Cerebral Autoregulation in Patients With Symptomatic Cerebral Atherosclerotic Stenosis

In this multi-center prospective observational study within a cohort of symptomatic cerebral atherosclerotic stenosis (sCAS) patients, 850 subjects were planed to be enrolled to explore the relationship between cerebral autoregulation (CA) and stroke recurrence, determine the threshold values of CA parameter for predicting stroke recurrence associated with particular stenosis.

Ischemic stroke is a tremendous public health burden that seriously endangers the health of Chinese population symptomatic cerebral atherosclerotic stenosis (sCAS) is responsible for about 33-50% of ischemic stroke in China and highly associated with the risk of stroke recurrence.

Cerebral autoregulation (CA) is the main protective mechanism that modulates cerebral blood flow to satisfy regional cerebral perfusion demands despite of variations in arterial blood pressure (ABP). Thus, CA supposed to be particularly considered when choosing individual therapeutic strategy in sCAS patients. In clinical practice, applying transcranial Doppler combined with servo-controlled plethysmograph assessing CA has been proved a feasible method in cerebral atherosclerotic stenosis patients. Especially in those severe stenosis patients, CA is probably compromised in varying degrees, whereas whether and to what extent CA parameters have the capability to predict stroke recurrence has not been illustrated.

Thus, the aim of the study was to assess CA after acute ischemic stroke or transient ischemic attack within 2 years follow-up to explore the relationship between CA and stroke recurrence and determine the threshold values of CA parameter to predict stroke recurrence. CA measurement will be performed at 0-3 and 10-30 days after ischemic cerebrovascular events. Clinical information, neuroimaging data, biochemical examinations and follow-up information will be collected and recorded in case report form (CRF) once signing of informed consent.

Eligibility Criteria:
Inclusion Criteria:

* Age ranging from 18 to 80, both genders
* Unilateral internal carotid artery (ICA) or M1 segment of middle cerebral artery (MCA) stenosis (rate of stenosis ranging from 50-99%)
* Acute ischemic cerebrovascular events (TIA or ischemic stroke) within cerebral stenotic artery supplying area
* Onset of disease \<30 d before enrollment
* Modified Ranking Scale (mRS) ≤1 before stroke onset
* National Institutes of Health Stroke Scale (NIHSS) ≤20
* Sufficient bilateral temporal bone windows for insonation of the middle cerebral artery
* Be conscious, and able to cooperate with CA assessment
* Willing to participate and sign the informed consent

Exclusion Criteria:

* Vertebral artery (VA), basilar artery (BA), anterior cerebral artery (ACA), or posterior cerebral artery (PCA) stenosis; Bilateral internal carotid artery (ICA) or M1 segment of middle cerebral artery (MCA) stenosis(rate of stenosis ranging from 50-99%)
* Patients who have received or plan to undergo intravascular interventional treatment/endarterectomy
* Other intracranial diseases, including cerebral hemorrhage (primary or secondary), intracranial neoplasm, aneurysm, arteriovenous malformation, etc.
* Evidence for embolic stroke, such as atrial fibrillation, prosthetic valve surgery, and suspected endocarditis, etc.
* Arrhythmia, anemia and hyperthyroidism which may influence the stability of cerebral blood flow diagnosed by two physicians by electrocardiogram and laboratory tests.
* Dementia, severe anxiety, depression, and other mental diseases
* Malignant neoplasm and expected lifetime \<2 years
* Enrolled in other clinical trails within 6 months