Point-of-Care Ultrasound in Neurology - Report of the EAN SPN/ESNCH/ERcNsono Neuro-POCUS Working Group.

In the last decade, ultrasound examination in neurology has been undergoing a significant expansion of its modalities. In parallel, there is an increasing demand for rapid and high-quality diagnostics in various acute diseases in the prehospital setting, the emergency room, intensive care unit, and during surgical or interventional procedures. Due to the growing need for rapid answers to clinical questions, there is particular demand for diagnostic ultrasound imaging. The Neuro-POCUS working group, a joint project by the European Academy of Neurology Scientific Panel Neurosonology, the European Society of Neurosonology and Cerebral Hemodynamics, and the European Reference Centers in Neurosonology (EAN SPN/ESNCH/ERcNsono Neuro-POCUS working group), was given the task of creating a concept for point-of-care ultrasound in neurology called "Neuro-POCUS". We introduce here a new ultrasound examination concept called point-of-care ultrasound in neurology (Neuro-POCUS) designed to streamline conclusive imaging outside of the ultrasound center, directly at the bedside. The aim of this study is to encourage neurologists to add quick and disease-oriented Neuro-POCUS to accompany the patient in the critical phase as an adjunct not a substitution for computed tomography, magnetic resonance imaging, or standard comprehensive neurosonology examination. Another goal is to avoid unwanted complications during imaging-free periods, ultimately resulting in advantages for the patient.

Extracranial ultrasound following mechanical thrombectomy in patients with acute stroke.

BACKGROUND AND PURPOSE: Mechanical thrombectomy (MT) is standard care for patients suffering from an ischemic stroke due to a large vessel occlusion. Immediate and follow-up transcranial ultrasound examinations after MT were shown to have a diagnostic benefit. However, it is unclear whether repeated extracranial ultrasound after MT has an additional diagnostic yield, that is, depicts new findings. METHODS: Retrospectively, from our prospective database we identified all patients after MT who presented for a follow-up examination between January 2017 and March 2020 and who had received an ultrasound examination after MT and at follow-up. Clinical data were extracted from our database. Ultrasound images of all patients were revisited to identify new findings at follow-up compared to examination after MT. RESULTS: Ninety-one patients were identified appropriate for further analysis, with a mean age of 67.8 ± 16 years. Median National Institute of Health Stroke Scale at admission was 11 ± 8.5 points. At baseline ultrasound, 18 patients (19.8%) had no atherosclerotic alterations and 73 patients (82.2%) had a plaque burden of ≥1 plaque. During follow-up, in 5 patients (5.5%) a pathological finding presented in first examination evolved dynamically, that is, normalized. Vessel status of all other patients was stable, especially, in no patient a new relevant pathological finding occurred. CONCLUSIONS: Although sonographic normalization of pathologic findings was observed, pathologic new findings were not detected during follow-up. This study provides first data for a discussion of the role of ultrasound in a structured stroke care after MT. However, larger studies are required to improve the understanding.

The EFSUMB Guidelines and Recommendations for the Clinical Practice of Contrast-Enhanced Ultrasound (CEUS) in Non-Hepatic Applications: Update 2017 (Long Version).

The updated version of the EFSUMB guidelines on the application of non-hepatic contrast-enhanced ultrasound (CEUS) deals with the use of microbubble ultrasound contrast outside the liver in the many established and emerging applications.

The EFSUMB Guidelines and Recommendations for the Clinical Practice of Contrast-Enhanced Ultrasound (CEUS) in Non-Hepatic Applications: Update 2017 (Short Version).

The updated version of the EFSUMB guidelines on the application of non-hepatic contrast-enhanced ultrasound (CEUS) deals with the use of microbubble ultrasound contrast outside the liver in the many established and emerging applications.

Possible morphological pathomechanisms of ischemic stroke in the posterior circulation of patients with vertebral artery hypoplasia.

BACKGROUND: The clinical significance of vertebral artery hypoplasia (VAH) and the possible pathomechanism of ischemic stroke in patients with VAH are still not completely clear. METHODS: In a group of 80 posterior circulation strokes (PCS) patients, we compared the location of the ischemic areas in VAH (n = 26) and non-VAH (n = 54) group. We assessed the side of VAH (diameter equal to or less than 2.5 mm) with the stroke localization. RESULTS: The possible morphological stroke pathomechanisms in the VAH group--"blood flow reorganization" (n = 11) and "pathway liberation for embolization" (n = 10) - were represented equally and may also act together (n = 3). In two cases, the stroke pathomechanism was unknown. The frequency of the presence of conventional risk factors--hypertension (p = 1.0), diabetes mellitus (p = 0.62), hyperlipidemia (p= 1.0) and smoking (p = 1.0)--and the stroke etiology--cardioembolism (p = 0.80), atherosclerotic changes of large (p = 0.76) and small vessels (p = 0.79)--did not differ between the two subgroups. CONCLUSION: In patients with VAH, the combination of several pathomechanisms of ischemic stroke and the contribution of several risk factors can cause the clinical manifestation of PCS.

