Table 5.

Clinical studies utilizing Mean Flow Velocity Index (Mx) or Systolic Flow Velocity Index (Sx) measurements in subarachnoid hemorrhage patients.

References	Citation	Study size	SAH grade	Critical observations
Soehle et al., 2004	(21)	32	WFNS 1-5	Baseline Mx and Sx values in SAH patients were similar to previously reported values for healthy volunteers. Vasospasm (15/32 patients) significantly increased both Mx and Sx values.
Budohoski et al., 2012	(154)	96	WFNS 1-5	Sx values are higher in patients who develop DCI (0.09; 32/98) vs. those who do not (0.00; 66/98). Higher Sx values at days 0–5 post-ictus independently predict DCI, but not vasospasm.
Calviere et al., 2015	(155)	30	WFNS 1-3	Mx within 4 days and at 7 days post-SAH ictus, but not at 14 days post-ictus, is higher compared to previously reported values for healthy volunteers. Mx alone did not predict the development of DCI. Worsening Mx, combined with the presence of vasospasm, predicted the development of DCI.
Zweifel et al., 2010	(156)	27	WFNS 2-5	13/51 individual Mx measurements indicated disturbed autoregulation (Mx >0.15). Mx correlated with TOx measurements when both recordings time-averaged over the recording interval. Non-averaged correlations were highly variable.

These studies included SAH patients only. DCI, delayed cerebral ischemia; Mx, Mean flow velocity index; SAH, Subarachnoid hemorrhage; Sx, Systolic flow velocity index; TOx, Tissue oxygenation index; WFNS, World Federation of Neurosurgical Societies scale.