Worldwide access to evidence‐based mental health literature: How useful is PubMed in Anglo‐Saxon and non‐Anglo‐Saxon countries?

The aim of this study was to verify the presence of cultural variety among the psychiatric journals available on PubMed, the major online tool for accessing literature. Data for analysis were taken from a survey of the world psychiatric journals indexed in Index Medicus 1999 (IM), the alphabetical list used by PubMed, and from the mean impact factor (IF) values of the journals. Approximately 80% of international psychiatric literature available on PubMed is published in Anglo-Saxon countries, especially in the USA (59.8% of the total). The widespread use of the English language (94.9% of all the journals) further stresses the dominance of the Anglo-Saxon cultural model, as do the mean IF values of Anglo-Saxon journals compared to non-Anglo-Saxon publications (3.252 vs. 1.693; P=0.0079). The under-representation of non-Anglo-Saxon cultural models on PubMed plays a negative role for bringing about a truly multicultural literature in psychiatry.     

Is paternal postpartum depression associated with maternal postpartum depression? Population‐based study in Brazil

OBJECTIVE: To describe the prevalence of paternal postpartum depression (PPD) as well as its association with maternal PPD. METHOD: A population-based random sample of 386 couples was assessed from the sixth to the 12th week postpartum for demographic characteristics, alcohol misuse (AUDIT) and depressive symptoms [Beck Depression Inventory (BDI)]. Logistic regression was employed to control for potential confounders. RESULTS: In the BDI, 26.3% of mothers and 11.9% of fathers scored above the selected threshold of 10. Mild maternal depression [odds ratio (OR) 3.31, 95% CI 1.52-7.20] and moderate to severe maternal depression (OR 8.44, 95% CI 3.53-20.21) were associated with paternal PPD. CONCLUSION: Paternal PPD is a clinically meaningful phenomenon. Fathers should be evaluated for mood disorders in the postpartum, especially when their partner is depressed.     

Does early treatment improve outcomes in N‐methyl‐d‐aspartate receptor encephalitis?

N‐methyl‐d ‐aspartate (NMDA) receptor encephalitis is a treatable cause of autoimmune encephalitis in both children and adults. It is still unclear if the natural history of the condition in children is altered by early treatment with immunosuppressive therapy. We looked at the outcomes of five children (two males, three females; mean age 6y 9mo, range 4–8y) who were treated empirically for autoimmune encephalitis within a brief period of presentation. Features that led clinicians to suspect autoimmune encephalitis included prominent neuropsychiatric features, movement disorder, seizures, and dysautonomic features. Immunosuppressive therapy was carried out in all cases. In this series of children, in whom the median time from symptom onset to treatment was 5 days and median length of time for follow‐up was 24 months, four out of the five (80%) recovered to their baseline. Early initiation of immunosuppressive therapy may result in improved clinical outcomes.     

What's special about task in dystonia? A voxel‐based morphometry and diffusion weighted imaging study

Numerous brain imaging studies have demonstrated structural changes in the basal ganglia, thalamus, sensorimotor cortex, and cerebellum across different forms of primary dystonia. However, our understanding of brain abnormalities contributing to the clinically well‐described phenomenon of task specificity in dystonia remained limited. We used high‐resolution magnetic resonance imaging (MRI) with voxel‐based morphometry and diffusion weighted imaging with tract‐based spatial statistics of fractional anisotropy to examine gray and white matter organization in two task‐specific dystonia forms, writer's cramp and laryngeal dystonia, and two non–task‐specific dystonia forms, cervical dystonia and blepharospasm. A direct comparison between both dystonia forms indicated that characteristic gray matter volumetric changes in task‐specific dystonia involve the brain regions responsible for sensorimotor control during writing and speaking, such as primary somatosensory cortex, middle frontal gyrus, superior/inferior temporal gyrus, middle/posterior cingulate cortex, and occipital cortex as well as the striatum and cerebellum (lobules VI‐VIIa). These gray matter changes were accompanied by white matter abnormalities in the premotor cortex, middle/inferior frontal gyrus, genu of the corpus callosum, anterior limb/genu of the internal capsule, and putamen. Conversely, gray matter volumetric changes in the non–task‐specific group were limited to the left cerebellum (lobule VIIa) only, whereas white matter alterations were found to underlie the primary sensorimotor cortex, inferior parietal lobule, and middle cingulate gyrus. Distinct microstructural patterns in task‐specific and non–task‐specific dystonias may represent neuroimaging markers and provide evidence that these two dystonia subclasses likely follow divergent pathophysiological mechanisms precipitated by different triggers. © 2014 International Parkinson and Movement Disorder Society     

Does alpha phase modulate visual target detection? Three experiments with tACS‐phase‐based stimulus presentation

