Temper outbursts in Prader-Willi syndrome: causes, behavioural and emotional sequence and responses by carers

Disengagement of somatostatin neurons from lateral septum circuitry by oxytocin and vasopressin restores social-fear extinction and suppresses aggression outbursts in Prader-Willi syndrome model

Background

Responding to social signals by expressing the correct behavior is not only challenged in autism, but also in diseases with high prevalence of autism, like Prader-Willi Syndrome (PWS). Clinical evidence suggests aberrant pro-social behavior in patients can be regulated by intranasal oxytocin (OXT) or vasopressin (AVP). However, what neuronal mechanisms underlie impaired behavioral responses in a socially-aversive context, and how can they be corrected, remains largely unknown.

Methods

Using the Magel2 knocked-out (KO) mouse model of PWS (crossed with CRE-dependent transgenic lines), we devised optogenetic, physiological and pharmacological strategies in a social-fear-conditioning paradigm. Pathway specific roles of OXT and AVP signaling were investigated converging on the lateral septum (LS), a region which receives dense hypothalamic inputs.

Results

OXT and AVP signaling promoted inhibitory synaptic transmission in the LS, which failure in Magel2KO mice disinhibited somatostatin (SST) neurons and disrupted social-fear extinction. The source of OXT and AVP deficits mapped specifically in the supraoptic nucleus→LS pathway of Magel2KO mice disrupting social-fear extinction, which could be corrected by optogenetic or pharmacological inhibition of SST-neurons in the LS. Interestingly, LS SST-neurons also gated the expression of aggressive behavior, possibly as part of functional units operating beyond local septal circuits.

Conclusions

SST cells in the LS play a crucial role in integration and expression of disrupted neuropeptide signals in autism, thereby altering the balance in expression of safety versus fear. Our results uncover novel mechanisms underlying dysfunction in a socially-aversive context, and provides a new framework for future treatments in autism-spectrum disorders.

Characterising the behaviours in most severe and least severe emotional outbursts in young people

Emotional outbursts are displays of intense, challenging behaviour and are prevalent in individuals with neurodevelopmental disorders. Outbursts present a danger to individuals and their carers and are cited as reasons for referral to mental health services. However, it is currently unclear how the characteristics of outbursts may determine their severity. Carers (n = 214) of individuals aged between 6 and 25 and experiencing outbursts at least once per month completed the Emotional Outburst Questionnaire. Questionnaire items were used to compare behaviours observed in most severe and least severe outbursts through quantitative and content analyses of open ended data. Signs of physiological arousal and aggression were seen significantly more in most severe outbursts compared to least severe outbursts. Least severe outbursts were seen more frequently, but most severe outbursts were reported to have a longer duration, be at a higher intensity, and have a longer recovery time. Additionally, associations were found between reduced eye contact and most severe outbursts, as well as expression of suicidal ideation and most severe outbursts. Certain behaviours, notably forms of aggression and physiological arousal, are associated with most severe outbursts. Findings of this study may allow future work examining cross-disorder differences in outbursts to inform targeted interventions aiming to reduce outburst severity and impact. Additionally, identification of such outburst characteristics could aid in measurement of outburst severity, which would allow for more reliable and valid studies on outburst interventions.

Cross-Cultural Comparison of the Contexts Associated with Emotional Outbursts

The causal relationship between emotional outbursts and emotion dysregulation is proposed to be heterogeneous, but cultural influences have not been considered despite established cultural differences in emotional processes (e.g., increased motivation to suppress emotions in interdependent cultures). Responses to the Brazilian Portuguese version of the Emotional Outburst Questionnaire were collected from 327 caregivers of young people (6-25 years) with autism spectrum disorder, Down's syndrome, or intellectual disability. Responses were compared to a previous sample of 268 responses from the English version of the questionnaire. The latent factor structure of the contextual items was measurement invariant across both versions. The Brazilian responses were classified into three distinct clusters (Sensory Sensitivity; Perceived Safety; Perceived Unsafety) which considerably overlapped with the English clusters.

Behaviours that Challenge in SATB2-associated Syndrome: Correlates of Self-injury, Aggression and Property Destruction

