Subarachnoid Aneurysm Hemorrhage

Despite its lower incidence rate within the stroke population and tendency to affect younger individuals, SAH carries the highest risk of PSCI. The neural mechanisms underlying these cognitive deficits remain poorly understood, but potential factors include treatment approaches, underlying disease pathophysiology, post-disease complications, or alterations in neural connectivity\[10\]. Previous literature indicates that cognitive deficits in SAH primarily manifest in areas such as visuospatial skill, verbal memory language abilities (including verbal comprehension, verbal fluency, abstract language), executive function (working memory) and attention. These impairments significantly impact patients' ability to perform ADL independently and return to work, despite motor function recovery.

The goal of this observational study is to learn about the protein heterogeneity in extracellular vesicles (EVs) derived from different human blood circulatory regions of patients with ruptured or unruptured intracranial aneurysms. The main objectives are: Reveal the proteomic heterogeneity of EVs in different blood circulatory regions of the human body。 Reveal the proteomic differences of EVs in cerebral feeding arteries and draining veins between patients with aneurysmal subarachnoid hemorrhage and those without hemorrhage. Explore EV-derived protein biomarkers that reflect the diagnosis and prognosis of subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is a life-threatening neurological illness: it is bleeding in the brain after a bulging blood vessel (a brain aneurysm) ruptures. Although SAH accounts for only 5% of all strokes, it often happens in middle age and it puts a significant burden on many patients during their most productive years. Complications following SAH are common, and they can cause major long-term disability. Only one medication - nimodipine - has been proven to benefit the health and wellbeing of these patients. All SAH patients should receive nimodipine for 21 days at a fixed dose. However, our early work suggested that all patients are not getting equal amounts of nimodipine into their blood. In addition, the two different forms (structural mirror images) of nimodipine might have different effects. Reduced amounts of nimodipine in the blood may lessen its benefit and contribute to worsening health and wellbeing of SAH patients. The overall goal of this research is to see what happens with different nimodipine doses and to confirm whether the two forms of nimodipine have different effects. The investigators will conduct a multi-centre study in adult patients admitted for SAH in Canada and the USA. The investigators will collect blood samples to determine the amount of each type of nimodipine in each participant's body, and then will check to see how each participant is doing at 90 days following SAH. They will also check other factors affecting nimodipine levels, so that they can in the future suggest dose recommendations that are actually tailored to each patient.

An observational study of patients with emerging or established severe cerebral vasospasm after subarachnoid haemorrhage, employing multimodal neuromonitoring.