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AJNR. American Journal of Neuroradiology Jul 2021Neurologic events have been reported in patients with coronavirus disease 2019 (COVID-19). However, a model-based evaluation of the spatial distribution of these events...
BACKGROUND
Neurologic events have been reported in patients with coronavirus disease 2019 (COVID-19). However, a model-based evaluation of the spatial distribution of these events is lacking.
PURPOSE
Our aim was to quantitatively evaluate whether a network diffusion model can explain the spread of small neurologic events.
DATA SOURCES
The MEDLINE, EMBASE, Scopus, and LitCovid data bases were searched from January 1, 2020, to July 19, 2020.
STUDY SELECTION
Thirty-five case series and case studies reported 317 small neurologic events in 123 unique patients with COVID-19.
DATA ANALYSIS
Neurologic events were localized to gray or white matter regions of the Illinois Institute of Technology (gray-matter and white matter) Human Brain Atlas using radiologic images and descriptions. The total proportion of events was calculated for each region. A network diffusion model was implemented, and any brain regions showing a significant association (< .05, family-wise error-corrected) between predicted and measured events were considered epicenters.
DATA SYNTHESIS
Within gray matter, neurologic events were widely distributed, with the largest number of events (∼10%) observed in the bilateral superior temporal, precentral, and lateral occipital cortices, respectively. Network diffusion modeling showed a significant association between predicted and measured gray matter events when the spread of pathology was seeded from the bilateral cerebellum (=0.51, < .001, corrected) and putamen (=0.4, = .02, corrected). In white matter, most events (∼26%) were observed within the bilateral corticospinal tracts.
LIMITATIONS
The risk of bias was not considered because all studies were either case series or case studies.
CONCLUSIONS
Transconnectome diffusion of pathology via the structural network of the brain may contribute to the spread of neurologic events in patients with COVID-19.
Topics: Brain; COVID-19; Cerebral Cortex; Gray Matter; Humans; Magnetic Resonance Imaging; White Matter
PubMed: 33888458
DOI: 10.3174/ajnr.A7113 -
Neurology India 2020The incidence and prevalence of Parkinson's (PD) are increasing rapidly in developing countries. PD is difficult to diagnose based on clinical assessment. Presently,...
The incidence and prevalence of Parkinson's (PD) are increasing rapidly in developing countries. PD is difficult to diagnose based on clinical assessment. Presently, magnetic resonance imaging (MRI) methods such as R2* and Quantitative Susceptibility Mapping (QSM) were found to be useful in diagnosing the PD based on the iron deposition in different regions of the brain. The objective of this review was to evaluate the efficacy of QSM over R2* in assessment of PD. A comprehensive literature search was made on PubMed-Medline, CINAHL, Science Direct, Scopus, Web of Science, and the Cochrane library databases for original research articles published between 2000 and 2018. Original articles that reported the efficacy of QSM and R2* in assessment of PD were included. A total of 327 studies were identified in the literature search. However, only ten studies were eligible for analysis. Of the ten studies, five studies compared the accuracy of QSM over R2* in measuring the iron deposition in different regions of brain in PD. Our review found that QSM has better accuracy in identifying iron deposition in PD patients compared to R2*. However, there is discrepancy in the results between MRI Imaging methods and Postmortem studies. Additional longitudinal research studies are needed to provide a strong evidence base for the use of MRI imaging methods such as R2*and QSM in accurately measuring iron deposition in different regions of brain and serve as biomarkers in PD.
Topics: Brain; Caudate Nucleus; Globus Pallidus; Humans; Iron; Magnetic Resonance Imaging; Parkinson Disease; Putamen; Red Nucleus; Sensitivity and Specificity; Substantia Nigra; Thalamus
PubMed: 32415005
DOI: 10.4103/0028-3886.284377 -
Frontiers in Psychiatry 2024Although schizophrenia has traditionally been interpreted as a disorder of thought, contemporary perspectives suggest that it may be more appropriate to conceptualize it...
Although schizophrenia has traditionally been interpreted as a disorder of thought, contemporary perspectives suggest that it may be more appropriate to conceptualize it as a disorder of language connectivity. The linguistic anomalies present in schizophrenia possess distinctive characteristics that, despite certain connections, are not comparable to aphasic disorders. It is proposed that these anomalies are the result of dysfunctions in verbal self-monitoring mechanisms, which may influence other neuropsychological dimensions. This study set out to examine the neuropsychological dimensions associated with alterations in the neural networks of verbal self-monitoring in schizophrenic language, based on the scientific evidence published to date. Exhaustive searches were conducted in PubMed, Web of Science, and Scopus to identify magnetic resonance studies that evaluated verbal self-monitoring mechanisms in schizophrenia. Of a total of 133 articles identified, 22 were selected for qualitative analysis. The general findings indicated alterations in frontotemporoparietal networks and in systems such as the insula, amygdala, anterior cingulate cortex, putamen, and hippocampus. Despite the heterogeneity of the data, it is concluded that language plays a fundamental role in schizophrenia and that its alterations are linked with other neuropsychological dimensions, particularly emotional and perceptual ones.
PubMed: 38501094
DOI: 10.3389/fpsyt.2024.1356726 -
Frontiers in Psychology 2012Structural magnetic resonance imaging (sMRI) studies of anxiety disorders in children and adolescents are limited. Posttraumatic stress disorder (PTSD) and obsessive...
OBJECTIVES
Structural magnetic resonance imaging (sMRI) studies of anxiety disorders in children and adolescents are limited. Posttraumatic stress disorder (PTSD) and obsessive compulsive disorder (OCD) have been best studied in this regard. We systematically reviewed structural neuroimaging findings in pediatric PTSD and OCD.
METHODS
The literature was reviewed for all sMRI studies examining volumetric parameters using PubMed, ScienceDirect, and PsychInfo databases, with no limit on the time frame of publication. Nine studies in pediatric PTSD and six in OCD were suitable for inclusion.
RESULTS
Volumetric findings were inconsistent in both disorders. In PTSD, findings suggest increased as well as decreased volumes of the prefrontal cortex (PFC) and corpus callosum; whilst in OCD studies indicate volumetric increase of the putamen, with inconsistent findings for the anterior cingulate cortex (ACC) and frontal regions.
CONCLUSIONS
Methodological differences may account for some of this inconsistency and additional volume-based studies in pediatric anxiety disorders using more uniform approaches are needed.
PubMed: 23272001
DOI: 10.3389/fpsyg.2012.00568