associated with symptom severity in people living with MS. Methods: Participants with MS and healthy controls (HC) with no history of cardiac conditions were recruited to self-collect HR data sampled from a chest strap HR monitor (PolarH10). Short-term HR signal was collected for five minutes, and time and frequency HRV analyses were performed and compared between groups. HRV values were then compared to self-reported distress (Kessler Psychological Distress Scale) and MS participants' self-reported measures of symptom burden (SymptoMScreen). Results: A total of n = 23 adults with MS (51 ± 12 years, 65 % female, median Patient Determined Disease Steps [PDDS]: 3.0) and n = 23 HCs (43 ± 18 years, 40 % female) completed the study procedures. All participants were able to complete the chest strap placement and HR data capture independently. Participants with MS, compared to the HC participants, had a significantly lower parasympathetic activation as shown by lower values of the root mean square of successive differences between normal heartbeats (RMSSD: 21.86 ± 9.84 vs. 43.13 ± 20.98 ms, p = 0.002) and of high-frequency (HF) power band (HF-HRV: 32.69 ± 12.01 vs. 42.39 ± 7.96 nu, p = 0.016), indicating an overall lower HRV in the MS group. Among individuals with MS, HF-HRV was significantly correlated with the severity of self-reported MS symptoms (r = -0.548, p = 0.010). Participants with MS also reported higher levels of distress compared to HC participants (18.32 ± 6.05 vs. 15.00 ± 4.61, p = 0.050), and HRV correlated with the severity of distress in MS participants (r = -0.569, p = 0.007). A significant mediation effect was also observed, with emotional distress fully mediating the association between HRV and symptom burden. Conclusions: These findings suggest the potential for ANS dysfunction, as measured by HRV (i.e., lower value of HF power), to be utilized as an objective marker of symptom burden in people living with MS. Moreover, it is apparent that the relationship between HRV and symptom burden is mediated by emotional distress.

Home-administered transcranial direct current stimulation is a feasible intervention for depression: an observational cohort study.

Transcranial direct current stimulation (tDCS) is an emerging treatment for major depression. We recruited participants with moderate-to-severe major depressive episodes for an observational clinical trial using Soterix Medical's tDCS telehealth platform as a standard of care. The acute intervention consisted of 28 sessions (5 sessions/week, 6 weeks) of the left anodal dorsolateral prefrontal cortex (DLPFC) tDCS (2.0 mA × 30 min) followed by a tapering phase of weekly sessions for 4 weeks (weeks 7-10). The n = 16 completing participants had a significant reduction in depressive symptoms by week 2 of treatment [Montgomery-Åsberg Depression Rating Scale (MADRS), Baseline: 28.00 ± 4.35 vs. Week 2: 17.12 ± 5.32, p < 0.001] with continual improvement across each biweekly timepoint. Acute intervention responder and remission rates were 75 and 63% and 88 and 81% following the taper period (week 10).

Moving intra-individual variability (IIV) towards clinical utility: IIV measured using a commercial testing platform.

OBJECTIVES: Intra-individual variability (IIV), measured across repeated response times (RT) during continuous psychomotor tasks, is an early marker of cognitive change in the context of neurodegeneration. To advance IIV towards broader application in clinical research, we evaluated IIV from a commercial cognitive testing platform and compared it to the calculation approaches used in experimental cognitive studies. METHODS: Cognitive assessment was administered in participants with multiple sclerosis (MS) during the baseline of an unrelated study. Cogstate was used for computer-based measures providing three timed-trial tasks measuring simple (Detection; DET) and choice (Identification; IDN) RT and working memory (One-Back; ONB). IIV for each task was automatically output by the program (calculated as a log10-transformed standard deviation or "LSD"). We calculated IIV from the raw RTs using coefficient of variation (CoV), regression-based, and ex-Gaussian methods. The IIV from each calculation was then compared by rank across participants. RESULTS: A total of n = 120 participants with MS aged 20-72 (Mean ± SD, 48.99 ± 12.09) completed the baseline cognitive measures. For each task, the interclass correlation coefficient was generated. Each ICC showed that LSD, CoV, ex-Gaussian, and regression methods clustered strongly (Average ICC for DET: 0.95 with 95% CI [0.93, 0.96]; Average ICC for IDN: 0.92 with 95% CI [0.88 to 0.93]; Average ICC for ONB: 0.93 with 95% CI [0.90 to 0.94]). Correlational analyses indicated the strongest correlation between LSD and CoV for all tasks (rs ≥ 0.94). CONCLUSION: The LSD was consistent with research-based methods for IIV calculations. These findings support the use of LSD for the future measurement of IIV for clinical studies.

Tolerability and feasibility of at-home remotely supervised transcranial direct current stimulation (RS-tDCS): Single-center evidence from 6,779 sessions.

