Table 7.
Summary of studies of TES (tDCS, tACS) in older adults.
| N | Mean age/age range (years) | Active electrode position; size (cm) | Reference electrode position; size (cm) | Current (mA) | Duration (min); # of sessionsa | AEsb | References |
|---|---|---|---|---|---|---|---|
| tDCS | |||||||
| 25 | 63.7/56–80 | L or R DLPFC (F3/4) (A); 35 cm2 | Contralateral cheek (C); 35 cm2 | 1.5 | 10 | N/R | (Berryhill and Jones, 2012) |
| 28 | 68.4/50–85 | L and R DLPFC (F3/4) (A or C); 35 cm2 | – | 2 | 15 | None/slight itching during the first 30 s of stimulation | (Boggio et al., 2010) |
| 32 | 67.9 | L or R DLPFC or parietal (A); 35 cm2 | Contralateral supraorbital (C); 35 cm2 | 1.5 | 6 | None | (Brambilla et al., 2015) |
| 23 | 51–69 | L M1 (A); 45 cm2 | R supraorbital (C) | 2 | 20; 5x | N/R | (Dumel et al., 2016) |
| 20 | 66.5/61–83 | L DLPFC (A); 35 cm2 | R shoulder (C) | 2 | 10 | Itchiness (26/21%), burning (21/37%), heat (5/0%), pinching (74/68%), iron taste (11/11%), effect on performance (5/5%)1,2B | (Fertonani et al., 2014) |
| 20 | 62.1/50–80 | R temporo-parietal (A); 35 cm2 | L supraorbital (C); 100 cm2 | 1 | 20 | N/R | (Floel et al., 2012) |
| 20 | 68.3 | L M1 (A); 35 cm2 | R supraorbital (C); 51 cm2 | 1 | 30 | N/R | (Fujiyama et al., 2014) |
| 11 | 63.0/55–80 | Ipsi M1 (A); 25 cm2, L M1-R M1 (D) | Contralateral supraorbital (C) | 1 | 15 | None | (Goodwill et al., 2013) |
| 12 | 66.0 | Ipsi M1 (A); 25 cm2 | Contralateral supraorbital (C) | 1 | 15 | N/R | (Goodwill et al., 2015) |
| 22 | 57.5 | Ipsi cerebellum (A); 25 cm2 | Ipsi buccinators muscle (C) | 2 | 15 | None Rating2A of discomfort: sham 1.9 ± 0.1, anodal 1.5 ± 0.1; Rating2A of pain: sham 1.3 ± 0.04, anodal 1.6 ± 0.2 |
(Hardwick and Celnik, 2014) |
| 98 | 71.0/65–86 | L or R DLPFC (F3/4) (A or C); 35 cm2 | Vertex (A or C) | 1 | 37.5 | Greater levels of itchiness in real compared to sham stimulation2B | (Harty et al., 2014) |
| 16 | 73.4/65–83 | L M1 (A); 25 cm2 | Contralateral supraorbital (C) | 1 | 20 | N/R | (Heise et al., 2014) |
| 36 | 66.6 | R M1 (A); 35 cm2 | Contralateral supraorbital (C); 100 cm2 | 1 | 20 | Itching, tingling when current was increased Rating2A of attention (>8), fatigue (<8), discomfort (<1.5): no differences and no changes from pre to post stimulation | (Hoff et al., 2015) |
| 10 | 69.0/62–74 | L IFG (A); 5×7 | R supraorbital (C) | 2 | 20 | None/Mild tingling | (Holland et al., 2011) |
| 10 | 69.0/56–87 | L M1 (A); 25 cm2 | Contralateral supraorbital (C) | 1 | 20 | None Rating2A of attention, fatigue, discomfort: no differences |
(Hummel et al., 2010) |
| 72 | 64.4/55–73 | R PFC (F4) or parietal (P4) (A); 35 cm2 | Contralateral cheek (C) | 1.5 | 10; 10x | N/R | (Jones et al., 2015) |
| 20 | 66.6/60–77 | L/R parietal (P3/4) (A); 25 cm2 | Contralateral supraorbital (C); 35 cm2 | 1 | 15 | Slightly more burning sensation during active stimulation sessions, tingling, itching2B | (Learmonth et al., 2015) |
| 20 | 68.2/61–77 | L M1 (C3); 5×7, L M1-R M1 (D) | Right supraorbital (A); 100 cm2 | 1 | 30 | None | (Lindenberg et al., 2013) |