SATB2-associated syndrome (SAS) is a genetic syndrome characterised by intellectual disability, severe speech delay, and palatal and dental problems. Behaviours that challenge (BtC) are reported frequently; however, there is limited research on specific forms of BtC and the correlates of these behaviours. The current study explores correlates of well-defined BtC, self-injury, aggression, and property destruction, in SAS. Eighty-one parents/caregivers of individuals with SAS (53.1% male, Mage 10.12 years) completed questionnaire measures of health, behavioural, emotional, and autism characteristics. Individuals with SAS were grouped based on caregiver responses to the presence or absence of self-injury, aggression, and property destruction on the Challenging Behaviour Questionnaire. Rates of self-injury, aggression and property destruction were 42%, 77% and 49%, respectively. Between-group comparisons were conducted to compare characteristics between behaviour groups. Significantly differing characteristics were entered into separate hierarchical logistic regressions for each form of BtC. Behavioural comparisons indicated variation in the characteristics associated with each behaviour. All hierarchical logistic regression models were significant (p < .001): self-injury (χ2(5) = 38.46, R2 = 0.571), aggression (χ2(4) = 25.12, R2 = 0.414), property destruction (χ2(4) = 23.70, R2 = 0.346), explaining between 34.6% and 57.1% of the variance in behaviour presence. This is the first study to identify correlates of self-injury, aggression, and property destruction in SAS. Variability in the characteristics associated with each behaviour highlights the importance of specificity when examining BtC. Understanding correlates of specific forms of BtC has important implications for informing SAS-associated pathways to behavioural outcomes and the implementation of tailored behavioural interventions.

Systematic Review: Emotion Dysregulation in Syndromic Causes of Intellectual and Developmental Disabilities

OBJECTIVE

To summarize the current state of the literature regarding emotion dysregulation (ED) in syndromic intellectual disabilities (S-IDs) in 6 of the most common forms of S-IDs-Down syndrome, fragile X syndrome (FXS), tuberous sclerosis complex, Williams syndrome, Prader-Willi syndrome, and Angelman syndrome-and to determine future research directions for identification and treatment of ED.

METHOD

PubMed bibliographic database was searched from date of inception to May 2021. PRISMA 2020 guidelines were followed with the flowchart, table of included studies, list of excluded studies, and checklist provided. Filters applied included human research and English. Only original research articles were included in the final set, but review articles were used to identify secondary citations of primary studies. All articles were reviewed for appropriateness by 2 authors and summarized. Inclusion criteria were met by 145 articles (Down syndrome = 29, FXS = 55, tuberous sclerosis complex = 11, Williams syndrome = 18, Prader-Willi syndrome = 24, Angelman syndrome = 8).

RESULTS

Each syndrome review was summarized separately and further subdivided into articles related to underlying neurobiology, behaviors associated with ED, assessment, and targeted intervention. FXS had the most thorough research base, followed by Down syndrome and Prader-Willi syndrome, with the other syndromes having more limited available research. Very limited research was available regarding intervention for all disorders except FXS.

CONCLUSION

Core underlying characteristics of S-IDs appear to place youth at higher risk for ED, but further research is needed to better assess and treat ED in S-IDs. Future studies should have a standard assessment measure of ED, such as the Emotion Dysregulation Inventory, and explore adapting established curricula for ED from the neurotypical and autism spectrum disorder fields.

Establishing the transdiagnostic contextual pathways of emotional outbursts

Emotional outbursts or temper outbursts are challenging behaviours commonly experienced by people with neurodevelopmental disorders and people who have experienced childhood adversity, which can negatively impact individuals and their families. Emotional outbursts may manifest in different situations via unique pathways distinguished by context-specific differences in the regulation and expression of emotions. Caregivers (N = 268) of young people (6-25 years) with emotional outbursts completed a bespoke caregiver-report questionnaire. Potential pathways were identified by examining the patterns of antecedents and setting events related to outbursts through factor and cluster analyses. Six contextual factors were derived from the Emotional Outburst Questionnaire. Based on these factors, the responses were classified into three clusters, which may represent potential pathways of emotional outbursts. The three clusters were characterized by the increased likelihood of outbursts: (1) across all setting events and triggers; (2) in safe setting events; (3) in unsafe setting events. These potential pathways may be related to: (1) differences in sensory processing; (2) masking of emotions in unsafe environments; (3) differences in safety perception. This framework supports a transdiagnostic account of emotional outbursts and may facilitate the development of pathway-specific intervention strategies.

Understanding Phasic Irritability: Anger and Distress in Children's Temper Outbursts

Pediatric irritability can be highly impairing and is implicated in adverse outcomes. The phasic component, characterized by temper outbursts, is a frequent impetus to seek treatment. This study tested whether a previously described anger-distress model of tantrums applies to an outpatient sample of school-age children with clinically impairing temper outbursts (TO; 5.0-9.9 years; N = 86), and examined the clinical relevance of resulting factors through associations with measures of psychopathology, and differences between children with TO and two groups without: children with ADHD (n = 60) and healthy controls (n = 45). Factor analyses established a three-factor model: High Anger, Low Anger, Distress. These factors had unique associations with measures of irritability, externalizing problems, and internalizing problems in the TO group. Additionally, an interaction between groups and outburst factors emerged. Results provide evidence for the presence and clinical utility of the anger-distress model in children's outbursts and suggest avenues for future pediatric irritability research.

The Hyperphagia Questionnaire: Insights From a Multicentric Validation Study in Individuals With Prader Willi Syndrome

BACKGROUND/OBJECTIVES

The present study aimed to validate the Italian version of the Hyperphagia Questionnaire (HQ), a 11-items questionnaire developed to assess hyperphagia in individuals with Prader-Willi syndrome (PWS). This is a complex neurodevelopmental disorder characterized by endocrine dysfunction, hypotonia, intellectual disability, psychiatric disorders and obesity.

