145. Transcranial Direct Current Stimulation (tDCS) and cerebral vasomotor reserve: A study in healthy subjects

• Published in: Clinical neurophysiology 2013-11, Vol.124 (11), p.e221-e221
• Main Authors: Tognazzi, S, Giorli, E, Briscese, L, Bocci, T, Priori, A, Orlandi, G, Sette, M. Del, Sartucci, F
• Format: Article
• Language: English
• Subjects: Neurology
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2013.06.172

Cerebral vasomotor reserve (VMR) is the capability of cerebral arterioles to change their diameter in response to various stimuli, such hypercapnia. tDCS effects on cerebral haemodynamic have been poorly studied. Twenty-five healthy subjects (6M and 19F; 21–50 years; mean ± 26,43) underwent anodal/cathodal and sham tDCS on right primary motor area. Before and after tDCS, we assessed VMR by Transcranial Doppler measuring Breath Holding Index (BHI: percentage increase in flow velocity (PIV) weighted by the time the breath is held-30 s-). We also assessed Heart Rate Variability (HRV), the dynamic changes of the interval between consecutive heart beats, in particular after Valsalva manouver, such a sympathetic nervous system (SNS) activation index. A-tDCS decreased both VMR, BHI and HRV ( p < 0,05), but increased HRV after Valsalva, whereas C-tDCS increased both VMR, BHI and HRV ( p < 0,05), and reduced HRV after Valsalva; Sham does not provide statistically significant of both VMR, BHI and HRV ( p > 0.05). tDCS modify both VMR and HRV. HRV changes suggest that VMR modulation could be mediated by SNS. Shame stimulation without any changes of the parameters would confirm our hypothesis. Further studies are needed to confirm these hypothesis, in order to modulate VMR.