Elisa Giorli1,2, Silvia Tognazzi1, Lucia Briscese1, Tommaso Bocci1,2, Andrea Mazzatenta3, Alberto Priori4, Giovanni Orlandi1, Massimo Del Sette5, Ferdinando Sartucci1,6. 1. Department of Clinical and Experimental Medicine, Pisa University, Medical School, Pisa, Italy. 2. Department of Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Siena, Italy. 3. CNR Neuroscience Institute, Pisa, Italy. 4. Department of Medical Surgical Pathophysiology and Transplants, Fondazione IRCCS "Ca' Granda" Ospedale Maggiore di Milano, Milan, Italy. 5. Unit of Neurology, Sant' Andrea Hospital, La Spezia, Italy. 6. Faculty of Veterinary Medicine, Unit of Sensorial Physiology, Teramo University, Teramo, Italy.
Abstract
BACKGROUND AND PURPOSE: Cerebral vasomotor reserve (VMR) is the capability of cerebral arterioles to change their diameter in response to various stimuli, such hypercapnia. Changes of VMR due to transcranial direct current stimulation (tDCS) have been poorly studied. METHODS: Twenty-five healthy subjects underwent anodal/cathodal and sham tDCS on right primary motor area. Before and after tDCS, we assessed VMR by Transcranial Color-Coded Sonography (TCCS) calculating trought Breath Holding Index (BHI) and Heart Rate Variability (HRV), in particular after Valsalva manouver. RESULTS: A-tDCS decreased VMR and BHI (p < 0.05), whereas C-tDCS increased VMR, and BHI (p < 0.05); Sham doesn't provide statistically significant of both VMR, BHI and HRV (p > 0.05). CONCLUSIONS: Our study confirms that tDCS induces a modification of bilateral VMR with a polarity-specific effect; based on this bilateral MFV and BHI modifications, we can speculate an involvement of the SNS in the VMR regulation.
BACKGROUND AND PURPOSE: Cerebral vasomotor reserve (VMR) is the capability of cerebral arterioles to change their diameter in response to various stimuli, such hypercapnia. Changes of VMR due to transcranial direct current stimulation (tDCS) have been poorly studied. METHODS: Twenty-five healthy subjects underwent anodal/cathodal and sham tDCS on right primary motor area. Before and after tDCS, we assessed VMR by Transcranial Color-Coded Sonography (TCCS) calculating trought Breath Holding Index (BHI) and Heart Rate Variability (HRV), in particular after Valsalva manouver. RESULTS: A-tDCS decreased VMR and BHI (p < 0.05), whereas C-tDCS increased VMR, and BHI (p < 0.05); Sham doesn't provide statistically significant of both VMR, BHI and HRV (p > 0.05). CONCLUSIONS: Our study confirms that tDCS induces a modification of bilateral VMR with a polarity-specific effect; based on this bilateral MFV and BHI modifications, we can speculate an involvement of the SNS in the VMR regulation.