In recent years, the influence of alpha (7–13 Hz) phase on visual processing has received a lot of attention. Magneto‐/encephalography (M/EEG) studies showed that alpha phase indexes visual excitability and task performance. Studies with transcranial alternating current stimulation (tACS) aim to modulate oscillations and causally impact task performance. Here, we applied right occipital tACS (O2 location) to assess the functional role of alpha phase in a series of experiments. We presented visual stimuli at different pre‐determined, experimentally controlled, phases of the entraining tACS signal, hypothesizing that this should result in an oscillatory pattern of visual performance in specifically left hemifield detection tasks. In experiment 1, we applied 10 Hz tACS and used separate psychophysical staircases for six equidistant tACS‐phase conditions, obtaining contrast thresholds for detection of visual gratings in left or right hemifield. In experiments 2 and 3, tACS was at EEG‐based individual peak alpha frequency. In experiment 2, we measured detection rates for gratings with (pseudo‐)fixed contrast. In experiment 3, participants detected brief luminance changes in a custom‐built LED device, at eight equidistant alpha phases. In none of the experiments did the primary outcome measure over phase conditions consistently reflect a one‐cycle sinusoid. However, post hoc analyses of reaction times (RT) suggested that tACS alpha phase did modulate RT for specifically left hemifield targets in both experiments 1 and 2 (not measured in experiment 3). This observation requires future confirmation, but is in line with the idea that alpha phase causally gates visual inputs through cortical excitability modulation.     

Ethnicity a risk factor? The relation between ethnicity and large‐ and small‐vessel disease in White people,Black people,and Asians within a hospital‐based population

Background: Previous studies suggest that in patients with ischaemic stroke, White people often present with large‐vessel and Black people with small‐vessel strokes. This study investigates the relation between large‐ and small‐vessel disease, and ethnicity in White, Black, and Asian patients in Amsterdam, the Netherlands. Methods: In a hospital‐based population of 668 patients ethnicity was determined by self‐identification. The relation between ethnicity and carotid stenosis, as an indicator of large‐vessel disease, was determined using univariate analysis, and adjusted for age, gender, hypertension and smoking. Subsequently the relation between ethnicity and lacunar infarcts, as a manifestation of small‐vessel disease, was investigated. Results: The odds ratio for having carotid stenosis, compared to White patients, was 0.55 (0.23–1.33) for Blacks, 0.53 (0.18–1.52) for Asians, and 0.64 (0.14–2.85) for other ethnicities. The adjusted odds ratio for a non‐White patient compared to a White patient was 0.44 (0.19–1.02) (P = 0.05). The non‐White patients more often presented with lacunar infarcts compared to Whites. Conclusion: We found an association between White patients and the presence of carotid artery stenosis. Not only in Black but also in Asian patients the association with carotid artery stenosis was substantially lower. In the non‐White population there was an association with lacunar infarcts compared to Whites.     

How does stroke restrict participation in long‐term post‐stroke survivors?

OBJECTIVE: To explore the factors determining 'restricted participation' in a selected population of long-term post-stroke survivors. MATERIALS AND METHODS: Seventy-three consecutive post-stroke inpatients were scored for mood and restriction in participation by means of self-administered questionnaires, respectively the Hospital Anxiety and Depression Scale (HADS/A; HADS/D) and London Handicap Scale (LHS). Neurological impairment and functional disability were evaluated with the Unified Neurological Stroke Scale (UNSS) and Functional Independence Measure (FIM). RESULTS: Physical independence and occupation were the most severely affected domains on the LHS. UNSS, FIM, HADS/A, HADS/D scores were significant determinants of restriction in participation at univariate analysis performed with each LHS domain. FIM score and emotional status finally emerged as the independent determinants of restricted participation for the LHS domains most related to body function (mobility, physical independence, occupation). Depression was the determinant factor for orientation and social integration. CONCLUSION: Functional disability and mood disorders may independently contribute to the restricted participation of post-stroke patients. Most of the LHS domains remain stable over time.     

How reliable are gray matter disruptions in specific reading disability across multiple countries and languages? insights from a large‐scale voxel‐based morphometry study

The neural basis of specific reading disability (SRD) remains only partly understood. A dozen studies have used voxel‐based morphometry (VBM) to investigate gray matter volume (GMV) differences between SRD and control children, however, recent meta‐analyses suggest that few regions are consistent across studies. We used data collected across three countries (France, Poland, and Germany) with the aim of both increasing sample size (236 SRD and controls) to obtain a clearer picture of group differences, and of further assessing the consistency of the findings across languages. VBM analysis reveals a significant group difference in a single cluster in the left thalamus. Furthermore, we observe correlations between reading accuracy and GMV in the left supramarginal gyrus and in the left cerebellum, in controls only. Most strikingly, we fail to replicate all the group differences in GMV reported in previous studies, despite the superior statistical power. The main limitation of this study is the heterogeneity of the sample drawn from different countries (i.e., speaking languages with varying orthographic transparencies) and selected based on different assessment batteries. Nevertheless, analyses within each country support the conclusions of the cross‐linguistic analysis. Explanations for the discrepancy between the present and previous studies may include: (1) the limited suitability of VBM to reveal the subtle brain disruptions underlying SRD; (2) insufficient correction for multiple statistical tests and flexibility in data analysis, and (3) publication bias in favor of positive results. Thus the study echoes widespread concerns about the risk of false‐positive results inherent to small‐scale VBM studies. Hum Brain Mapp 36:1741–1754, 2015. © 2015 Wiley Periodicals, Inc.     

