[Safety of patient care on an interprofessional training ward in visceral surgery]

BACKGROUND

Interprofessional training wards (ITW) are increasingly being integrated into teaching and training concepts in visceral surgery clinics.

OBJECTIVE

How safe is patient care on an ITW in visceral surgery?

MATERIAL AND METHODS

Data collection took place from November 2021 to December 2022. In this nonrandomized prospective evaluation study the frequency and severity of adverse events (AE) in 3 groups of 100 patients each in a tertiary referral center hospital for visceral surgery were investigated. The groups consisted of patients on the ITW and on the conventional ward before and after implementation of the ITW. The Global Trigger Tool (GTT) was used to search for AE. Simultaneously, a survey of the treatment was conducted according to the Picker method to measure patient reported outcome.

RESULTS

Baseline characteristics and clinical outcome parameters of the patients in the three groups were comparable. The GTT analysis found 74 nonpreventable and 5 preventable AE in 63 (21%) of the patients and 12 AE occurred before the hospital stay. During the hospital stay 50 AE occurred in the operating theater and 17 on the conventional ward. None of the five preventable AE (in 1.7% of the patients) was caused by the treatment on the ITW. Patients rated the safety on the ITW better than in 90% of the hospitals included in the Picker benchmark cohort and as good as on the normal ward.

CONCLUSION

The GTT-based data as well as from the patients' point of view show that patient care on a carefully implemented ITW in visceral surgery is safe.

Association between Neuron-Specific Enolase, Memory Function, and Postoperative Delirium after Transfemoral Aortic Valve Replacement

INTRODUCTION

Although transfemoral aortic valve replacement (TAVR) is a safe treatment for elderly patients with severe aortic valve stenosis, postoperative microembolism has been described. In this secondary endpoint analysis of the POST-TAVR trial, we aimed to investigate whether changes in neuron-specific enolase (NSE)-a biomarker of neuronal damage-are associated with changes in memory function or postoperative delirium (POD).

MATERIALS AND METHODS

This was a prospective single-center study enrolling patients undergoing elective TAVR. Serum NSE was measured before and 24 h after TAVR. POD was diagnosed using CAM-ICU testing. Memory function was assessed before TAVR and before hospital discharge using the "Consortium to Establish a Registry for Alzheimer's Disease" (CERAD) word list and the digit span task (DST) implemented in "∆elta-App".

RESULTS

Subjects' median age was 82 years (25th to 75th percentile: 77.5-85.0), 42.6% of subjects were women. CERAD scores significantly increased from pre- to post-TAVR, with p < 0.001. POD occurred in 4.4% (6/135) of subjects at median 2 days after TAVR. After TAVR, NSE increased from a median of 1.85 ng/mL (1.30-2.53) to 2.37 ng/mL (1.69-3.07), p < 0.001. The median increase in NSE was 40.4% (13.1-138.0) in patients with POD versus 17.3% (3.3-43.4) in those without POD (p = 0.17).

CONCLUSIONS

Memory function improved after TAVR, likely due to learning effects, with no association to change in NSE. Patients with POD appear to have significantly higher postoperative levels of NSE compared to patients without POD after TAVR. This finding suggests that neuronal damage, as indicated by NSE elevation, may not significantly impair assessed memory function after TAVR.

NT-proBNP/urine hepcidin-25 ratio and cardiorenal syndrome type 1 in patients with severe symptomatic aortic stenosis

Background: This study aimed to determine whether novel and conventional cardiorenal biomarkers in patients before transcatheter aortic valve implantation may be associated with cardiorenal syndrome (CRS) type 1. Methods: Serum NT-proBNP and urine biomarkers (hepcidin-25, NGAL, IL-6) were measured before and 24 h after transcatheter aortic valve implantation. Results: 16/95 patients had CRS type 1. Those patients had longer length of stay in hospital (12.5 [9.0-16.0] vs 9.0 [8-12] days; p = 0.025) and were more frequently readmitted to hospital within 6 months after discharge (46.7 vs 15.6%; odds ratio: 4.7; 95% CI: 1.5-15.5; p = 0.007). The NT-proBNP/urine hepcidin-25 ratio (odds ratio: 2.89; 95% CI: 1.30-6.41; p = 0.009) was an independent modifier of CRS type 1. Conclusion: The NT-proBNP/urine hepcidin-25 ratio appears to be a modifier of risk of CRS type 1.

Weight a minute: the smaller and more immature, the more predictable the autonomic regulation?

AIM

To investigate the relation between autonomic regulation, measured using heart rate variability (HRV), body weight and degree of prematurity in infants. Further to assess utility to include body weight in a machine learning-based sepsis prediction algorithm.

METHODS

Longitudinal cohort study including 378 infants hospitalised in two neonatal intensive care units. Continuous vital sign data collection was performed prospectively from the time of NICU admission to discharge. Clinically relevant events were annotated retrospectively. HRV described using sample entropy of inter-beat intervals and assessed for its correlation with body weight measurements and age. Weight values were then added to a machine learning-based algorithm for neonatal sepsis detection.

RESULTS

Sample entropy showed a positive correlation with increasing body weight and postconceptual age. Very low birth weight infants exhibited significantly lower HRV compared to infants with a birth weight >1500g. This persisted when reaching similar weight and at the same postconceptual age. Adding body weight measures did not significantly change the algorithm's ability to predict sepsis.

CONCLUSION

We reveal a positive correlation of HRV with increasing body weight and maturation in infants. Restricted HRV, proven helpful in detecting acute events such as neonatal sepsis, might reflect prolonged impaired development of autonomic control.

Vital sign-based detection of sepsis in neonates using machine learning

AIM

Sepsis is a leading cause of morbidity and mortality in neonates. Early diagnosis is key but difficult due to non-specific signs. We investigate the predictive value of machine learning-assisted analysis of non-invasive, high frequency monitoring data and demographic factors to detect neonatal sepsis.

METHODS

Single centre study, including a representative cohort of 325 infants (2866 hospitalisation days). Personalised event timelines including interventions and clinical findings were generated. Time-domain features from heart rate, respiratory rate and oxygen saturation values were calculated and demographic factors included. Sepsis prediction was performed using Naïve Bayes algorithm in a maximum a posteriori framework up to 24 h before clinical sepsis suspicion.

RESULTS

Twenty sepsis cases were identified. Combining multiple vital signs improved algorithm performance compared to heart rate characteristics alone. This enabled a prediction of sepsis with an area under the receiver operating characteristics curve of 0.82, up to 24 h before clinical sepsis suspicion. Moreover, 10 h prior to clinical suspicion, the risk of sepsis increased 150-fold.