Common variation in PHACTR1 is associated with susceptibility to cervical artery dissection.

Cervical artery dissection (CeAD), a mural hematoma in a carotid or vertebral artery, is a major cause of ischemic stroke in young adults although relatively uncommon in the general population (incidence of 2.6/100,000 per year). Minor cervical traumas, infection, migraine and hypertension are putative risk factors, and inverse associations with obesity and hypercholesterolemia are described. No confirmed genetic susceptibility factors have been identified using candidate gene approaches. We performed genome-wide association studies (GWAS) in 1,393 CeAD cases and 14,416 controls. The rs9349379[G] allele (PHACTR1) was associated with lower CeAD risk (odds ratio (OR) = 0.75, 95% confidence interval (CI) = 0.69-0.82; P = 4.46 × 10(-10)), with confirmation in independent follow-up samples (659 CeAD cases and 2,648 controls; P = 3.91 × 10(-3); combined P = 1.00 × 10(-11)). The rs9349379[G] allele was previously shown to be associated with lower risk of migraine and increased risk of myocardial infarction. Deciphering the mechanisms underlying this pleiotropy might provide important information on the biological underpinnings of these disabling conditions.

CCSVI and MS: a statement from the European Society of neurosonology and cerebral hemodynamics.

To systematically review the ultrasonographic criteria proposed for the diagnosis of chronic cerebrospinal venous insufficiency (CCSVI). The authors analyzed the five ultrasonographic criteria, four extracranial and one intracranial, suggested for the diagnosis of CCSVI in multiple sclerosis (MS), together with the references from which these criteria were derived and the main studies that explored the physiology of cerebrospinal drainage. The proposed CCSVI criteria are questionable due to both methodological and technical errors: criteria 1 and 3 are based on a scientifically incorrect application of data obtained in a different setting; criteria 2 and 4 have never been validated before; criterion 2 is technically incorrect; criteria 3 and 5 are susceptible to so many external factors that it is difficult to state whether the data collected are pathological or a variation from the normal. It is also unclear how it was decided that two or more of these five ultrasound criteria may be used to diagnose CCSVI, since no validation of these criteria was performed by different and independent observers nor were they blindly compared with a validated gold-standard investigation. The European Society of Neurosonology and Cerebral Hemodynamics (ESNCH) has considerable concerns regarding the accuracy of the proposed criteria for CCSVI in MS. Therefore, any potentially harmful interventional treatment such as transluminal angioplasty and/or stenting should be strongly discouraged.

Transcranial contrast imaging of cerebral perfusion in patients with space-occupying intracranial lesions.

OBJECTIVE: The aim of this study was to evaluate a deficit in cerebral perfusion after administration of the contrast agent SonoVue (Bracco Altana Pharma, Konstanz, Germany) in patients with intracranial space-occupying lesions. METHODS: We used transcranial duplex sonography to examine 10 healthy volunteers and 4 patients. Of the patients, one 55-year-old woman had an intracranial glioblastoma; one 54-year-old woman had an intracranial hemorrhage; and one 49-year-old woman and one 69-year-old man had a malignant middle cerebral artery infarction. A decompressive craniectomy was performed in the 2 patients with malignant middle cerebral artery infarction. Triggered images with pulsing intervals of 1000 milliseconds were used for the evaluation of time-intensity curves in several regions of interest. The mechanical index was set at 1.6; in patients with a craniectomy, the mechanical index was set at 1.1. RESULTS: In all patients, the perfusion deficit could be recognized in the ipsilateral hemisphere. The superimposition of the sonographic images with those from computed tomography or magnetic resonance imaging showed a good correspondence in shape and size in patients with a craniectomy. In patients without a craniectomy, a rough correspondence with findings from magnetic resonance imaging or computed tomography could be recognized. CONCLUSIONS: By using contrast-enhanced transcranial duplex sonography, it is possible to image the perfusion deficit in cerebral microcirculation in patients with intracranial space-occupying lesions. These results should be confirmed by more pathologic cases and correlated with magnetic resonance imaging and other neuroimaging techniques. Additionally, further technical development in sonographic systems is necessary to improve the diagnostics of cerebral perfusion deficit.

Dissection of the extracranial vertebral artery: clinical findings and early noninvasive diagnosis in 24 patients.

