Good theoretical debate, but insufficient proof of concept.

Bruineberg and colleagues argue that the patellar reflex cannot be modeled sufficiently with a Friston blanket due to counterintuitive sensorimotor boundaries. Although I agree with their theoretical discussion, their model of the patellar reflex is insufficiently based on clinical knowledge. Consequently, this example should not be applied to challenge Friston blankets. I will provide an alternative example.

Effect of Vectashield-induced fluorescence quenching on conventional and super-resolution microscopy.

Finding the right combination of a fluorescent dye and a mounting medium is crucial for optimal microscopy of fixed samples. It was recently shown that Vectashield, one of the most commonly used mounting media for conventional microscopy, can also be applied to super-resolution direct stochastic optical reconstruction microscopy (dSTORM). dSTORM utilizes conventional dyes and starts with samples in a fluorescent "ON" state. This helps in identifying structures of interest. Subsequently, labelled samples are induced into blinking, which is necessary for determining the position of single molecules and reconstruction of super-resolution images. This is only possible with certain fluorescent dyes and imaging buffers. One of the most widely used dyes for dSTORM, Alexa Fluor 647 (AF647), blinks in Vectashield. However, after preparing immunocytochemical samples in Vectashield, we noticed that the fluorescence intensity of AF647 is quenched. This is particularly evident for dimmer immunostainings, such as stainings of some components of neuronal cytoskeleton and axonal initial segment. Because structures of interest cannot be identified in quenched samples, loss of fluorescence intensity hinders imaging of AF647 in Vectashield. This has consequences for both conventional and dSTORM imaging. To overcome this, we provide: 1) a quantitative analysis of AF647 intensity in different imaging media, 2) a quantitative analysis of the suitability of Vectashield for dSTORM imaging of high and low-abundance AF647-labelled targets. Furthermore, for the first time, we quantitatively analyse the performance of Alexa Fluor Plus 647, a new variant of AF647-conjugated antibody, in dSTORM imaging.

Frequency, aetiology, and impact of vestibular symptoms in the emergency department: a neglected red flag.

OBJECTIVE: We aimed to determine the incidence of all vestibular symptoms in a large interdisciplinary tertiary emergency department (ED) and to assess stroke prevalence, and frequency of other life-threatening aetiologies. METHODS: In this 1-year retrospective study, we manually screened all medical records of 23,608 ED visits for descriptions of vestibular symptoms. Symptoms were classified according to the International Classification of Vestibular Disorders of the Bárány Society. We evaluated all patients older than 16 years in whom vestibular symptoms were the main or accompanying complaint. We extracted clinical, radiological, and laboratory findings as well as aetiologies from medical records. RESULTS: We identified a total of 2596 visits by 2464 patients (11% of ED visits) who reported at least one vestibular symptom. In 1677/2596 visits (64.6%), vestibular symptoms were the main reason for the ED consultation. Vestibular symptoms were classified as dizziness (43.8%), vertigo (33.9%), postural symptoms (6.5%), or more than one symptom (15.8%). In 324/2596 visits (12.5%), cerebrovascular events were the aetiology of vestibular symptoms, and in 355/2596 visits (13.7%), no diagnosis could be established. In 23.8% of visits with vestibular symptoms as the main complaint, the underlying condition was life-threatening. CONCLUSION: Frequency and impact of vestibular symptoms in patients visiting the ED were higher than previously reported, and life-threatening aetiologies such as strokes are common. Therefore, awareness among physicians regarding the importance of vestibular symptoms has to be improved.

Untangling operational failures of the Status Epilepticus Severity Score (STESS).

OBJECTIVE: To uncover clinical characteristics leading to false outcome prediction of the Status Epilepticus Severity Score (STESS), a validated and broadly used clinical scoring system for outcome prediction in status epilepticus (SE). METHODS: From 2005 to 2016, adult patients with SE treated at the University Hospital Basel, Switzerland, were included. To assess independent associations of variables differing between patients with false and correct prediction of death (STESS ≥ 3), multivariable logistic regression models were computed using automated selection. RESULTS: Among 467 patients, 12% died. The median STESS was 3 (interquartile range 2-4). Regarding prediction of death, the STESS was false-positive in 51% and false-negative in 1%. Patients surviving despite having a STESS ≥3 had less fatal etiologies, less nonconvulsive SE with coma, and lower Charlson Comorbidity Index, Simplified Acute Physiology Score II, and Acute Physiology and Chronic Health Evaluation II scores. In multivariable analyses, odds for survival were high with SE types other than nonconvulsive status with coma and low with an increasing Charlson Comorbidity Index in patients with a STESS ≥ 3 (odds ratio [OR]for survival 4.23, 95% confidence interval [CI] 2.33-9.60; and ORfor survival 0.86, 95% CI 0.75-0.98). In patients with SE types other than nonconvulsive with coma, the STESS was mainly increased because they were frequently older than 65 years and had no seizure history. CONCLUSIONS: The STESS frequently and inadequately predicts death especially in patients with SE other than nonconvulsive with coma and few comorbidities. Clinicians are urged to interpret a STESS ≥3 with caution in such patients.