CONCLUSION

The present algorithm using non-invasive patient data provides useful predictive value for neonatal sepsis detection. Machine learning-assisted algorithms are promising novel methods that could help individualise patient care and reduce morbidity and mortality.

The cerebrospinal fluid proteome of preterm infants predicts neurodevelopmental outcome

BACKGROUND

Survival rate increases for preterm infants, but long-term neurodevelopmental outcome predictors are lacking. Our primary aim was to determine whether a specific proteomic profile in cerebrospinal fluid (CSF) of preterm infants differs from that of term infants and to identify novel biomarkers of neurodevelopmental outcome in preterm infants.

METHODS

Twenty-seven preterm infants with median gestational age 27 w + 4 d and ten full-term infants were enrolled prospectively. Protein profiling of CSF were performed utilizing an antibody suspension bead array. The relative levels of 178 unique brain derived proteins and inflammatory mediators, selected from the Human Protein Atlas, were measured.

RESULTS

The CSF protein profile of preterm infants differed from that of term infants. Increased levels of brain specific proteins that are associated with neurodevelopment and neuroinflammatory pathways made up a distinct protein profile in the preterm infants. The most significant differences were seen in proteins involved in neurodevelopmental regulation and synaptic plasticity, as well as components of the innate immune system. Several proteins correlated with favorable outcome in preterm infants at 18-24 months corrected age. Among the proteins that provided strong predictors of outcome were vascular endothelial growth factor C, Neurocan core protein and seizure protein 6, all highly important in normal brain development.

CONCLUSION

Our data suggest a vulnerability of the preterm brain to postnatal events and that alterations in protein levels may contribute to unfavorable neurodevelopmental outcome.

Neonatal sepsis prediction through clinical decision support algorithms: A systematic review

AIM

To systematically summarise the current evidence of employing clinical decision support algorithms (CDSAs) using non-invasive parameters for sepsis prediction in neonates.

METHODS

A comprehensive search in PubMed, CENTRAL and EMBASE was conducted. Screening, data extraction and risk of bias were performed by two authors. The certainty of the evidence was assessed using GRADE.

PROSPERO ID

CRD42020205143.

RESULTS

After abstract and full-text screening, 36 studies comprising 18,096 infants were included. Most CDSAs evaluated heart rate (HR)-based parameters. Two publications derived from one randomised-controlled trial assessing HR characteristics reported significant reduction in 30-day septicaemia-related mortality. Thirty-four non-randomised studies found promising yet inconclusive results.

CONCLUSION

Heart rate-based parameters are reliable components of CDSAs for sepsis prediction, particularly in combination with additional vital signs and demographics. However, inconclusive evidence and limited standardisation restricts clinical implementation of CDSAs outside of a controlled research environment. Further experimentation and comparison of parameter combinations and testing of new CDSAs are warranted.

The rhythm of a preterm neonate's life: ultradian oscillations of heart rate, body temperature and sleep cycles

The objectives are to characterize oscillations of physiological functions such as heart rate and body temperature, as well as the sleep cycle from behavioral states in generally stable preterm neonates during the first 5 days of life. Heart rate, body temperature as well as behavioral states were collected during a daily 3-h observation interval in 65 preterm neonates within the first 5 days of life. Participants were born before 32 weeks of gestational age or had a birth weight below 1500 g; neonates with asphyxia, proven sepsis or malformation were excluded. In total 263 observation intervals were available. Heart rate and body temperature were analyzed with mathematical models in the context of non-linear mixed effects modeling, and the sleep cycles were characterized with signal processing methods. The average period length of an oscillation in this preterm neonate population was 159 min for heart rate, 290 min for body temperature, and the average sleep cycle duration was 19 min. Oscillation of physiological functions as well as sleep cycles can be characterized in very preterm neonates within the first few days of life. The observed parameters heart rate, body temperature and sleep are running in a seemingly uncorrelated pace at that stage of development. Knowledge about such oscillations may help to guide nursing and medical care in these neonates as they do not yet follow a circadian rhythm.

Multichannel Esophageal Heart Rate Monitoring of Preterm Infants

OBJECTIVE

Autonomic dysregulation in preterm infants requires continuous monitoring of vital signs such as heart rate over days to months. Unfortunately, common surface electrodes are prone to electrocardiography (ECG) signal artifacts and cause serious skin irritations during long-term use. In contrast, esophageal ECG is known to be very sensitive due to the proximity of electrodes and heart and insensitive to external influences. This study addresses if multichannel esophageal ECG qualifies for heart rate monitoring in preterm infants.

METHODS

We recorded esophageal leads with a multi-electrode gastric feeding tube in a clinical study with 13 neonates and compared the heartbeat detection performance with standard surface leads. A computationally simple and versatile ECG wave detection algorithm was used.

RESULTS

Multichannel esophageal ECG manifested heartbeat sensitivity and positive predictive value greater than 98.5% and significant less false negative (FN) ECG waves as compared to surface ECG due to site-typical electrode motion artifacts. False positive bradycardia as indicated with more than 13 consecutive FN ECG waves was equally expectable in esophageal and surface channels. No adverse events were reported for the multi-electrode gastric feeding tube.

CONCLUSION

Heart rate monitoring of preterm infants with multiple esophageal electrodes is considered as feasible and reliable. Less signal artifacts will improve the detection of bradycardia, which is crucial for immediate interventions, and reduce alarm fatigue.

SIGNIFICANCE

Due to the possibility to integrate the multichannel ECG into a gastric feeding tube and meanwhile omit harmful skin electrodes, the presented system has great potential to facilitate future intensive care of preterm infants.

Caffeine preserves quiet sleep in preterm neonates

Caffeine is widely used in preterm neonates suffering from apnea of prematurity (AOP), and it has become one of the most frequently prescribed medications in neonatal intensive care units. Goal of this study is to investigate how caffeine citrate treatment affects sleep-wake behavior in preterm neonates. The observational study consists of 64 preterm neonates during their first 5 days of life with gestational age (GA) <32 weeks or very low birthweight of < 1500 g. A total of 52 patients treated with caffeine citrate and 12 patients without caffeine citrate were included. Sleep-wake behavior was scored in three stages: active sleep, quiet sleep, and wakefulness. Individual caffeine concentration of every neonate was simulated with a pharmacokinetic model. In neonates with GA ≥ 28 weeks, wakefulness increased and active sleep decreased with increasing caffeine concentrations, whereas quiet sleep remained unchanged. In neonates with GA < 28 weeks, no clear caffeine effects on sleep-wake behavior could be demonstrated. Caffeine increases fraction of wakefulness, alertness, and most probably also arousability at cost of active but not quiet sleep in preterm neonates. As such, caffeine should therefore not affect time for physical and cerebral regeneration during sleep in preterm neonates.

