Acute ischemic stroke outcomes in patients with COVID-19: a systematic review and meta-analysis

BACKGROUND

Although patients with COVID-19 have a higher risk of acute ischemic stroke (AIS), the impact on stroke outcomes remains uncertain.

AIMS

To determine the clinical outcomes of patients with AIS and COVID-19 (AIS-COVID+).

METHODS

We performed a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Our protocol was registered with the International Prospective Register of Systematic Reviews (CRD42020211977). Systematic searches were last performed on June 3, 2021 in EMBASE, PubMed, Web-of-Science, Scopus, and CINAHL Databases.

INCLUSION CRITERIA

(1) studies reporting outcomes on AIS-COVID+; (2) original articles published in 2020 or later; (3) study participants aged ≥18 years.

EXCLUSION CRITERIA

(1) case reports with <5 patients, abstracts, review articles; (2) studies analyzing novel interventions. Risk of bias was assessed using the Mixed Methods Appraisal Tool. Random-effects models estimated the pooled OR and 95% confidence intervals (95% CI) for mortality, modified Rankin Scale (mRS) score, length of stay (LOS), and discharge disposition.

RESULTS

Of the 43 selected studies, 46.5% (20/43) reported patients with AIS without COVID-19 (AIS-COVID-) for comparison. Random-effects model included 7294 AIS-COVID+ and 158 401 AIS-COVID-. Compared with AIS-COVID-, AIS-COVID+ patients had higher in-hospital mortality (OR=3.87 (95% CI 2.75 to 5.45), P<0.001), less mRS scores 0-2 (OR=0.53 (95% CI 0.46 to 0.62), P<0.001), longer LOS (mean difference=4.21 days (95% CI 1.96 to 6.47), P<0.001), and less home discharge (OR=0.31 (95% CI 0.21 to 0.47), P<0.001).

CONCLUSIONS

Patients with AIS-COVID had worse outcomes, with almost fourfold increased mortality, half the odds of mRS scores 0-2, and one-third the odds of home discharge. These findings confirm the significant impact of COVID-19 on early stroke outcomes.

A case of cryptococcoma in an immunocompetent man with polysubstance use

Cryptococcus most commonly affects the pulmonary and central nervous systems in patients who are immunocompromised. It is most likely to present as meningitis. However, it can affect immunocompetent patients in the cerebral parenchyma. Here we describe a rare case of cryptococcoma in an immunocompetent male patient who originally presented with headache and possible seizure-like activity and had IV drug use as a risk factor. Cryptococcomas are a rare manifestation of the disease, and can present due to Cryptococcus gatti. Definite diagnosis is dependent on culture of the organism and treatment includes a long course of anti-fungals.

Clinical Outcomes and Costs of Recurrent Ischemic Stroke: A Systematic Review

OBJECTIVE

Recurrent stroke patients suffer significant morbidity and mortality, representing almost 30% of the stroke population. Our objective was to determine the clinical outcomes and costs of recurrent ischemic stroke (recurrent-IS).

METHODS

Our study protocol was registered with the International Prospective Register of Systematic Reviews (CRD42020192709). Following PRISMA guidelines, our medical librarian conducted a search in EMBASE, PubMed, Web-of-Science, Scopus, and CINAHL (last performed on August 25, 2020).

INCLUSION CRITERIA

(1) Studies reporting clinical outcomes and/or costs of recurrent-IS; (2) Original research published in English in year 2010 or later; (3) Study participants aged ≥18 years.

EXCLUSION CRITERIA

(1) Case reports/studies, abstracts/posters, Editorial letters/reviews; (2) Studies analyzing interventions other than intravenous thrombolysis and thrombectomy. Four independent reviewers selected studies with review of titles/abstracts and full-text, and performed data extraction. Discrepancies were resolved by a senior independent arbitrator. Risk-of-bias was assessed using the Mixed Methods Appraisal Tool.

