Headache Attributed to Reversible Cerebral Vasoconstriction Syndrome (RCVS).

Reversible cerebral vasoconstriction syndrome (RCVS) is a condition with variable outcomes presenting a new onset thunderclap headache accompanied by focal neurological symptoms or seizures. It can be idiopathic or arise secondarily to a variety of trigger factors. The condition is increasingly recognized in clinical practice, but many facets remain poorly understood. This article aims to clarify the headache characteristics in RCVS, the temporal association of angiographic findings, the potential association of the condition with SARS-CoV-2 infection, and the clinical presentation of RCVS in children and is based on a systematic PRISMA search for published analytical or large descriptive observational studies. Data from 60 studies that fulfilled specific criteria were reviewed. Most people with RCVS exhibit a typical thunderclap, explosive, or pulsatile/throbbing headache, or a similar acute and severe headache that takes longer than 1 min to peak. Atypical presentations or absence of headaches are also reported and may be an underrecognized phenotype. In many cases, headaches may persist after resolution of RCVS. Focal deficits or seizures are attributed to associated complications including transient ischemic attacks, posterior reversible encephalopathy syndrome, ischemic stroke, cerebral edema, and intracranial hemorrhage. The peak of vasoconstriction occurs usually within two weeks after clinical onset, possibly following a pattern of centripetal propagation, and tends to resolve completely within 3 months, well after symptoms have subsided. There are a few reports of RCVS occurring in relation to SARS-CoV-2 infection, but potential underlying pathophysiologic mechanisms and etiological associations have not been confirmed. RCVS occurs in children most often in the context of an underlying disease. Overall, the available data in the literature are scattered, and large-scale prospective studies and international collaborations are needed to further characterize the clinical presentation of RCVS.

Visual snow: A systematic review and a case series.

BACKGROUND: Visual Snow Syndrome is a recently recognized neurological condition presenting, continuous, tiny dots across the entire visual field, accompanied by nyctalopia, photophobia and palinopsia that persist for months. It may be part of migraine aura spectrum, yet its definition is still questionable. Diagnostic criteria for Visual Snow Syndrome are included in the supplemental material of ICHD-3. We aimed to summarize recent data to improve the understanding of Visual Snow Syndrome. METHODS: After presenting four new cases, we conducted a PRISMA systematic search in PubMed/MEDLINE and Embase databases using the keyword "visual snow" with specific inclusion and exclusion criteria. RESULTS: From the 855 articles identified 30 were included for the qualitative analysis. These reports covered five aspects related to Visual Snow Syndrome: epidemiology, clinical features, comorbidities, pathophysiology, and treatment. We found limited data concerning Visual Snow Syndrome's epidemiology (one study). Clinical presentation (22 articles) and the comorbidities (migraine with aura and tinnitus most often, five reports) are described in detail. The pathophysiology of Visual Snow Syndrome is only approached with hypotheses, but several neuroimaging studies have been identified (seven articles). Treatment is based on single case reports only. CONCLUSION: Data for Visual Snow Syndrome are few and not strong enough to support Visual Snow Syndrome as a medical identity. Further investigation is needed.

Headaches in the emergency department -a survey of patients' characteristics, facts and needs.

BACKGROUND AND AIM: Headache is very often the cause for seeking an emergency department (ED). However, less is known about the different diagnosis of headache disorders in the ED, their management and treatment. The aim of this survey is to analyse the management of headache patients in two different ED in Europe. METHODS: This retrospective survey was performed from September 2018 until January 2019. Patients were collected from the San Luca Hospital, Milan, Italy and the Ordensklinikum Barmherzige Schwestern, Linz, Austria. Only patients with a non-traumatic headache, as the primary reason for medical clarification, were included. Patients were analysed for their complexity and range of examination, their diagnoses, acute treatment and overall efficacy rate. RESULTS: The survey consists of 415 patients, with a mean age of 43.32 (SD ±17.72); 65% were female. Technical investigation was performed in 57.8% of patients. For acute treatment non-steroidal-anti-inflammatory drugs (NSAIDs) were the most used, whereas triptans were not given. A primary headache disorder was diagnosed in 45.3% of patients, being migraine the most common, but in 32% of cases the diagnosis was not further specified. Life-threatening secondary headaches accounted for less than 2% of cases. CONCLUSIONS: The vast majority of patients attending an ED because of headache are suffering from a primary headache disorder. Life-threatening secondary headaches are rare but seek attention. NSAIDs are by far the most common drugs for treating headaches in the ED, but not triptans.

Protein-templated gold nanoparticle synthesis: protein organization, controlled gold sequestration, and unexpected reaction products.

Emerging applications that exploit the properties of nanoparticles for biotechnology require that the nanoparticles be biocompatible or support biological recognition. These types of particles can be produced through syntheses that involve biologically relevant molecules (proteins or natural extracts, for example). Many of the protocols that rely on these molecules are performed without a clear understanding of the mechanism by which the materials are produced. We have investigated a previously described reaction in which gold nanoparticles are produced from the reaction of chloroauric acid and proteins in solution. We find that modifications to the starting conditions can alter the product from the expected solution-suspended colloids to a product where colloids are formed within a solid, fibrous protein structure. We have interrogated this synthesis, exploiting the change in products to better understand this reaction. We have evaluated the kinetics and products for 7 different proteins over a range of concentrations and temperatures. The key factor that controls the synthetic outcome (colloid or fiber) is the concentration of the protein relative to the gold concentration. We find that the observed fibrous structures are more likely to form at low protein concentrations and when hydrophilic proteins are used. An analysis of the reaction kinetics shows that AuNP formation occurs faster at lower protein (fiber-forming) concentrations than at higher protein (colloid-forming) concentrations. These results contradict traditional expectations for reaction kinetics and protein-fiber formation and are instructive of the manner in which proteins template gold nanoparticle production.