NFĸB signaling drives myocardial injury via CCR2+ macrophages in a preclinical model of arrhythmogenic cardiomyopathy

Nuclear factor kappa-B (NFκB) is activated in arrhythmogenic cardiomyopathy (ACM) patient-derived iPSC-cardiac myocytes under basal conditions and inhibition of NFκB signaling prevents disease in Dsg2mut/mut mice, a robust mouse model of ACM. Here, we used genetic approaches and single cell RNA sequencing to define the contributions of immune signaling in cardiac myocytes and macrophages in the natural progression of ACM using Dsg2mut/mut mice. We found that NFκB signaling in cardiac myocytes drives myocardial injury, contractile dysfunction, and arrhythmias in Dsg2mut/mut mice. NFκB signaling in cardiac myocytes mobilizes macrophages expressing C-C motif chemokine receptor-2 (CCR2+ cells) to affected areas within the heart, where they mediate myocardial injury and arrhythmias. Contractile dysfunction in Dsg2mut/mut mice is caused both by loss of heart muscle and negative inotropic effects of inflammation in viable muscle. Single nucleus RNA sequencing and cellular indexing of transcriptomes and epitomes (CITE-seq) studies revealed marked pro-inflammatory changes in gene expression and the cellular landscape in hearts of Dsg2mut/mut mice involving cardiac myocytes, fibroblasts and CCR2+ macrophages. Changes in gene expression in cardiac myocytes and fibroblasts in Dsg2mut/mut mice were dependent on CCR2+ macrophage recruitment to the heart. These results highlight complex mechanisms of immune injury and regulatory crosstalk between cardiac myocytes, inflammatory cells and fibroblasts in the pathogenesis of ACM.

Basic and translational mechanisms in inflammatory arrhythmogenic cardiomyopathy

Arrhythmogenic cardiomyopathy (ACM) is a familial, nonischemic heart disease typically inherited via an autosomal dominant pattern (Nava et al., [1]; Wlodarska et al., [2]). Often affecting the young and athletes, early diagnosis of ACM can be complicated as incomplete penetrance with variable expressivity are common characteristics (Wlodarska et al., [2]; Corrado et al., [3]). That said, of the five desmosomal genes implicated in ACM, pathogenic variants in desmocollin-2 (DSC2) and desmoglein-2 (DSG2) have been discovered in both an autosomal-recessive and autosomal-dominant pattern (Wong et al., [4]; Qadri et al., [5]; Chen et al., [6]). Originally known as arrhythmogenic right ventricular dysplasia (ARVD), due to its RV prevalence and manifesting in the young, the disease was first described in 1736 by Giovanni Maria Lancisi in his book "De Motu Cordis et Aneurysmatibus" (Lancisi [7]). However, the first comprehensive clinical description and recognition of this dreadful disease was by Guy Fontaine and Frank Marcus in 1982 (Marcus et al., [8]). These two esteemed pathologists evaluated twenty-two (n = 22/24) young adult patients with recurrent ventricular tachycardia (VT) and RV dysplasia (Marcus et al., [8]). Initially, ARVD was thought to be the result of partial or complete congenital absence of ventricular myocardium during embryonic development (Nava et al., [9]). However, further research into the clinical and pathological manifestations revealed acquired progressive fibrofatty replacement of the myocardium (McKenna et al., [10]); and, in 1995, ARVD was classified as a primary cardiomyopathy by the World Health Organization (Richardson et al., [11]). Thus, now classifying ACM as a cardiomyopathy (i.e., ARVC) rather than a dysplasia (i.e., ARVD). Even more recently, ARVC has shifted from its recognition as a primarily RV disease (i.e., ARVC) to include left-dominant (i.e., ALVC) and biventricular subtypes (i.e., ACM) as well (Saguner et al., [12]), prompting the use of the more general term arrhythmogenic cardiomyopathy (ACM). This review aims to discuss pathogenesis, clinical and pathological phenotypes, basic and translational research on the role of inflammation, and clinical trials aimed to prevent disease onset and progression.

Platelet activation and endothelial dysfunction biomarkers in acute coronary syndrome: the impact of PCSK9 inhibition

AIMS

Platelet activation and endothelial dysfunction contribute to adverse outcomes in patients with acute coronary syndromes (ACS). The goals of this study were to assess the impact of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition on markers of platelet activation and endothelial dysfunction in ACS patients and the interaction among PCSK9, platelets, and endothelial cells (ECs) on left internal mammary artery (LIMA) vascular endothelium using specimens obtained during coronary artery bypass surgery (CABG).

