Table 2.
Summary table of factors affecting CA and neurovascular coupling in LVO.
| Non-modifiable factor(s) | Method of CA or CBF assessment (parameter) | Key findings | Author/Reference |
|---|---|---|---|
|
TFA (phase shift, gain, coherence) | CA impaired early and begins to normalize gradually at 72–96 h; CA impairment can persist beyond 7 days up to 3 months | Sheriff et al. (12) Kwan et al. (13) |
|
TFA (phase shift) | Worse CA in AH compared with UH Worse CA in hypo perfused viable tissue compared with normal tissue |
Petersen et al. (14) Hecht et al. (15) |
| b. Posterior circulation | TFA (phase shift) | Basilar stenosis patients with decreased phase shift (worse CA) more likely to have new AIS and poor 90 day outcome | Gong et al., 2013 (24) |
| c. Anterior circulation (extracranial atherosclerosis) | Mx (correlation coefficient) | CA impaired not only in severe ICA (70–99%) but also moderate (>50%) stenosis | Tang et al. (30) |
| 3. Specific disease subtype a. ICAD |
TFA (phase, coherence) TFA (phase, gain) ARI |
Ipsilateral CA in hypoperfusion related ICAD closely correlated to collateral status and CBF (MRI ASL) Asymptomatic MCA stenosis with ipsilateral CA impairment Symptomatic MCA stenosis with bilateral CA impairment |
Tian et al. (32) Wang et al. (34) Gong et al. (36) Chen et al. (35) |
| b. MMD | TFA (RoR, phase, gain, coherence) NIRS, COx, HVx |
Dynamic CA impaired even in early stages of MMD; autoregulatory parameters well correlated with angiographic stage of MMD Optimum MAP and LLA during indirect revascularization can be identified |
Chen et al. (38) Lee et al. (39) |
| Modifiable factor(s) | Method of CA or CBF assessment (parameter) | Key findings | Author/Reference |
|---|---|---|---|
|
ARI TFA (phase shift, gain, coherence) |
CA impaired in subjects not responding to IVT; had worse outcomes per early NIHSS Complete recanalization (TICI 3) associated with better CA profile than incomplete (TICI 2b or lower) |
Nogueira et al. (42) Sheriff et al. (12) |
|
NIRS; time correlation analysis n/a n/a |
MAP opt at which CA is most preserved can be calculated. More time within autoregulatory limits (AL) associated with less HT and infarct growth; more time above ULA associated with worse 90 day mRS Peak SBP post MT of 158 mm Hg able to discriminate better outcomes BP overcorrection (intensive SBP < 120 mmHg) post MT associated with worse outcomes |
Petersen et al. (14) Mistry et al. (51) Yang et al. (50) |
|
n/a n/a n/a |
Propofol and sevoflurane associated with less CA impairment Combination of remifentanil and propofol preserves CA (especially where concern for hypotension) No dedicated CA data comparing GA versus CS; Randomized trials SIESTA and GOLIATH showing trends in outcome benefit favoring GA but multicenter RCT pending |
Messick et al. (58) Leslie-Mazwi et al. (59) Simonsen et al. (60)Schönenberger et al. (61) |
|
n/a | Intraprocedural MT ETCO2 higher in the good clinical outcome group (~35 compared with ~32 mm Hg) | Takahashi et al. (64) |
|
ARI n/a |
Decrease in CA from lying to sitting position in mild AIS; HeadPoST study with median NIHSS 4 in general AIS showed no difference (No randomized data specific to LVO) | Lam et al. (70) Anderson et al. (71) |
AH, Affected Hemisphere; AIS, Acute Ischemic Stroke; ARI, Autoregulation Index; ASL, Arterial Spin Labeling; BP, Blood Pressure; CA, Cerebral Autoregulation; CBF, Cerebral Blood Flow; CBFv, Cerebral Blood Flow Velocity; CMRO2, Cerebral Metabolic Rate of Oxygen Extraction; CVR, Cerebrovascular Resistance; CVRi, Cerebrovascular Resistance Index; Cox, Cerebral Oximetry Index; CPP, Cerebral Perfusion Pressure; CS, Conscious Sedation; CT, Computed Tomography; CrCP, Critical Closing Pressure; ETCO2, End-Tidal Carbon Dioxide; GA, General Anesthesia; HT, Hemorrhagic Transformation; HVx, Hemoglobin Volume Index; ICA, Intracerebral Atherosclerosis; ICAD, Intracerebral Atherosclerotic Disease; ICH, Intracerebral Hemorrhage; IVT, Intravenous Thrombolysis; LLO, Lower Limit of Autoregulation; LVO, Large Vessel Occlusion; MAPopt, Optimum Mean Arterial Pressure; MCA, Middle Cerebral Artery; MAP, Mean Arterial Pressure; MMD, Moya moya Disease; MRI, Magnetic Resonance Imaging; MT, Mechanical Thrombectomy; NIHSS, National Institutes of Health Stroke Scale; NIRS, Near Infrared Spectroscopy; PaCO2, Partial Pressure of Carbon Dioxide in Arterial Blood; PaO2, Partial Pressure of Oxygen; PET, Positron Emission Tomography; PI, Pulsatility Index; RCT, Randomized Control Trial; RoR, Rate of Recovery; SBP, Systolic Blood Pressure; TFA, Transfer Function Analysis; TICI, Thrombolysis in Cerebral Infarction; TNK, Tenecteplase; tPA, Tissue Plasminogen Activator; UH, Unaffected Hemisphere; ULA, Upper Limit of Autoregulation.
n/a, Not Applicable or Available (Refers to studies where CA was not an outcome variable).