| 32 | 67.9 | L/R DLPFC or parietal (A); 35 cm2 | Contralateral supraorbital (C) | 1.5 | 6 | Itching, irritation2B | (Manenti et al., 2013) |
| 37 | 61 | L PFC (F3) (A); 35 cm2 | Right supraorbital (C) | 0.8–23 | 20 | None2B | (Manor et al., 2016) |
| 20 | 68.0/60–76 | L IFG (A) | Right supraorbital (C); 100 cm2 | 1 | 20 | None | (Meinzer et al., 2013) |
| 18 | 68.4/61–77 | L M1 (C3) (A); 35 cm2, L M1-R M1 (D) | Right supraorbital (C); 100 cm2− | 1 | 30 | None | (Meinzer et al., 2014b) |
| 30 | 69.0/65–75 | L DLPFC (F3) (A); 35 cm2 | Right supraorbital (C); 100 cm2 | 1 or 2 | 25 | None | (Nilsson et al., 2015) |
| 38 | 63.2 | L M1 or R cerebellum (A); 35 cm2 | Contralateral supraorbital (M1 tDCS) or L trapezius muscle (cerebellar tDCS) (C) | 2 | 17 | N/R | (Panouillères et al., 2015) |
| 8 | 75.0/63–84 | L M1 (A); 25 cm2 | Contralateral supraorbital (C) | 1 | 20 | Mild tingling, burning (during the initial 30 s of anodal/sham) | (Parikh and Cole, 2014) |
| 40 | 69.7 | L and R DLPFC (F3/4) (A); 25 cm2 | Non-dominant arm (C) | 2 | 30; 10x | None | (Park et al., 2014) |
| 54 | 66.9/60–82 | L M1 (A); 25 cm2 | Contralateral supraorbital (C); 51 cm2 | 1.5 | 20 | N/R | (Puri et al., 2015) |
| 14 | 65.0/55–69 | L or R anterior temporal (T3/4) (A); 35 cm2 | Contralateral cheek (C) | 1.5 | 15 | N/R | (Ross et al., 2011) |
| 36 | 67.2 | L DLPFC (F3) (A); 35 cm2 | R supraorbital (C) | 1.5 | 15 | Itching, irritation2B | (Sandrini et al., 2014) |
| 28 | 68.9 | L DLPFC (F3) (A); 35 cm2 | R supraorbital (C) | 1.5 | 15 | Itching, irritation at the beginning of anodal/sham stimulation2B | (Sandrini et al., 2016) |
| 20 | 63.0 | L DLPFC (F3) (A); 35 cm2 | R supraorbital (C) | 2 | 20 | None | (Zhou et al., 2015) |
| 15 | 68.5/55–88 | L M1 (A or C); 25 cm2 | R supraorbital (A or C) | 1 | 20 | N/R | (Zimerman et al., 2013) |
| N | Active electrode position; size (cm) | Reference electrode position; size (cm) | Current (mA), frequency | Duration (min); # of sessionsa | AEs/stimulation-induced sensationsb | ||
|
| |||||||
| tACS | |||||||
| 12 | L temporo-parietal (CP5); 35 cm2 | R supraorbital; 100 cm2 | 1; 6 Hz | 20 | Tingling (3), itching (1), tiredness (2), loss of concentration (2)2B | (Antonenko et al., 2016) | |
| 24 | Parieto-occipital (Cz-Oz); 35 cm2 | – | 1.5; 8–12 Hz | 20; 5x | N/R | (Muller et al., 2015) | |
A, anodal; bi, bilateral stimulation with two anodal plus two reference electrodes; C, cathodal; D, dual; DLPFC, dorsolateral prefrontal cortex; IFG, inferior frontal cortex; Ipsi, ipsilateral to the dominant hand (mostly right-handed subjects); L, left; N/R, not reported; R, right.
1
First number reflects AEs during anodal-offline (before task) and second number reflects sensations reported for anodal-online (during task) performance. 2A/B Rating on 10-point/5-point scale (0/1 = none/low, 5/10 = strong/high).
3
Determined individually.
a
Number after semicolon indicates number of consecutive sessions.
b
Were reported, numbers in brackets represent number/percentage of participants reporting the respective AE in active stimulation condition.