Visual Hallucinations in Eye Disease and Lewy Body Disease

Objective: Visual hallucinations (VH) most commonly occur in eye disease (ED), Parkinson’s disease (PD), and Lewy body dementia (LBD). The phenomenology of VH is likely to carry important information about the brain areas within the visual system generating them. Methods: Data from five controlled cross-sectional VH studies (164 controls, 135 ED, 156 PD, 79 (PDD 48 + DLB 31) LBD) were combined and analysed. The prevalence, phenomenology, frequency, duration, and contents of VH were compared across diseases and gender. Results: Simple VH were most common in ED patients (ED 65% vs. LBD 22% vs. PD 9%, Chi-square [χ2] test: χ2=31.43, df=2, p<0.001), whilst complex VH were more common in LBD (LBD 76% vs. ED 38%, vs PD 28%, Chi-square test: χ2=96.80, df=2, p<0.001). The phenomenology of complex VH was different across diseases and gender. ED patients reported more “flowers” (ED 21% vs. LBD 6% vs. PD 0%, Chi-square test: χ2=10.04, df=2, p=0.005) and “body parts” (ED 40% vs. LBD 17% vs. PD 13%, Chi-square test: χ2=11.14, df=2, p=0.004); in contrast LBD patients reported “people” (LBD 85% vs. ED 67% vs. PD 63%, Chi-square test: χ2=6.20, df=2, p=0.045) and “animals/insects” (LBD 50% vs. PD 42% vs. ED 21%, Chi-square test: χ2=9.76, df=2, p=0.008). Males reported more “machines” (13 % vs. 2%, Chi-square test: χ2=6.94, df=1, p=0.008), whilst females reported more “family members/children” (48% vs. 29%, Chi-square test: χ2=5.10, df=1, p=0.024). Conclusions: The phenomenology of VH is likely related to disease specific dysfunctions within the visual system and to past, personal experiences.

Effects of Anxiety on Anticipation and Visual Search in Dynamic, Time-Constrained Situations

We tested the predictions of Attentional Control Theory (ACT) by examining how anxiety affects visual search strategies, performance efficiency, and performance effectiveness using a dynamic, temporal-constrained anticipation task. Higher and lower skilled players viewed soccer situations under 2 task constraints (near vs. far situation) and were tested under high (HA) and low (LA) anxiety conditions. Response accuracy (effectiveness) and response time, perceived mental effort, and eye-movements (all efficiency) were recorded. A significant increase in anxiety was evidenced by higher state anxiety ratings on the MRF-L scale. Increased anxiety led to decreased performance efficiency because response times and mental effort increased for both skill groups whereas response accuracy did not differ. Anxiety influenced search strategies, with higher skilled players showing a decrease in number of fixation locations for far situations under HA compared with LA condition when compared with lower skilled players. Findings provide support for ACT with anxiety impairing processing efficiency and, potentially, top-down attentional control across different task constraints.

Assessment of the role of LASER-Doppler in the treatment of port-wine stains in infants

BACKGROUND Port-wine stains (PWS) are malformations of capillaries in 0.3% of newborn children. The treatment of choice is by pulsed dye LASER (PDL), and requires several sessions. The efficacy of this treatment is at present evaluated on the basis of clinical inspection and of digital photographs taken throughout the treatment. LASER-Doppler imaging (LDI) is a noninvasive method of imaging the perfusion of the tissues by the microcirculatory system (capillaries). The aim of this paper is to demonstrate that LDI allows a quantitative, numerical evaluation of the efficacy of the PDL treatment of PWS. METHOD The PDL sessions were organized according to the usual scheme, every other month, from September 1, 2012, to September 30, 2013. LDI imaging was performed at the start and at the conclusion of the PDL treatment, and simultaneously on healthy skin in order to obtain reference values. The results evidenced by LDI were analyzed according to the "Wilcoxon signed-rank" test before and after each session, and in the intervals between the three PDL treatment sessions. RESULTS Our prospective study is based on 20 new children. On average, the vascularization of the PWS was reduced by 56% after three laser sessions. Compared with healthy skin, initial vascularization of PWS was 62% higher than that of healthy skin at the start of treatment, and 6% higher after three sessions. During the 2 months between two sessions, vascularization of the capillary network increased by 27%. CONCLUSION This study shows that LDI can demonstrate and measure the efficacy of PDL treatment of PWS in children. The figures obtained when measuring the results by LDI corroborate the clinical assessments and may allow us to refine, and perhaps even modify, our present use of PDL and thus improve the efficacy of the treatment.

