Zoek de verschillen! De kracht van variatie in de vasculaire neurologie

Oratie uitgesproken door Prof. dr. Marieke J.H. Wermer bij de aanvaarding van het ambt van hoogleraar met als leeropdracht Neurologie, in het bijzonder neurovasculaire aandoeningen aan de Universiteit Leiden op vrijdag 14 juni 2019LUMC / Geneeskund

Sex-specific microRNAs in neurovascular units in ischemic stroke

Accumulating evidence pinpoints sex differences in stroke incidence, etiology and outcome. Therefore, more understanding of the sex-specific mechanisms that lead to ischemic stroke and aggravation of secondary damage after stroke is needed. Our current mechanistic understanding of cerebral ischemia states that endothelial quiescence in neurovascular units (NVUs) is a major physiological parameter affecting the cellular response to neuron, astrocyte and vascular smooth muscle cell (VSMC) injury. Although a hallmark of the response to injury in these cells is transcriptional activation, noncoding RNAs such as microRNAs exhibit cell-type and context dependent regulation of gene expression at the post-transcriptional level. This review assesses whether sex-specific microRNA expression (either derived from X-chromosome loci following incomplete X-chromosome inactivation or regulated by estrogen in their biogenesis) in these cells controls NVU quiescence, and as such, could differentiate stroke pathophysiology in women compared to men. Their adverse expression was found to decrease tight junction affinity in endothelial cells and activate VSMC proliferation, while their regulation of paracrine astrocyte signaling was shown to neutralize sex-specific apoptotic pathways in neurons. As such, these microRNAs have cell type-specific functions in astrocytes and vascular cells which act on one another, thereby affecting the cell viability of neurons. Furthermore, these microRNAs display actual and potential clinical implications as diagnostic and prognostic biomarkers in ischemic stroke and in predicting therapeutic response to antiplatelet therapy. In conclusion, this review improves the current mechanistic understanding of the molecular mechanisms leading to ischemic stroke in women and highlights the clinical promise of sex-specific microRNAs as novel diagnostic biomarkers for (silent) ischemic stroke.Paroxysmal Cerebral Disorder

Management decisions on unruptured intracranial aneurysms before and after implementation of the PHASES score

Background: In management decisions on saccular unruptured intracranial aneurysms (UIAs) the risk of rupture is an important factor. The PHASES score, introduced in 2014, provides absolute 5-year risks of rupture based on six easily retrievable patient and aneurysm characteristics. We assessed whether management decisions on UIAs changed after implementation of the PHASES score. Patient and methods: We included all patients with UIAs who were referred to two Dutch tertiary referral centers for aneurysm care in the Netherlands (University Medical Center Utrecht (UMCU) and Leiden University Medical Center (LUMC)) between 2011 and 2017. Analyses were done on an aneurysm level. We calculated the overall proportion of UIAs with a decision to treat before and after PHASES implementation and studied the influence of age and center on post-implementation management changes. Results: We included 623 patients with 803 UIAs. The proportion of UIAs with a decision to treat was 123/360 (34.2%) before and 117/443 (26.4%) after PHASES implementation (absolute risk difference:-7.8%; 95% CI: -14.1 to-1.4). The decision to treat was made at a higher median PHASES score after implementation (7 points (IQR 5;10) pre-versus 8 points (IQR 5;10) post-implementation; p = 0.14). The reduced proportion with a treatment decision after implementation was most pronounced in patients <50 years (-22.3%; 95% CI:-39.2 to -3.4) and was restricted to treatment decisions made at the UMCU (-10.6%; 95% CI:-18.5 to-2.5). Discussion and conclusions: Management of UIAs changed following implementation of the PHASES score, but the impact of PHASES implementation on treatment decisions differed across age subgroups and centers.Paroxysmal Cerebral Disorder

On the ability to exploit signal fluctuations in pseudocontinuous Arterial Spin Labeling for inferring the major flow territories from a traditional perfusion scan

