Effects of anodal tDCS stimulation in predictable and unpredictable task switching performance: The possible involvement of the parietal cortex

Potential scalp acupuncture and brain stimulation targets for common neurological disorders: evidence from neuroimaging studies

BACKGROUND

Scalp acupuncture is a promising potential therapy for neurological disorders. However, the development of its stimulation targets-both in identifying novel targets and refining the precision of their localization-has advanced slowly, largely due to the inadequate integration of brain science findings. This study leverages advances in brain neuroimaging to identify evidence-based cortical targets, enhancing the potential of scalp acupuncture and other brain stimulation techniques.

METHODS

Using the Neurosynth Compose platform, systematic meta-analyses of neuroimaging studies were conducted to identify potential surface cortical targets for ten neurological conditions: Subjective Cognitive Decline (SCD), Mild Cognitive Impairment (MCI), Alzheimer's Disease (AD), Parkinson's Disease (PD), Multiple System Atrophy (MSA), Post-Stroke Aphasia (PSA), Primary Progressive Aphasia (PPA), Dyslexia, Chronic Pain, and Disorders of Consciousness (DoC). These targets were projected onto the scalp, further localized using scalp acupuncture lines, traditional acupoints and EEG 10-20 system.

RESULTS

We have identified specific cortical targets for scalp acupuncture associated with ten neurological disorders. Our findings are broadly consistent with current scalp acupuncture protocols while introducing additional new stimulation targets, such as the inferior temporal gyrus for memory processing and the angular gyrus for visuospatial attention. Additionally, the identified targets align with evidence from non-invasive brain stimulation, supporting therapeutic strategies for conditions such as movement disorders and cognitive impairments by targeting areas like the dorsolateral prefrontal cortex and primary motor cortex.

CONCLUSION

Our findings provide a foundation for developing a brain imaging-based scalp acupuncture protocol for neurological disorders. The identified targets may also be used as brain stimulation targets for these disorders.

Role and related mechanisms of non-invasive brain stimulation in the treatment of Tourette syndrome

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by impaired or delayed functional development. Although the pathology of TS remains to be determined, the continuous development of science and technology has provided new perspectives to understand its pathological mechanism. Research into non-invasive brain stimulation (NIBS) techniques, such as transcranial magnetic stimulation and direct current stimulation, have shown promising therapeutic potential in clinical studies. Furthermore, NIBS has been shown to affect the brain of patients with TS, including synaptic transmission, release of neurotransmitters, in addition to the activation of microglial cells and astrocytes. However, an exploration of the innate mechanisms is still lacking. This review aims to summarize the pathogenesis of TS and intervention with NIBS in clinical patients with TS. It aims to provide a theoretical basis for more in-depth investigations of innovative therapies for TS in the future.

Relationship Between the Parietal Cortex and Task Switching: Transcranial Direct Current Stimulation Combined with an Event-related Potential Study

Task switching refers to a set of cognitive processes involved in shifting attention from one task to another. In recent years, researchers have applied transcranial direct current stimulation (tDCS) to investigate the causal relationship between the parietal cortex and task switching. However, results from available studies are highly inconsistent. This may be due to the unclear understanding of the underlying mechanisms. Therefore, the current study utilized event-related potential (ERP) analysis to investigate the modulatory effects of tDCS on task-switching processes. Twenty-four subjects were recruited to perform both predictable and unpredictable parity/magnitude tasks under anodal (RA) and sham conditions. The results showed no significant changes in behavioral performance. However, marked tDCS-induced ERP changes were observed. Specifically, for the predictable task switching, compared with the sham condition, the target-N2 component occurred significantly earlier for switch trials than repeat trials under the RA condition in males, while no difference was found in females. For unpredictable task switching, under the sham condition, the P2 peak was significantly larger for switch trials compared with repeat trials, whereas this difference was not observed under the RA condition. These results indicated the causal relationship between the right parietal cortex and exogenous adjustment processes involved in task switching. Moreover, anodal tDCS over the right parietal cortex may lead to the manifestation of gender differences.