Theta burst stimulation improves overt visual search in spatial neglect independently of attentional load

Visual neglect is considerably exacerbated by increases in visual attentional load. These detrimental effects of attentional load are hypothesised to be dependent on an interplay between dysfunctional inter-hemispheric inhibitory dynamics and load-related modulation of activity in cortical areas such as the posterior parietal cortex (PPC). Continuous Theta Burst Stimulation (cTBS) over the contralesional PPC reduces neglect severity. It is unknown, however, whether such positive effects also operate in the presence of the detrimental effects of heightened attentional load. Here, we examined the effects of cTBS on neglect severity in overt visual search (i.e., with eye movements), as a function of high and low visual attentional load conditions. Performance was assessed on the basis of target detection rates and eye movements, in a computerised visual search task and in two paper-pencil tasks. cTBS significantly ameliorated target detection performance, independently of attentional load. These ameliorative effects were significantly larger in the high than the low load condition, thereby equating target detection across both conditions. Eye movement analyses revealed that the improvements were mediated by a redeployment of visual fixations to the contralesional visual field. These findings represent a substantive advance, because cTBS led to an unprecedented amelioration of overt search efficiency that was independent of visual attentional load.

False normal Lung Clearance Index in infants with cystic fibrosis due to software algorithms.

BACKGROUND Lung clearance index (LCI), a marker of ventilation inhomogeneity, is elevated early in children with cystic fibrosis (CF). However, in infants with CF, LCI values are found to be normal, although structural lung abnormalities are often detectable. We hypothesized that this discrepancy is due to inadequate algorithms of the available software package. AIM Our aim was to challenge the validity of these software algorithms. METHODS We compared multiple breath washout (MBW) results of current software algorithms (automatic modus) to refined algorithms (manual modus) in 17 asymptomatic infants with CF, and 24 matched healthy term-born infants. The main difference between these two analysis methods lies in the calculation of the molar mass differences that the system uses to define the completion of the measurement. RESULTS In infants with CF the refined manual modus revealed clearly elevated LCI above 9 in 8 out of 35 measurements (23%), all showing LCI values below 8.3 using the automatic modus (paired t-test comparing the means, P < 0.001). Healthy infants showed normal LCI values using both analysis methods (n = 47, paired t-test, P = 0.79). The most relevant reason for false normal LCI values in infants with CF using the automatic modus was the incorrect recognition of the end-of-test too early during the washout. CONCLUSION We recommend the use of the manual modus for the analysis of MBW outcomes in infants in order to obtain more accurate results. This will allow appropriate use of infant lung function results for clinical and scientific purposes.

Accuracy of tidal breathing measurement of FloRight compared to an ultrasonic flowmeter in infants.