Comparison of MICRO-ID Listeria Method with Conventional Biochemical Methods for Identification of Listeria Isolated From Food and Environmental Samples: Collaborative Study

Fourteen laboratories participated in a collaborative study to evaluate the ability of the MICRO-ID Listeria identification method to correctly identify Listeria isolated from food and environmental sources. Each collaborator received 60 isolates consisting of 51 Listeria and 9 non-Listeria cultures. All isolates were identified by conventional biochemical analyses in the principal laboratory. Cultures were checked for purity by Gram staining and examined for oxidase and catalase activities. Only Gram positive, oxidase negative, catalase positive cultures were tested with the method. Colonies from trypticase soy agar with 0.6% yeast extract were suspended in 4.6 ml_ physiological saline to a MacFarland No. 1 turbidity standard and used to inoculate the test strip. In addition, the hemolytic reaction of each isolate was determined by using the Christie-Atkins-Munch-Peterson (CAMP) test and by stabbing sheep blood agar. Identification of Listeria is based on the octal code obtained from the strip and the hemolytic reaction of the isolate. The MICRO-ID Listeria method agreed with conventional biochemical identification for 98.0% of L. monocytogenes, 77.1% of L. seeligeri, 98.0% of L ivanovii, 96.4% of L. grayi/L. murrayi, 73.9% of L. welshimeri, and 100% of L innocua isolates. A large percentage of errors in identification of the L. seeligeri and L ivanovii cultures was caused by inaccurate reading of the CAMP and hemolysis tests rather than errors in the test strip. The method was adopted first action by AOAC International.

The time course of distractor-based response activation with predictable and unpredictable target onset

Electrophysiological recording in a temporal flanker task (i.e., distractors preceding the targets) has demonstrated that distractor processing is adjusted to the overall utility of the distractors. Under high utility, that is, distractors are predictive of the target/response, distractors immediately activate the corresponding response (as indicated by the lateralized readiness potential, LRP). This activation has been shown to be markedly postponed when the target predictably occurs delayed. To investigate the occurrence and time course of distractor-related response activation under conditions of unpredictable target onset, we randomly varied the stimulus-onset asynchrony (SOA) between distractors and targets and recorded the distractor-evoked LRP. When the distractor utility was high, an LRP occurred shortly after distractor presentation. In case of a long SOA the time course of this LRP was characterized by a drop back to baseline and a subsequent re-activation that reached a substantial level before target onset. These results suggest that distractor processing is characterized by sophisticated adjustments to experienced utility and temporal constraints of the task as well as by further control processes that regulate premature response activation.

Beta-blockers for prevention and treatment of retinopathy of prematurity in preterm infants

BACKGROUND

Retinopathy of prematurity (ROP) is a vision-threatening disease of preterm neonates. The use of beta-adrenergic blocking agents (beta-blockers), which modulate the vasoproliferative retinal process, may reduce the progression of ROP or even reverse established ROP.

OBJECTIVES

To determine the effect of beta-blockers on short-term structural outcomes, long-term functional outcomes, and the need for additional treatment, when used either as prophylaxis in preterm infants without ROP, stage 1 ROP (zone I), or stage 2 ROP (zone II) without plus disease or as treatment in preterm infants with at least prethreshold ROP.

SEARCH METHODS

We searched the Cochrane Neonatal Review Group Specialized Register; CENTRAL (in the Cochrane Library Issue 7, 2017); Embase (January 1974 to 7 August 2017); PubMed (January 1966 to 7 August 2017); and CINAHL (January 1982 to 7 August 2017). We checked references and cross-references and handsearched abstracts from the proceedings of the Pediatric Academic Societies Meetings.

SELECTION CRITERIA

We considered for inclusion randomised or quasi-randomised clinical trials that used beta-blockers for prevention or treatment of ROP in preterm neonates of less than 37 weeks' gestational age.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane and the Cochrane Neonatal Review Group. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included three randomised trials (N = 366) in this review. Two of these studies were at high risk of bias. All studies reported on prevention of ROP and compared oral propranolol with placebo or no treatment. We found no trials assessing beta-blockers in infants with established stage 2 or higher ROP with plus disease.In one trial, study medication was started after one week of life, i.e. prior to the first ROP screening. The other two trials included preterm infants if they had stage 2 or lower ROP without plus disease. Based on the GRADE assessment, we considered evidence to be of low quality for the following outcomes: rescue treatment with anti-VEGF or laser therapy; and arterial hypotension or bradycardia requiring inotropic support. Evidence was of moderate quality for the following outcomes: progression to stage 2 with plus disease; progression to stage 3 ROP; and progression to stage 4 or 5 ROP.Meta-analysis of three trials (N = 366) suggested beneficial effects of oral beta-blockers on the risk of requiring anti-VEGF agents (typical risk ratio (RR) 0.32, 95% confidence interval (CI) 0.12 to 0.86; I² = 0%; typical risk difference (RD) -0.06, 95% CI -0.10 to -0.01; I² = 75%; number needed to treat for an additional beneficial outcome (NNTB) 18, 95% CI 14 to 84) and laser therapy (typical RR 0.54, 95% CI 0.32 to 0.89; typical RD -0.09, 95% CI -0.16 to -0.02; I² = 31%; NNTB 12, 95% CI 8 to 47). Meta-analysis of two trials (N = 161) demonstrated a beneficial effect of oral beta-blockers on progression to stage 3 ROP (typical RR 0.60, 95% CI 0.37 to 0.96; I² = 0%; typical RD -0.15, 95% CI -0.28 to -0.02; I² = 73%; NNTB 7, 95% CI 5 to 67). There was no significant effect of oral beta-blockers on progression to stage 2 ROP with plus disease or to stage 4 or 5 ROP. Although meta-analysis did not indicate a significant effect of beta-blockers on arterial hypotension or bradycardia, propranolol dosage in one study was reduced by 50% in infants of less than 26 weeks' gestational age due to severe hypotension, bradycardia, and apnoea in several participants. Analyses did not indicate significant effects of beta-blockers on complications of prematurity or mortality. None of the trials reported on long-term visual impairment.