METHODS

Parents of 219 individuals with PWS (age range 3-54 years; Mage = 17.90; 108 Males), recruited in 12 hospitals in Italy responded to HQ during routine visits. In function of the level of analyses the sample was divided into two subgroups (<18> years) or into four age-subgroups (2.5-4.5; 4.5-8; 8-18; >18 years) corresponding to different clinical stages.

RESULTS

Confirmatory factor analysis (CFA) confirmed the three hyperphagic subdimensions of the original structure (behavior, drive, and severity), but one item was dropped out, reducing the final version to 10 items. Using multi-group CFA, HQ showed satisfactory indexes of measurement invariance by age. Good indexes of internal consistency (Cronbach's alpha and McDonald's Omega coefficients) were found for each subdimension. The three hyperphagia subdimensions positively converged with other food-related measures: emotional overeating, food enjoyment, food responsiveness, and satiety responsiveness. A significant increase of all hyperphagic subdimensions was found across age groups. Higher hyperphagic levels were found in participants with higher body mass index. Hyperphagic drive differently increased in function of the interaction between age and underlying genetic mechanisms.

CONCLUSION

The Italian version of the HQ is a psychometrically valid and reliable instrument for assessing hyperphagia in individuals with PWS. This tool may prove useful to evaluate the efficacy of pharmacologic and rehabilitative treatments.

Study of the deficit in planning abilities of adults with Prader-Willi Syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a complex developmental genetic disorder associated with intellectual disability and deficits in executive functions which result in disorganisation and poor personal autonomy.

AIMS

This study aimed to determine impairments in planning skills of adults with PWS, in relation with their intellectual disabilities, as well as the influence of food compulsions on their performance.

METHODS AND PROCEDURES

A modified version of the Zoo Map from the Behavioural Assessment of the Dysexecutive Syndrome was used in three groups: a group of adults with PWS in comparison with two groups both matched on chronological age, one with typical development (TD) and one with intellectual disability (ID).

OUTCOMES AND RESULTS

Compared to TD adults, both adults with PWS and ID showed increased planning time and lower raw scores on the planning task. The execution time and the number of errors were higher in the PWS group compared to the comparison groups. All three groups performed worse in the non-food condition only for number of errors and raw score.

CONCLUSIONS AND IMPLICATIONS

Planning abilities were impaired in PWS adults. Results also showed that intellectual level plays a role in participants' performance. These findings are essential to understand the difficulties of people with PWS daily life.

Behavioral features in Prader-Willi syndrome (PWS): consensus paper from the International PWS Clinical Trial Consortium

Prader-Willi syndrome (PWS) is a rare neurodevelopmental genetic disorder associated with a characteristic behavioral phenotype that includes severe hyperphagia and a variety of other behavioral challenges such as temper outbursts and anxiety. These behaviors have a significant and dramatic impact on the daily functioning and quality of life for the person with PWS and their families. To date, effective therapies addressing these behavioral challenges have proven elusive, but several potential treatments are on the horizon. However, a limiting factor for treatment studies in PWS is the lack of consensus in the field regarding how to best define and measure the complex and interrelated behavioral features of this syndrome. The International PWS Clinical Trials Consortium (PWS-CTC, www.pwsctc.org) includes expert PWS scientists, clinicians, and patient advocacy organization representatives focused on facilitating clinical trials in this rare disease. To address the above gap in the field, members of the PWS-CTC “Behavior Outcomes Working Group” sought to develop a unified understanding of the key behavioral features in PWS and build a consensus regarding their definition and description. The primary focus of this paper is to present consensus definitions and descriptions of key phenotypic PWS behaviors including hyperphagia, temper outbursts, anxiety, obsessive–compulsive behaviors, rigidity, and social cognition deficits. Patient vignettes are provided to illustrate the interrelatedness and impact of these behaviors. We also review some available assessment tools as well as new instruments in development which may be useful in measuring these behavioral features in PWS.

Firing activity of locus coeruleus noradrenergic neurons decreases in necdin-deficient mice, an animal model of Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by multiple respiratory, cognitive, endocrine, and behavioral symptoms, such as central apnea, intellectual disabilities, exaggerated stress responses, and temper tantrums. The locus coeruleus noradrenergic system (LC-NE) modulates a diverse range of behaviors, including arousal, learning, pain modulation, and stress-induced negative affective states, which are possibly correlated with the pathogenesis of PWS phenotypes. Therefore, we evaluated the LC-NE neuronal activity of necdin-deficient mice, an animal model of PWS.

METHODS

Heterozygous necdin-deficient mice (B6.Cg-Ndntm1ky) were bred from wild-type (WT) females to generate WT (+m/+p) and heterozygotes (+m/-p) animals, which were examined of LC-NE neuronal activity, developmental reflexes, and plethysmography.

