Table 4.

Summary of non-invasive brain stimulation in post-stroke aphasia (PSA).

Methods	Major Characteristics	Advantages	Limitations
rTMS (repetitive transcranial magnetic stimulation)	Based on generating a magnetic pulse that induces power in various regions of the cerebral cortex. The rTMS procedure consists of regularly applied pulses of a given frequency within approximately 15 min. Depending on the frequency used, there is low-frequency stimulation (<1 Hz), which inhibits cortical excitability, and high-frequency stimulation (>1 Hz), which increases cortical excitability.	Balance the excitability of both hemispheres, as well as realign the linguistic network.	The need to establish the optimal treatment protocol and to take into account individual variability.	[100,101,102]
tDCS (transcranial direct current stimulation)	Non-invasive and safe therapeutic technique for stimulating the brain. This enables the polarization of the cell membranes of neurons, increasing or decreasing the level of cortical excitation. The nature of the induced cortical lesion depends on the electrode pole.	Normalization of brain activity promotes self-recovery.	The need for further clinical trials on a larger group of PSA.	[103]