Post-mortem findings in Spanish patients with COVID-19; a special focus on superinfections

IntroductionWhole-body autopsies may be crucial to understand coronavirus disease 2019 (COVID-19) pathophysiology. We aimed to analyze pathological findings in a large series of full-body autopsies, with a special focus on superinfections. MethodsThis was a prospective multicenter study that included 70 COVID-19 autopsies performed between April 2020 and February 2021. Epidemiological, clinical and pathological information was collected using a standardized case report form. ResultsMedian (IQR) age was 70 (range 63.75-74.25) years and 76% of cases were males. Most patients (90%,) had at least one comorbidity prior to COVID-19 diagnosis, with vascular risk factors being the most frequent. Infectious complications were developed by 65.71% of the patients during their follow-up. Mechanical ventilation was required in most patients (75.71%) and was mainly invasive. In multivariate analyses, length of hospital stay and invasive mechanical ventilation were significantly associated with infections (p = 0.036 and p = 0.013, respectively). Necropsy findings revealed diffuse alveolar damage in the lungs, left ventricular hypertrophy in the heart, liver steatosis and pre-infection arteriosclerosis in the heart and kidneys. ConclusionOur study confirms the main necropsy histopathological findings attributed to COVID-19 in a large patient series, while underlining the importance of both comorbid conditions and superinfections in the pathology

Comparison of background EEG activity of different groups of patients with idiopathic epilepsy using Shannon spectral entropy and cluster-based permutation statistical testing.

Idiopathic epilepsy is characterized by generalized seizures with no apparent cause. One of its main problems is the lack of biomarkers to monitor the evolution of patients. The only tools they can use are limited to inspecting the amount of seizures during previous periods of time and assessing the existence of interictal discharges. As a result, there is a need for improving the tools to assist the diagnosis and follow up of these patients. The goal of the present study is to compare and find a way to differentiate between two groups of patients suffering from idiopathic epilepsy, one group that could be followed-up by means of specific electroencephalographic (EEG) signatures (intercritical activity present), and another one that could not due to the absence of these markers. To do that, we analyzed the background EEG activity of each in the absence of seizures and epileptic intercritical activity. We used the Shannon spectral entropy (SSE) as a metric to discriminate between the two groups and performed permutation-based statistical tests to detect the set of frequencies that show significant differences. By constraining the spectral entropy estimation to the [6.25-12.89) Hz range, we detect statistical differences (at below 0.05 alpha-level) between both types of epileptic patients at all available recording channels. Interestingly, entropy values follow a trend that is inversely related to the elapsed time from the last seizure. Indeed, this trend shows asymptotical convergence to the SSE values measured in a group of healthy subjects, which present SSE values lower than any of the two groups of patients. All these results suggest that the SSE, measured in a specific range of frequencies, could serve to follow up the evolution of patients suffering from idiopathic epilepsy. Future studies remain to be conducted in order to assess the predictive value of this approach for the anticipation of seizures

5-fold cross-validation (80/20).

<p>5-fold cross-validation (80/20).</p

Results of the ROC analysis for all channels.

<p>The best channels are O1 and O2 since we want to minimize the false positive rate while having a good true positive rate.</p

Result of the permutation test.

<p>Mean and confidence interval of the LSE for epileptic patients group 1 and group 2 in red and blue respectively. Interval of statistical significance in black. We show zoomed windows of significant frequencies overlapping the entire spectral range at each electrode. There exists significance in all channels at <i>p</i> = 0.0086 at least in the range of frequencies [6.25–12.89)Hz.</p

Clusters for the permutation test.

<p>Channel and frequency neighbors found by running the clustering stage of the permutation test for the local spectral entropy.</p

Linear fit of SSE vs time elapsed (<i>log</i>₁₀) from last crisis (left) and boxplot of the SSE of healthy subjects in the band of frequencies of interest (right).

<p>The fit suggests that the SSE decreases as the time from the last crisis increases. Moreover, it should be noted that the SSE values seems to asymptotically converge in time to the levels of control subjects.</p

Reading networks in children with dyslexia compared to children with ocular motility disturbances revealed by fMRI

Developmental dyslexia is a neurological disorder whose underlying biological and cognitive causes are still being investigated, a key point of great significance, because it will determine the best therapeutic approach to use.Using functional magnetic resonance imaging, we studied the brain activation pattern while reading in the most eloquent cortical areas from the two reading routes, phonological and orthographic, and the strength of their association with reading scores in 66 Spanish children aged 9-12 years divided into three groups: typically developing readers (controls), dyslexic readers and readers with monocular vision due to ocular motility disorders but with a normal reading development, to assess whether (or not) the neuronal network for reading in children with dyslexia has similarities with that in children with impaired binocular vision due to ocular motility disorders.We found that Spanish-speaking children with dyslexia have a brain circuit for reading that differs from that in children with monocular vision. Individuals with dyslexia tend to hypoactivate some of the more eloquent areas in the left hemisphere engaged by the phonological route, especially the visual word form area and left Wernicke´s area, and try to compensate this deficit by activating eloquent areas related to the orthographic route, such as the anterior part of the visual word form area and the posterior regions of both middle temporal gyri. That is, they seem to compensate for impairment in the phonological route through orthographic routes of both hemispheres.Our results suggest that ocular motility disturbances do not play a causal role in dyslexia. Dyslexia seems to be a neurological disorder that requires early recognition and evidence-based assessments and treatment to achieve the best possible outcome

Classification analysis for electrodes O1 and O2.

<p>(a) Boxplot and (b) ROC curve corresponding to the classification analysis of the two groups of epileptic patients using values from channels O1 and O2. Red lines in the boxes mark the median and edges the 25th and 75th percentiles of the data.</p

Epochs automatically marked to be rejected.

<p>The picture shows (a) one epoch (in red) of the first channel of one recorded EEG signal that does not satisfy the limits for kurtosis (rejkurt) used to identify background EEG signal; and (b) two epochs of the second channel of one recorded EEG signal that probably (jointprob) do not belong to background EEG signal.</p