Panel A shows blood pressure (BP) and blood flow velocity (BFV) waveforms from the right and left MCAs (MCAR and MCAL respectively) during the VM for a normotensive subject (top 3 panels). The duration of the VM straining is indicated by a horizontal line. The thick black line indicates the BPR and BFVR that reflect the characteristic VM oscillation. Bottom 3 panels show BPR and BFVR in the MCAR and MCAL. Arrows indicate phases at the BPR and BFVR minima. With normal autoregulation, BFVR minimum preceded BPR minimum. Panel B shows BP and BFV waveforms for a subject with a left temporal infarct (MCAR = non stroke-side MCA, MCAL = stroke side MCA) (top 3 panels). Horizontal line indicates duration of the VM. Black thick line indicates the BPR and BFVR obtained from the BP and BFV raw waveforms. Bottom 3 panels show BPR and BFVR in the non-stroke side MCA and in the stroke-side MCA expressed as a function of BPVM phase. Arrows indicate that the phase at BFV minimum was similar to the phase at BP minimum.