[Interdisciplinary neurovascular networks: state of the art]. / Interdisziplinäre neurovaskuläre Netzwerke: eine Standortbestimmung.

BACKGROUND: In order to treat the complete spectrum of neurovascular diseases at a high level of quality, which goes beyond the purely acute treatment of stroke, the German Stroke Society (DSG) together with the German Societies for Neurosurgery and Neuroradiology developed a certification procedure for neurovascular networks (NVN). Structurally, a NVN consists of a coordinating center with at least three neurovascular network partners with a certified stroke unit. From 2018 to 2020 a total of 15 NVN have so far been audited and certified according to this new standard. OBJECTIVE: How efficient are the NVN? Are high standards maintained? MATERIAL AND METHODS: The reports of the audits were analyzed. The data were taken from the period 2017-2019. RESULTS: The 15 NVN treated a total of 86,510 stroke patients in the years examined and were networked with a total of 107 partner clinics, which were situated an average of 25 km from the coordinating center and transferred a total of 2726 patients. The coordinating centers performed 2463 thrombectomies and treated 2383 patients with nontraumatic intracerebral bleeding. In 712 patients with acute aneurysmatic subarachnoid hemorrhages endovascular treatment was carried out and clipping in 401. The audit was successful in the majority of the NVN. CONCLUSION: The certification process of NVN has been successfully established and the audits proved to be a useful instrument for quality control and improvement. The 15 NVN are highly efficient and treat more than one quarter of stroke patients in German stroke units.

[Structures of endovascular recanalization in Germany : Cross-sectional survey of certified stroke units 2016-2018]. / Strukturen der endovaskulären Rekanalisation in Deutschland : Querschnittserhebung in zertifizierten Stroke-Units 2016 bis 2018.

In this cross-sectional study data from 299 certified stroke units (SU) in Germany were analyzed from January 2016 to December 2018 and included comprehensive stroke centers (CSC 34%), local SU (62%), and telemedical SU (4%). In a total of 2487 SU monitor beds, 251,539 cases of stroke treatment were documented. The number of monitor beds (10.8 vs. 7.2) and stroke cases per year (1143 vs. 708) were significantly higher in CSC than in local SU. A total of 9251 endovascular recanalization (ER) procedures were performed annually by 475 interventionalists. The overall rate of ER was 3.7% of all stroke cases, including intracerebral hemorrhage (ICH) and transient ischemic attacks (TIA). A total of 124 of the SUs (41.5%) had a 24/7 ER structure in which 55% of all stroke treatments and 96% of all ERs were carried out. In the vast majority of CSC the ER structure was robust (≥4 interventionalists, 52%) or acceptable (3 interventionalists, 27%). In contrast, the majority of local SU (88%) had to transfer patients for ER over average distances of 40 km (range 1-160 km). Overall, the ER structures in Germany between 2016 and 2018 could be described as good to very good.

[Revised certification criteria for regional and national stroke units in Germany]. / Aktualisierte Zertifizierungskriterien für regionale und überregionale Stroke-Units in Deutschland.

The revised criteria for regional and national German stroke units (SU) defined by the SU commission of the German Stroke Society come into effect on 1 July 2015. Due to the already high level of quality, various aspects only needed minor adjustments and definitions; therefore, the majority of minimum structural standards were carried forward. For medical personnel thresholds for when staff further recruitment is necessary were defined for the first time. The current evidence for endovascular thrombectomy (ET) resulted in enhanced standards for acute brain vessel imaging, network formation and timely transport between regional and national SUs with and without ET capability. It further confirmed certification criteria for national SUs that have been valid since 2012: at least two neurointerventionalists as staff members enabling ET on a 24/7 basis. Diagnostic of atrial fibrillation (AF) has been newly implemented following current evidence and internal audits on an annual basis have now become obligatory. Overall, activities to ensure and improve quality must not only be restricted to the minimally required criteria of SU certification but should also incorporate recommendations of the SU commission. The continuous further development of German SU in recent years underlines the importance of the certification procedure as a guarantee of a minimum standard and as the driving force of sustainable quality improvements.

