TABLE 9.

Studies and experimental characteristics of tES literature for TBI.

Authors	Subjects	Stimulation parameters				Neuroimaging		Conclusion
		Type	Current	Duration	Location	Type	Feature
Zhang et al., 2020	10	tDCS	2 mA, 20 min	twice daily, 5 sessions per week for 4 weeks	Anode: Prefrontal area and left DLPFC, cathode: neck and F4.	EEG	Approximate entropy and cross-approximate entropy Relative power in	A-tDCS over the prefrontal area and left DLPFC improves psychomotor inhibition state. The recovery might be related to increased excitability in local and distant cortical networks connecting the sensorimotor area to the prefrontal area.
Straudi et al., 2019	10	tDCS	2 mA, 40 min	5 sessions per week for 2 weeks	Anode: bilaterally primary motor cortex, cathode: Nasion.	EEG	delta (1–3.5 Hz), theta (3.5–7.5 Hz), alpha1 (8–10 Hz), alpha2 (11–13 Hz), beta1 (13.5–18 Hz), beta2 (18.5–30 Hz)	This study tested and evaluated the preliminary effects of bilateral anodal transcranial direct current stimulation in patients with disorders of consciousness.
O’Neil-Pirozzi et al., 2017	8	tDCS	2 mA, 20 min	3 sessions (48 h apart)	Anode: left DLPFC, cathode: right supraorbital area.	EEG		Individuals with memory impairments
							Power spectrum in theta (4–8 Hz), alpha	secondary to chronic TBI may benefit from
							(8–13 Hz), and P300.	LDLPFC anodal tDCS.
							Power spectrum in
Ulam et al., 2015	26	tDCS	1 mA, 20 min	10 sessions consecutive day	Anode: left DLPFC (F3), cathode: right supraorbital area (Fp2).	EEG	delta (1–4 Hz), theta (4–8 Hz), alpha (8–10 Hz), beta1 (12–25 Hz), beta2 (25–30 Hz)	Ten anodal tDCS sessions may beneficially modulate regulation of cortical excitability for patients with TBI.