Choroid plexus perfusion and intracranial cerebrospinal fluid changes after angiogenesis

Abstract

Recent studies have provided evidence that cortical brain ischemia may influence choroid plexus function, and such communication may be mediated by either traditional CSF circulation pathways and/or a possible glymphatic pathway. Here we investigated the hypothesis that improvements in arterial health following neoangiogenesis alter (i) intracranial CSF volume and (ii) choroid plexus perfusion in humans. CSF and tissue volume measurements were obtained from T1-weighted MRI, and cortical and choroid plexus perfusion were obtained from perfusion-weighted arterial spin labeling MRI, in patients with non-atherosclerotic intracranial stenosis (e.g. Moyamoya). Measurements were repeated after indirect surgical revascularization, which elicits cortical neoangiogenesis near the revascularization site ( n = 23; age = 41.8 ± 13.4 years), or in a cohort of participants at two time points without interval surgeries ( n = 10; age = 41.7 ± 10.7 years). Regression analyses were used to evaluate dependence of perfusion and volume on state (time 1 vs. 2). Post-surgery, neither CSF nor tissue volumes changed significantly. In surgical patients, cortical perfusion increased and choroid plexus perfusion decreased after surgery; in participants without surgeries, cortical perfusion reduced and choroid plexus perfusion increased between time points. Findings are discussed in the context of a homeostatic mechanism, whereby arterial health, paravascular flow, and/or ischemia can affect choroid plexus perfusion.

Non-invasive measurement of choroid plexus apparent blood flow with arterial spin labeling

“…The choroid plexus blood flow of this work should be interpreted as apparent perfusion because of the partial volume effect in ASL images. Recent work showed consistent results between ASL and radiograph on rat brains [ 49 ], and our approach in this work was consistent with previous human studies [ 33 , 35 ]. Therefore, equivalent detectability was expected in this ASL study.…”

“…Our study clearly demonstrated the kinetics of perfusion labeled signal and its spatial distribution. The apparent blood flow measured in this work was in agreement with Johnson et al’s ASL study [ 33 ].…”

“…Recently, we reported the feasibility of detecting choroid plexus perfusion using ASL in abstract form [ 31 , 32 ], but the blood flow quantification methods were not fully developed. Johnson et al [ 33 ] implemented this method to evaluate perfusion changes after angiogenesis, but they used a single delay ASL experiment, which couldn’t provide the dynamic characteristics of choroid plexus perfusion. Evans et al [ 34 ] reported a successful detection of CSF generation on animal models using a pulsed ASL with a long echo time.…”

Non-Invasive Measurement of Choroid Plexus Blood Flow with Arterial Spin Labeling

“…Total blood flow of the choroid plexus showed about 38% variance, which could be from the inter-subject variation, including the choroid plexus volume variation and the average blood flow variation. Our results showed about 25% variation for either, which was consistent with the previous studies [19,30].…”

“…Our study clearly demonstrated the kinetics of perfusion labeled signal and its spatial distribution. The blood flow measured in this work was in agreement with Johnson et al's ASL study [30], although studies based on radioactive tracers and animal models reported higher blood flow. Total blood flow of the choroid plexus showed about 38% variance, which could be from the inter-subject variation, including the choroid plexus volume variation and the average blood flow variation.…”