INTRODUCTION: The ability to deploy transcranial direct current stimulation (tDCS) at home is a key usability advantage to support scaling for pivotal clinical trials. We have established a home-based tDCS protocol for use in clinical trials termed remotely supervised (RS)-tDCS. OBJECTIVE: To report the tolerability and feasibility of tDCS sessions completed to date using RS-tDCS in clinical trials. METHODS: We analyzed tolerability (i.e., adverse events, AEs) reported in six Class I/II/III trials using RS-tDCS to study symptom outcomes over 10 to 60 daily applications. Across the six clinical trials, 308 participants (18-78 years old) completed an average of 23 sessions for a total of 6779 RS-tDCS administrations. The majority of participants were diagnosed with multiple sclerosis, and open-label trials included those diagnosed with a range of other conditions (e.g., Parkinson's disease, post-stroke aphasia, traumatic brain injury, cerebellar ataxia), with minimum-to-severe neurologic disability. Clinical trial feasibility (i.e., treatment fidelity and blinding integrity) was examined using two Class I randomized controlled trials (RCTs). RESULTS: No serious AEs occurred. Across administrations, three sessions (0.04%) were aborted due to discomfort, but no participant discontinued due to tolerability. The AEs most commonly reported by participants were tingling (68%), itching (41%) and warmth sensation (42%) at the electrode site, and these were equally reported in active and sham tDCS conditions. The two Class I RCTs resulted in rapid enrollment, high fidelity to treatment completion, and blinding integrity. CONCLUSIONS: At-home RS-tDCS is tolerable, including when used over extended periods of time. Home-based RS-tDCS is feasible and can enable Class I tDCS clinical trial designs.

An Interview-Based Assessment of the Experience of Cognitive Impairment in Multiple Sclerosis: The Cognitive Assessment Interview (CAI).

Background: Cognitive impairment is a common feature of multiple sclerosis (MS). A semi-structured interview, including informant input, can characterize the experience of individuals living with MS and cognitive involvement. Objective: We administered the Cognitive Assessment Interview (CAI), a patient- and informant-based semi-structured interview, to characterize the experience of cognitive impairments in those living with MS. Methods: Trained raters administered the CAI to a sample of MS participants and their informants enrolled for a trial of cognitive remediation. Cognitive impairments on the CAI were characterized and compared to those captured by neuropsychological and self-report measures. Results: A total of n = 109 MS participants (mean age = 50.3 ± 12.2) and their available informants (n = 71) were interviewed. Participants reported experiencing processing speed (90/106, 85%), working memory (87/109, 80%), and learning and memory (79/109, 72%) problems most commonly. CAI-based ratings were moderately correlated with a self-report measure (Multiple Sclerosis Neuropsychological Screening Questionnaire, r s = 0.52, p < 0.001) and only mildly correlated with objective neuropsychological measures specific to executive functions (r s = 0.21, p = 0.029). For those with informant interviews, ratings were overall consistent, suggesting that the CAI is valid even in cases in which an informant is unavailable and the interview is conducted with the patient alone (as is often the case in clinical and research settings). Conclusions: The CAI provides a semi-structured interview to characterize the experience of cognitive impairment in MS, with findings representing real-world functioning, adding valuable information to both self-report measures and neuropsychological assessment.

Telerehabilitation benefits patients with multiple sclerosis in an urban setting.

INTRODUCTION: People living with multiple sclerosis (MS) often require rehabilitation to manage their symptoms. Telerehabilitation offers improved access to treatment options by reducing travel time and cost. Our telerehabilitation program pairs training exercises simultaneously with transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique. In the current study, we characterized the benefits of our remotely supervised tDCS (RS-tDCS) at-home telerehabilitation protocol in an urban sample of MS participants. METHODS: Participants with MS were recruited to complete a telerehabilitation trial using tDCS paired with cognitive rehabilitation at-home using remote supervision (RS-tDCS). Participant time and travel costs for study visits to our clinic in midtown New York City were calculated. RESULTS: Forty-four patients with MS (aged 18 to 71) with mild to severe neurologic disability (Expanded Disability Status Scale score median = 3.5, range: 0.0 to 8.0) completed the survey. Round-trip clinic attendance required 2.3 ± 2.3 h and US $27.04 ± 38.13 for out-of-pocket expenses. Participants rated difficulty of clinic attendance as moderately to significantly difficult (2.5 ± 1.3). Severity of neurologic disability accounted for the greatest variance in difficulty attending clinic (30%, p < 0.001). RS-tDCS had 95% treatment compliance and 93% of participants reported satisfaction with the at-home treatment. DISCUSSION: Attending clinic is associated with significant costs for patients with neurologic disorders, even in urban settings. Rehabilitation can be delivered at home and supervised in real-time via videoconference.