Illness severity scoring in status epilepticus-When STESS meets APACHE II, SAPS II, and SOFA.

OBJECTIVE: To characterize a critically ill cohort with status epilepticus (SE) by the illness severity scoring systems SAPS II (Simplified Acute Physiology Score II), APACHE II (Acute Physiology and Chronic Health Evaluation II), and SOFA (Sequential Organ Failure Assessment), and to compare their performance with the STESS (Status Epilepticus Severity Score) for outcome prediction. METHODS: The prospective cohort study was carried out at the University Hospital Basel, a Swiss tertiary academic medical care center. Consecutive adult SE patients hospitalized in the intensive care units from 2011 to 2016 were included. Illness severity scores and additional clinical data were recorded. Logistic regression models using automated variable selection were applied to identify scores associated with no return to functional and neurological baseline and death. Measures of discrimination and calibration were assessed. RESULTS: Among 184 patients, 33% returned to baseline. Median scores of the illness severity scores were within the lowest third of the possible scoring ranges, and all differed significantly between patients with and without return to baseline. The areas under the receiver operating curves for the prediction of no return to baseline and death ranged from 0.64 to 0.73, with the highest value for the STESS predicting no return to baseline. Measures of calibration revealed adequate model fit for all analyses. Among integral components of the scoring systems, only the Glasgow Coma Scale (GCS) differed significantly between patients with and without return to baseline. In multivariable analyses, decreasing GCS and increasing STESS had the strongest associations (odds ratio [OR] = 0.84, 95% confidence interval [CI] = 0.77-0.93 and OR = 1.34, 95% CI = 1.05-1.68, respectively) with no return to baseline independent of all other scoring systems, whereas the APACHE II revealed the strongest association with death (OR = 1.15, 95% CI = 1.06-1.25). SIGNIFICANCE: Although complex illness severity scoring systems in SE patients facilitate benchmarking and comparisons with other severely ill patient cohorts, they offer no advantages over the STESS and GCS regarding prediction of no return to baseline.

Venovenous extracorporeal membrane oxygenation to treat hypercapnia in a morbidly obese patient.

Morbid obesity plays an increasingly important role in healthcare. Patients who are severely obese often suffer from a range of medical problems. One problem is obesity-related hypoventilation syndrome with its resulting hypercapnia. We report a case of a 33-year-old female patient who was in an extraordinarily bad medical state, with severe hypercapnia (pCO2 15.1 kPa), sepsis, acute anuric kidney failure and resulting acidosis (pH 6.96). Her body mass index was 84 kg/m2. Her chances of survival were considered very low after failed attempts at noninvasive ventilation. Based on prior research, we refrained from intubation and chose venovenous extracorporeal membrane oxygenation to treat the hypercapnia. In the entire medical literature, we are not aware of a similarly extraordinary case of obesity-related hypoventilation syndrome that could finally be treated successfully. The idea behind this case report is to consider venovenous extracorporeal membrane oxygenation as an alternative to intubation in this patient collective.

Ginkgo biloba extract EGb 761® alleviates neurosensory symptoms in patients with dementia: a meta-analysis of treatment effects on tinnitus and dizziness in randomized, placebo-controlled trials.