[FEES for neurogenic dysphagia: training curriculum of the German Society of Neurology and the German Stroke Society]. / FEES für neurogene Dysphagien : Ausbildungscurriculum der Deutschen Gesellschaft für Neurologie und Deutschen Schlaganfall-Gesellschaft.

Neurogenic dysphagia is one of the most frequent and prognostically relevant neurological deficits in a variety of disorders, such as stroke, parkinsonism and advanced neuromuscular diseases. Flexible endoscopic evaluation of swallowing (FEES) is now probably the most frequently used tool for objective dysphagia assessment in Germany. It allows evaluation of the efficacy and safety of swallowing, determination of appropriate feeding strategies and assessment of the efficacy of different swallowing manoeuvres. The literature furthermore indicates that FEES is a safe and well-tolerated procedure. In spite of the huge demand for qualified dysphagia diagnostics in neurology, a systematic FEES education has yet not been established. The structured training curriculum presented in this article aims to close this gap and intends to enforce a robust and qualified FEES service. As management of neurogenic dysphagia is not confined to neurologists, this educational program is applicable to other clinicians and speech language therapists with expertise in dysphagia as well.

[FEES in the stroke unit: recommendations for implementation in the clinical routine]. / FEES auf der Stroke-Unit : Empfehlungen zur Umsetzung im klinischen Alltag.

Dysphagia occurs in about 50 % of patients with acute stroke, is strongly related to early complications, such as aspiration pneumonia and is a major cause of increased morbidity and mortality in acute stroke. Flexible endoscopic evaluation of swallowing (FEES) has proven to be an easy to use, non-invasive tool for assessment of dysphagia in acute stroke, significantly adding accuracy to the clinical evaluation of dysphagia. With respect to the growing use of FEES in German stroke units this article summarizes recommendations for implementation and execution.A 3-step process is recommended to acquire the relevant knowledge and skills for carrying out FEES. After a systematic training (first step), swallowing endoscopy should be done under close supervision (second step) which is then followed by independent practice coupled with indirect supervision (third step). In principle, FEES should adopt a team approach involving both neurologists and speech language pathologists (SLP) or alternatively speech therapists. The allocation of responsibilities between these two professions should be kept flexible and should be adjusted to the individual level of education. Reducing the role of the SLP to mere assistance work in particular should be avoided. To enhance interprofessional communication and to allow for a smooth and efficient workflow, endoscopic grading of stroke-related dysphagia should adopt a standardized score that also includes protective and rehabilitative measures as well as nutritional recommendations. A major task for the future is to develop an educational curriculum for FEES that takes the specific needs of stroke unit care into account and is applicable to both physicians and SLPs.

[Regional and national stroke units in Germany: amended certification criteria]. / Regionale und überregionale Stroke-Units in Deutschland : Aktualisierte Zertifizierungskriterien.

Stroke units (SU) have been certified for many years by the German Stroke Society (DSG) and the German Stroke Aid Foundation (SDSH). Since 2009 this is now undertaken in the third generation by the LGA InterCert of the Technical Surveillance Society of Rhineland (TÜV Rheinland). This article presents the amended certification criteria which came into effect in 2012. Many criteria and definitions could be further defined and specified and residual grey areas and fields of conflict could be reduced. For the first time a distinction has been made between the minimum requirements relevant for certification and additional recommendations by the SU Commission of the DSG. In this manner the authors are aiming to motivate SU operators not just to align quality assurance measures to the minimum requirements but to deliberately go beyond them. There is a great deal of evidence to indicate that this will not only serve to increase the motivation of personnel and the quality of treatment but simultaneously the economic situation can also be improved.

Factors influencing in-hospital mortality and morbidity in patients treated on a stroke unit.