AUTHORS' CONCLUSIONS

Limited evidence of low-to-moderate quality suggests that prophylactic administration of oral beta-blockers might reduce progression towards stage 3 ROP and decrease the need for anti-VEGF agents or laser therapy. The clinical relevance of those findings is unclear as no data on long-term visual impairment were reported. Adverse events attributed to oral propranolol at a dose of 2 mg/kg/d raise concerns regarding systemic administration of this drug for prevention of ROP at the given dose. There is insufficient evidence to determine the efficacy and safety of beta-blockers for prevention of ROP due to high risk of bias in two included trials and the lack of long-term functional outcomes. We would encourage researchers to conduct large, well-designed trials to confirm or refute the role of beta-blockers for prevention and treatment of ROP in preterm infants. Trials should report on long-term visual impairment. Researchers should consider dose-finding studies of systemic beta-blockers and topical administration of beta-blockers, in order to optimise drug delivery and minimise adverse events.

Leaks during multiple-breath washout: characterisation and influence on outcomes

Nitrogen multiple-breath washout (N₂MBW) is increasingly used in patients with cystic fibrosis. The current European Respiratory Society/American Thoracic Society consensus statement for MBW recommends the rejection of measurements with leaks. However, it is unclear whether this is necessary for all types of leaks. Here, our aim was to 1) model and 2) apply air leaks, and 3) to assess their influence on the primary MBW outcomes of lung clearance index and functional residual capacity.

We investigated the influence of air leaks at various locations (pre-, intra- and post-capillary), sizes, durations and stages of the washout. Modelled leaks were applied to existing N₂MBW data from 10 children by modifying breath tables. In addition, leaks were applied to the equipment during N₂MBW measurements performed by one healthy adolescent.

All modelled and applied leaks resulted in statistically significant but heterogeneous effects on lung clearance index and functional residual capacity. In all types of continuous inspiratory leaks exceeding a certain size, the end of the washout was not reached. For practical application, we illustrated six different “red flags”, i.e. signs that enable easy identification of leaks during measurements.

Air leaks during measurement significantly influence N₂MBW outcomes. The influence of leaks on MBW outcomes is dependent on the location, relation to breath cycle, duration, stage of washout and size of the leak. We identified a range of signs to help distinguish leaks from physiological noise.

The influence of leaks on nitrogen MBW outcomes is complex, dynamic and dependent on the size, duration, location and position of leaks during the washout and breathing cyclehttp://ow.ly/PbHV30hB91H

Pain therapy in haemophilia in Germany

One of many challenges in the treatment of persons with haemophilia is the selection and application of appropriate pain-relieving therapies. The current situation of pain management for persons with haemophilia in Germany was evaluated using a survey with the intention of identifying potential areas for improvement. Results of 685 respondents showed that 86% experienced episodes of pain and that pain was already present in 66% of children and adolescents. Joint pain was the most common type of pain (92%), remarkably so even in 80% of young patients. Half of the patients received pharmacological therapy for the pain and 46% of the patients received physiotherapy. Priority and sequence of the contacted physicians and therapists for diagnosis and therapy is described. Satisfaction with pain therapy was expressed by 56% of participants and 18% felt their pain not treated sufficiently.

The results of the survey will be used to develop measures for improvement of long-term care of haemophilia patients regarding pain therapy.

Surface electromyography for analysis of heart rate variability in preterm infants

OBJECTIVE

Characterizing heart rate variability (HRV) in neonates has gained increased attention and is helpful in quantifying maturation and risk of sepsis in preterm infants. Raw data used to derive HRV in a clinical setting commonly contain noise from motion artifacts. Thoracic surface electromyography (sEMG) potentially allows for pre-emptive removal of motion artifacts and subsequent detection of interbeat interval (IBI) of heart rate to calculate HRV. We tested the feasibility of sEMG in preterm infants to exclude noisy raw data and to derive IBI for HRV analysis. We hypothesized that a stepwise quality control algorithm can identify motion artifacts which influence IBI values, their distribution in the time domain, and outcomes of nonlinear time series analysis.

APPROACH

This is a prospective observational study in preterm infants  <6 days of age. We used 100 sEMG measurements from 24 infants to develop a semi-automatic quality control algorithm including synchronized video recording, threshold-based sEMG envelope curve, optimized QRS-complex detection, and final targeted visual inspection of raw data.

MAIN RESULTS

Analysis of HRV from sEMG data in preterm infants is feasible. A stepwise algorithm to exclude motion artifacts and improve QRS detection significantly influenced data quality (34% of raw data excluded), distribution of IBI values in the time domain, and nonlinear time series analysis. The majority of unsuitable data (94%) were excluded by automated steps of the algorithm.

SIGNIFICANCE

Thoracic sEMG is a promising method to assess motion artifacts and calculate HRV in preterm neonates.

Task Dominance Determines Backward Inhibition in Task Switching

Switching between tasks is assumed to be accompanied by inhibiting currently irrelevant, but competing tasks. A dominant task that strongly interferes with performing a weaker task may receive especially strong inhibition. We tested this prediction by letting participants switch among three tasks that differ in dominance: a location discrimination task with strong stimulus–response bindings (responding with left-hand and right-hand button presses to stimuli presented left or right to the fixation cross) was combined with a color/pattern and a shape discrimination task, for which stimulus–response mappings were arbitrary (e.g., left-hand button press mapped to a red stimulus). Across three experiments, the dominance of the location task was documented by faster and more accurate responses than in the other tasks. This even held for incompatible stimulus–response mappings (i.e., right-hand response to a left-presented stimulus and vice versa), indicating that set-level compatibility (i.e., “dimension overlap”) was sufficient for making this location task dominant. As a behavioral marker for backward inhibition, we utilized n-2 repetition costs that are defined by higher reaction times for a switch back to a just abandoned and thus just inhibited task (ABA sequence) than for a switch to a less recently inhibited task (CBA, n-2 non-repetition). Reliable n-2 task repetition costs were obtained for all three tasks. Importantly, these costs were largest for the location task, suggesting that inhibition indeed was stronger for the dominant task. This finding adds to other evidence that the amount of inhibition is adjusted in a context-sensitive way.

Dynamics and complexity of body temperature in preterm infants nursed in incubators

BACKGROUND

Poor control of body temperature is associated with mortality and major morbidity in preterm infants. We aimed to quantify its dynamics and complexity to evaluate whether indices from fluctuation analyses of temperature time series obtained within the first five days of life are associated with gestational age (GA) and body size at birth, and presence and severity of typical comorbidities of preterm birth.

METHODS

We recorded 3h-time series of body temperature using a skin electrode in incubator-nursed preterm infants. We calculated mean and coefficient of variation of body temperature, scaling exponent alpha (Talpha) derived from detrended fluctuation analysis, and sample entropy (TSampEn) of temperature fluctuations. Data were analysed by multilevel multivariable linear regression.