Dissection of cervical arteries causes ischemic stroke in young adults. This reports the clinical, ultrasonographic, and neuroradiological findings in 24 patients with 28 vertebral artery dissections in the neck (4 occurring bilaterally). In 20 patients (83%), the dissection was temporally related to trauma. No patients had an underlying vascular disease, for example, atherosclerosis or fibromuscular dysplasia. In all, the major initial manifestation was pain in the occipital or neck region. The next most common symptoms were vertigo and nausea (in 17 patients). Clinical manifestations were vertebrobasilar transient ischemic attack (TIA) (5 patients: in 2 patients vestibulocerebellar TIA, in 1 patient visual TIA, in 1 patient motor TIA, and in 1 patient brain stem TIA with perioral paresthesia), cerebellar infarction (10 patients, in 4 patients bilateral), brainstem infarction (5 patients), posterior cerebral artery territory infarction (1 patient), and multiple vertebrobasilar ischemic lesions (3 patients). Typical angiographic findings were irregular narrowing of the vessel lumen or a tapering stenosis with distal occlusion. Magnetic resonance imaging showed a thickened vessel wall with hematoma signal at the site of the dissection. Duplex color-flow imaging was valuable for the early diagnosis of extracranial vertebral artery dissection and for follow-up examinations. The distal V1- and the proximal V2-segment (at the level of C6 vertebra) was the most frequent localization of dissections (in 43%). The outcome was favorable except for 2 patients with basilar artery occlusion. Embolism to the basilar artery may be avoided by early administration of anticoagulants.

Combined effects of hemoglobin A1c and C-reactive protein on the progression of subclinical carotid atherosclerosis: the INVADE study.

BACKGROUND AND PURPOSE: Glycohemoglobin (hemoglobin A1c [HbA1c]) and high-sensitivity C-reactive protein (hsCRP) are risk indicators for atherosclerosis. Limited information exists regarding the combined effects of inflammation and hyperglycemia. We investigated the joint effects of both parameters on early carotid atherosclerosis progression and major vascular events in diabetic and nondiabetic subjects. METHODS: We analyzed the data of INVADE (Intervention Project on Cerebrovascular Diseases and Dementia in the Community of Ebersberg, Bavaria), a prospective, population-based study conducted in 3534 subjects (mean age, 69 years). In addition to common risk factors, measurements of carotid intima-media thickness (IMT), hsCRP, and HbA1c were performed at baseline and after 2 years of follow-up. RESULTS: For the entire population, IMT progression was significantly related to HbA1c (P=0.003) but not to hsCRP (P=0.06) after risk factor adjustment. The interaction hsCRPxHbA1c was highly significant (P=0.001), and the most pronounced IMT progression was seen in subjects with both parameters in the fourth quartiles compared with subjects with both parameters in the first quartiles (0.028 [0.025, 0.031] versus 0.012 mm/year [0.007, 0.019]; P=0.0013). We observed a significant joint effect of HbA1c and hsCRP on IMT progression in the diabetic (n=882) as well as the nondiabetic subgroup (n=2652). Subjects with HbA1c and hsCRP in the upper 2 quartiles had an increased risk for new vascular events (adjusted hazard ratio in diabetics: 4.3 [1.8, 7.3]; P=0.001; nondiabetics: 2.9 [1.6, 4.7]; P=0.001). CONCLUSIONS: The combination of hyperglycemia and inflammation is associated with an advanced early carotid atherosclerosis progression and an increased risk of new vascular events in diabetic as well as nondiabetic subjects.

Evaluation of arteriovenous malformations (AVMs) with transcranial color-coded duplex sonography: does the location of an AVM influence its sonographic detection?

OBJECTIVE: The clinical value of transcranial color-coded duplex sonography (TCCS) in the evaluation of arteriovenous malformations (AVMs) has not yet been fully investigated. In this study, 54 intracranial AVMs confirmed by angiography were prospectively examined over 6 years. The purpose of the study was to describe their typical sonographic features and to define sensitivity for diagnosis with regard to the location of an AVM. METHODS: Transcranial color-coded duplex sonographic findings for 54 patients with intracranial AVMs are presented. The vessels of the circle of Willis were identified by location, course, and direction of flow on color flow images. RESULTS: In accordance with digital subtraction angiography, the intracranial AVMs could be visualized in 42 cases (sensitivity, 77.8%). The pathologic vessels were coded in different shades of blue and red, corresponding to varying blood flow directions in the AVM. The major feeding vessels could be easily identified. Hemodynamic parameters showing increased systolic and diastolic flow velocities and a decreased pulsatility index were better attainable with TCCS than with conventional transcranial Doppler sonography. Arteriovenus malformations located near the cortex, that is, in the parietal, frontal, occipital, and cerebellar regions of the brain, could not be visualized. In contrast, AVMs located in the basal regions were very easy to image (sensitivity, 88.9%). Additionally, TCCS proved useful for follow-up examinations postoperatively or after embolization. CONCLUSIONS: Transcranial color-coded duplex sonography is a valuable noninvasive method for the diagnosis and long-term follow-up of intracranial AVMs. Arteriovenous malformations located in the axial imaging plane can be more easily detected. Nevertheless, TCCS should not be used as a screening method.

The axial imaging plane--the main domain of the transcranial color-coded duplex ultrasonography?

Transcranial color-coded duplex ultrasonography (TCCS) makes possible the visualization of basal cerebral arteries through color-coding the flow velocity information. This method is well established in the clinical routine for the diagnostics of pathological processes in cerebrovascular disease. The present review describes the examination technique, normal and pathological findings, such as stenosis and occlusion of intracranial arteries, as well as intracranial vascular malformations focussing on the advantages of the examination in the axial imaging planes.