The cognitive-motor interference (CMI) produced by simultaneous performance of a cognitive and a motor task has been proposed as a marker of real-life impairment of people with Multiple Sclerosis (pwMS), yet there is no consensus on the dual task (DT) procedure. This study aimed to compare DT performance of pwMS and healthy controls (HC) under different instructions and to examine its association with neuropsychological and clinical variables. PwMS (N = 23; relapsing-remitting course) and HC (N = 24) completed the cognitive (Verbal Fluency) and motor (walking) tasks under three conditions: independently or as single task (ST), both tasks simultaneously at best capacity or double prioritization (DT-DP), and only the cognitive task at best capacity while walking at preferred speed or cognitive prioritization (DT-CP). Compared to HC, pwMS walked significantly slower and produced less correct words under all conditions. The distance walked by pwMS and HC significantly differed between conditions (DT-CP< DT-DP< ST). PwMS produced more words during ST respective to DT-DP and DT-CP, with no difference between both DT conditions. HC showed no differences in cognitive performance between conditions. Motor and cognitive dual-task costs (DTC) were similar between groups. Only in pwMS, the cognitive DTC of DT-DP was different from zero. CMI measures correlated with neuropsychological, symptomatic, physiological (cognitive event-related potentials) and clinical variables. These results suggest that cognitive performance while walking is impaired in pwMS, but not in HC. CMI over cognitive performance might be a potential early marker of cognitive decline in pwMS, which may be enhanced by the instruction to prioritize both tasks in DT.

OBJECTIVE: To generate normative data for the phonological and semantic verbal fluency tests (VFT) in Spanish-speaking pediatric populations. METHOD: The sample consisted of 4,373 healthy children from nine countries in Latin America (Chile, Cuba, Ec

The technique of transauricular vagus nerve stimulation (taVNS) is methodologically applied by placing electrodes on the auricular region, specifically on the cymba, cavum, or tragus, to stimulate the vagus nerve non-invasively. Additionally, the earlobe, which is not innervated by the vagus nerve, can serve as a placebo site for control stimulation. The stimulation intensity is adjusted between 0.5-3.0 mA, with session durations ranging from 20-60 min, administered either daily or weekly, depending on the study protocol. The total number of sessions varies according to the protocol, extending from a few weeks to several months. Ethically, research involving taVNS must adhere to regulations set by the local Agency for Medicines and Health Products and European Union guidelines. Approval from an Ethical Committee is required for studies involving healthy participants, while a Medical Ethical Committee is necessary for clinical research, ensuring that written information and informed consent are provided. Additionally, rigorous exclusion criteria must be established to safeguard participant safety, excluding pregnant individuals, those with cardiovascular, pulmonary, or metabolic diseases, psychiatric disorders, epilepsy, hypertension, or those using medications affecting the autonomic nervous system. In terms of clinical outcomes, the current study protocol demonstrated promising results with taVNS in patients with Disorders of Consciousness, showing significant improvement in alertness recovery and response to stimuli. Patients treated with taVNS experienced neurophysiological changes compared to the control group. Moreover, electroencephalographic biomarkers can be utilized to evaluate treatment efficacy, even in the absence of observable behavioral indicators. These findings suggest significant clinical potential for taVNS in managing Disorder of Consciousness, although the lack of specific regulations for taVNS underscores the need to adhere to international scientific best practices and seek consensus on European guidelines for its research application.