METHODS AND RESULTS

Acute coronary syndromes patients enrolled in the Evolocumab in ACS trials were randomized to placebo or a single dose of 420 mg evolocumab within 24 h of hospitalization. Serum samples for analysis of platelet factor 4 (PF4) and P-selectin, markers of platelet activation, and von Willebrand factor (vWF), a marker of endothelial dysfunction, were obtained at baseline and 30 days. Additionally, LIMA segments obtained during CABG from patients who were and were not receiving evolocumab were immunostained with PCSK9; CD61, a platelet-specific marker; and CD31, an endothelial cell-specific marker. Forty-six participants were randomized to placebo or to evolocumab. Controlling for baseline levels, PF4 and vWF were significantly lower in the evolocumab, than in the placebo, group at 30 days. Immunostaining of LIMA specimens from twelve participants undergoing CABG revealed colocalization of PCSK9, CD61, and CD31 at the vascular endothelium. Administration of evolocumab was associated with decreased overlap of PCSK9, CD61, and CD31.

CONCLUSIONS

Proprotein Convertase Subtilisin/Kexin 9 inhibition decreases markers of platelet activation and endothelial dysfunction in ACS patients. PCSK9 is associated with platelets and vascular ECs in LIMA segments and PCSK9 inhibition decreases that interaction.

Mechanisms of Innate Immune Injury in Arrhythmogenic Cardiomyopathy

Inhibition of nuclear factor kappa-B (NFκB) signaling prevents disease in Dsg2 mut/mut mice, a model of arrhythmogenic cardiomyopathy (ACM). Moreover, NFκB is activated in ACM patient-derived iPSC-cardiac myocytes under basal conditions in vitro . Here, we used genetic approaches and sequencing studies to define the relative pathogenic roles of immune signaling in cardiac myocytes vs. inflammatory cells in Dsg2 mut/mut mice. We found that NFκB signaling in cardiac myocytes drives myocardial injury, contractile dysfunction, and arrhythmias in Dsg2 mut/mut mice. It does this by mobilizing cells expressing C-C motif chemokine receptor-2 (CCR2+ cells) to the heart, where they mediate myocardial injury and arrhythmias. Contractile dysfunction in Dsg2 mut/mut mice is caused both by loss of heart muscle and negative inotropic effects of inflammation in viable muscle. Single nucleus RNA sequencing and cellular indexing of transcriptomes and epitomes (CITE-seq) studies revealed marked pro-inflammatory changes in gene expression and the cellular landscape in hearts of Dsg2 mut/mut mice involving cardiac myocytes, fibroblasts and CCR2+ cells. Changes in gene expression in cardiac myocytes and fibroblasts in Dsg2 mut/mut mice were modulated by actions of CCR2+ cells. These results highlight complex mechanisms of immune injury and regulatory crosstalk between cardiac myocytes, inflammatory cells, and fibroblasts in the pathogenesis of ACM.

BRIEF SUMMARY

We have uncovered a therapeutically targetable innate immune mechanism regulating myocardial injury and cardiac function in a clinically relevant mouse model of Arrhythmogenic Cardiomyopathy (ACM).

Efficacy and Safety of Angiotensin Receptor Blockers in a Pre-Clinical Model of Arrhythmogenic Cardiomyopathy

