Lumbar Puncture Complications: A Review of Current Literature.

PURPOSE OF REVIEW: This paper reviews the complications of lumbar puncture with a focus on post-dural puncture headache including pathophysiology, risk factors, prevention, and treatment. RECENT FINDINGS: Recent research has focused on understanding the multifactorial mechanisms of post-dural puncture headache and improving prevention and treatment strategies. Small caliber, pencil-point type needles are encouraged to minimize the risk of post-dural puncture headaches, especially in populations that are at higher risk for complication. While new medications and procedures show promise in small cohorts, conservative medical management and epidural blood patch are still the first and second-line treatments for PDPH. Post-dural puncture headache is the most frequent complication of lumbar puncture. There are both modifiable and nonmodifiable risk factors to consider when performing this procedure. Conservative medical management and procedure-based therapies exist for when complications of lumbar puncture arise.

Epidemiology, Risk Factors and Outcomes of Pneumomediastinum in Patients with Coronavirus Disease 2019: A Case-Control Study.

Background: Since the beginning of the ongoing Coronavirus Disease 2019 (COVID-19) pandemic, pneumomediastinum has been reported in patients with COVID-19 pneumonia and acute respiratory distress syndrome. It has been suggested that pneumomediastinum may portend a worse outcome in such patients although no investigation has established this association definitively. Research Question: We hypothesized that the finding of pneumomediastinum in the setting of COVID-19 disease may be associated with a worse clinical outcome. The purpose of this study was to determine if the presence of pneumomediastinum was predictive of increased mortality in patients with COVID-19. Study Design and Methods: A retrospective case-control study utilizing clinical data and imaging for COVID-19 patients seen at our institution from 3/7/2020 to 5/20/2020 was performed. 87 COVID-19 positive patients with pneumomediastinum were compared to 87 COVID-19 positive patients without pneumomediastinum and to a historical group of patients with pneumomediastinum during the same time frame in 2019. Results: The incidence of pneumomediastinum was increased more than 6-fold during the COVID-19 pandemic compared to 2019 (P = <.001). 1.5% of all COVID-19 patients and 11% of mechanically ventilated COVID-19 patients at our institution developed pneumomediastinum. Patients who developed pneumomediastinum had a significantly higher PEEP and lower P/F ratio than those who did not (P = .002 and .033, respectively). Pneumomediastinum was not found to be associated with increased mortality (P = .16, confidence interval [CI]: 0.89-2.09, 1.37). The presence of concurrent pneumothorax at the time of pneumomediastinum diagnosis was associated with increased mortality (P = .013 CI: 1.15-3.17, 1.91). Conclusion: Pneumomediastinum is not independently associated with a worse clinical prognosis in COVID-19 positive patients. The presence of concurrent pneumothorax was associated with increased mortality.

Eye-Tracking Evidence of a Maintenance Bias in Social Anxiety.

BACKGROUND: The mechanisms and triggers of the attentional bias in social anxiety are not yet fully determined, and the modulating role of personality traits is being increasingly acknowledged. AIMS: Our main purpose was to test whether social anxiety is associated with mechanisms of hypervigilance, avoidance (static biases), vigilance-avoidance or the maintenance of attention (dynamic biases). Our secondary goal was to explore the role of personality structure in shaping the attention bias. METHOD: Participants with high vs low social anxiety and different personality structures viewed pairs of faces (free-viewing eye-tracking task) representing different emotions (anger, happiness and neutrality). Their eye movements were registered and analysed for both whole-trial (static) and time-dependent (dynamic) measures. RESULTS: Comparisons between participants with high and low social anxiety levels did not yield evidence of differences in eye-tracking measures for the whole trial (latency of first fixation, first fixation direction, total dwell time), but the two groups differed in the time course of overt attention during the trial (dwell time across three successive time segments): participants with high social anxiety were slower in disengaging their attention from happy faces. Similar results were obtained using a full-sample, regression-based analysis. CONCLUSION: Our results speak in favour of a maintenance bias in social anxiety. Preliminary results indicated that personality structure may not affect the maintenance (dynamic) bias of socially anxious individuals, although depressive personality structures may favour manifestations of a (static) hypervigilance bias.

The 1-min Screening Test for Reading Problems in College Students: Psychometric Properties of the 1-min TIL.