RESULTS

Data of satisfactory technical quality were obtained from 285/357 measurements (80%) in 73/90 infants (81%) with a mean (range) GA of 30.1 (24.0-34.0) weeks. We found a positive association of Talpha with increasing levels of respiratory support after adjusting for GA and birth weight z-score (p<0.001; R2 = 0.38).

CONCLUSION

Dynamics and complexity of body temperature in incubator-nursed preterm infants show considerable associations with GA and respiratory morbidity. Talpha may be a useful marker of autonomic maturity and severity of disease in preterm infants.

Lung clearance index and moment ratios at different cut-off values in infant multiple-breath washout measurements

BACKGROUND

Multiple-breath washout (MBW) is increasingly used for infant lung function testing. Current guidelines recommend calculating lung clearance index (LCI) and functional residual capacity (FRC) at 2.5% of normalized tracer gas concentration, without clear recommendation for moment ratios (MR). Whether the 2.5% cut-off has the highest discriminative power to detect ventilation inhomogeneity in infants with lung diseases is unknown.

METHODS

We used sulfur-hexafluoride MBW measurements from 32 infants with cystic fibrosis, 32 preterm infants, and 32 healthy controls at postmenstrual age of 41-54 weeks. We compared the discriminative power to detect pathological values above the upper limit of normal for 12 different cut-offs between 20% and 1.5% for first and second MR (MR1, MR2), LCI, and FRC.

RESULTS

MR and LCI results changed significantly at different cut-offs. Mean MR2 in infants with cystic fibrosis increased from 2.4 to 7.2 units between 20% and 1.5% SF₆ . The ability of MR and LCI to discriminate between health and disease increased significantly with lower cut-offs. The 1.5% cut-off showed highest discriminative power: in infants with cystic fibrosis pathological MR2 values were found in 27 out of 89 (30%) and for LCI in 28/89 (32%). In preterm infants, pathological MR2 values were detected in 39 out of 73 (53%), and for LCI in 35/73 (48%). FRC remained stable throughout the washout.

CONCLUSION

In infants, the diagnostic performance of MBW strongly depends on the point of analysis. The cut-off with the highest discriminative power to detect ventilation inhomogeneity in infants with cystic fibrosis and after preterm birth was at 1.5% tracer gas concentration. Pediatr Pulmonol. 2016;51:1373-1381. © 2016 Wiley Periodicals, Inc.

Strategic control over extent and timing of distractor-based response activation

In choice reaction time (RT) tasks, performance is often influenced by the presence of nominally irrelevant stimuli, referred to as distractors. Recent research provided evidence that distractor processing can be adjusted to the utility of the distractors: Distractors predictive of the upcoming target/response were more attended to and also elicited stronger motor responses. In an event-related potential (ERP) study, we investigated whether not only the extent of distractor processing (as suggested by these previous results), but also the timing of distractor-based response activation is subject to strategic control. In a temporal flanker task, in which a distractor stimulus preceded the target, we manipulated distractor utility (i.e., by varying the proportion of congruent distractor-target combinations, 75% vs. 25%) as well as the stimulus onset asynchrony (SOA) between distractors and targets (350 ms vs. 1,000 ms) in different blocks of trials. The distractor-locked lateralized readiness potential (LRP) was overall larger in blocks with a high proportion of congruent trials indicating stronger distractor-based response activation when distractor utility was high. Of importance, the LRPs occurred overall later when the SOA was long. This suggests that distractor-based response activation can be postponed and thus adjusted to the temporal factors of the context. Modulations of early visual potentials (P1 and N1) indicate that this postponement of motor activation is related to both sensory-perceptual downgrading of distractor stimuli and reduced activation of task-relevant stimulus-response transformation processes at the time of distractor perception. (PsycINFO Database Record

Neuromyelitis optica spectrum disorder coinciding with hematological immune disease: A case report

INTRODUCTION

Recently defined consensus criteria for the diagnosis of neuromyelitis optica spectrum disorders (NMOSD) allow establishing the diagnosis in patients without elevated AQP4-Ab and optic nerve involvement. According to the new extended definition, NMOSD is closely associated with extensive spinal cord inflammation occurring in the course of systemic autoimmune diseases as sarcoidosis or lupus erythematodes. NMOSD occurring in the course of hematological disease have not yet been reported in the literature.

CASE REPORT

A 38 year old male subsequently developed thrombocytopenia, hemolytic anemia and agranulocytosis over a 23 month period. Three months after an episode of agranulocytosis, he noticed ascending sensory disturbances and progressive weakness of his legs. Within two days, symptoms worsened to give almost complete paraplegia and loss of sensation below a midthoracic level. MRI revealed signal hyperintensity and edema in T2-weighted sequences reaching from the 2nd cervical to the 9th thoracic vertebral body. Two years later, he developed a second episode with lesions in the spinal cord and periventricular areas of brain stem and thalamus.

CONCLUSION

The relapsing time course and the topographical pattern of central nervous system lesions restricted to axial brain structures and the spinal cord fulfill the criteria that have recently been defined for AQP4-Ab-negative NMO-spectrum disease. Systematic studies on the association of hematological autoimmune phenomena and spinal cord disease are needed to clarify whether this coincidence is just a casual phenomenon or whether it points to a yet undiscovered but perhaps therapeutically interesting link of immunological mechanisms affecting both organ systems.

Early selection versus late correction: Age-related differences in controlling working memory contents

We examined whether a reduced ability to ignore irrelevant information is responsible for the age-related decline of working memory (WM) functions. By means of event-related brain potentials, we will show that filtering is not out of service in older adults but shifted to a later processing stage. Participants performed a visual short-term memory task (change-detection task) in which targets were presented along with distractors. To allow early selection, a cue was presented in advance of each display, indicating where the targets were to appear. Despite this relatively easy selection criterion, older adults' filtering was delayed as indicated by the amplitude pattern of the contralateral delay activity. Importantly, WM-equated younger adults did not show a delay indicating that the delay is specific to older adults and not a general phenomenon that comes with low WM capacity. Moreover, the analysis of early visual potentials revealed qualitatively different perceptual/attentional processing between the age groups. Young adults exhibited stronger distractor sensitivity that in turn facilitated filtering. Older adults, in contrast, seemed to initially store distractors and to suppress them after the fact. These early selection versus late-correction modes suggest an age-related shift in the strategy to control the contents of WM. (PsycINFO Database Record

Immediate effects of phototherapy on sleep in very preterm neonates: an observational study

Process C (internal clock) and Process S (sleep-wake homeostasis) are the basis of sleep-wake regulation. In the last trimester of pregnancy, foetal heart rate is synchronized with the maternal circadian rhythm. At birth, this interaction fails and an ultradian rhythm appears. Light exposure is a strong factor influencing the synchronization of sleep-wake processes. However, little is known about the effects of phototherapy on the sleep rhythm of premature babies. It was hypothesized that sleep in preterm infants would not differ during phototherapy, but that a maturation effect would be seen. Sleep states were studied in 38 infants born < 32 weeks gestational age and/or < 1 500 g birth weight. Videos of 3 h were taken over the first 5 days of life. Based on breathing and movement patterns, behavioural states were defined as: awake; active sleep; or quiet sleep. Videos with and without phototherapy were compared for amounts of quiet sleep and active states (awake + active sleep). No significant association between phototherapy and amount of quiet sleep was found (P = 0.083). Analysis of videos in infants not under phototherapy revealed an increase in time spent awake with increasing gestational age. The current data suggest that the ultradian rhythm of preterm infants seems to be independent of phototherapy, supporting the notion that sleep rhythm in this population is mainly driven by their internal clock.