BACKGROUND: Tinnitus and dizziness are frequent in old age and often seen as concomitant symptoms in patients with dementia. In earlier clinical trials, Ginkgo biloba extract EGb 761® was found to alleviate tinnitus and dizziness in elderly patients. Consequently, a meta-analysis was conducted to evaluate the effects of EGb 761® at a daily dose of 240 mg on tinnitus and dizziness associated with dementia. METHODS: Randomized, placebo-controlled clinical trials of G. biloba extract EGb 761® identified by a systematic database search were included in a meta-analysis if they met all of the following selection criteria: 1) diagnosis of dementia according to generally accepted criteria, 2) treatment period of at least 20 weeks, 3) outcome measures covering at least two of the three conventional domains of assessment, 4) presence and severity of dizziness and tinnitus were assessed, and 5) assessment was done before and after randomized treatment. RESULTS: Five trials that met the inclusion criteria were included in the meta-analysis. The risk of bias was judged as low, with Jadad scores of 3 and 5. In all trials, 11-point box scales were used to assess the severity of tinnitus and dizziness. Overall, EGb 761® was superior to placebo, with weighted mean differences for change from baseline, calculated in meta-analyses using random effects models, of -1.06 (95% CI: -1.77, -0.36) for tinnitus (p = 0.003) and -0.77 (95% CI: -1.44, -0.09) for dizziness (p = 0.03). CONCLUSION: Our findings support the notion that EGb 761® is also effective in alleviating concomitant neurosensory symptoms in patients with dementia.

Associations between periodic social events and status epilepticus-An 11-year cohort study.

OBJECTIVES: Periodic social events may influence the incidence and course of status epilepticus (SE), likely explained by patients' behavioral changes regarding alcohol intake, sleep, and compliance with antiseizure medication. However, data regarding the association between such events and SE are lacking. The aim of this study was to identify and quantify associations between periodic social events and the incidence, etiology, and outcome of SE. METHODS: Adult patients who were admitted to a tertiary academic medical care center with SE from 2005 to 2015 were included. Associations between periodic social events (including birthday, Christmas, New Year's Eve, carnival, national holiday) and the number and etiologies of SE over time were calculated using linear and Poisson regression. Logistic regression was applied to identify associations between time from social events and outcome. RESULTS: Four hundred nine patients with a median age of 66 years (interquartile range 52-76) were analyzed. The number of total SE events and SE in patients with known epilepsy peaked within 2 weeks following social events and then decreased with each additional day (incidence rate ratio [IRR]per day 0.99, 95% confidence interval [CI] 0.98-0.99; P < .001 and IRRper day 0.99, 95% CI 0.98-0.99; P < .001, respectively) and week (IRRper week 0.94, 95% CI 0.93-0.95; P < .001 and IRRper week 0.94, 95% CI 0.92-0.96; P < .001, respectively). The highest proportion of epilepsy patients not taking antiseizure medication was seen closest to social events and decreased thereafter (IRRper day 0.99, 95% CI 0.98-0.99; P = .003). There was no association between time from social events and outcome. SIGNIFICANCE: Our findings support the hypothesis that periodic social events in adults may be associated with an increase in SE and should heighten awareness for SE in this context. Clinicians are urged to inform epilepsy patients regarding this association and to instruct them on preventive measures around such events.

Dizziness in the emergency department: an update on diagnosis.

This review aims to assist emergency physicians in finding the underlying aetiology when a patient presents with dizziness to the emergency department. After reading this review, the emergency physician will be able to consider the most relevant differential diagnoses and have an idea about dangerous aetiologies that require immediate action. The emergency physician will also know what diagnostic steps need to be taken at what time, such as the three-component HINTS Test (Head Impulse, Nystagmus, and Test-of-Skew), which helps with distinguishing central from peripheral causes of the acute vestibular syndrome. Furthermore, episodic vestibular syndromes and chronic vestibular syndromes are discussed in detail. The five most frequent categories of dizziness are vasovagal syncope / orthostatic hypotension (22.3%), vestibular causes (19.9%), fluid and electrolyte disorders (17.5%), circulatory/pulmonary causes (14.8%) and central vascular causes (6.4%). Given that it would neither be economical nor practical to send all patients to specialists from the start, we present general guidelines for the diagnostic workup of patients presenting with dizziness to the emergency department. This review will focus on epidemiology, aetiologies, differential diagnoses and diagnostics. Treatment is described in a separate article.

Treatment of dizziness: an interdisciplinary update.