Reading is a central cognitive domain, but little research has been devoted to standardized tests for adults. We, thus, examined the psychometric properties of the 1-min version of Teste de Idade de Leitura (Reading Age Test; 1-min TIL), the Portuguese version of Lobrot L3 test, in three experiments with college students: typical readers in Experiment 1A and B, dyslexic readers and chronological age controls in Experiment 2. In Experiment 1A, test-retest reliability and convergent validity were evaluated in 185 students. Reliability was >.70, and phonological decoding underpinned 1-min TIL. In Experiment 1B, internal consistency was assessed by presenting two 45-s versions of the test to 19 students, and performance in these versions was significantly associated (r = .78). In Experiment 2, construct validity, criterion validity and clinical utility of 1-min TIL were investigated. A multiple regression analysis corroborated construct validity; both phonological decoding and listening comprehension were reliable predictors of 1-min TIL scores. Logistic regression and receiver operating characteristics analyses revealed the high accuracy of this test in distinguishing dyslexic from typical readers. Therefore, the 1-min TIL, which assesses reading comprehension and potential reading difficulties in college students, has the necessary psychometric properties to become a useful screening instrument in neuropsychological assessment and research. Copyright © 2017 John Wiley & Sons, Ltd.

Prometaphase APCcdh1 activity prevents non-disjunction in mammalian oocytes.

The first female meiotic division (meiosis I, MI) is uniquely prone to chromosome segregation errors through non-disjunction, resulting in trisomies and early pregnancy loss. Here, we show a fundamental difference in the control of mammalian meiosis that may underlie such susceptibility. It involves a reversal in the well-established timing of activation of the anaphase-promoting complex (APC) by its co-activators cdc20 and cdh1. APC(cdh1) was active first, during prometaphase I, and was needed in order to allow homologue congression, as loss of cdh1 speeded up MI, leading to premature chromosome segregation and a non-disjunction phenotype. APC(cdh1) targeted cdc20 for degradation, but did not target securin or cyclin B1. These were degraded later in MI through APC(cdc20), making cdc20 re-synthesis essential for successful meiotic progression. The switch from APC(cdh1) to APC(cdc20) activity was controlled by increasing CDK1 and cdh1 loss. These findings demonstrate a fundamentally different mechanism of control for the first meiotic division in mammalian oocytes that is not observed in meioses of other species.

Lexical and phonological processes in dyslexic readers: evidence from a visual lexical decision task.

The aim of the present study was to investigate whether reading failure in the context of an orthography of intermediate consistency is linked to inefficient use of the lexical orthographic reading procedure. The performance of typically developing and dyslexic Portuguese-speaking children was examined in a lexical decision task, where the stimulus lexicality, word frequency and length were manipulated. Both lexicality and length effects were larger in the dyslexic group than in controls, although the interaction between group and frequency disappeared when the data were transformed to control for general performance factors. Children with dyslexia were influenced in lexical decision making by the stimulus length of words and pseudowords, whereas age-matched controls were influenced by the length of pseudowords only. These findings suggest that non-impaired readers rely mainly on lexical orthographic information, but children with dyslexia preferentially use the phonological decoding procedure--albeit poorly--most likely because they struggle to process orthographic inputs as a whole such as controls do. Accordingly, dyslexic children showed significantly poorer performance than controls for all types of stimuli, including words that could be considered over-learned, such as high-frequency words. This suggests that their orthographic lexical entries are less established in the orthographic lexicon.

APCcdh1 activity in mouse oocytes prevents entry into the first meiotic division.

Fully grown mammalian oocytes maintain a prophase I germinal-vesicle stage arrest in the ovary for extended periods before a luteinizing hormone surge induces entry into the first meiotic division. Cdh1 is an activator of the anaphase-promoting complex (APC) and APCcdh1 is normally restricted to late M to early G1 phases of the cell cycle. Here, we find that APCcdh1 is active in mouse oocytes and is necessary to maintain prophase arrest.

Essential CDK1-inhibitory role for separase during meiosis I in vertebrate oocytes.

Separase not only triggers anaphase of meiosis I by proteolytic cleavage of cohesin on chromosome arms, but in vitro vertebrate separase also acts as a direct inhibitor of cyclin-dependent kinase 1 (Cdk1) on liberation from the inhibitory protein, securin. Blocking separase-Cdk1 complex formation by microinjection of anti-separase antibodies prevents polar-body extrusion in vertebrate oocytes. Importantly, proper meiotic maturation is rescued by chemical inhibition of Cdk1 or expression of Cdk1-binding separase fragments lacking cohesin-cleaving activity.