Arrhythmogenic Cardiomyopathy (ACM) is a familial heart disease, characterized by contractile dysfunction, ventricular arrhythmias (VAs), and the risk of sudden cardiac death. Currently, implantable cardioverter defibrillators and antiarrhythmics are the mainstays in ACM therapeutics. Angiotensin receptor blockers (ARBs) have been highlighted in the treatment of heart diseases, including ACM. Yet, recent research has additionally implicated ARBs in the genesis of VAs and myocardial lipolysis via the peroxisome proliferator-activated receptor gamma (PPARγ) pathway. The latter is of particular interest, as fibrofatty infiltration is a pathological hallmark in ACM. Here, we tested two ARBs, Valsartan and Telmisartan, and the PPAR agonist, Rosiglitazone, in an animal model of ACM, homozygous Desmoglein-2 mutant mice (Dsg2mut/mut). Cardiac function, premature ventricular contractions (PVCs), fibrofatty scars, PPARα/γ protein levels, and PPAR-mediated mRNA transcripts were assessed. Of note, not a single mouse treated with Rosiglitazone made it to the study endpoint (i.e., 100% mortality: n = 5/5). Telmisartan-treated Dsg2mut/mut mice displayed the preservation of contractile function (percent ejection fraction [%EF]; 74.8 ± 6.8%EF) compared to Vehicle- (42.5 ± 5.6%EF) and Valsartan-treated (63.1 ± 4.4%EF) mice. However, Telmisartan-treated Dsg2mut/mut mice showed increased cardiac wall motion abnormalities, augmented %PVCs, electrocardiographic repolarization/depolarization abnormalities, larger fibrotic lesions, and increased expression of PPARy-regulated gene transcripts compared to their Dsg2mut/mut counterparts. Alternatively, Valsartan-treated Dsg2mut/mut mice harbored fewer myocardial scars, reduced %PVC, and increased Wnt-mediated transcripts. Considering our findings, caution should be taken by physicians when prescribing medications that may increase PPARy signaling in patients with ACM.

Proprotein convertase subtilisin/kexin type 9 (PCSK9), platelet activation and interaction with the vascular endothelium: the impact of PCSK9 inhibition with evolocumab in acute coronary syndrome

Background/Introduction

Platelet activation and endothelial dysfunction may contribute to adverse outcomes in patients with acute myocardial infarction. Pre-clinical studies indicate PCSK9 enhances platelet activation.

Purpose

Our goals were (1) to examine the role of PCSK9 as a potential mediator of platelet activation in patients with acute coronary syndrome (ACS) and (2) to perform immunohistochemical studies of left internal mammary artery (LIMA) specimens to examine interactions among PCSK9, platelets, and endothelial cells in specimens obtained during coronary bypass surgery.

Methods

Participants from the Evolocumab in Acute Coronary Syndrome trials (EVACS; NCT03515304, NCT04082442), with a NSTEMI and a troponin-I of >5 ng/ml or a STEMI were randomized to placebo or to 420 mg SC of evolocumab, a monoclonal anti-PCSK9 antibody, within 24 hours of hospitalization. We performed serial ex vivo analysis of PF4, a marker of platelet activation, in serum samples obtained at baseline (prior to study drug administration) and at day 30. PF4 values were normalized to total platelet count. All of the participants were on guideline-directed therapies for ACS. Additionally, LIMA samples from patients undergoing coronary bypass surgery were immunostained with PCSK9, the endothelial cell transmembrane glycoprotein CD31 (platelet endothelial cell adhesion molecule-1) and the platelet surface marker CD61 (integrin beta-3). Outcome data were summarized using medians and interquartile ranges.

Results

Forty-six participants were randomized in a 1:1 fashion to placebo or to evolocumab. Mean (±SD) age of the cohort was 60±13 years, 48% were women and 22% were African American. Baseline PF4 levels (expressed as ng/1k platelets) were similar between the two groups (placebo: 9.3 [4–12] vs evolocumab 8.0 [4–12], p=0.8). In the placebo group, there was a significant increase in PF4 at 30 days to 13.1 [11–14], p<0.01 (baseline vs 30 days). In contrast, there was no significant change from baseline in the evolocumab group at 30 days (10.7 [6–13]), which was significantly lower than the placebo group (p=0.04). Furthermore, immunostaining of LIMA specimens obtained from patients during coronary artery bypass surgery revealed colocalization of PCSK9, CD31, and CD61 on the vascular endothelial cell surface (see Figure).

Conclusion

PCSK9 inhibition with evolocumab decreases platelet activation in ACS patients on dual anti-platelet therapy. PCSK9 is associated with platelets and endothelial cells at the vascular endothelium. PCSK9 is a potential mediator of the interaction between platelets and vascular endothelial cells in patients with coronary artery disease.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Amgen