Event‐related functional near‐infrared spectroscopy (fNIRS) based on craniocerebral correlations: Reproducibility of activation?

The purpose of the present study was to assess the retest reliability of cortical activation detected by event-related functional near-infrared spectroscopy (fNIRS) based on craniocerebral correlations. Isolated functional activation was evoked in the motor cortex by a periodically performed finger-tapping task. During 44-channel fNIRS recording, 12 subjects performed 30 trials of right and left index finger tapping in two sessions. The retest interval was set to 3 weeks. Simple correlations of the contrast t-values supplemented by scatterplots, channel-wise intraclass correlation coefficients (ICC), as well as reproducibility indices for the size and the location of the detected activation were calculated. The results at the group level showed sufficient single measure ICCs (up to 0.80) and excellent reproducibility of the size and the location (up to 89% were reproducible). Comparisons of the intersession group amplitudes demonstrate that the fNIRS signals were stable across time in a retest study design: the number of significant differences was less than randomly occurring false-positive activated channels if an alpha level of 5% is chosen. Effect size analyses indicated that the intersession amplitude differences are small (mean < 0.25). For deoxyhemoglobin and oxyhemoglobin distinct statistical power profiles were revealed regarding the activation vs. baseline contrast as well as the intersession amplitude differences, indicating a higher sensitivity of deoxyhemoglobin for local hemodynamic changes. The results suggest that sensorimotor activation assessed by event-related fNIRS based on craniocerebral correlations is sufficiently reproducible at the group level.     

Abstinence from cocaine‐self‐administration activates the nELAV/GAP ‐43 pathway in the hippocampus: A stress‐related effect?

We previously demonstrated that nELAV/GAP‐43 pathway is pivotal for learning and its hippocampal expression is up‐regulated by acute stress following repeated cocaine administration. We therefore hypothesized that abstinence‐induced stress may sustain nELAV/GAP‐43 pathway during early abstinence following 2 weeks of cocaine self‐administration. We found that contingent, but not non‐contingent, cocaine exposure selectively increases hippocampal nELAV, but not GAP‐43, expression immediately after the last self‐administration session, an effect that wanes after 24 h and that comes back 7 days later when nELAV activation becomes associated with increased expression of GAP‐43, an effect again observed only in animals self‐administering the psychostimulant. Such effect is specific for nELAV since the ubiquitous ELAV/HuR is unchanged. This nELAV profile suggests that its initial transient alteration is perhaps related to the daily administration of cocaine, while the increase in the nELAV/GAP‐43 pathway following a week of abstinence may reflect the activation of this cascade as a target of stressful conditions associated with drug‐related memories. © 2016 Wiley Periodicals, Inc.     

Activity‐dependent Wnt 7 dendritic targeting in hippocampal neurons: Plasticity‐ and tagging‐related retrograde signaling mechanism?

Wnt proteins have emerged as transmembrane signaling molecules that regulate learning and memory as well as synaptic plasticity at central synapses (Inestrosa and Arenas (2010) Nat Rev Neurosci 11:77‐86; Maguschak and Ressler (2011) J Neurosci 31:13057‐13067; Tabatadze et al. (2012) Hippocampus 22: 1228‐1241; Fortress et al. (2013) J Neurosci 33:12619‐12626). For example, there is both a training‐selective and Wnt isoform‐specific increase in Wnt 7 levels in hippocampus seven days after spatial learning in rats (Tabatadze et al. (2012) Hippocampus 22: 1228‐1241). Despite growing interest in Wnt signaling pathways in the adult brain, intracellular distribution and release of Wnt molecules from synaptic compartments as well as their influence on synaptic strength and connectivity remain less well understood. As a first step in such an analysis, we show here that Wnt 7 levels in primary hippocampal cells are elevated by potassium or glutamate activation in a time‐dependent manner. Subsequent Wnt 7 elevation in dendrites suggests selective somato‐dendritic trafficking followed by transport from dendrites to their spines. Wnt 7 elevation is also TTX‐reversible, establishing that its elevation is indeed an activity‐dependent process. A second stimulation given 6 h after the first significantly reduces Wnt 7 levels in dendrites 3 h later as compared to non‐stimulated controls suggesting activity‐dependent Wnt 7 release from dendrites and spines. In a related experiment designed to mimic the release of Wnt 7, exogenous recombinant Wnt 7 increased the number of active zones in presynaptic terminals as indexed by bassoon. This suggests the formation of new presynaptic release sites and/or presynaptic terminals. Wnt signaling inhibitor sFRP‐1 completely blocked this Wnt 7‐induced elevation of bassoon cluster number and cluster area. We suggest that Wnt 7 is a plasticity‐related protein involved in the regulation of presynaptic plasticity via a retrograde signaling mechanism as previously proposed (Routtenberg (1999) Trends in Neuroscience 22:255‐256). These findings provide support for this proposal, which offers a new perspective on the synaptic tagging mechanism (Redondo and Morris (2011) Nat Rev Neurosci 12:17‐30). © 2013 Wiley Periodicals, Inc.