Sigh-induced changes of breathing pattern in preterm infants

Sighs are thought to play an important role in control of breathing. It is unclear how sighs are triggered, and whether preterm birth and lung disease influence breathing pattern prior to and after a sigh in infants. To assess whether frequency, morphology, size, and short-term variability in tidal volume (V_T) before, during, and after a sigh are influenced by gestational age at birth and lung disease (bronchopulmonary dysplasia, BPD) in former preterm infants and healthy term controls measured at equivalent postconceptional age (PCA). We performed tidal breathing measurements in 143 infants during quiet natural sleep at a mean (SD) PCA of 44.8 (1.3) weeks. A total of 233 sighs were analyzed using multilevel, multivariable regression. Sigh frequency in preterm infants increased with the degree of prematurity and severity of BPD, but was not different from that of term controls when normalized to respiratory rate. After a sigh, V_T decreased remarkably in all infants (paired t-test: P < 0.001). There was no major effect of prematurity or BPD on various indices of sigh morphology and changes in V_T prior to or after a sigh. Short-term variability in V_T modestly increased with maturity at birth and infants with BPD showed an earlier return to baseline variability in V_T following a sigh. In early infancy, sigh-induced changes in breathing pattern are moderately influenced by prematurity and BPD in preterm infants. The major determinants of sigh-related breathing pattern in these infants remain to be investigated, ideally using a longitudinal study design.

Neural Signatures of Controlled and Automatic Retrieval Processes in Memory-based Decision-making

Decision-making often requires retrieval from memory. Drawing on the neural ACT-R theory [Anderson, J. R., Fincham, J. M., Qin, Y., & Stocco, A. A central circuit of the mind. Trends in Cognitive Sciences, 12, 136-143, 2008] and other neural models of memory, we delineated the neural signatures of two fundamental retrieval aspects during decision-making: automatic and controlled activation of memory representations. To disentangle these processes, we combined a paradigm developed to examine neural correlates of selective and sequential memory retrieval in decision-making with a manipulation of associative fan (i.e., the decision options were associated with one, two, or three attributes). The results show that both the automatic activation of all attributes associated with a decision option and the controlled sequential retrieval of specific attributes can be traced in material-specific brain areas. Moreover, the two facets of memory retrieval were associated with distinct activation patterns within the frontoparietal network: The dorsolateral prefrontal cortex was found to reflect increasing retrieval effort during both automatic and controlled activation of attributes. In contrast, the superior parietal cortex only responded to controlled retrieval, arguably reflecting the sequential updating of attribute information in working memory. This dissociation in activation pattern is consistent with ACT-R and constitutes an important step toward a neural model of the retrieval dynamics involved in memory-based decision-making.

A Review of the Role of Cue Processing in Task Switching

The role of cue processing has become a controversial topic in research on cognitive control using task-switching procedures. Some authors suggested a priming account to explain switch costs as a form of encoding benefit when the cue from the previous trial is repeated and hence challenged theories that attribute task-switch costs to task-set (re)configuration. A rich body of empirical evidence has evolved that indeed shows that cue-encoding repetition priming is an important component in task switching. However, these studies also demonstrate that there are usually substantial “true” task-switch costs. Here, we review this behavioral, electrophysiological, and brain imaging evidence. Moreover, we describe alternative approaches to the explicit task-cuing procedure, such as the usage of transition cues or the task-span procedure. In addition, we address issues related to the type of cue, such as cue transparency. We also discuss methodological and theoretical implications and argue that the explicit task-cuing procedure is suitable to address issues of cognitive control and task-set switching.

Controlling conflict from interfering long-term memory representations

Remembering is more than an activation of a memory trace. As retrieval cues are often not uniquely related to one specific memory, cognitive control should come into play to guide selective memory retrieval by focusing on relevant while ignoring irrelevant information. Here, we investigated, by means of EEG and fMRI, how the memory system deals with retrieval interference arising when retrieval cues are associated with two material types (faces and spatial positions), but only one is task-relevant. The topography of slow EEG potentials and the fMRI BOLD signal in posterior storage areas indicated that in such situations not only the relevant but also the irrelevant material becomes activated. This results in retrieval interference that triggers control processes mediated by the medial and lateral PFC, which are presumably involved in biasing target representations by boosting the task-relevant material. Moreover, memory-based conflict was found to be dissociable from response conflict that arises when the relevant and irrelevant materials imply different responses. The two types of conflict show different activations in the medial frontal cortex, supporting the claim of domain-specific prefrontal control systems.

[Recurrent hypoglycemia and a large intraabdominal tumor in a 61-year-old woman]

HISTORY AND ADMISSION FINDINGS

A 61-year-old woman was found unconscious by her husband. The emergency doctor detected hypoglycemia (blood glucose 1.7 mmol/l). This was the first such event, the patient had not been known to have diabetes mellitus. At admission the physical examination and the laboratory findings revealed no abnormalities.

INVESTIGATIONS

A fasting test was aborted shortly after the start because of the onset of neurological symptoms. An insulinoma was excluded by detecting suppressed levels of insulin and C-peptide. Computed tomography of the abdomen revealed a mesenteric tumour of 9 cm in diameter, which was identified immunhistologically as a grade 1 follicular lymphoma (FL).  After exclusion of endocrinological causes the recurrent hypoglycaemia was diagnozed as part of a paraneoplastic syndrome associated with a non-islet cell tumour hypoglycaemia (NICTH) with a newly diagnosed FL.

TREATMENT AND COURSE

Specific medication with the CD20 antibody rituximab (375 mg/m2, once per week for a total of four cycles) was initiated. There were no further episodes of hypoglycaemia. After one year the patient remains free of any symptoms.