Photogrammetric evaluation of corrective surgery for trigonocephaly

The aim of this study was to capture preoperative, postoperative, and follow-up head shapes of male trigonocephaly patients who underwent fronto-orbital remodelling (FOR), using three-dimensional (3D) photography. Fifty-seven male infants with metopic synostosis operated on using standardized FOR during a 5-year period were included. All measurements were compared with those of an age-matched healthy control cohort (n = 253 for early postoperative comparison, n = 43 for the 1-year follow-up comparison) to determine the effect of FOR at 14 days and at 1 year post-surgery. Intracranial volume, frontal angle, nasofrontal angle, interfrontoparietal-interparietal ratio, and inter-orbital distances were measured 1 day preoperatively, 14 days and 1 year postoperatively. Mean age at surgery was 9.7 ± 1.1 months. Prior to surgery, boys with metopic synostosis showed a reduced intracranial volume (-7.0%, P < 0.001), frontal angle (-10.2%, P < 0.001), interfrontoparietal-interparietal ratio (-4.9%, P < 0.01), and orbital distances (-6.5%, P < 0.001) compared to the reference group, but values did not differ significantly from the specific control group after surgery (all P> 0.05). This was consistent by the time of the follow-up examination. Corrective surgery should therefore aim to achieve volume expansion and correction of the deformity. Furthermore, 3D photogrammetry provides a valuable alternative to computed tomography scans in the diagnosis of metopic synostosis, significantly reducing the amount of radiation exposure to the brain.

An appraisal of laboratory models of androgenetic alopecia: A systematic review

Background

Androgenetic alopecia (AGA) is the most common form of non‐scarring alopecia in humans. Several studies have used different laboratory models to study the pathogenesis and interventions for AGA. These study models have proved beneficial and have led to the approval of two drugs. However, the need to build on existing knowledge remains by examining the relevance of study models to the disease.

Objective

We sought to appraise laboratory or pre‐clinical models of AGA.

Method

We searched through databases (PubMed, ScienceDirect, Web of Science, World CAT, Scopus and Google Scholar) for articles on AGA‐related studies from 1942 to March 2019 with a focus on study models.

Results

The search rendered 101 studies after screening and deduplication. Several studies (70) used in vitro models, mostly consisting of two‐dimensional monolayer cells for experiments involving the characterization of androgen and 5‐alpha reductase (5AR) and inhibition thereof, the effects of dihydrotestosterone (DHT) and biomarker(s) of AGA. Twenty‐seven studies used in vivo models of mice and monkeys to investigate DHT synthesis, the expression and inhibition of 5AR and hair growth. Only four studies used AGA‐related or healthy excisional/punch biopsy explants as ex vivo models to study the action of 5AR inhibitors and AGA‐associated genes. No study used three‐dimensional [3‐D] organoids or organotypic human skin culture models.

Conclusion

We recommend clinically relevant laboratory models like human or patient‐derived 3‐D organoids or organotypic skin in AGA‐related studies. These models are closer to human scalp tissue and minimize the use of laboratory animals and could ultimately facilitate novel therapeutics.

Spatio-temporal analysis of the risk of depression at district-level and association with greenness based on the Heinz Nixdorf Recall Study

In urban health studies where spatial and temporal changes are of importance, spatio-temporal variations are usually neglected. For the Heinz Nixdorf Recall Study, we investigate spatio-temporal variation in analyses of effects of urban greenness on depression by including spatio-temporal random effect terms in a Poisson model on district level. Our results show negative associations between greenness and depression. The findings suggest strong temporal autocorrelation and weak spatial effects. Even if the weak spatial effects are suggestive of neglecting them, as in our case, spatio-temporal random effects should be taken into account to provide reliable inference in urban health studies.

Topographic bone thickness maps to evaluate the intuitive placement of titanium miniplates for nasal prostheses

The aim of this study was to evaluate the intuitive placement of titanium miniplates. The hypothesis was that virtual planning can improve miniplate placement. Twenty patients were included in the study. These patients were fitted with 21 titanium miniplates (16 y-plates, three t-plates, and two u-plates) to retain nasal prostheses between 2005 and 2017. Colour-coded topographic bone thickness maps (TBTMs) were created in fused pre- and postoperative computed tomography. Implants were virtually transposed at the position of highest bone thickness. The bone thickness index (BTI) was calculated as the sum of points assigned at each screw (1 point per millimetre up to 4 mm, and 5 points for greater values) divided by the number of screws. One plate broke after 2.8 years, thus plate survival after 5 years was 91% using the Kaplan-Meier method. The BTI for all 21 plates increased from 3.4 to 4.1 points using virtual transposition (P<0.001). No significant changes were observed in t- and u-plates, but the median BTI increased from 3.1 to 4.1 points (P<0.0005) in 16 y-plates. The change was substantial (≥0.5 points) in 9/16 y-plates. Therefore, the hypothesis that virtual planning improves implant placement was accepted.