Neuro Imaging Researc

Pain perception in women with menstrually-related migraine

BackgroundCyclic hormonal fluctuations influence migraine incidence and severity. Previously, we described reduced menstrual cyclicity in estradiol levels and dermal blood flow reaction to capsaicin in female migraineurs. It is unclear whether pain perception in women with migraine is influenced by the menstrual cycle.MethodsWomen with menstrually-related migraine (n = 14), healthy age-matched controls (n = 10) and postmenopausal women (n = 15) were asked to grade trigeminal and non-trigeminal painful stimuli on a numeric pain rating scale on menstrual cycle day 19-21 (mid-luteal) and day 1-2 (early follicular).ResultsIn women with menstrually-related migraine, trigeminal pain remained low throughout the cycle. Controls showed increased trigeminal pain during the mid-luteal phase compared to the early follicular phase. Changes throughout the cycle were significantly different between women with MRM and controls.ConclusionThe compromised menstrual cyclicity of pain perception in women with menstrually-related migraine parallels our earlier findings on estradiol levels and dermal blood flow.Paroxysmal Cerebral Disorder

Migraine prevalence in patients with unruptured intracranial aneurysms: A case-control study

Paroxysmal Cerebral Disorder

Duplex ultrasonography for the detection of vertebral artery stenosis A comparison with CT angiography

Paroxysmal Cerebral Disorder

Funnel-freezing versus heat-stabilization for the visualization of metabolites by mass spectrometry imaging in a mouse stroke model

Functional Genomics of Muscle, Nerve and Brain Disorder

Optical coherence tomography detects retinal changes in hereditary cerebral amyloid angiopathy

Background and purpose Investigating mutation carriers with Dutch-type hereditary (D-) cerebral amyloid angiopathy (CAA), offers the possibility to identify markers in pre- and symptomatic stages of CAA. Optical coherence tomography (OCT) has shown potential to detect retinal changes in several neurodegenerative diseases. The aim of the present exploratory study was to investigate thinning of retinal layers as a possible (early) biomarker in D-CAA mutation carriers. Methods Twenty-one D-CAA mutation carriers (n = 8 presymptomatic,n = 13 symptomatic, median age 50 years) and nine controls (median age 53 years) were scanned using spectral-domain OCT. Symptomatic mutation carriers were defined as having a history of >= 1 symptomatic intracerebral hemorrhage. D-CAA mutation carriers and controls were recruited from our D-CAA cohort and a healthy control cohort. Total peripapillary retinal nerve fiber layer (pRNFL) thickness, six regions of pRNFL, total macular volume (TMV), and individual macular region thickness were measured and analysed, adjusted for age. Results The overall median (interquartile range) thickness of pRNFL was lower in symptomatic, but not presymptomatic D-CAA mutation carriers compared with controls [91 (86-95) mu m vs. 99 (87-108) mu m;P = 0.006]. Both presymptomatic [111 (93-122) mu m vs. 131 (123-143) mu m;P < 0.001] and symptomatic carriers [119 (95-128) mu m vs. 131 (123-143) mu m;P = 0.034] had a thinner temporal-superior quadrant of the pRNFL versus controls. TMV or individual macular layer thickness did not differ between carriers and controls. Conclusions Thinning of the retinal nerve fiber layer may be a candidate marker of disease in hereditary CAA. Further studies are needed to determine whether retinal thinning is present in sporadic CAA and estimate its value as a marker for disease progression.Ophthalmic researc

Quantitative measurement of cortical superficial siderosis in cerebral amyloid angiopathy

Cerebral amyloid angiopathy (CAA) is a cerebrovascular disease affecting the small arteries in the brain with hallmark depositions of amyloid-β in the vessel wall, leading to cognitive decline and intracerebral hemorrhage (ICH). An emerging MRI marker for CAA is cortical superficial siderosis (cSS) as it is strongly related to the risk of (recurrent) ICH. Current assessment of cSS is mainly done on T2*- weighted MRI using a qualitative score consisting of 5 categories of severity which is hampered by ceiling effects. Therefore, the need for a more quantitative measurement is warranted to better map disease progression for prognosis and future therapeutic trials. We propose a semi-automated method to quantify cSS burden on MRI and investigated it in 20 patients with CAA and cSS. The method showed excellent inter-observer (Pearson’s 0.991, P In conclusion, semi-automated segmenting and quantifying cSS is feasible and repeatable and may be used for further studies in CAA cohorts.Radiolog