Publications by authors named "Paul Nyquist"

Brain ischemia is a major cause of neurological dysfunction and mortality worldwide. It occurs not only acutely, such as in acute ischemic stroke (AIS), but also in chronic conditions like cerebral small vessel disease (cSVD). Any other conditions resulting in brain hypoperfusion can also lead to ischemia.

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Introduction: White matter hyperintensity (WMH) is typically classified into periventricular and deep WMH (PVWMH and DWMH) based on its proximity to the ventricles. While WMH volume has been associated with the cognitive performance and decline in patients with cerebral small vessel disease, the relative contributions of PVWMH and DWMH to the cognitive profile of these patients remain unclear. Therefore, we aimed to determine the differences in association of PVWMH and DWMH with a battery of cognitive tests in a group of middle-aged population at risk for cardiovascular disease.

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  • Subcortical brain structures play a crucial role in various developmental and psychiatric disorders, and a study analyzed brain volumes in 74,898 individuals, identifying 254 genetic loci linked to these volumes, which accounted for up to 35% of variation.
  • The research included exploring gene expression in specific neural cell types, focusing on genes involved in intracellular signaling and processes related to brain aging.
  • The findings suggest that certain genetic variants not only influence brain volume but also have potential causal links to conditions like Parkinson’s disease and ADHD, highlighting the genetic basis for risks associated with neuropsychiatric disorders.
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  • Subcortical brain structures play a crucial role in various disorders, and a study analyzed the genetic basis of brain volumes in nearly 75,000 individuals of European ancestry, revealing 254 loci linked to these volumes.
  • The research identified significant gene expression in neural cells, relating to brain aging and signaling, and found that polygenic scores could predict brain volumes across different ancestries.
  • The study highlights genetic connections between brain volumes and conditions like Parkinson's disease and ADHD, suggesting specific gene expression patterns could be involved in neuropsychiatric disorders.
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  • The study investigates the relationship between sex hormones and brain health in postmenopausal women with Type 2 Diabetes who are overweight or obese, highlighting how hormonal levels may impact brain volume.* -
  • Researchers found that females with detectable levels of total testosterone had a higher brain volume-to-intracranial volume ratio, indicating a potential protective effect of testosterone on brain health, although this effect diminished after adjusting for age and body mass index.* -
  • The results underscore the complexity of brain health in relation to hormonal levels, but the study's conclusions are limited by a small sample size and low levels of some hormones.*
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  • Previous research indicates a link between lower mitochondrial DNA (mtDNA) copy number and neurodegenerative diseases, prompting investigation into the relationship between mtDNA CN in blood and Alzheimer disease endophenotypes.
  • The study involved dementia-free individuals from various community cohorts, measuring mtDNA CN and analyzing its association with cognitive function and brain MRI markers over specified timeframes.
  • Findings showed that higher mtDNA CN correlates with better cognitive performance, independent of several confounding factors, with consistent results observed in both cross-sectional and prospective analyses, although the latter showed a weaker association.
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Objective: The aim of this study was to provide the evidence base to guide interconversion of the modified Rankin Scale (mRS) and Glasgow Outcome Scale (GOS) in neurological research.

Methods: A retrospective analysis of paired mRS and GOS recordings was conducted using datasets with the following selection criteria: (1) patients had haemorrhagic stroke, (2) simultaneous mRS and GOS measurements were available, and (3) data sharing was possible. The relationship between mRS and GOS was assessed using correlation analysis.

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Candidate gene studies have identified genetic variants associated with clinical outcomes following aneurysmal subarachnoid haemorrhage (aSAH), but no genome-wide association studies have been performed to date. Here we report the results of the discovery phase of a two-stage genome-wide meta-analysis of outcome after aSAH. We identified 157 independent loci harbouring 756 genetic variants associated with outcome after aSAH (p < 1 × 10), which require validation.

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Background: Coronavirus disease (COVID-19) has led to changes in how healthcare is delivered. Here, through the administration of surveys, we evaluated telehealth use and views in US intensive care units (ICUs) during the pandemic.

Methods: From June 2020 to July 2021, voluntary, electronic surveys were provided to ICU leaders of Johns Hopkins Medical Institution (JHMI) hospitals, members of the Neurocritical Care Society (NCS) who practice in the US, and Society of Critical Care Medicine (SCCM) members practicing adult medicine.

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Background The periventricular white matter is more sensitive to the systemic hemodynamic alterations than the deep white matter because of differences in its vascular structure and systemic circulation relationship. We hypothesize that periventricular white matter hyperintensity (PVWMH) volume shows greater association than deep white matter hyperintensity (DWMH) volume with vascular properties (VPs) reflecting arterial stiffness and cardiovascular remodeling, indicators of the systemic circulation. Methods and Results A total of 426 participants (age, 59.

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Aneurysmal subarachnoid haemorrhage (aSAH) results in persistent clinical deficits which prevent survivors from returning to normal daily functioning. Only a small fraction of the variation in clinical outcome following aSAH is explained by known clinical, demographic and imaging variables; meaning additional unknown factors must play a key role in clinical outcome. There is a growing body of evidence that genetic variation is important in determining outcome following aSAH.

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  • Measures of information processing speed vary among individuals and decline with age, with studies indicating that genetic factors account for up to 67% of the variation in older adults.
  • Researchers used the Illumina HumanExome Bead Chip to analyze genetic variants' impact on the Digit-Symbol Substitution Test (DSST) scores in over 30,000 participants aged 45 and older, adjusting for age, gender, and education.
  • Significant findings included variants in the RNF19A gene among Europeans and suggestive associations for genes such as SLC22A7 and OR51A7 among African-Americans, highlighting the need for further research on the role of these genes in cognitive function.
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Efforts to develop effective neuroprotective therapies for ischemic stroke have had little success to date. One promising approach to neuroprotection is ischemic postconditioning, which utilizes brief bouts of ischemia after acute ischemic stroke to elicit neuroprotection, although the mechanism is largely unknown. As the primary components of transient ischemia are local hypoxia and acidosis, and hypoxic postconditioning has had little success, it is possible that the acidosis component may be the primary driver.

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Acute respiratory distress syndrome (ARDS) has been associated with secondary acute brain injury (ABI). However, there is sparse literature on the mechanism of lung-mediated brain injury and prevalence of ARDS-associated secondary ABI. We aimed to review and elucidate potential mechanisms of ARDS-mediated ABI from preclinical models and assess the prevalence of ABI and neurological outcome in ARDS with clinical studies.

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