This review provides an update on interdisciplinary treatment for dizziness. Dizziness can have various causes and the treatment offered should depend on the cause. After reading this article, the clinician will have an overview of current treatment recommendations. Recommendations are made for the most prevalent causes of dizziness including acute and chronic vestibular syndromes, vestibular neuritis, benign paroxysmal positional vertigo, endolymphatic hydrops and Menière's disease, vestibular paroxysmia and vestibular migraine, cardiac causes, transient ischaemic attacks and strokes, episodic ataxia type 2, persistent postural-perceptual dizziness, bilateral vestibulopathy, degenerative, autoimmune and neoplastic diseases, upbeat- and downbeat nystagmus. Recommendations include clinical approaches (repositioning manoeuvres), medication (adding, removing or changing current medication depending on aetiology), vestibular physiotherapy, ergotherapy and rehabilitation, treatment of chest pain or stroke units and surgical interventions. If symptoms are acute and severe, medication with antivertigo agents is recommended as a first step, for a maximum period of 3 days. Following initial symptom control, treatment is tailored depending on aetiology. To assist the clinician in obtaining a useful overview, the level of evidence and number needed to treat are reported whenever possible based on study characteristics. In addition, warnings about possible arrhythmias due to medication are issued, and precautions to enable these to be avoided are discussed.

Emergency response to out-of-hospital status epilepticus: A 10-year observational cohort study.

OBJECTIVE: To determine the implications of first responses of emergency medical services (EMS) to out-of-hospital status epilepticus (SE) on outcome. METHODS: From 2005 to 2014, prehospital and in-hospital data were assessed in consecutive adults admitted to an academic medical center with out-of-hospital SE. Logistic regression was performed to identify variables with a robust association between missed epileptic events by the EMS and no recovery to functional baseline in survivors. RESULTS: Among 213 SE patients, 150 were admitted via EMS. While nonconvulsive SE (NCSE) was missed by the EMS in 63.7%, convulsive SE (CSE) was not missed except in 4 patients with transformation into subtle SE. Missed NCSE was more likely with older age (odds ratio [OR]per year 1.06, 95% confidence interval [CI] 1.02-1.10, p = 0.003) and no seizure history (OR 6.64, 95% CI 2.43-18.1, p < 0.001). The area under the receiver operating characteristic curve for prediction of missed NCSE by these variables was 0.839. Independent predictors for not receiving benzodiazepines were increasing age (ORper year 1.05, 95% CI 1.01-1.08, p = 0.008) and higher Glasgow Coma Scale score (ORper increasing unit 1.21, 95% CI 1.09-1.36, p = 0.001). Missed NCSE was independently associated with increased odds for no return to functional baseline in survivors (OR 3.83, 95% CI 1.22-11.98, p = 0.021). CONCLUSIONS: Among patients admitted with out-of-hospital SE, CSE is mostly recognized while NCSE is frequently missed especially in patients with increasing age and no seizure history. This calls for heightened awareness for out-of-hospital NCSE in such patients, as missed NCSE is associated with lack of treatment and less recovery to functional baseline in survivors independent of established outcome predictors.

Resting in darkness improves downbeat nystagmus: evidence from an observational study.

Resting in an upright position during daytime decreases downbeat nystagmus (DBN). When measured in brightness only, that is, without intermitting exposure to darkness, it does not make a significant difference whether patients have previously rested in brightness or in darkness. In real-world scenarios, people are often exposed to brightness and darkness intermittently. The aim of this study was to analyze whether resting in brightness or resting in darkness was associated with a lower post-resting DBN after intermitting exposures to brightness and darkness. Eight patients were recorded with three-dimensional video-oculography in brightness and darkness conditions, each following two 2-h resting intervals under either brightness or darkness resting conditions. The dependent variable was DBN intensity, measured in mean slow phase velocity. A repeated measures ANOVA with the factors measurement condition (brightness vs. darkness), resting condition (brightness vs. darkness), and time (after first vs. second resting interval) showed a significant effect for the factor resting condition, where previous resting in darkness was associated with a significantly lower DBN relative to previous resting in brightness (P < 0.01). The clinical relevance is to advise patients with DBN to rest in darkness.

Gravity matters: Motion perceptions modified by direction and body position.

Motion coherence thresholds are consistently higher at lower velocities. In this study we analysed the influence of the position and direction of moving objects on their perception and thereby the influence of gravity. This paradigm allows a differentiation to be made between coherent and randomly moving objects in an upright and a reclining position with a horizontal or vertical axis of motion. 18 young healthy participants were examined in this coherent threshold paradigm. Motion coherence thresholds were significantly lower when position and motion were congruent with gravity independent of motion velocity (p=0.024). In the other conditions higher motion coherence thresholds (MCT) were found at lower velocities and vice versa (p<0.001). This result confirms previous studies with higher MCT at lower velocity but is in contrast to studies concerning perception of virtual turns and optokinetic nystagmus, in which differences of perception were due to different directions irrespective of body position, i.e. perception took place in an egocentric reference frame. Since the observed differences occurred in an upright position only, perception of coherent motion in this study is defined by an earth-centered reference frame rather than by an ego-centric frame.

