4. Discussion
post-stroke, motor impairments, neuromuscular rehabilitation post-stroke, a loss of motor function, stroke, somatosensory deficits, urinary incontinence, pain, leg motor deficits, attention and motor imagery, MP, Sensory impairments
STROKE, MOTION SICKNESS, URINARY INCONTINENCE, CORTEX
We investigated the sequential use of tDCS and MI-BCI, as well as the use of a VR and an MP device, for neurological recovery in people with a loss of motor function due to stroke. The aim of this research was to measure and compare the effects of tDCS in a post-stroke patient. Overall, we report two important results: first, an improvement in somatosensory parameters; second, a correlation between cycling velocities and the Mu, low beta, and high beta rhythms. However, despite the good results that we have obtained, as our findings are based on only one subject, the results of such analyses should be treated with considerable caution.The existing literature on tDCS has primarily focused on upper-limb rehabilitation [Assessing post-stroke body function and structure is crucial in quantifying motor impairments, predicting outcomes, monitoring recovery and therapy responses, and guiding treatment decisions. Valid and standardized measures are essential in assessing various aspects, including neural systems, gait velocity for leg motor deficits, and somatosensory deficits. The FMA quantitatively evaluates motor and sensory impairment in post-stroke subjects and, in our study, it showed gradual improvements in coordination and movement speed on the hemiparetic side, likely due to active locomotion using our BCI and physical training. We believe that combining this with tDCS in our protocol potentiated brain plasticity. Our results differ from a related study [The Semmes Weinstein Monofilaments test was employed to assess the somatosensory parameter, offering an inexpensive, non-invasive, and user-friendly means of quantifying skin pressure detection thresholds. Our results demonstrated the recovery of protective sensitivity, discrimination of various sensory attributes, and transitions from incapacity to diminished protective sensation at specific sites. Sensory impairments after stroke, spanning various modalities, including tactility, pain, temperature, pressure, vibration, proprioception, stereognosis, and graphesthesia, are closely tied to activity limitations and participation restrictions [Clinical evidence supports tDCS’ efficacy in enhancing muscular strength, motor coordination, and mobility, emphasizing its non-invasive potential in optimizing post-stroke neuromuscular rehabilitation and improving life quality [tDCS is a neuromodulatory technique gaining prominence in the realm of neuromuscular rehabilitation post-stroke. Through the application of low-intensity electrical currents to the cerebral cortex, tDCS engenders neuronal membrane polarization, thereby creating alterations in cortical excitability within specific brain regions. Mainly targeting the motor cortex, tDCS endeavors to induce synaptic plasticity, thereby facilitating the restructuring of neural pathways disrupted by stroke [In the context of EEG analysis during tDCS and BCI application, distinctive neural oscillatory bands are scrutinized for insights into the neural mechanisms at play. Mu band analysis reveals that positioning the anode over the affected hemisphere’s primary motor cortex potentially increases excitability in relevant regions, augmenting desynchronization tendencies, and is possibly linked to bolstered attention and motor imagery processes. Concurrently, cathodal placement over the cerebellum of the unaffected hemisphere might exert inter-hemispheric connectivity effects and cerebellar modulation over motor function, whose concerted influence results in augmented synchronization within the Mu band. Likewise, in the low beta band, anodal tDCS placement appears to modulate cortical excitability, concomitantly raising synchronization levels, possibly associated with enhanced sensory processing. In the high beta band, the combined effect of tDCS and BCI is projected to induce cortical inhibition, instigating desynchronization within select cortical regions, potentially related to motor activity regulation. Notably, cathodal placement over the unaffected hemisphere’s cerebellum may facilitate functional integration between pertinent regions, leading to elevated synchronization. To summarize, the combination of tDCS and BCI, with specific montage arrangements, exerts a discernible influence on diverse brain oscillatory patterns, leading to distinctive synchronization and desynchronization responses, as delineated in our research.Despite noticeable progress in functional recovery, statistical significance in terms of both ambulatory and sensory outcomes was not achieved. In addition, an important limitation of this study was the evaluation of only one subject. However, it is important to consider the context in which the study was conducted, during the height of the COVID-19 pandemic, which influenced the chosen methodology. Nevertheless, this preliminary study is still valuable as it provides a foundation for future studies involving a larger and more diverse participant group.A potential pathway to explore for the promotion of a wider range of neurophysiological engagement conducive to enhancing functional recovery is to augment the frequency and duration of the training sessions over several weeks. This strategic intensification may have the potential to enhance the inherent neurological modulatory effects of tDCS, which could lead to more substantial advancements in facilitating rehabilitative progress related to ambulation, for example.Importantly, it should be noted that interruptions occurred during some protocol sessions, as the participant had urinary incontinence and discomfort caused by motion sickness while using the VR glasses.