Electrophysiological correlates of impaired reading in dyslexic pre-adolescent children.

In this study, event related potentials (ERPs) were used to investigate the extent to which dyslexics (aged 9-13 years) differ from normally reading controls in early ERPs, which reflect prelexical orthographic processing, and in late ERPs, which reflect implicit phonological processing. The participants performed an implicit reading task, which was manipulated in terms of letter-specific processing, orthographic familiarity, and phonological structure. Comparing consonant- and symbol sequences, the results showed significant differences in the P1 and N1 waveforms in the control but not in the dyslexic group. The reduced P1 and N1 effects in pre-adolescent children with dyslexia suggest a lack of visual specialization for letter-processing. The P1 and N1 components were not sensitive to the familiar vs. less familiar orthographic sequence contrast. The amplitude of the later N320 component was larger for phonologically legal (pseudowords) compared to illegal (consonant sequences) items in both controls and dyslexics. However, the topographic differences showed that the controls were more left-lateralized than the dyslexics. We suggest that the development of the mechanisms that support literacy skills in dyslexics is both delayed and follows a non-normal developmental path. This contributes to the hemispheric differences observed and might reflect a compensatory mechanism in dyslexics.

The interaction between surface color and color knowledge: behavioral and electrophysiological evidence.

In this study, we used event-related potentials (ERPs) to evaluate the contribution of surface color and color knowledge information in object identification. We constructed two color-object verification tasks - a surface and a knowledge verification task - using high color diagnostic objects; both typical and atypical color versions of the same object were presented. Continuous electroencephalogram was recorded from 26 subjects. A cluster randomization procedure was used to explore the differences between typical and atypical color objects in each task. In the color knowledge task, we found two significant clusters that were consistent with the N350 and late positive complex (LPC) effects. Atypical color objects elicited more negative ERPs compared to typical color objects. The color effect found in the N350 time window suggests that surface color is an important cue that facilitates the selection of a stored object representation from long-term memory. Moreover, the observed LPC effect suggests that surface color activates associated semantic knowledge about the object, including color knowledge representations. We did not find any significant differences between typical and atypical color objects in the surface color verification task, which indicates that there is little contribution of color knowledge to resolve the surface color verification. Our main results suggest that surface color is an important visual cue that triggers color knowledge, thereby facilitating object identification.

Does emotional valence modulate word recognition? A behavioral study manipulating frequency and arousal.

Effects of emotional valence have been observed in lexical decision tasks, suggesting that valence information modulates early word recognition. However, is still unclear the processing advantage of the different valence categories, and how these advantages might be modulated by word frequency and arousal. To clarify this question, a lexical decision task was designed using emotional words as stimuli. Emotional words were divided into three categories: 60 positive, 60 negative, and 60 neutral words. Word frequency was manipulated into low and high conditions and arousal was controlled among experimental conditions (word valence and frequency). In the first experiment, 54 participants performed the task with a maximum stimuli exposure time of 2000 ms. In a follow-up experiment, 42 participants performed the same task with two shorter fixed time exposures (150 ms and 300 ms). The results were similar between experiments: positive words were recognized faster and negative words were recognized slower than neutral ones. Furthermore, this valence effect was modulated by word frequency, affecting only words that take longer to be recognized (low-frequency words). However, the valence by frequency interaction was attenuated for high-arousal words when the pressure to respond was high (short exposure time - 150 ms). Overall, the results confirm that the emotional status of a word can affect word processing at early stages when automatic processes are taking place.

Nutcracker Syndrome: A Cause of Hematuria and Low Back Pain in Young Patients.

Nutcracker syndrome is a clinical condition in which there is compression of the left renal vein in its path between the abdominal aorta and the superior mesenteric artery. This phenomenon can cause abdominal or low back pain and hematuria. It is a rare clinical entity, although probably underdiagnosed. The diagnosis is essentially clinical and based on imaging, but necessarily a diagnosis of exclusion. We present the case of a 21-year-old boy who came to the Emergency Department with hematuria and low back pain. After exhaustive study and exclusion of other possible clinical entities, the diagnosis was confirmed to be nutcracker syndrome. Despite its usually benign expression, this entity should not be forgotten in the diagnostic process of cases of hematuria and low back pain, especially in young patients.