OBJECTIVE: To determine the extent that demographics, clinical characteristics, comorbidities, and complications contribute to the risk of in-hospital mortality and morbidity in acute stroke. METHODS: Data of consecutive patients admitted to 14 stroke units cooperating within the Berlin Stroke Register were analyzed. The association of demographics, clinical characteristics, comorbidities, and complications with the risk of in-hospital death and poor outcome at discharge was assessed, and independent attributable risks were calculated, applying average sequential attributable fractions. RESULTS: In a 3-year period, 16,518 consecutive patients with ischemic or hemorrhagic stroke were documented. In-hospital mortality was 5.4%, and 45.7% had a poor outcome (modifed Rankin Scale score ≥3). In patients with length of stay (LOS) ≤7 days, 37.5% of in-hospital deaths were attributed to stroke severity, 23.1% to sociodemographics (age and prestroke disability), and 28.9% to increased intracranial pressure (iICP) and other complications. In those with LOS >7 days, age and stroke severity accounted for 44.1%, whereas pneumonia (12.2%), other complications (12.6%), and iICP (8.3%) contributed to one-third of in-hospital deaths. For poor outcome, attributable risks were similar for prestroke disability, stroke severity, pneumonia, and other complications regardless of the patient's LOS. CONCLUSIONS: Approximately two-thirds of early death and poor outcome in acute stroke is attributed to nonmodifiable predictors, whereas main modifiable factors are early complications such as iICP, pneumonia, or other complications, on which stroke unit treatment should focus to further improve the prognosis of acute stroke.

[Comprehensive stroke unit]. / Erweiterte Stroke-Unit.

The concept of a "comprehensive stroke unit" (in German: Erweiterte Stroke-Unit) is an additional structural option for those stroke units already certified in Germany. Its aim is to complement the semi-intensive management of stroke unit patients in Germany by early mobilisation and neuropsychological rehab procedures. This concept is recommended in many European countries as well. It is based on the proof of efficacy of the combined treatment package in several randomised controlled trials. According to the Helsingborg Declaration, every stroke patient in Europe should have access to a chain of care best provided by a comprehensive stroke unit. Both early mobilisation and rehabilitation treatment can be integrated and continued without creating an interface between the acute stroke unit and the general neurological or medical ward. The monitoring beds of the acute stroke unit and the non-monitoring "enhanced care" beds are located within the same geographical area of the hospital and are run as a comprehensive stroke care entity. Continuous management of the acute stroke patients by the same team on the same unit means an increase in quality of care, better usage of staff resources and an additional gain in time. The scientific background of the advantages of a comprehensive stroke unit is described as are the structural and staff requirements. The clientel particularly benefiting from treatment on wards with enhanced care beds is described, and the spectrum of treatment services is defined. This concept will be used as the basis for an add-on qualification of already certified German stroke units. An important step was to fit the requirements of the comprehensive stroke unit to the already existing facilities and their infrastructures. From an economic point of view, the comprehensive stroke unit is expected to be cost-effective, either balanced or even positive.

Obliterating intracranial vasculopathy mimicking multiple sclerosis.

BACKGROUND: The first ever diagnosis of multiple sclerosis (MS) requires consideration of both diagnostic criteria and differential diagnosis. Clinicians are particularly challenged by rare conditions which may mimic MS symptoms and relapses. CASE REPORT: We report the case of a young female patient who presented with relapsing left hemispheric symptoms that were highly suspicious of MS but were caused by an idiopathic occlusive angiopathy of the circle of Willis. CONCLUSION: Occlusive disease of the great cerebral arteries in young patients is a rare but important differential diagnosis of MS. It has to be considered in patients presenting with the first symptoms suspicious of MS as substantial treatment consequences will arise.

Sensitivity of neurovascular ultrasound for the detection of spontaneous cervical artery dissection.

The reported sensitivity of neurovascular ultrasound (nUS) for detecting spontaneous cervical artery dissection (sCAD) varies from 80% to 96% in the internal carotid artery (ICA) and from 70% to 86% in the vertebral arteries (VA). The aim of this study was to assess the sensitivity of nUS compared to MRI of the neck and MR angiography for the detection of sCAD. Forty consecutive patients with sCAD proven by 1.5T MRI were investigated by nUS within 48 hours of admission. A total of 52 cases of sCAD were detected by MRI, equally distributed (n=26, 50%) in the ICA and VA territories. Two sCADs affecting the ICA (n=2, 8%) and two sCADs of the VA (n=2, 8%) had normal initial nUS findings. The sensitivity of nUS in detecting sCAD is high, about 92% for both vascular territories. However, intramural hematomas may be missed either when they are located outside the arterial segments directly visible by nUS or if they are too small to cause hemodynamically significant stenosis.