Real-time computer-based visual feedback improves visual acuity in downbeat nystagmus - a pilot study.

BACKGROUND: Patients with downbeat nystagmus syndrome suffer from oscillopsia, which leads to an unstable visual perception and therefore impaired visual acuity. The aim of this study was to use real-time computer-based visual feedback to compensate for the destabilizing slow phase eye movements. METHODS: The patients were sitting in front of a computer screen with the head fixed on a chin rest. The eye movements were recorded by an eye tracking system (EyeSeeCam®). We tested the visual acuity with a fixed Landolt C (static) and during real-time feedback driven condition (dynamic) in gaze straight ahead and (20°) sideward gaze. In the dynamic condition, the Landolt C moved according to the slow phase eye velocity of the downbeat nystagmus. The Shapiro-Wilk test was used to test for normal distribution and one-way ANOVA for comparison. RESULTS: Ten patients with downbeat nystagmus were included in the study. Median age was 76 years and the median duration of symptoms was 6.3 years (SD +/- 3.1y). The mean slow phase velocity was moderate during gaze straight ahead (1.44°/s, SD +/- 1.18°/s) and increased significantly in sideward gaze (mean left 3.36°/s; right 3.58°/s). In gaze straight ahead, we found no difference between the static and feedback driven condition. In sideward gaze, visual acuity improved in five out of ten subjects during the feedback-driven condition (p = 0.043). CONCLUSIONS: This study provides proof of concept that non-invasive real-time computer-based visual feedback compensates for the SPV in DBN. Therefore, real-time visual feedback may be a promising aid for patients suffering from oscillopsia and impaired text reading on screen. Recent technological advances in the area of virtual reality displays might soon render this approach feasible in fully mobile settings.

Group effort in resuscitation teams.

Baumeister and colleagues underline that individual identification and differentiation of selves are important characteristics for group performance. They name specialization, moral responsibility, and efficiency as vital components of well-functioning groups. In my commentary, I transfer their framework to the group effort within resuscitation teams to discuss for the first time how these components determine teamwork during resuscitation.

No short-term effects of calorie-controlled Mediterranean or fast food dietary interventions on established biomarkers of vascular or metabolic risk in healthy individuals.

BACKGROUND/OBJECTIVES: This study addressed the question whether the composition of supposedly 'healthy' or 'unhealthy' dietary regimes has a calorie-independent short-term effect on biomarkers of metabolic stress and vascular risk in healthy individuals. SUBJECTS/METHODS: Healthy male volunteers (age 29.5 ± 5.9 years, n = 39) were given a standardized baseline diet for two weeks before randomization into three groups of different dietary regimes: fast food, Mediterranean and German cooking style. Importantly, the amount of calories consumed per day was identical in all three groups. Blood samples were analyzed for biomarkers of cardiovascular risk and metabolic stress after two weeks of the baseline diet and after two weeks of the assigned dietary regime. RESULTS: No dietary intervention affected the metabolic or cardiovascular risk profile when compared in-between groups or compared to baseline. Subjects applied to the Mediterranean diet showed a statistically significant increase of uric acid compared to baseline and compared to the German diet group. Plasma concentrations of urea were significantly higher in both the fast food group and the Mediterranean group, when compared to baseline and compared to the German diet group. No significant differences were detected for the levels of vitamins, trace elements or metabolic stress markers (8-hydroxy-2-deoxyguanosine, malondialdehyde and methylglyoxal, a potent glycating agent). Established parameters of vascular risk (e.g. LDL-cholesterol, lipoprotein(a), homocysteine) were not significantly changed in-between groups or compared to baseline during the intervention period. CONCLUSIONS: The calorie-controlled dietary intervention caused neither protective nor harmful short-term effects regarding established biomarkers of vascular or metabolic risk. When avoiding the noxious effects of overfeeding, healthy individuals can possess the metabolic capacity to compensate for a potentially disadvantageous composition of a certain diet.