Component processes subserving rapid automatized naming in dyslexic and non-dyslexic readers.

The current study investigated which time components of rapid automatized naming (RAN) predict group differences between dyslexic and non-dyslexic readers (matched for age and reading level), and how these components relate to different reading measures. Subjects performed two RAN tasks (letters and objects), and data were analyzed through a response time analysis. Our results demonstrated that impaired RAN performance in dyslexic readers mainly stem from enhanced inter-item pause times and not from difficulties at the level of post-access motor production (expressed as articulation rates). Moreover, inter-item pause times account for a significant proportion of variance in reading ability in addition to the effect of phonological awareness in the dyslexic group. This suggests that non-phonological factors may lie at the root of the association between RAN inter-item pauses and reading ability. In normal readers, RAN performance was associated with reading ability only at early ages (i.e. in the reading-matched controls), and again it was the RAN inter-item pause times that explain the association.

The influence of color information on the recognition of color diagnostic and noncolor diagnostic objects.

In the present study, the authors explore in detail the level of visual object recognition at which perceptual color information improves the recognition of color diagnostic and noncolor diagnostic objects. To address this issue, 3 object recognition tasks with different cognitive demands were designed: (a) an object verification task; (b) a category verification task; and (c) a name verification task. The authors found that perceptual color information improved color diagnostic object recognition mainly in tasks for which access to the semantic knowledge about the object was necessary to perform the task; that is, in category and name verification. In contrast, the authors found that perceptual color information facilitates noncolor diagnostic object recognition when access to the object's structural description from long-term memory was necessary--that is, object verification. In summary, the present study shows that the role of perceptual color information in object recognition is dependent on color diagnosticity.

Object naming in dyslexic children: more than a phonological deficit.

In the present study, the authors investigate how some visual factors related to early stages of visual-object naming modulate naming performance in dyslexia. The performance of dyslexic children was compared with 2 control groups-normal readers matched for age and normal readers matched for reading level-while performing a discrete naming task in which color and dimensionality of the visually presented objects were manipulated. The results showed that 2-dimensional naming performance improved for color representations in control readers but not in dyslexics. In contrast to control readers, dyslexics were also insensitive to the stimulus's dimensionality. These findings are unlikely to be explained by a phonological processing problem related to phonological access or retrieval but suggest that dyslexics have a lower capacity for coding and decoding visual surface features of 2-dimensional representations or problems with the integration of visual information stored in long-term memory.

Reading Comprehension Predictors in European Portuguese Adults.

Research on the predictors of reading comprehension has been largely focused on school-aged children and mainly in opaque orthographies, hindering the generalization of the results to adult populations and more transparent orthographies. In the present study, we aim to test two versions of the Simple View of Reading (SVR): the original model and an extended version, including reading fluency and vocabulary. Additional mediation models were analyzed to verify if other reading comprehension predictors (rapid automatized naming, phonological decoding, phonological awareness, morphological awareness, and working memory) have direct effects or if they are mediated through word reading and reading fluency. A sample of 67 typical adult Portuguese readers participated in this study. The SVR model accounted for 27% of the variance in reading comprehension, with oral language comprehension displaying a larger contribution than word reading. In the extended SVR model, reading fluency and vocabulary provided an additional and significant contribution of 7% to the explained variance. Moreover, vocabulary influenced reading comprehension directly and indirectly, via oral language comprehension. In the final mediation model, the total mediation hypothesis was rejected, and only morphological awareness showed a direct effect on reading comprehension. These results provide preliminary evidence that the SVR (with the possible addition of vocabulary) might be a reliable model to explain reading comprehension in adult typical readers in a semitransparent orthography. Furthermore, oral language comprehension and vocabulary were the best predictors in the study, suggesting that remediation programs addressing reading comprehension in adults should promote these abilities.

Orthographic depth and its impact on universal predictors of reading: a cross-language investigation.

