The effect of endovascular baroreflex amplification on central sympathetic nerve circuits and cerebral blood flow in patients with resistant hypertension: A functional MRI study

Figures

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  Figure 1. Flow chart of participant progress through the trial. SBP, systolic blood pressure.

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  Figure 2. Salience Network identified by resting-state analysis. The salience network (SN) identified by group independent component analysis (ICA). Slice locations in Montreal Neurological Institute space indicated are indicated at the top left of each slice.

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  Figure 3. Significant BOLD signal intensity changes in cortical brain regions activated by the Valsalva maneuver. (A) Significant activated clusters resulting from the whole-brain analysis with the contrast high Valsalva maneuver pressure (~40 mmHg) minus low Valsalva maneuver pressure (0–10 mmHg) (n = 13; threshold of 3.1 for p < 0.05) overlaid onto the T1 reference image of SPM12. Data was corrected for motion, physiological noise and scanner drift. Slice locations in Montreal Neurological Institute space indicated are indicated at the top left of each slice. (B) Group-averaged BOLD responses (mean ± Standard Error in shaded areas) upon the high-pressure Valsalva maneuver at baseline (blue) and 3 months after implantation (red). Responses are shown for cortical brain regions that showed significant differences for the subtraction contrast HV minus LV task condition 3 months after implantation. The 6 high-pressure Valsalva maneuvers are averaged and normalized at the subject level before averaging at group level (n = 13). Except for the temporal lobe regions, the BOLD response shows a biphasic time course upon the high-pressure Valsalva maneuver.

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  Figure 4. Significant BOLD signal intensity changes in brainstem regions activated by the Valsalva maneuver. (A) Significant activated clusters resulting from the brainstem-specific analysis with the contrast high Valsalva maneuver pressure (~40 mmHg) minus low Valsalva maneuver pressure (0–10 mmHg) (n = 13; threshold of 3.1 for p < 0.05) overlaid onto the T1 reference image of SPM12. Data was corrected for motion, physiological noise and scanner drift. Slice locations in Montreal Neurological Institute space indicated are indicated at the top left of each slice. (B) Group-averaged BOLD responses (mean ± Standard Error in shaded areas) upon the high-pressure Valsalva maneuver at baseline (blue) and 3 months after implantation (red). Responses are shown for cortical brain regions that showed significant differences for the subtraction contrast HV minus LV task condition 3 months after implantation. The 6 high-pressure Valsalva maneuvers are averaged and normalized at the subject level before averaging at group level (n = 13).

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  Figure 5. Mean cerebral blood flow (ml/100 gr/min) at baseline and 3 months after MobiusHD implantation. Group cerebral blood flow (CBF) maps before (A) and 3 months after (B) Endovascular Baroreflex Amplification (EVBA). Data of subjects were averaged for display. Representative brain sections are shown.