Aivostimulaation

Aivostimulaation is a set of techniques that modulate neural activity in the brain by delivering electrical or magnetic stimuli. The goal is to alter patterns of brain activity and network interactions in a controlled way. Methods are categorized as noninvasive, using external devices, or invasive, requiring implanted hardware.

Noninvasive approaches include transcranial magnetic stimulation (TMS), which uses magnetic fields to influence cortical neurons, and transcranial direct current stimulation (tDCS), which applies weak electrical currents through scalp electrodes. Additional methods such as transcranial alternating current stimulation (tACS) and related protocols are studied for their potential to affect cognition and mood. These techniques are typically used in research and clinical contexts to relieve symptoms or probe brain function.

Invasive techniques involve implanting electrodes or devices that deliver electrical stimulation directly to deep brain regions or to peripheral nerves connected to the brain. Deep brain stimulation (DBS) targets structures like the subthalamic nucleus for movement disorders; vagus nerve stimulation (VNS) and responsive neurostimulation are used for epilepsy and other conditions. Such procedures carry surgical risks and require ongoing management.

The mechanisms vary by method but commonly involve modulation of cortical excitability, neurochemical release, and changes in network connectivity and plasticity. Evidence supports the use of TMS for treatment-resistant depression and DBS for certain movement disorders and epilepsy, with ongoing research into broader indications and optimization.

Applications span medicine, psychiatry, and neuroscience research. While noninvasive methods have favorable safety profiles, invasive methods entail risks, including infection, hemorrhage, and stimulation-related adverse effects. Ethical considerations address patient consent, potential cognitive and personality effects, access, and the need for monitoring and regulation.

Future directions focus on personalization, closed-loop systems that adjust stimulation in real time based on brain signals, and integration with imaging and biomarkers to guide therapy and study brain function.