INTRODUCTION Monitoring breathing pattern is especially relevant in infants with lung disease. Recently, a vest-based inductive plethysmograph system (FloRight®) has been developed for tidal breathing measurement in infants. We investigated the accuracy of tidal breathing flow volume loop (TBFVL) measurements in healthy term-born infants and infants with lung disease by the vest-based system in comparison to an ultrasonic flowmeter (USFM) with a face mask. We also investigated whether the system discriminates between healthy infants and those with lung disease. METHODS Floright® measures changes in thoracoabdominal volume during tidal breathing through magnetic field changes generated by current-carrying conductor coils in an elastic vest. Simultaneous TBFVL measurements by the vest-based system and the USFM were performed at 44 weeks corrected postmenstrual age during quiet unsedated sleep. TBFVL parameters derived by both techniques and within both groups were compared. RESULTS We included 19 healthy infants and 18 infants with lung disease. Tidal volume per body weight derived by the vest-based system was significantly lower with a mean difference (95% CI) of -1.33 ml/kg (-1.73; -0.92), P < 0.001. Respiratory rate and ratio of time to peak tidal expiratory flow over total expiratory time (tPTEF/tE) did not differ between the two techniques. Both systems were able to discriminate between healthy infants and those with lung disease using tPTEF/tE. CONCLUSION FloRight® accurately measures time indices and may discriminate between healthy infants and those with lung disease, but demonstrates differences in tidal volume measurements. It may be better suited to monitor breathing pattern than for TBFVL measurements.

The influence of naturalistic, directionally non-specific motion on the spatial deployment of visual attention in right-hemispheric stroke

An impairment of the spatial deployment of visual attention during exploration of static (i.e., motionless) stimuli is a common finding after an acute, right-hemispheric stroke. However, less is known about how these deficits: a) are modulated through naturalistic motion (i.e., without directional, specific spatial features); and, b) evolve in the subacute/chronic post-stroke phase. In the present study, we investigated free visual exploration in three patient groups with subacute/chronic right-hemispheric stroke and in healthy subjects. The first group included patients with left visual neglect and a left visual field defect (VFD), the second patients with a left VFD but no neglect, and the third patients without neglect or VFD. Eye movements were measured in all participants while they freely explored a traffic scene without (static condition) and with (dynamic condition) naturalistic motion, i.e., cars moving from the right or left. In the static condition, all patient groups showed similar deployment of visual exploration (i.e., as measured by the cumulative fixation duration) as compared to healthy subjects, suggesting that recovery processes took place, with normal spatial allocation of attention. However, the more demanding dynamic condition with moving cars elicited different re-distribution patterns of visual attention, quite similar to those typically observed in acute stroke. Neglect patients with VFD showed a significant decrease of visual exploration in the contralesional space, whereas patients with VFD but no neglect showed a significant increase of visual exploration in the contralesional space. No differences, as compared to healthy subjects, were found in patients without neglect or VFD. These results suggest that naturalistic motion, without directional, specific spatial features, may critically influence the spatial distribution of visual attention in subacute/chronic stroke patients.

Rhinovirus Infections and Associated Respiratory Morbidity in Infants: A Prospective Cohort Study.

BACKGROUND Risk factors promoting rhinovirus (RV) infections are inadequately described in healthy populations, especially infants. OBJECTIVES To determine the frequency of symptomatic and asymptomatic RV infections and identify possible risk factors from host and environment among otherwise healthy infants. METHODS In a prospective birth cohort, respiratory health was assessed in 41 term-born infants by weekly telephone interviews during the first year of life, and weekly nasal swabs were collected to determine RV prevalence. In a multilevel logistic regression model, associations between prevalence and respiratory symptoms during RV infections and host/environmental factors were determined. RESULTS 27% of nasal swabs in 41 infants tested positive for RVs. Risk factors for RV prevalence were autumn months (OR=1.71, p=0.01, 95% CI 1.13-2.61), outdoor temperatures between 5-10 °C (OR=2.33, p=0.001, 95% CI 1.41-3.86), older siblings (OR=2.60, p=0.001, 95% CI 1.50-4.51) and childcare attendance (OR=1.53, p=0.07, 95% CI 0.96-2.44). 51% of RV-positive samples were asymptomatic. Respiratory symptoms during RV infections were less likely during the first three months of life (OR=0.34, p=0.003, 95% CI 0.17-0.69) and in infants with atopic mothers (OR=0.44, p=0.008, 95% CI 0.24-0.80). Increased tidal volume (OR=1.67, p=0.03, 95% CI 1.04-2.68) and outdoor temperatures between 2-5 °C (OR=2.79, p=0.02, 95% CI 1.17-6.61) were associated with more symptoms. CONCLUSIONS RVs are highly prevalent during the first year of life, and most infections are asymptomatic. Frequency of RV infections is associated with environmental factors, while respiratory symptoms during RV infections are linked to host determinants like infant age, maternal atopy, or premorbid lung function.