RESULTS

Initial search yielded 20,428 studies. Based on inclusion/exclusion criteria, 9 studies were selected, consisting of 24,499 recurrent-IS patients. In 5 studies, recurrent-IS ranged from 4.4-56.8% of the ischemic stroke cohorts at 3 or 12 months, or undefined follow-up. Mean age was 60-80 years and female proportions were 38.5-61.1%. Clinical outcomes included mortality 11.6-25.9% for in-hospital, 30-days, or 4-years (3 studies). In one study from the U.S., mean in-hospital costs were $17,121(SD-$53,693) and 1-year disability costs were $34,639(SD-$76,586) per patient.

CONCLUSIONS

Our study highlights the paucity of data on clinical outcomes and costs of recurrent-IS and identifies gaps in existing literature to direct future research.

Neurodevelopmental malformations of the cerebellum and neocortex in the Shank3 and Cntnap2 mouse models of autism

There are many mouse models of autism with broad use in neuroscience research. Genetic background can be a major contributor to the phenotype observed in any mouse model of disease, including genetic models of autism. C57BL/6 mice display spontaneous glio-neuronal heterotopia in the cerebellar vermis and neocortex which may also exist in mouse models of autism created on this background. In the present report, we document the presence of cerebellar and neocortical heterotopia in heterozygous and KO Shank3 and Cntnap2 mice which are due to the C57BL/6 genotype and discuss the role these malformations may play in research using these genetic models of autism.

Primary Literature In Clinical Neuroscience for In-Person Or Remote Instruction

Structure and function relationships in the nervous system are a major component of neuroscience education. Readings and/or discussion of lesion studies in animal models are often used to demonstrate how brain injury/damage affects specific behaviors or cognitive processes. In contrast, primary literature in clinical neuroscience is less often used to teach brain structure and function relationships and this literature often describes remarkable stories of preserved brain function despite major brain injury/lesion. Here we describe a series of published articles in clinical neuroscience that we used in an undergraduate neuroscience course that challenge the simplistic views of brain localization of function and demonstrate the dynamic and plastic properties of the brain. Discussion of these primary articles can take place in-person or remote via video conferencing platforms.

Traumatic microbleeds suggest vascular injury and predict disability in traumatic brain injury

Traumatic microbleeds are small foci of hypointensity seen on T2*-weighted MRI in patients following head trauma that have previously been considered a marker of axonal injury. The linear appearance and location of some traumatic microbleeds suggests a vascular origin. The aims of this study were to: (i) identify and characterize traumatic microbleeds in patients with acute traumatic brain injury; (ii) determine whether appearance of traumatic microbleeds predict clinical outcome; and (iii) describe the pathology underlying traumatic microbleeds in an index patient. Patients presenting to the emergency department following acute head trauma who received a head CT were enrolled within 48 h of injury and received a research MRI. Disability was defined using Glasgow Outcome Scale-Extended ≤6 at follow-up. All magnetic resonance images were interpreted prospectively and were used for subsequent analysis of traumatic microbleeds. Lesions on T2* MRI were stratified based on 'linear' streak-like or 'punctate' petechial-appearing traumatic microbleeds. The brain of an enrolled subject imaged acutely was procured following death for evaluation of traumatic microbleeds using MRI targeted pathology methods. Of the 439 patients enrolled over 78 months, 31% (134/439) had evidence of punctate and/or linear traumatic microbleeds on MRI. Severity of injury, mechanism of injury, and CT findings were associated with traumatic microbleeds on MRI. The presence of traumatic microbleeds was an independent predictor of disability (P < 0.05; odds ratio = 2.5). No differences were found between patients with punctate versus linear appearing microbleeds. Post-mortem imaging and histology revealed traumatic microbleed co-localization with iron-laden macrophages, predominately seen in perivascular space. Evidence of axonal injury was not observed in co-localized histopathological sections. Traumatic microbleeds were prevalent in the population studied and predictive of worse outcome. The source of traumatic microbleed signal on MRI appeared to be iron-laden macrophages in the perivascular space tracking a network of injured vessels. While axonal injury in association with traumatic microbleeds cannot be excluded, recognizing traumatic microbleeds as a form of traumatic vascular injury may aid in identifying patients who could benefit from new therapies targeting the injured vasculature and secondary injury to parenchyma.