This is a new technology in the field of non –invasive electrical stimulation of the human brain and it is directly having an interference with the cortical rhythms. tACS is the external application of oscillating electrical currents and it has the ability to influence cortical excitability and activity. The expectation is to synchronise or desynchronize with a since resonance frequency through cortical oscillations. If this is applied for a long time it can lead to neuroplastic effects which is the ability to bring about changes to the brain in terms of function. When tACS is applied in phase it can lead to improvement in the cognition . Depending on the types of waves applied , for instance if alpha rhythms are applied it helps in improving the motor performance and application of beta intrusions can deteriorate it. tACS when applied with both alpha and beta frequencies can induce retinal phosphenes.
When used in most studies tACS is used without a DC offset and the simple form uses sinusoidal stimulation. Also other wave forms are possible such as rectangular current shapes. The vital parameters which could shape the direction and duration of tACS induced effects happen to be the intensity, phase of stimulation and the frequency. However, the effect of tACS on motor evoked potential hasn’t been studied in detail yet. By increasing the duration of the transcranial direct current stimulation it results in a prolongation of the induced after effects.
tACS may be agreat way to treat schizophrenic patients without detrimental effects. As we all know psychotic disorders are devastating mental diseases which are associated due to the dysfunctional brain networks. Gamma oscillations form a bioelectric market for celebral network disorders with therapeutic and prognostic capacity. It accompanies sensorimotor and cognitive deficits which is already present in schizophrenia.
Thus, use of tACS would be an appropriate way to prevent therapeutic modality as it can influence cognitive performance as well as neural oscillations.
tACS could play a grate role in helping some patients with abnormal oscillatory patterns and the same is true for Parkinson’s disease too. This is achieved through the attenuating or resetting of the anomalous oscillations. The Parkinson’s disease resting tremor can be bisected by tACS.
Further, it is seen that by using a 200 kHz frequency it helps to treat patients with recurrent gliobastoma, which are tumours which can occur in the supportive brain tissue. When high stimulation frequency is applied to the transcranial region it inhibits the growth of treatment resistant tumours with basically no side effects.
In conclusion tACS could become a great technique in the near future for treating patients with mental diseases.