Predictive value of the Essen Stroke Risk Score and Ankle Brachial Index in acute ischaemic stroke patients from 85 German stroke units.

BACKGROUND: Risk stratification can contribute to individualised optimal secondary prevention in patients with cerebrovascular disease. OBJECTIVE: To prospectively investigate the prediction of the Essen Stroke Risk Score (ESRS) and a pathological Ankle Brachial Index (ABI) in consecutive patients hospitalised with acute ischaemic stroke or transient ischaemic attack (TIA) in 85 neurological stroke units throughout Germany. METHODS: 852 patients were prospectively documented on standardised case report forms, including assessment of ESRS and ABI. After 17.5 months, recurrent cerebrovascular events, functional outcome or death could be assessed in 729 patients predominantly via central telephone interview. RESULTS: After discharge from the documenting hospital, recurrent stroke occurred in 41 patients (5.6%) and recurrent TIA in 15 patients (2.1%). 52 patients (7.1%) had died, 33 (4.5%) from cardiovascular causes. Patients with an ESRS > or = 3 (vs <3) had a significantly higher risk of recurrent stroke or cardiovascular death (9.7% vs 5.1%; odds ratio (OR) 2.00, 95% confidence interval (CI) 1.08 to 3.70) and a higher recurrent stroke risk (6.9% vs 3.7%; OR 1.93, 95% CI 0.95 to 3.94). Patients with an ABI < or = 0.9 (vs > 0.9) had a significantly higher risk of recurrent stroke or cardiovascular death (10.4% vs 5.5%; OR 2.00, 95% CI 1.12 to 3.56) and a higher recurrent stroke risk (6.6% vs 4.6%; OR 1.47, 95% CI 0.76 to 2.83). CONCLUSION: Our prospective follow-up study shows a significantly higher rate of recurrent stroke or cardiovascular death and a clear trend for a higher rate of recurrent stroke in patients with acute cerebrovascular events classified as high risk by an ESRS > or = 3 or a pathological ABI.

Assessment of skin extensibility and joint hypermobility in patients with spontaneous cervical artery dissection and Ehlers-Danlos syndrome.

Ehlers-Danlos syndrome (EDS) is a hereditary connective tissue disorder. One important clinical characteristic of classical type EDS is skin hyperextensibility. Examination of clinical evidence and electron microscopic views of skin biopsies suggest that connective tissue abnormalities resembling very mild EDS are present in a sizable proportion of patients with spontaneous cervical artery dissection (sCAD). Manual assessment of skin extensibility is difficult. Therefore, non-invasive machine-aided measurement of skin extensibility was used and compared with manual assessment of skin extensibility and joint hyperextensibility. Patients with classical EDS, vascular-type EDS, sCAD and healthy patients were evaluated. Skin extensibility was measurably and palpably elevated in all patients with classical type EDS but not in sCAD patients or patients with vascular-type EDS compared to healthy control individuals. Our method is able to measure the increased skin extensibility in classical type EDS. Increased skin extensibility is not present in sCAD patients.

Accuracy of perfusion-CT in predicting malignant middle cerebral artery brain infarction.