RESULTS

On slice electrophysiology, LC-NE neurons of Ndntm1ky mice with necdin deficiency showed significantly decreased spontaneous activities and impaired excitability, which was mediated by enhanced A-type voltage-dependent potassium currents. Ndntm1ky mice also exhibited the neonatal phenotypes of PWS, such as hypotonia and blunt respiratory responses to hypercapnia.

CONCLUSIONS

LC-NE neuronal firing activity decreased in necdin-deficient mice, suggesting that LC, the primary source of norepinephrine in the central nervous system, is possibly involved in PWS pathogenesis.

Skin Picking in People with Prader-Willi Syndrome: Phenomenology and Management

Skin picking is highly prevalent in people with Prader-Willi syndrome (PWS). This study addressed the temporal (frequency, duration) and wider characteristics (e.g. type of skin picked, apparent motivations, or management strategies) of skin picking to inform intervention strategies. Nineteen parents/carers who observe skin picking shown by the person they care for completed a semi-structured interview. Results were consistent with previous research but advanced the field by finding that most participants picked skin with an imperfection and that parents/carers most commonly use distraction as a management strategy. Interventions that are behavioural, support emotion regulation and/ or are used in the typically developing population are therefore likely to be beneficial for future research.

Psychological treatment strategies for challenging behaviours in neurodevelopmental disorders: what lies beyond a purely behavioural approach?

PURPOSE OF REVIEW

Challenging behaviour shown by individuals with neurodevelopmental disorders (NDDs) has a major negative impact. There is robust evidence for the efficacy of treatments based on applied behaviour analysis. However, such approaches are limited in important ways - providing only part of the whole solution. We reviewed the literature to provide an overview of recent progress in psychological treatments for challenging behaviour and how these advance the field beyond a purely behavioural approach.

RECENT FINDING

We identified 1029 articles via a systematic search and screened for those implementing a psychological intervention with individuals with NDD (or caregivers) and measuring the potential impact on challenging behaviour. Of the 69 included studies published since 2018, more than 50% implemented a purely behavioural intervention. Other studies could generally be categorized as implementing parent training, meditation, skill training or technology-assisted interventions.

SUMMARY

Greater consideration of the interplay between behavioural and nonbehavioural intervention components; systematic approaches to personalization when going beyond the behavioural model; mental health and broad social communication needs; and models that include cognitive and emotional pathways to challenging behaviour; is needed to advance the field. Furthermore, technology should not be overlooked as an important potential facilitator of intervention efforts.

Food and Non-Food-Related Behavior across Settings in Children with Prader-Willi Syndrome

This study sought to describe food- and non-food-related behaviors of children aged 3 to 18 years with Prader–Willi syndrome (PWS) in home and school settings, as assessed by 86 parents and 63 teachers using 7 subscales of the Global Assessment of Individual’s Behavior (GAIB). General Behavior Problem, Non-Food-Related Behavior Problem, and Non-Food-Related Obsessive Speech and Compulsive Behavior (OS/CB) scores did not differ significantly between parent and teacher reports. Food-Related Behavior Problem scores were higher in parent versus teacher reports when the mother had less than a college education (difference of 13.6 points, 95% Confidence Interval (CI) 5.1 to 22). Parents assigned higher Food-Related OS/CB scores than teachers (difference of 5.7 points, 95% CI 2.4 to 9.0). Although teachers reported fewer Food-Related OS/CB, they scored overall OS/CB higher for interfering with daily activities compared with parents (difference of 0.9 points, 95% CI 0.4 to 1.4). Understanding how behaviors manifest in home and school settings, and how they vary with socio-demographic and patient characteristics can help inform strategies to reduce behavior problems and improve outcomes.

Temper outbursts in Lowe syndrome: Characteristics, sequence, environmental context and comparison to Prader-Willi syndrome

BACKGROUND

There is limited research into the nature and aetiology of temper outbursts in people with intellectual disabilities. In this study, we describe the phenomenology and environmental context of temper outbursts in Lowe syndrome, a rare genetic syndrome in which outbursts are purportedly frequent.

METHOD

A temper outburst interview (TOI) was conducted with caregivers of seventeen individuals with Lowe syndrome to generate an account of the behavioural sequence, common antecedents and consequences of temper outbursts, and to enable comparisons with similar work on Prader-Willi syndrome.

RESULTS

Outbursts in Lowe syndrome were frequently triggered by thwarted goal-directed behaviour and were associated with high levels of physical aggression and property destruction.

CONCLUSIONS

Form and sequence of outbursts showed similarities to Prader-Willi syndrome and to behaviours reported in literature on typically developing children. The results highlight the importance of considering shared aetiology as well as syndrome-specific pathways in the development of outbursts.

