Cerebral autoregulation is heterogeneous in different stroke mechanism of ischemic stroke caused by intracranial atherosclerotic stenosis

Abstract

Background and Purpose Intracranial atherosclerotic stenosis (ICAS) is the most common cause of ischemic stroke (IS) and is associated with stroke recurrence. It results in IS due to a variety of mechanisms. However, the influence of brain reserve mechanism on different stroke mechanism is still unclear. Cerebral autoregulation (CA) is an important brain reserve mechanism and is impaired after IS. This study aimed to explore the impaired pattern of CA and assess the association between CA and stroke risk factors in different stroke mechanism caused by ICAS. Methods IS patients with ICAS (50%–99% stenosis/occlusion) in middle cerebral artery (MCA) or internal carotid artery were enrolled to receive CA examinations within 7 days after onset. Healthy volunteers were also recruited as controls. CA was recorded from spontaneous fluctuations of blood pressure and MCA flow velocity. Transfer function analysis was used to derive CA parameters, including phase difference (PD) and coherence in the low‐frequency range (0.06–0.12 Hz). Results A total of 89 IS patients and 90 healthy controls were included. Compared with controls, CA was impaired ipsilaterally in patients with parent artery atherosclerosis occluding penetrating artery (POPA) while CA was bilaterally impaired in other stroke mechanisms. And CA on ipsilateral hemisphere was correlated with hypertension/hyperlipidemia in patients with POPA ( r = −0.481, p = .008; r = −0.484, p = .008). While CA on ipsilateral hemisphere was correlated with perfusion parameter including the arterial spin‐labeling (ASL) parameter cerebral blood flow (CBF) ( r = 0.893, p = .007) and collateral circulation status the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) ( r = 0.610, p = .021) in patients with hypoperfusion mechanism. Conclusion In IS patients, CA was impaired heterogeneously and was correlated with different risk factors in varied stroke mechanism. CA can be as an informative determinant of stroke risk in patients with ICAS and to help improving individualized treatment strategies in the presence of ischemic stroke caused by ICAS.

Intraoperative Cerebral Hemodynamic Monitoring during Carotid Endarterectomy via Diffuse Correlation Spectroscopy and Near-Infrared Spectroscopy

“…During the pre-CEA phase, we observed that the highest correlation greater than 0.3 was in the SH group on the ipsilateral hemisphere ( Figure 6 , SH group). Since the shunt utilization was decided either intraoperatively based on EEG changes or pre-surgically based on the patient’s stroke history and neurological evaluation, ipsilaterally weakened CAR in the SH group during this phase may reflect the degrees of their past ischemic stroke or transient ischemic attacks [ 37 , 38 ]. The better CAR in the SCS group than in other groups during the pre-CEA phase may actually be an indication of the ability to maintain constant CBF i for elevated MAP ( Figure 6 , p = 0.003).…”

Cerebrovascular Gi Proteins Protect Against Brain Hypoperfusion and Collateral Failure in Cerebral Ischemia

“…From a vascular perspective, alterations in G protein signaling involving monoamines such as adrenaline, noradrenaline, serotonin, dopamine, and histamine could be directly associated with cerebral hypoperfusion, a well-known imaging hallmark of neurodegenerative diseases [21,51,52]. Cerebral hypoperfusion is also a common risk factor in cerebrovascular diseases such as cerebral microbleeds and stroke [53,54]. Therefore, G i PCR-driven signaling for the maintenance of CBF may be relevant to identify novel therapeutic targets.…”

Functional Assessment of Cerebral Artery Stenosis by Angiography-Based Quantitative Flow Ratio: A Pilot Study

“…Three-dimensional DSA images can be considered in future QFR computation. Notably, autoregulation and collateral circulation further complicate the cerebral hemodynamic status (Tian et al, 2021). More studies were required to continuously improve the method of QFR computation.…”