BACKGROUND: We performed a prospective study on patients with middle cerebral artery(MCA) ischemic stroke to evaluate the accuracy of perfusion-CT imaging(PCT) to predict the development of malignant brain infarction (MBI). METHODS: 106 patients(women 37 %, mean age 65 years)underwent native cranial computed tomography (CCT), CT angiography(CTA) and PCT after a median of 2 h after stroke onset. We assessed the patency of the MCA and the area of tissue ischemia (AIT)according to cerebral blood flow(CBF), cerebral blood volume (CBV) and time-to-peak (TTP)maps. Optimum sensitivity, specificity,positive (PPV) and negative predictive values (NPV) were calculated for the end-point MBI (= midline shift > 5 mm or decompressive surgery) by means of receiver operating characteristics(ROC). RESULTS: 20 patients (19 %)developed a MBI. In these patients,a larger AIT was found in all perfusion maps as compared to the remaining patients (p < 0.001). All perfusion maps had a very high NPV (95.4-98.4 %), a high sensitivity (85-95 %) and specificity (71.6-77.9 %) and only a moderate PPV (44-47.4 %). Best prediction was found for CBF maps with AIT of > 27.9 % of the hemisphere. CONCLUSION: PCT allows the discrimination of patients without a relevant risk for MBI from those having a 50 % risk of MBI development. Due to the high sensitivity and specificity, PCT is a reliable tool in detecting MBI. Because of PCT's better availability, it is the method of choice at present for an early risk stratification of acute stroke patients.

Low rate of contrast-induced Nephropathy after CT perfusion and CT angiography in acute stroke patients.

BACKGROUND: The aim of the study was to assess (i) the rate of contrast-induced nephropathy (CIN), (ii) the amount and time course of renal dysfunction, (iii) the identification of risk factors and calculation of a risk score for CIN in acute stroke patients after CT perfusion (CTP) and CT angiography (CTA). METHODS: 162 patients were investigated,who had received 140 ml of non-ionic low osmolar contrast agent (300 mg iodine per ml, Ultravist 300, Schering AG) for CTA and CTP. We assessed electrolytes, creatinine, and creatinine clearance before and up to 7 days after administration of contrast agent. In addition, the risk factors for CIN were recorded and a previously validated risk score for CIN was calculated. We also assessed the amount of crystalloid fluid substitution and newly prescribed drugs. CIN was defined as an increase of the serum creatinine-level of > 0.5 mg/dl or > 25% above baseline within 48 hours after contrast agent administration. RESULTS: 154 patients (94 %) received crystalloid fluid substitution (mean 6.1 l) within 48 h after contrast agent administration. During follow-up the creatinine values and the creatinine clearance remained stable while sodium and potassium increased significantly (p < 0.0001) after contrast agent administration. In patients with a pathological creatinine value on admission (n = 40), the creatinine clearance did not decrease significantly (p = 0.18). The risk score for developing a CIN was low in the majority of stroke patients. A manifest CIN occurred in 3 patients (2 %). No patient had to be hemodialysed. CONCLUSION: CIN is a rare complication in acute stroke patients examined by multimodal contrast-based CT due to the low prevalence of risk factors associated with CIN. In conjunction with appropriate fluid substitution, low osmolar nonionic contrast agents seem to be safe in clinical routine.

Association between single nucleotide polymorphisms in the lysyl oxidase-like 1 gene and spontaneous cervical artery dissection.

BACKGROUND: Spontaneous cervical artery dissection (sCAD) is a common cause of stroke in patients below 55 years. Dermal connective tissue abnormalities have been observed in up to 60% of patients. A chromosomal locus for connective tissue abnormalities associated with sCAD has been mapped to chromosome 15q24 to a candidate region containing the lysyl oxidase-like 1 gene (LOXL1). LOXL1 an excellent candidate susceptibility gene for non-familial sCAD was investigated by mutation analysis and a genetic association study. METHODS: We sequenced the whole coding region of the LOXL1 gene in 15 sCAD patients and performed a genetic association study in 157 sCAD patients using 12 single nucleotide polymorphisms (SNP). RESULTS: The SNP rs3825942 (Gly153Asp) showed marginal association with sCAD on an allele basis and in the dominant genetic model, and intronic SNP rs893817 under a recessive model only. None of the SNP haplotypes was associated with sCAD. CONCLUSIONS: Genetic variation in LOXL1 might play a role as a risk factor for sCAD.

Polyarterial clustered recurrence of cervical artery dissection seems to be the rule.

