Table 1.
Cerebellar tDCS studies (listed in chronological order)
| Authors | Year | Subjects | Patients | Polarity | Montage | Parameters | Technique | Effects |
|---|---|---|---|---|---|---|---|---|
| Motor functions | ||||||||
| Galea et al. | 2009 | 16 | — | Anodal\cathodal\sham | Active electrode over the right cerebellum Reference on the ipsilateral buccinator muscle |
2 mA; 25 min; AEA = 25 cm2 | Cerebello-brain inhibition | tDCS could modulate in a focal and polarity-specific manner the cerebellar control of the brain |
| Jayaram et al. | 2012 | 17 | — | Anodal\cathodal\sham | Active electrode over the right/left cerebellum Reference on the ipsilateral buccinator muscle |
2 mA; 15 min; AEA = 25 cm2 | Split-belt walking task | A-cerebellar tDCS applied during walking improved locomotor adaptation, whereas C-cerebellar tDCS worsened it |
| Galea et al. | 2012 | 72 | — | Anodal\sham | Active electrode over the right cerebellum Reference on the ipsilateral buccinator muscle |
2 mA; 15 min; AEA = 25 cm2 | Visuomotor adaptation | Cerebellar tDCS caused faster adaptation to the visuomotor transformation |
| Hamada et al. | 2012 | 18 | — | Anodal\cathodal\sham | Active electrode over the right cerebellum Reference on the ipsilateral buccinator muscle |
2 mA; 15 min; AEA = 25 cm2 | Paired associative stimulation | Plasticity induced by PAS25 was blocked by concurrent A- and C-cerebellar tDCS |
| Sadnicka et al. | 2013 | 12 | — | Anodal\cathodal\sham | Active electrode over the right cerebellum Reference on the ipsilateral buccinator muscle |
2 mA; 20 min; AEA = 25 cm2 | Motor surround inhibition | Neither A- nor C-cerebellar tDCS modulated the magnitude of mSI |
| Shah et al. | 2013 | 8 | — | Anodal\cathodal\sham | Active electrode over the non-dominant cerebellum Reference over the ipsilateral buccinator muscle |
1 mA; 15 min; AEA = 8 cm2 | Ankle visuomotor learning | A- and C-cerebellar tDCS improved target-tracking accuracy of the ankle |
| Grimaldi & Manto | 2013 | — | 9 | Anodal\cathodal\sham | Active electrode over the right cerebellum Reference on the contralateral supra-orbital area |
1 mA; 20 min; AEA = 20 cm2 | Stretch reflex responses in upper limb | A-cerebellar tDCS reduced the amplitudes of long-latency stretch reflexes |
| Dutta et al. | 2014 | 12 | — | Anodal\sham | Active electrode over the left cerebellum Reference on the forehead above the right supraorbital ridge |
1 mA; 15 min; AEA = 35 cm2 | Voluntary visually cued muscle activity in the tibialis anterior muscle | A-cerebellar tDCS worsened different aspects of visually cued voluntary contraction of a lower limb muscle |
| Grimaldi et al. | 2014 | 2 | Anodal\sham | Active electrode over the right cerebellum followed by contralateral motor cortex Reference on the contralateral supra-orbital area |
1 mA; 20 min; AEA = 20 cm2 | Evaluation of upper limb tremor and dysmetria | Cerebello-cerebral tDCS improved upper limb tremor and hypermetria | |
| Hardwick & Celnik | 2014 | 33 | — | Anodal\sham | Active electrode over the lateral cerebellum (dominant hand) Reference on the ipsilateral buccinator muscle |
2 mA; 15 min; AEA = 25 cm2 | Center-out reaching task | A-cerebellar tDCS enhanced motor adaptation in older individuals |
| Zuchowski et al. | 2014 | 30 | — | Anodal\sham\cathodal | Active electrode over the right cerebellum Reference on the right buccinator muscle |
2 mA; during the acquisition phase AEA = 35 cm2 | Eyeblink conditioning | A-cerebellar tDCS enhanced acquisition-conditioned eyeblink responses; C-cerebellar tDCS reduced it |
| Herzfeld et al. | 2014 | 50 | — | Anodal\sham\cathodal | Active electrode over the right cerebellum Reference on the right buccinator muscle |
2 mA; 25 min; AEA = 25 cm2 | Force field learning | A-cerebellar tDCS enhanced the error-dependent learning process; C-cerebellar tDCS impaired it |
| Non-motor functions | ||||||||
| Ferrucci et al. | 2008 | 13 | — | Anodal\cathodal\sham | Active electrode over the cerebellum Reference on the right shoulder |
2 mA; 15 min; AEA = 35 cm2 | Sternberg task | A- and C-cerebellar tDCS both impaired the practice-dependent improvement in the reaction times |
| Boehringer et al. | 2012 | 40 | — | Cathodal\sham | Active electrode over the right cerebellum Reference on the buccinator muscle |
2 mA; 25 min; AEA = 25 cm2 | Forward and backward digit spans | C-cerebellar tDCS reduced forward digit spans and blocked the practice-dependent increase in backward digit spans |
| Pope & Miall | 2012 | 22 | — | Anodal\cathodal\sham | Active electrode over the right cerebellum Reference on the right shoulder |
2 mA; 20 min; AEA = 25 cm2 | Paced auditory serial subtraction task and paced auditory serial addition task | Right C-cerebellar tDCS affected working memory and attention differentially depending on task difficulty |
| Ferrucci et al. | 2013 | 21 | — | Anodal\sham | Active electrode over the cerebellum Reference on the right shoulder |
2 mA; 20 min; AEA = 35 cm2 | Serial reaction time task | A-cerebellar tDCS improved procedural learning |
| Ferrucci et al. | 2013 | 21 | — | Anodal\cathodal\sham | Active electrode over the cerebellum Reference on the right shoulder |
2 mA; 20 min; AEA = 35 cm2 | Facial emotion recognition task | A- and C-cerebellar tDCS significantly enhanced the response to negative facial emotions |
| Macher et al. | 2014 | 16 | — | Anodal\cathodal\sham | Active electrode over the right cerebellum Reference on the right buccinator muscle |
2 mA; 25 min; AEA = 25 cm2 | Sternberg task | A-cerebellar tDCS caused an attenuated memory recognition capacity and haemodynamic signals |
| Chen et al. | 2014 | 10 | — | Anodal\cathodal\sham | Active electrode over the right cerebellum Reference on the right buccinator muscle |
2 mA; 25 min; AEA = 25 cm2 | Mismatch negativity | A-cerebellar tDCS increased peak amplitude of somatosensory MMN and C-cerebellar tDCS reduced it |
A-cerebellar tDCS, anodal cerebellar tDCS; AEA, active electrode area; C-cerebellar tDCS, cathodal cerebellar tDCS; mA, milliampere; MMN, mismatch negativity; mSI, motor surround inhibition; PAS25, paired associative stimulation with 25 ms interval.