Alphabetic orthographies differ in the transparency of their letter-sound mappings, with English orthography being less transparent than other alphabetic scripts. The outlier status of English has led scientists to question the generality of findings based on English-language studies. We investigated the role of phonological awareness, memory, vocabulary, rapid naming, and nonverbal intelligence in reading performance across five languages lying at differing positions along a transparency continuum (Finnish, Hungarian, Dutch, Portuguese, and French). Results from a sample of 1,265 children in Grade 2 showed that phonological awareness was the main factor associated with reading performance in each language. However, its impact was modulated by the transparency of the orthography, being stronger in less transparent orthographies. The influence of rapid naming was rather weak and limited to reading and decoding speed. Most predictors of reading performance were relatively universal across these alphabetic languages, although their precise weight varied systematically as a function of script transparency.

The influence of surface color information and color knowledge information in object recognition.

In order to clarify whether the influence of color knowledge information in object recognition depends on the presence of the appropriate surface color, we designed a name-object verification task. The relationship between color and shape information provided by the name and by the object photo was manipulated in order to assess color interference independently of shape interference. We tested three different versions for each object: typically colored, black and white, and nontypically colored. The response times on the nonmatching trials were used to measure the interference between the name and the photo. We predicted that the more similar the name and the photo are, the longer it would take to respond. Overall, the color similarity effect disappeared in the black-and-white and nontypical color conditions, suggesting that the influence of color knowledge on object recognition depends on the presence of the appropriate surface color information.

Visual rapid naming and phonological abilities: different subtypes in dyslexic children.

One implication of the double-deficit hypothesis for dyslexia is that there should be subtypes of dyslexic readers that exhibit rapid naming deficits with or without concomitant phonological processing problems. In the current study, we investigated the validity of this hypothesis for Portuguese orthography, which is more consistent than English orthography, by exploring different cognitive profiles in a sample of dyslexic children. In particular, we were interested in identifying readers characterized by a pure rapid automatized naming deficit. We also examined whether rapid naming and phonological awareness independently account for individual differences in reading performance. We characterized the performance of dyslexic readers and a control group of normal readers matched for age on reading, visual rapid naming and phonological processing tasks. Our results suggest that there is a subgroup of dyslexic readers with intact phonological processing capacity (in terms of both accuracy and speed measures) but poor rapid naming skills. We also provide evidence for an independent association between rapid naming and reading competence in the dyslexic sample, when the effect of phonological skills was controlled. Altogether, the results are more consistent with the view that rapid naming problems in dyslexia represent a second core deficit rather than an exclusive phonological explanation for the rapid naming deficits. Furthermore, additional non-phonological processes, which subserve rapid naming performance, contribute independently to reading development.

Reading and reading-related skills in adults with dyslexia from different orthographic systems: a review and meta-analysis.

An individual diagnosed with dyslexia in childhood typically remains dyslexic throughout his/her life. However, the cognitive profile of adults with dyslexia has been less explored than that of children. This meta-analytic study is intended to clarify three questions: (1) To what extent, and in what manner, do adults with reading difficulties (dyslexia) differ from typical adult readers in measures of reading and writing competence and related cognitive skills?; (2) To what extent do speed measures pose a greater challenge than accuracy measures in an adult population that has already had years of print exposure?; and (3) To what extent does orthographic transparency modulate the reading profile of adults with dyslexia? A total of 178 studies comparing adults with dyslexia and matched controls were reviewed. The results showed that adults with dyslexia exhibited poor performance on almost all reading and writing tasks expressed by very large effect sizes (range 1.735 ≤ d ≤ 2.034), except for reading comprehension (d = 0.729). Deficits in reading- and writing-related variables are also present but with a lower expression (range 0.591 ≤ d ≤ 1.295). These difficulties are exacerbated for speed measures, especially for word and pseudoword reading, phonological awareness and orthographic knowledge. Orthographic transparency proved to be a significant moderator of dyslexic deficits in word and pseudoword reading, reading comprehension, spelling and phonological awareness, with the expression of the deficits being weaker on transparent-as opposed to intermediate and opaque-orthographies. Overall, the meta-analysis shows that reading and writing difficulties persist in adulthood and are more pronounced in speed measures. Moreover, symptoms are more severe for reading and writing than they are for measures tapping into the cognitive processes underlying reading skills. Orthographic transparency has a significant effect on the manifestation of dyslexia, with dyslexia symptoms being less marked on transparent orthographies. In addition, phonological awareness seems to be a minor problem in adulthood, especially for transparent orthographies.