BACKGROUND: Spontaneous cervical artery dissection (sCAD) in multiple neck arteries (polyarterial sCAD) is traditionally thought to represent a monophasic disorder suggesting nearly simultaneous occurrence of the various intramural hematomas. Its incidence ranges from 10 to 28%. The recurrence rate of sCAD in general over up to 8.6 years has been recorded to be 0 to 8%. OBJECTIVE: To analyze more precisely the temporal and spatial neuroangiologic course of sCAD with particular focus on polyarterial manifestation. METHODS: We prospectively investigated 36 consecutive patients with sCAD unexceptionally proven by MR imaging at 1.5 T. We reinvestigated these patients by two follow-up MR examinations. The first follow-up MR examination was performed after a mean of 16 +/- 13 days, and the last MR study after a mean of 7 +/- 2 months after the initial diagnosis. RESULTS: Systematic data evaluation of the 36 patients revealed the following phenomena of sCAD: 1) seemingly simultaneous polyarterial sCAD on the initial MRI scan (n = 2; 6%); 2) recurrent sCAD in one or several initially uninvolved cervical arteries during follow-up (n = 9; 25%). These latter sCAD occurred as an early polyarterial recurrent event within 1 to 4 weeks in 7 patients (19%), and as a delayed polyarterial recurrent event within 5 to 7 months in 2 patients (6%). Under a spatial perspective, sCAD recurrence took place in one additional cervical artery in 5 patients (14%), or in more than one previously uninvolved cervical artery in 4 patients (11%). All patients except one with sCAD recurrence remained asymptomatic or had local symptoms only. One patient experienced a significant clinical deterioration due to ischemic stroke with acute impairment of cerebral hemodynamics. During follow-up, patients received transient oral anticoagulation for at least 6 months with subsequent acetylsalicylic acid (ASA). CONCLUSION: More often than previously thought, the recurrence of spontaneous cervical artery dissection (sCAD) involves multiple cervical arteries in sequence. sCAD recurrence frequently appears to cluster within the first 2 months after the index event, rather than occurring steadily over time. The prognosis of recurring sCAD appears benign, particularly in patients already receiving antithrombotic therapy.

Connective tissue and vascular phenotype in patients with cervical artery dissection.

BACKGROUND: Clinical observations and electron microscopic investigation of skin biopsies demonstrated connective tissue abnormalities in a sizeable proportion of patients with spontaneous cervical artery dissection (sCAD), suggesting an unknown connective tissue disorder as a risk factor for sCAD. OBJECTIVE: To evaluate in a case-control setting if patients with sCAD exhibit clinical signs indicative of a connective tissue disorder or show a vascular phenotype. METHODS: We investigated 43 consecutive patients with sCAD and 43 consecutive patients of similar age with ischemic stroke of other etiology. All patients underwent standardized MRI of the head and neck. The clinical investigation contained 25 items characteristic for connective tissue diseases such as hyperextensible skin, articular hypermobility, capillary fragility, and facial stigmata. A sum score counting all positive items was calculated. Additionally, the diameter of the common carotid artery (CCA) and vertebral artery (VA) and heart valve pathologies were assessed. RESULTS: Connective tissue sum scores did not differ between the sCAD group (mean 2.37 +/- 2.1, median 2) and the control group (mean 1.95 +/- 1.9, median 2, p = 0.34). One sCAD patient had osteogenesis imperfecta (2.3%) and exhibited the highest sum score of 8. The diameter of the CCA and VA and the prevalence of heart valve pathologies did not show any significant differences between groups. CONCLUSION: The connective tissue and vascular phenotype did not differ significantly between patients with spontaneous cervical artery dissection (sCAD) and control subjects with ischemic stroke of other etiology. These findings argue against a clinically apparent connective tissue disorder underlying sCAD. The prevalence of known connective tissue diseases in sCAD patients is low.

A distinctive case of fibromuscular dysplasia.

Fibromuscular dysplasia (FMD) is a rare, non-inflammatory angiopathy, which can affect the brain supplying arteries. Usually, the diagnosis is based on conventional and/or MR angiography. We present a patient with multisegmental stenoses of the internal carotid artery (ICA) where the diagnosis of FMD is based on an eye-catching ultrasound finding.