Brief Report: Challenging Behaviors in Toddlers and Preschoolers with Angelman, Prader-Willi, and Williams Syndromes

Children with neurogenetic syndromes (NGS) experience comorbid challenging behaviors and psychopathology. We examined challenging behaviors in 86 toddlers and preschoolers across three NGS [Angelman syndrome (AS), Prader-Willi syndrome (PWS), and Williams syndrome (WS)] and 43 low-risk controls (LRC), using the Child Behavior Checklist for Ages 1½-5. Challenging behavior profiles differed across NGS, with generally elevated behaviors in AS and WS, but not PWS, relative to LRC. Withdrawn and autism spectrum symptoms were particularly elevated in AS. Although several profiles were similar to those previously reported in older children and adults, we also observed inconsistencies that suggest non-linear developmental patterns of challenging behaviors. These findings underscore the importance of characterizing early challenging behaviors to inform atypical phenotypic development and targeted intervention.

Guanfacine Extended Release for the Reduction of Aggression, Attention-Deficit/Hyperactivity Disorder Symptoms, and Self-Injurious Behavior in Prader-Willi Syndrome-A Retrospective Cohort Study

Objective: To examine the role of Guanfacine Extended Release (GXR) in the management of behavioral disturbances in patients with Prader-Willi Syndrome (PWS). Methods: Twenty from a total of 27 individuals with genetically confirmed PWS, 6-26 years of age, with the following symptoms were identified: significant aggression/agitation, skin picking, and/or symptoms of attention-deficit/hyperactivity disorder (ADHD). Response to GXR for the above noted symptoms was categorized as improved, worsened, or unchanged, while assessing for side effects and tolerability. Results: Eleven of the 20 individuals reported skin-picking, 17 reported aggression/agitation, and 16 reported symptoms of ADHD. Nine (81.8%), 14 (82.3%), and 15 (93.7%) individuals showed an improvement in skin-picking, aggression/agitation, and ADHD, respectively, while on GXR treatment. Two patients with prior complaints of psychotic symptoms did not respond to GXR. Of note, no abnormal weight gain or significant adverse reaction was observed in this group, while on GXR. Conclusions: In this study, GXR demonstrated improvement in symptoms of skin picking, aggression/agitation, and ADHD in patients with PWS. GXR was not effective in reducing psychosis or agitation related to psychotic symptoms. Future studies are warranted to further establish the utility of GXR in PWS patients.

Psychopathological disorders in Prader-Willi syndrome

Prader-Willi syndrome is a genetic disorder caused by chromosomal changes in segment 15q11-q13 including cognitive, mental, and behavioral symptoms, as well as a specific physical phenotype. Both the most common psychopathological changes (intellectual disability, obsessions, impulsivity, autism spectrum disorders, self-injuries) and the main psychiatric comorbidities (affective disorders, psychosis, obsessive-compulsive disorder, autism spectrum disorder) are characterized by a great heterogeneity, which warrants the need for better identification of their frequency and clinical signs. In addition to its effects on body compositionand hypotony, growth hormone has been shown to be useful for regulating patient behavior, and psychoactive drugs are also an option. Other alternatives have shown promising results in experimental trials. Adequate understanding of the psychopathology associated to Prader-Willi syndrome would allow for improving clinical approach, symptom identification, detection of comorbidities, and administration of more effective treatments, leading to better clinical outcomes.

The characteristics of temper outbursts in Prader-Willi syndrome

The purpose of this study was to develop a comprehensive understanding of temper outbursts in Prader-Willi syndrome (PWS). A survey was developed from interviews conducted with individuals with PWS and their caregivers. The survey was completed by 101 primary caregivers. The findings suggest that outburst frequency decreases with age while duration increases. Adolescents exhibited more severe behaviors than children or adults. No differences were found across gender or genetic subtype. Provocations fit into three themes: goal blockage, social injustice, and difficulty dealing with change. Distracting the person or giving them space to calm down were the only management strategies judged effective. Risperidone, sertraline, and fluoxetine were the most common medications prescribed for outbursts, though parents reported only minor effects.

Mechanistic insights into the genetics of affective psychosis from Prader-Willi syndrome

Schizophrenia and bipolar disorder are common, severe, and disabling psychotic disorders, which are difficult to research. We argue that the genetically determined neurodevelopmental disorder Prader-Willi syndrome (PWS), which is associated with a high risk of affective psychotic illness, can provide a window into genetic mechanisms and associated neural pathways. People with PWS can all show non-psychotic psychopathology and problem behaviours, but the prevalence of psychotic illness differs markedly by genetic subtype; people with PWS due to chromosome 15 maternal uniparental disomy have higher prevalence of psychotic illness compared with patients with PWS due to 15q11-13 deletions of paternal origin. On the basis of this observation and the neural differences between genetic subtypes, we hypothesise that the combined effects of the absent expression of specific maternally imprinted genes at 15q11-13, and excess maternally imprinted or paternally expressed genes on chromosome 15, affect the γ-aminobutyric acid-glutamatergic pathways and associated neural networks that underpin mood regulation and sensory processing, resulting in psychotic illness. We propose a model of potential mechanisms of psychosis in PWS, which might be relevant in the general population, and should inform future research.

