TY  - JOUR
A1  - Albanna, Walid
A1  - Conzen, Catharina
A1  - Weiss, Miriam
A1  - Seyfried, Katharina
A1  - Kotliar, Konstantin
A1  - Schmidt, Tobias Philip
A1  - Kuerten, David
A1  - Hescheler, Jürgen
A1  - Bruecken, Anne
A1  - Schmidt-Trucksäss, Arno
A1  - Neumaier, Felix
A1  - Wiesmann, Martin
A1  - Clusmann, Hans
A1  - Schubert, Gerrit Alexander
T1  - Non-invasive assessment of neurovascular coupling after aneurysmal subarachnoid hemorrhage: a prospective observational trial using retinal vessel analysis
JF  - Frontiers in Neurology
N2  - Delayed cerebral ischemia (DCI) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH) and can lead to infarction and poor clinical outcome. The underlying mechanisms are still incompletely understood, but animal models indicate that vasoactive metabolites and inflammatory cytokines produced within the subarachnoid space may progressively impair and partially invert neurovascular coupling (NVC) in the brain. Because cerebral and retinal microvasculature are governed by comparable regulatory mechanisms and may be connected by perivascular pathways, retinal vascular changes are increasingly recognized as a potential surrogate for altered NVC in the brain. Here, we used non-invasive retinal vessel analysis (RVA) to assess microvascular function in aSAH patients at different times after the ictus.
Y1  - 2021
U6  - http://dx.doi.org/10.3389/fneur.2021.690183
SN  - 1664-2295
VL  - 12
IS  - 12
SP  - 1
EP  - 15
ER  - 
TY  - JOUR
A1  - Albanna, W.
A1  - Conzen, C.
A1  - Weiss, M.
A1  - Clusmann, H.
A1  - Fuest, M.
A1  - Mueller, M.
A1  - Brockmann, M.A.
A1  - Vilser, W.
A1  - Schmidt-Trucksäss, A.
A1  - Hoellig, A.
A1  - Seiz, M.
A1  - Thomé, C.
A1  - Kotliar, Konstantin
A1  - Schubert, G.A.
T1  - Retinal Vessel Analysis (RVA) in the context of subarachnoid hemorrhage: A proof of concept study
JF  - PLoS ONE
N2  - Background
Timely detection of impending delayed cerebral ischemia after subarachnoid hemorrhage (SAH) is essential to improve outcome, but poses a diagnostic challenge. Retinal vessels as an embryological part of the intracranial vasculature are easily accessible for analysis and may hold the key to a new and non-invasive monitoring technique. This investigation aims to determine the feasibility of standardized retinal vessel analysis (RVA) in the context of SAH.

Methods
In a prospective pilot study, we performed RVA in six patients awake and cooperative with SAH in the acute phase (day 2–14) and eight patients at the time of follow-up (mean 4.6±1.7months after SAH), and included 33 age-matched healthy controls. Data was acquired using a manoeuvrable Dynamic Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and neurovascular coupling.

Results
Image quality was satisfactory in the majority of cases (93.3%). In the acute phase after SAH, retinal arteries were significantly dilated when compared to the control group (124.2±4.3MU vs 110.9±11.4MU, p<0.01), a difference that persisted to a lesser extent in the later stage of the disease (122.7±17.2MU, p<0.05). Testing for neurovascular coupling showed a trend towards impaired primary vasodilation and secondary vasoconstriction (p = 0.08, p = 0.09 resp.) initially and partial recovery at the time of follow-up, indicating a relative improvement in a time-dependent fashion.

Conclusion
RVA is technically feasible in patients with SAH and can detect fluctuations in vessel diameter and autoregulation even in less severely affected patients. Preliminary data suggests potential for RVA as a new and non-invasive tool for advanced SAH monitoring, but clinical relevance and prognostic value will have to be determined in a larger cohort.
Y1  - 2016
U6  - http://dx.doi.org/10.1371/journal.pone.0158781
SN  - 1932-6203
VL  - 11
IS  - 7
PB  - PLOS
CY  - San Francisco
ER  -