CONCLUSIONS

After exclusion of any endocrinological reasons for hypoglycemia, differential diagnosis should include NICTH as paraneoplastic syndrome. In rare cases a hematological malignancy may be the underlying disease. The specific treatment of this disease likewise represents the causal treatment of NICTH.

Memory-based Decision-making with Heuristics: Evidence for a Controlled Activation of Memory Representations

Many of our daily decisions are memory based, that is, the attribute information about the decision alternatives has to be recalled. Behavioral studies suggest that for such decisions we often use simple strategies (heuristics) that rely on controlled and limited information search. It is assumed that these heuristics simplify decision-making by activating long-term memory representations of only those attributes that are necessary for the decision. However, from behavioral studies alone, it is unclear whether using heuristics is indeed associated with limited memory search. The present study tested this assumption by monitoring the activation of specific long-term-memory representations with fMRI while participants made memory-based decisions using the “take-the-best” heuristic. For different decision trials, different numbers and types of information had to be retrieved and processed. The attributes consisted of visual information known to be represented in different parts of the posterior cortex. We found that the amount of information required for a decision was mirrored by a parametric activation of the dorsolateral PFC. Such a parametric pattern was also observed in all posterior areas, suggesting that activation was not limited to those attributes required for a decision. However, the posterior increases were systematically modulated by the relative importance of the information for making a decision. These findings suggest that memory-based decision-making is mediated by the dorsolateral PFC, which selectively controls posterior storage areas. In addition, the systematic modulations of the posterior activations indicate a selective boosting of activation of decision-relevant attributes.

Exploring cross-task compatibility in perceiving and producing facial expressions using electromyography

Using a dual-task methodology we examined the interaction of perceiving and producing facial expressions. In one task, participants were asked to produce a smile or a frown (Task 2) in response to a tone stimulus. This auditory-facial task was embedded in a dual-task context, where the other task (Task 1) required a manual response to visual face stimuli (visual-manual task). These face stimuli showed facial expressions that were either compatible or incompatible to the to-be-produced facial expression. Both reaction times and error rates (measured by facial electromyography) revealed a robust stimulus-response compatibility effect across tasks, suggesting that perceived social actions automatically activate corresponding actions even if perceived and produced actions belong to different tasks. The dual-task nature of this compatibility effect further testifies that encoding of facial expressions is highly automatic.

A new instrument for the assessment of patient-defined benefit in the treatment of allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is a common disease that affects health-related quality of life (HRQoL). Current and future health policy demands the assessment of patient-relevant treatment benefit for evaluation of treatments.

METHODS

We developed, validated and tested a standardized instrument for the assessment of patient-relevant needs and benefits in AR. In an open survey of patients with AR, 100 need and benefit items were generated. The items were condensed to a 25-item list by an expert panel. On this list, patient rates the personal importance of 25 treatment needs on a scale ranging from 'not at all' to 'very' before treatment (Patient Needs Questionnaire, PNQ). At the end of the treatment, patient rates the extent, to which these needs were achieved by treatment from 'did not help at all' to 'helped a lot' (Patient Benefit Questionnaire). The patient benefit index (PBI) is computed to provide a global weighted benefit parameter. This disease-specific instrument was validated in n = 104 patients with AR.

RESULTS

The PBI-AR showed good acceptability and feasibility in clinical routine. Reduction in nose and eye symptoms was rated most important. The PBI amounted to 2.2 (PBI ranges from 0 = 'no benefit' to 4 = 'maximum benefit'). Reliability of the PNQ was high (Cronbach's alpha = 0.9).The PBI was significantly correlated with relevant external validation criteria, such as patient satisfaction (R = 0.54) and HRQoL (R = 0.26).

CONCLUSION

The PBI-AR is a feasible, reliable and valid instrument for the standardized assessment of patient-relevant benefits in the treatment of AR.

Frontal and parietal contributions to arithmetic fact retrieval: a parametric analysis of the problem-size effect

The goal of the present study was to investigate the neuroanatomical basis of arithmetic fact retrieval. The rationale was that areas playing a crucial role in arithmetic fact retrieval should show a systematic increase of activation with increasing retrieval effort. To achieve this goal, we utilized the problem-size effect as this is known to be systematically related to retrieval effort. In contrast to many previous studies, we here took a parametric approach to account for the continuous increase of retrieval effort with problem size. BOLD signals were modeled with problem size as parametric regressor and negative slow waves of the EEG were categorized into six levels of problem size. The fMRI data showed that activation in the angular gyrus and ACC/SMA increased parametrically with problem size. The ERP data showed a systematic amplitude increase with increasing problem size, especially at fronto-central electrodes. Consistent with the fMRI data, source modeling localized this effect to the ACC. While these findings support previous notions about the crucial role of the angular gyrus during fact retrieval, they also provide evidence that the medial frontal cortex is involved when single-digit multiplications are solved. Thus, both parietal and frontal structures seem to be integral parts of a system that enables and controls arithmetic fact retrieval.

Control and interference in task switching--a review

The task-switching paradigm offers enormous possibilities to study cognitive control as well as task interference. The current review provides an overview of recent research on both topics. First, we review different experimental approaches to task switching, such as comparing mixed-task blocks with single-task blocks, predictable task-switching and task-cuing paradigms, intermittent instructions, and voluntary task selection. In the 2nd part, we discuss findings on preparatory control mechanisms in task switching and theoretical accounts of task preparation. We consider preparation processes in two-stage models, consider preparation as an all-or-none process, address the question of whether preparation is switch-specific, reflect on preparation as interaction of cue encoding and memory retrieval, and discuss the impact of verbal mediation on preparation. In the 3rd part, we turn to interference phenomena in task switching. We consider proactive interference of tasks and inhibition of recently performed tasks indicated by asymmetrical switch costs and n-2 task-repetition costs. We discuss stimulus-based interference as a result of stimulus-based response activation and stimulus-based task activation, and response-based interference because of applying bivalent rather than univalent responses, response repetition effects, and carryover of response selection and execution. In the 4th and final part, we mention possible future research fields.

Theta and alpha oscillations during working-memory maintenance predict successful long-term memory encoding

To date, much is known about the neural mechanisms underlying working-memory (WM) maintenance and long-term-memory (LTM) encoding. However, these topics have typically been examined in isolation, and little is known about how these processes might interact. Here, we investigated whether EEG oscillations arising specifically during the delay of a delayed matching-to-sample task reflect successful LTM encoding. Given previous findings of increased alpha and theta power with increasing WM load, together with the assumption that successful memory encoding involves processes that are similar to those that are invoked by increasing WM load, alpha and theta power should be higher for subsequently remembered stimuli. Consistent with this assumption, we found stronger alpha power for subsequently remembered stimuli over occipital-to-parietal scalp sites. Furthermore, stronger theta power was found for subsequently remembered stimuli over parietal-to-central electrodes. These results support the idea that alpha and theta oscillations modulate successful LTM encoding.

