09 July 2025 : Review article
Advances in Neuromodulation Techniques for Aphasia Rehabilitation: A Comprehensive Review
Jiayi Xia ADEFG 1, Yeping Chen BCFG 1, Song Pei ADEF 2*, Chunlei Shan ADEF 3,4,5, Jingjing Zhang EF 3, Zhiqing Zhou EF 3, Jiali Wu EF 3, Yao Lu BC 1, Yiyi Chen BC 1, Yunjia Chen DF 1DOI: 10.12659/MSM.947213
Med Sci Monit 2025; 31:e947213
Table 1 Comparison of transcranial direct current stimulation (tDCS), transcranial magnetic stimulation (TMS), and mirror neuron system (MNS) therapy in aphasia rehabilitation.
| Characteristics | Transcranial Direct Current Stimulation (tDCS) | Transcranial Magnetic Stimulation (TMS) | Mirror Neuron System (MNS) therapy |
|---|---|---|---|
| Non-invasiveness | Yes | Yes | Yes |
| Primary mechanism of action | Modulates cortical excitability via low-intensity direct current to enhance neural plasticity | Induces electrical currents via magnetic fields to modulate cortical excitability (excitation/inhibition) | Activates language-related neural circuits through action observation and imitation |
| Primary treatment targets | Left hemisphere language areas (eg, inferior frontal gyrus, IFG) or inhibitory modulation of right hemisphere homologous regions | Cortical areas (eg, Broca’s area, right IFG) with precise frequency-based modulation | Sensorimotor language networks involving Broca’s and Wernicke’s areas |
| Integration with speech therapy | Commonly combined with behavioral language therapy for synergistic effects | Often used with neuronavigation and speech therapy | Applied with action observation-execution paradigms to support language recovery |
| Typical treatment parameters | 1–2 mA current, 20–30 min per session | Low-frequency (≤1 Hz) inhibitory or high-frequency (≥5 Hz) excitatory protocols | Multiple action observation and imitation sessions per week |
| Indications | Primarily post-stroke aphasia (PSA), emerging in primary progressive aphasia (PPA) | PSA (chronic and subacute), exploratory use in PPA | PSA with motor-language impairment focus |
| Safety profile | Highly safe, with no reported cases of seizure induction; side effects are generally limited to mild skin discomfort | Generally safe, though rarely may induce seizures; possible transient side effects include headaches or scalp discomfort | Safe, as it mainly involves cognitive engagement through action observation, without causing physical discomfort |
| Target areas | Primarily targets cortical language regions, such as the left hemisphere language areas or right hemisphere inhibitory areas | Primarily targets cortical regions with limited penetration depth (approximately 1–3 cm beneath the scalp), but remain insufficient to precisely target deep brain structures | Focuses on motor neuron systems involved in language processing, including Broca’s and Wernicke’s areas |
| Treatment efficacy | Research shows significant improvements in naming ability and speech recovery | TMS has been shown to effectively improve naming and speech function | MNS Therapy has demonstrated efficacy in promoting language recovery in aphasia patients through action imitation |
| Limitations | Optimization of stimulation intensity, duration, and electrode placement is needed to account for individual variability | Variability in stimulation site, frequency selection, and individual responses | Limited effectiveness for language recovery not related to motor functions, with effects potentially task-specific |
| tDCS – transcranial direct current stimulation; TMS – transcranial magnetic stimulation; MNS – mirror neuron system; IFG – inferior frontal gyrus; PSA – post-stroke aphasia; PPA – primary progressive aphasia. | |||