The prognostic significance of the lymph node ratio in oral cancer differs for anatomical subsites

The aim of this study was to validate the prognostic significance of the lymph node ratio (LNR) in patients suffering from oral squamous cell carcinoma in regard to different anatomical subsites. A cohort of 430 patients was investigated to determine the rates of primary metastasis and local and regional disease recurrence. Correlation analysis of the LNR with relevant clinical and pathological parameters was performed. Receiver operating characteristic (ROC) curve analysis was conducted to evaluate the prognostic impact for different subsites. Significantly differing rates of primary metastasis and loco-regional disease recurrence were found for cancer of different anatomical subsites of the head and neck. Furthermore, ROC curve analysis suggested that LNR has prognostic relevance in subsets of cancer (tongue, P< 0.001; alveolar process, P= 0.04; maxilla, P= 0.03; buccal mucosa, P= 0.02). The LNR of cancer located in the soft palate (P= 0.6) and floor of the mouth (P= 0.11) showed little or no association with the clinical outcome. There is the need for a more sensitive consideration of the LNR as a factor in the assessment of risk and the treatment decision, as the anatomical subsite plays a crucial role in its impact on the clinical outcome.

Long-term donor site morbidity in head and neck cancer patients and its impact on quality of life: a cross-sectional study

Modern head and neck reconstructive surgery offers a multitude of different reconstructive options. In such cases, donor site morbidity is an important factor in the affected patient's decision-making. The aim of this study was to perform an objective comparison of donor site morbidity for the five most frequent microvascular donor sites in head and neck reconstructive surgery (radial forearm, anterolateral thigh, fibula, iliac crest, and scapula) using a uniform testing system. In this cross-sectional study, 117 donor sites were analyzed (106 for malignant disease and 11 for non-malignant disease): 73 radial forearm, 14 scapula, 12 anterolateral thigh, 10 fibula, and eight iliac crest. Testing consisted of range of motion, muscle strength, and sensation. The non-affected side served as the control. Quality of life was assessed using the Washington Quality of Life Questionnaire version 4 in its German translation. Range of motion was restricted in 15 cases (12.8%). Muscle strength was decreased in 58 cases (49.6%). Sensation was reduced in 70 cases (60%). Concerning quality of life, 31.2% of patients were limited in their daily activities. The scapula flap showed the highest incidence of overall donor site morbidity. However, correlation between objective and subjective donor site impairment was weak and the majority of patients experienced only minor limitations.

MetaMap: an atlas of metatranscriptomic reads in human disease-related RNA-seq data

Background

With the advent of the age of big data in bioinformatics, large volumes of data and high-performance computing power enable researchers to perform re-analyses of publicly available datasets at an unprecedented scale. Ever more studies imply the microbiome in both normal human physiology and a wide range of diseases. RNA sequencing technology (RNA-seq) is commonly used to infer global eukaryotic gene expression patterns under defined conditions, including human disease-related contexts; however, its generic nature also enables the detection of microbial and viral transcripts.

Findings

We developed a bioinformatic pipeline to screen existing human RNA-seq datasets for the presence of microbial and viral reads by re-inspecting the non-human-mapping read fraction. We validated this approach by recapitulating outcomes from six independent, controlled infection experiments of cell line models and compared them with an alternative metatranscriptomic mapping strategy. We then applied the pipeline to close to 150 terabytes of publicly available raw RNA-seq data from  more than 17,000 samples from more than 400 studies relevant to human disease using state-of-the-art high-performance computing systems. The resulting data from this large-scale re-analysis are made available in the presented MetaMap resource.

Conclusions

Our results demonstrate that common human RNA-seq data, including those archived in public repositories, might contain valuable information to correlate microbial and viral detection patterns with diverse diseases. The presented MetaMap database thus provides a rich resource for hypothesis generation toward the role of the microbiome in human disease. Additionally, codes to process new datasets and perform statistical analyses are made available.