Autistic, Aberrant, and Food-Related Behaviors in Adolescents and Young Adults with Prader-Willi Syndrome: The Effects of Age and Genotype

The effects of age and genotype were examined, with regard to the severity of aberrant, autistic, and food-related behaviors in Prader-Willi syndrome (PWS), with an emphasis on the contrast between adolescents and young adults. The Aberrant Behavior Checklist Japanese version (ABC-J), the Food Related Problem Questionnaire (FRPQ), and the Pervasive Developmental Disorders Autism Society Japan Rating Scale (PARS) were administered to 65 PWS patients, including 20 adolescents (ages 12 to 17) and 45 young adults (ages 18 to 29). Significant differences (Mann-Whitney U tests) were found in ABC-J (p = 0.004) and PARS (p = 0.021), with lower scores in adolescents than in young adults. While DEL subgroups showed no significant differences between the two age groups in ABC-J (p = 0.063) and PARS (p = 0.134), mUPD subgroups showed a statistically significant difference in terms of ABC-J (p = 0.007). No significant differences were found between adolescents and young adults, in terms of FRPQ (p = 0.163). These results suggest that aberrant and autistic behaviors follow a marked worsening trend from around the age of 18. On the other hand, food-related behaviors give no sign of change at this transitory stage. Young adults with mUPD were found to be significantly more severe than adolescents with mUPD, in terms of aberrant behaviors.

Aberrant, autistic, and food-related behaviors in adults with Prader-Willi syndrome. The comparison between young adults and adults

This study aims to explore the differences of age as well as genotype in regards to the severity of behavioral symptoms in Prader-Willi syndrome (PWS), with emphasis on the comparison between youngadults and adults.The Food Related Problem Questionnaire (FRPQ), the Aberrant Behavior Checklist Japanese Version (ABC-J), and the Pervasive Developmental Disorders Autism Society Japan Rating Scale (PARS) were administered to 46 PWS patients, including 33 young adults (ages 18-28) and 13 adults(ages 30-45). To examine the differences between young adults and adults, Mann-Whitney U tests were conducted. Statistically significant differences were found in ABC-J (p = .027) and PARS (p = .046), with higher scores in young adults than adults. Such differences between the two age groups were still true for the subgroups having a paternal chromosome 15q deletion (DEL) for ABC-J (p = .050) and part of PARS ("Problematic behavior"; p = .007). By contrast, there was no significant differences between young adults and adults regarding FRPQ (p = .65).These results suggest that aberrant behaviors decline from around the ages of thirty, in PWS patients in general and in DEL subgroups in particular, while food-related behaviors give no indication of diminishing in spite of developmental growth.

Motor performance in Prader-Willi syndrome patients and its potential influence on caregiver's quality of life

Background

Prader-Willi syndrome (PWS) is a complex, multisystem genetic disorder characterized by a variety of physical, cognitive, and behavioral impairments. PWS is a unique sarcopenia model characterized by an abnormal increase in body fat mass and a decrease in muscle mass that predisposes patients to reduced physical activity, functional limitations, and disability. These manifestations may require both symptomatic and supportive management, thus negatively influencing their lifelong family caregiver’s quality of life. The aim of this study was to examine the functional motor performance of adults with PWS in Taiwan and to measure the quality of life of their primary family caregivers.

Methods

The functional motor tests consisted of the following: (1) 30-s sit-to-stand test, (2) timed up-and-go test, (3) hand grip and lateral pinch strength tests, and (4) Berg Balance Scale. The World Health Organization Quality of Life-short form (WHOQOL-BREF) and the Short-Form 36 Health Survey Questionnaire (SF-36) were used to evaluate health-related quality of life, and the parenting stress index was used to assess the magnitude of stress within the parent-child system.

Results

The participants included seven adults (two females and five males) with genetically confirmed PWS and their respective main caregivers. The mean age of the adults with PWS was 25.28 years; range 18–31 years, SD 5.10; the mean BMI was 29.2 kg/m², SD 6.43. All adults with PWS showed lower hand grip and lateral pinch strengths, fewer sit-to-stand cycles during the 30-s chair stand test, and greater average time during the timed up-and-go test when compared to the normative data on healthy adults. Balance was negatively correlated with the caregiver’s health concepts of social functioning (r_s −0.879, P = 0.009) and with role limitations due to physical problems (r_s −0.899, P = 0.006) and emotional problems (r_s −0.794, P = 0.033); hand grip strength was negatively correlated with bodily pain (r_s −0.800, P = 0.031), as assessed using the SF-36 questionnaire. The timed up-and-go test was positively correlated with the social relationship domain (r_s 0.831, P = 0.021), as assessed using the WHOQOL-BREF questionnaire. The parenting stress index showed no association with the PWS patient’s physical activities.