A study of the association between timing of solid food introduction in infants and overweight and obesity in pre-school aged children in NHANES 2003-2008

Background. Previous studies suggest an association between timing of introduction of solid food and increased risk of obesity in pre-school aged children, but no study included a representative sample of US children. We sought to examine whether there was any association between the timing of solid food introduction and overweight/obesity in pre-school aged children. Design/methods. Cross-sectional study of a nationally representative sample (N=2050) of US children aged 2 to 5 years with information on infant feeding practices and measured weight and height from the National Health and Nutrition Examination Survey 2003–2008. The main outcome measure was BMI for age and sex ≥ 85th percentile. The main exposure was timing of solid food introduction at < 4, 4–5, or ≥ 6 months of age. Binomial logistic regression was used in the analysis controlling for child's sex, birth weight and breastfeeding status as well as maternal age at birth, smoking status and socio-demographic variables. Results. Two thousand and fifty children were included in the sample; 51% male and 49% female; 57.1% Non-Hispanic White, 21.9% Hispanic, 14.0% Non-Hispanic Black, and 7% other race/ethnicity. Twenty-two percent of the children were overweight or obese. Sixty-nine percent were breastfed or fed breast milk at birth and 36% continued breastfeeding for ≥ six months. Solid foods were introduced before 4 months of age for 11.2% of the children; 30.3% received solid foods between 4 to 5 months; with 58.6% receiving solid foods at 6 months or later. Timing of solid food introduction was not associated with weight status (OR= 1.36, 95% CI [0.83–2.24]). Formula-fed infants and infants breastfed for < 4 months had increased odds of overweight and obesity (OR=1.54, 95% CI [1.05–2.27] and OR= 1.60, 95% CI [1.05–2.44], respectively) when compared to infants breastfed for ≥ 6 months. Conclusion. Timing of solid food introduction was not associated with weight status in a national sample of US children ages 2 to 5 years. More focus should be placed on promoting breastfeeding and healthy infant feeding practices as strategies to prevent obesity in children. ^

Work instability perception in a sample of psychologists

Considering work instability as a contextual stressor we designed a specific instrument to assess how it is perceived by a group of psychologists: The Perceived Uneasiness in Work Instability - Psychologists Inventory (in Spanish, IMPIL-PS). The data were collected from a 44-subject sample, both male and female, residents of the City of Buenos Aires and Greater Buenos Aires. We present data referring to sample characteristics and the areas with the greatest impact of the stressor are indicated. Recent research on work instability as a contextual stressor point out its influence on subjects' performance and behaviour.

Work instability perception in a sample of psychologists

Considering work instability as a contextual stressor we designed a specific instrument to assess how it is perceived by a group of psychologists: The Perceived Uneasiness in Work Instability - Psychologists Inventory (in Spanish, IMPIL-PS). The data were collected from a 44-subject sample, both male and female, residents of the City of Buenos Aires and Greater Buenos Aires. We present data referring to sample characteristics and the areas with the greatest impact of the stressor are indicated. Recent research on work instability as a contextual stressor point out its influence on subjects' performance and behaviour.

Work instability perception in a sample of psychologists

Considering work instability as a contextual stressor we designed a specific instrument to assess how it is perceived by a group of psychologists: The Perceived Uneasiness in Work Instability - Psychologists Inventory (in Spanish, IMPIL-PS). The data were collected from a 44-subject sample, both male and female, residents of the City of Buenos Aires and Greater Buenos Aires. We present data referring to sample characteristics and the areas with the greatest impact of the stressor are indicated. Recent research on work instability as a contextual stressor point out its influence on subjects' performance and behaviour.