Neural correlates of generating visual nouns and motor verbs in a minimal phrase context

The neural basis underlying the generation of nouns and verbs is still not completely understood. In classical generation tasks, specific features of the produced words can hardly be controlled. Therefore, the observed neural correlates of noun and verb production cannot be directly related to differences in specific features of the generated words. The present study seeks to address this issue by using a "minimal-phrase context" to elicit the activation of specific nouns and verbs. With this context, the to-be-generated words were highly constrained, and thus their semantic and other features (visual/action relatedness, word frequency, cloze probability, etc.) are well controlled. Thus, the present paradigm combines the advantages of classical word generation tasks (i.e., active semantic processing) with the advantages of tasks that allow for a high control of the experimental stimuli, such as passive viewing, reading, or lexical decision tasks. In an fMRI study, 17 participants generated verbs with strong motor and nouns with strong visual associations. Both noun and verb generation, compared to a rhyme generation baseline, elicited stronger activation in perisylvian language areas of the temporal and parietal cortex. In addition, stronger activation for nouns was found in the right middle/inferior temporal cortex. This activation supports the claim that noun generation is mediated by visual processing areas. Stronger activation for verb generation was found in the left superior temporal gyrus. Since this area is involved in motion perception, the results suggest that perceptual representations of movements mediate the generation of action verbs.

Measurements of the quadriceps femoris function after meniscus refixation at the stable athlete's knee

INTRODUCTION

The purpose of this study was to monitor the muscular changes regarding the isokinetic strength and torque pattern of the quadriceps femoris at the stable athlete's knee after meniscus tear refixation.

MATERIALS AND METHODS

Therefore 15 athletes (10 male, 5 female) performing recreational or competitional sports at least five times a week before injury were retrospectively examined in the average 2.5 years after isolated arthroscopic meniscus refixation using Inside Out technique. Next to function and sport activity focused scores the isokinetic peak torque (PT) and in the EMG have been analyzed compared to the uninjured knee.

RESULTS

The mean age was 31.26 years. The time between injury and surgery was in the average 13.7 days. According to our first results the data suggest a complete recovery of functional and muscular pattern after meniscus refixation at the stable athlete's knee. No significant EMG changes for quadriceps femoris were detectable. The PT was fully recovered. The functional and sport activity score analysis (Lysholm and Tegner score) showed no changes in the postoperative long-term follow up compared to the preinjured status.

CONCLUSION

Examining isokinetic PT and the EMG of the quadriceps femoris, these data show no side-to-side differences. Regarding the function and sports activity score system, the functionally high demand patients seem to profit by this procedure.

Natriuretic Properties of [2-p-Ethylphenylalanine] deamino-6-carba-oxytocin (Nacartocin) in Cats

Nacartocin, a synthetic analogue of oxytocin, [2-L-p-phenylalanine]deamino-6-carba-oxytocin has a specific natriuretic effect in cats. The doses of 0.05-10 micrograms/kg b.w. (0.05-10 nmols/kg) of Nacartocin applied i.v. caused a several fold increase in the excretion of sodium, while the excretion of kalium was only slightly enhanced.

Adjuvant therapy with edrecolomab versus observation in stage II colon cancer: a multicenter randomized phase III study

BACKGROUND

In a phase III study recruiting patients with stage II colon cancer the effect of adjuvant therapy with edrecolomab, a murine monoclonal antibody to the cell-surface glycoprotein 17-1A, was compared to observation alone.

PATIENTS AND METHODS

From January 1997 until July 2000 a total of 377 patients were postoperatively stratified according to tumor stage (T3 vs. T4) and center, and randomly allocated to either treatment with edrecolomab (cohort A, n = 183) or observation (cohort B, n = 194). Patients in cohort A received a total of 900 mg edrecolomab. The study was terminated prematurely because of discontinuation of drug supply in Germany.

RESULTS

305 patients were eligible for the primary endpoint of overall survival and 282 patients for disease-free survival. After a median follow-up of 42 months overall survival and disease-free survival were not significantly different. Toxicity was mild.

CONCLUSIONS

In the present study, postoperative adjuvant treatment with edrecolomab in patients with resected stage II colon cancer did not improve overall or disease-free survival.

Clinical and Electrophysiological Course of Acute Syphilitic Posterior Placoid Chorioretinitis

BACKGROUND

Syphilis can affect the anterior as well as the posterior segment of the eye at any stage.

HISTORY AND SIGNS

A 52-year-old man was referred to our clinic because of acute loss of his vision and hearing. Best corrected visual acuity (BCVA) was counting fingers (CF) right and 0.05 left eye, respectively. Fundoscopy revealed bilateral intraretinal macular haemorrhages and a large yellowish edematous lesion involving macula and midperipheral retina. Fluorescein angiography showed diffuse late edema. The visual field showed a defect corresponding to the edematous lesion. The "Ganzfeld" electroretinogram (ERG) was markedly reduced and the multifocal ERG in the affected area was not recordable.

THERAPY AND OUTCOME

VDRL, FTA-Abs and TPHA tests in serum and cerebrospinal fluid were positive. Intravenous penicillin therapy was initiated. BCVA, visual field and ERG eventually recovered completely.

CONCLUSIONS

Syphilis should be considered as a differential diagnosis in any unclear inflammatory ocular condition. Awareness of syphilitic posterior placoid chorioretinitis allows rapid diagnosis and therapy.

Comparing arithmetic and semantic fact retrieval: effects of problem size and sentence constraint on event-related brain potentials

Event-related potentials were recorded with 61 electrodes from 16 students who verified either the correctness of single-digit multiplication problems or the semantic congruency of sentences. Multiplication problems varied in size and sentence fragments in constraint. Both semantic and arithmetic incongruencies evoked a typical N400 with a clear parieto-central maximum. In addition, numerically larger problems (8x7), in comparison to smaller problems (3x2), evoked a negativity starting at about 360 ms whose maximum was located over the right temporal-parietal scalp. These results indicate that the arithmetic incongruency and the problem-size effect are functionally distinct. It is suggested that the arithmetic and the semantic incongruency effects are both functionally related to a context-dependent spread of activation in specialized associative networks, whereas the arithmetic problem-size effect is due to rechecking routines that go beyond basic fact retrieval.