Conclusions

All adults with PWS showed decreased upper and lower limb strength and functional mobility when compared to healthy adults. Some of their motor performance might have negative effects on their primary family members in terms of social participation and physical and emotional role limitations. Future research should explore the relationship between physical performances, psychological difficulties of PWS and caregiver’s QOL.

Rigidity in routines and the development of resistance to change in individuals with Prader-Willi syndrome

BACKGROUND

Individuals with Prader-Willi syndrome (PWS) commonly show debilitating resistance to change, which has been linked to cognitive deficits in task switching. Anecdotal reports suggest that exposure to flexibility in routines during development may be beneficial for limiting subsequent resistance to change in people with PWS, which is consistent with a beneficial role of such exposure on the development of task switching, highlighted in typical children. Here, we aim to investigate the development of resistance to change in individuals with PWS and hypothesise that exposure to increased rigidity in routines will be associated with increased subsequent resistance to change.

METHODS

An author-compiled informant report interview and two previously validated questionnaires were administered to the caregivers of 10 individuals with PWS (5-23 years). The interview examined rigidity in routines and resistance to change across life stages defined by easily distinguishable events (before school, during primary school, during secondary school, after school, currently), using open-ended and structured yes/no and 5-point Likert questions. Open-ended data were coded using an author-compiled system. Responses from two additional informants and data from the questionnaires were used to assess inter-informant reliability and concurrent validity of the structured questions.

RESULTS

The validity of the interview was supported by acceptable inter-rater reliability of the open-ended coding system and inter-informant reliability, internal consistency and concurrent validity of structured questions. Descriptive analyses of ratings of behaviour change showed a pattern of increasing resistance to change over the life course for the four oldest individuals, who had all been exposed to substantial rigidity in routines before and during primary school. Furthermore, only one individual - currently in primary school - was exposed to very little rigidity in routines before and during primary school, and he had showed a decrease in resistance to change after entering primary school. Open-ended data showed that more individuals currently evidencing little resistance to change had been exposed to parent or self-imposed flexibility in routines, than those currently evidencing substantial resistance to change. However, correlational analyses on rigidity and resistance to change ratings highlighted the possibility that rigidity during primary school is most relevant for developing resistance to change. Finally, open-ended data emphasised an important beneficial role of rigidity in routines for limiting the current challenging behaviour of individuals with high resistance to change.

CONCLUSION

Because task switching appears to evidence a period of high developmental sensitivity during early primary school years, we propose that this period may represent a critical time when increasing flexibility in the routines of children with PWS could limit the development of resistance to change. However, a careful balance would need to be struck, given the apparent benefit of rigid routines on current behaviour. Further work in this area is much needed.

Signalling changes to individuals who show resistance to change can reduce challenging behaviour

BACKGROUND & OBJECTIVES

Several neurodevelopmental disorders are associated with resistance to change and challenging behaviours - including temper outbursts - that ensue following changes to routines, plans or expectations (here, collectively: expectations). Here, a change signalling intervention was tested for proof of concept and potential practical effectiveness.

METHODS

Twelve individuals with Prader-Willi syndrome participated in researcher- and caregiver-led pairing of a distinctive visual-verbal signal with subsequent changes to expectations. Specific expectations for a planned subset of five participants were systematically observed in minimally manipulated natural environments. Nine caregivers completed a temper outburst diary during a four week baseline period and a two week signalling evaluation period.

RESULTS

Participants demonstrated consistently less temper outburst behaviour in the systematic observations when changes imposed to expectations were signalled, compared to when changes were not signalled. Four of the nine participants whose caregivers completed the behaviour diary demonstrated reliable reductions in temper outbursts between baseline and signalling evaluation.

LIMITATIONS

An active control group for the present initial evaluation of the signalling strategy using evidence from caregiver behaviour diaries was outside the scope of the present pilot study. Thus, findings cannot support the clinical efficacy of the present signalling approach.

CONCLUSIONS

Proof of concept evidence that reliable pairing of a distinctive cue with a subsequent change to expectation can reduce associated challenging behaviour is provided. Data provide additional support for the importance of specific practical steps in further evaluations of the change signalling approach.

Parent Recommendations for Family Functioning With Prader-Willi Syndrome: A Rare Genetic Cause of Childhood Obesity

Prader-Willi syndrome (PWS) is the most common genetic cause of childhood obesity. Neonates have hypotonia and may fail to growth and develop. Within a few years, behavioral problems occur along with insatiable hunger (hyperphagia) and the potential for excessive weight gain. The purpose of this study was to identify how families function when they have a child with PWS.

DESIGN AND METHODS

This qualitative descriptive study was based on 20 face-to-face, audio-taped interviews with parents. They were asked to identify family responses to PWS and offer recommendations. Data were transcribed, coded and analyzed for commonalities and themes.