The emerging role of mRNA methylation in normal and pathological behavior

Covalent RNA modifications were recently rediscovered as abundant RNA chemical tags. Similarly to DNA epigenetic modifications, they have been proposed as essential regulators of gene expression. Here we focus on 3 of the most abundant adenosine methylations: N6-methyladenosine (m⁶ A), N6,2'-O-dimethyladenosine (m⁶ Am) and N1-methyladenosine (m¹ A). We review the potential role of these modifications on mature mRNA in regulating gene expression within the adult brain, nervous system function and normal and pathological behavior. Dynamic mRNA modifications, summarized as the epitranscriptome, regulate transcript maturation, translation and decay, and thus crucially determine gene expression beyond primary transcription regulation. However, the extent of this regulation in the healthy and maladapted adult brain is poorly understood. Analyzing this novel layer of gene expression control in addition to epigenetics and posttranslational regulation of proteins will be highly relevant for understanding the molecular underpinnings of behavior and psychiatric disorders.

Environmental and mucosal microbiota and their role in childhood asthma

BACKGROUND

High microbial diversity in the environment has been associated with lower asthma risk, particularly in children exposed to farming. It remains unclear whether this effect operates through an altered microbiome of the mucosal surfaces of the airways.

METHODS

DNA from mattress dust and nasal samples of 86 school age children was analyzed by 454 pyrosequencing of the 16S rRNA gene fragments. Based on operational taxonomic units (OTUs), bacterial diversity and composition were related to farm exposure and asthma status.

RESULTS

Farm exposure was positively associated with bacterial diversity in mattress dust samples as determined by richness (P = 8.1 × 10^-6 ) and Shannon index (P = 1.3 × 10^-5 ). Despite considerable agreement of richness between mattress and nasal samples, the association of richness with farming in nasal samples was restricted to a high gradient of farm exposure, that is, exposure to cows and straw vs no exposure at all. In mattress dust, the genera Clostridium, Facklamia, an unclassified genus within the family of Ruminococcaceae, and six OTUs were positively associated with farming. Asthma was inversely associated with richness [aOR = 0.48 (0.22-1.02)] and Shannon index [aOR = 0.41 (0.21-0.83)] in mattress dust and to a lower extent in nasal samples [richness aOR 0.63 = (0.38-1.06), Shannon index aOR = 0.66 (0.39-1.12)].

CONCLUSION

The stronger inverse association of asthma with bacterial diversity in mattress dust as compared to nasal samples suggests microbial involvement beyond mere colonization of the upper airways. Whether inhalation of metabolites of environmental bacteria contributes to this phenomenon should be the focus of future research.

Intracranial volume (ICV) in isolated sagittal craniosynostosis measured by 3D photocephalometry: A new perspective on a controversial issue

BACKGROUND

There are still controversies regarding the intracranial volumes in patients with isolated sagittal craniosynostosis compared to a healthy population. This study aimed to compare the intracranial volume of children with sagittal synostosis and scaphocephaly to an age- and gender-matched control cohort using three-dimensional (3D) photogrammetry.

METHODS

62 boys and nine girls with sagittal craniosynostosis were included in this study. The intracranial volume was measured at the first clinical presentation. However, 3D photogrammetry was performed at children not younger than 3 months. The 3D photogrammetric data of 547 healthy boys and 287 healthy girls between the ages of 3-10 month was analyzed to establish an age- and gender-matched control group.

RESULTS

Male patients with sagittal synostosis showed a significantly reduced intracranial volume compared to the reference group. For female patients, the intracranial volume was slightly lower compared to the norm group, but not significantly.

CONCLUSIONS

Male children with sagittal synostosis showed significantly decreased intracranial volume between the age of 3 and 10 months compared to an age- and gender-matched control group. Female patients in the same age group presented a lower intracranial volume compared to the norm group. Measuring intracranial volume using 3D photogrammetry is a comparable and valuable alternative to CT scans that leads to a significant reduction of radiation exposure to the growing brain.

Management of pediatric delirium in critical illness: a practical update

Pediatric delirium (PD) is an acute state of brain dysfunction and is often seen in the pediatric intensive care unit (PICU). There is a growing awareness of its clinical interdisciplinary importance. The aim of this article was to describe the three clinical presentations, to evaluate the differential diagnosis and to give a concise and practical update for the pharmacological and non-pharmacological treatment of PD at the PICU, based on recent literature and expert opinions. We discuss an interdisciplinary flow chart which helps the reader dealing with the diagnosis and management of any acute emotional and or behavioral disturbance, of which PD is a special case.