RESULTS

There were twelve identified themes with two overarching themes of 1) taking action and 2) caring for oneself and family. Taking action was focused on achieving what was best for the child with PWS. Caring for oneself and family attempted to assure that all in the family were healthy, content, and living a fulfilling life under their circumstances.

CONCLUSIONS

This study revealed parental insight as to how they learned to creatively cope with a stressful family life. There was a recognition of inevitable sacrifice and the need for changes in expectations so as to help the child with PWS flourish while also focusing on the needs of all the members of the family.

PRACTICE IMPLICATIONS

Nursing and health care providers should be aware of these issues in the provision of anticipatory guidance to families contending with this genetic disorder.

Increased Exposure to Rigid Routines can Lead to Increased Challenging Behavior Following Changes to Those Routines

Several neurodevelopmental disorders are associated with preference for routine and challenging behavior following changes to routines. We examine individuals with Prader-Willi syndrome, who show elevated levels of this behavior, to better understand how previous experience of a routine can affect challenging behavior elicited by disruption to that routine. Play based challenges exposed 16 participants to routines, which were either adhered to or changed. Temper outburst behaviors, heart rate and movement were measured. As participants were exposed to routines for longer before a change (between 10 and 80 min; within participants), more temper outburst behaviors were elicited by changes. Increased emotional arousal was also elicited, which was indexed by heart rate increases not driven by movement. Further study will be important to understand whether current intervention approaches that limit exposure to changes, may benefit from the structured integration of flexibility to ensure that the opportunity for routine establishment is also limited.

Gender Differences in the Behavioral Symptom Severity of Prader-Willi Syndrome

Objectives. This study measured gender differences in Prader-Willi syndrome (PWS) in regard to the severity of behavioral symptoms. Methods. The Food Related Problem Questionnaire (FRPQ), the Aberrant Behavior Checklist Japanese Version, the Childhood Routines Inventory, the Pervasive Developmental Disorders Autism Society Japan Rating Scale, and Japanese ADHD-RS were administered to PWS patients (45 males aged 6 to 58 and 37 females aged 6 to 45). To examine the effects that gender and genotype have on the severity of each symptom, two-way ANOVAs were conducted. Results. Significant interactions were found only in regard to FRPQ scores, such as FRPQ total score (F(1, 78) = 8.43, p < 0.01). The FRPQ of male deletion (DEL) individuals was higher than that of female DEL and male mUPD. The FRPQ of male maternal uniparental disomy (mUPD) was lower than that of female mUPD. Conclusions. In terms of problem behaviors, routines, autistic behaviors, and hyperactivity, no significant differences were found. Food-related behaviors in DEL were more severe in males, although those in mUPD were less severe in males.

Cognitive and behavioural aspects of Prader-Willi syndrome

PURPOSE OF REVIEW

To provide a review of the recent advances in the diagnosis and treatment of psychiatric disorders in Prader-Willi syndrome (PWS).

RECENT FINDINGS

Research in the last 12 months has provided a descriptive prognosis of psychosis in PWS and highlighted the possible genes associated with the increased risk of psychosis for those with maternal uniparental disomy (mUPD). Several studies investigating social and communication skills have shown people with PWS to have difficulty with core, receptive and expressive language skills, interpreting emotional valence in faces, playing with children of their own age, understanding personal space and a developmental delay in the theory of mind. These social and communication deficits are often more pronounced in those with mUPD. Two recent clinical trials of oxytocin provide mixed results and highlight the need for an improved understanding of the neurobiological characteristics of the PWS brain. A recent pilot study suggests N-acetylcysteine may be a viable treatment for skin picking.

SUMMARY

Recent advances have contributed to our understanding of the emotional and behavioural problems associated with PWS, and provided directions for further research.

Learning by observation and learning by doing in Prader-Willi syndrome

BACKGROUND

New competencies may be learned through active experience (learning by doing) or observation of others' experience (learning by observation). Observing another person performing a complex action accelerates the observer's acquisition of the same action, limiting the time-consuming process of learning by doing. Here, we compared learning by observation and learning by doing in individuals with Prader-Willi syndrome (PWS). It is hypothesized that PWS individuals could show more difficulties with learning by observation than learning by doing because of their specific difficulty in interpreting and using social information.

METHODS

The performance of 24 PWS individuals was compared with that of 28 mental age (MA)- and gender-matched typically developing (TD) children in tasks of learning a visuo-motor sequence by observation or by doing. To determine whether the performance pattern exhibited by PWS participants was specific to this population or whether it was a nonspecific intellectual disability effect, we compared the PWS performances with those of a third MA- and gender-matched group of individuals with Williams syndrome (WS).

RESULTS

PWS individuals were severely impaired in detecting a sequence by observation, were able to detect a sequence by doing, and became as efficient as TD children in reproducing an observed sequence after a task of learning by doing. The learning pattern of PWS children was reversed compared with that of WS individuals.

CONCLUSIONS

The observational learning deficit in PWS individuals may be rooted, at least partially, in their incapacity to understand and/or use social information.