Associations between cognitive performance and the rehabilitation, medical care and social support provided to French children with Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder with a characteristic behavioural phenotype. A multidisciplinary approach to care is required to prevent multiple medical complications in individuals affected by PWS. The aim of this study was to describe the rehabilitation, medical care, educational and social support provided to school-aged French PWS patients with varying neuropsychological profiles. Data were obtained from a French multicentre study that included patients aged 4-20 years with diverse genetic syndromes. Nineteen PWS subjects with a mean age of 9.2 years were included. The mean full-scale intellectual quotient (IQ) was 58 (Wechsler scale). There were frequent dissociations between verbal and performance IQ that were not associated with a specific profile. We also observed lower autonomy and communication scores (5.3 years and 5.9 years equivalent, respectively, Vineland scale), the absence of hyperactivity (Conners scale), and the presence of behavioural abnormalities (CBCL scale). Multidisciplinary medical supervision was generally coordinated by the paediatric endocrinologist and did not always include follow-up with all of the recommended specialists, in particular with a paediatric psychiatrist. Analysis of multidisciplinary rehabilitation conducted in public and private-sector establishment revealed failings in psychological support, occupational therapy and dietary follow-up. Regarding education, most children younger than 10 years were in normal schools, while older individuals were often cared for in medico-social institutions. In conclusion, children and adolescents with PWS generally received appropriate care. Though there have been considerable improvements in the management of children with PWS, reference centres should continue reinforcing the coordination of multidisciplinary supervision.

A 24-Week Physical Activity Intervention Increases Bone Mineral Content without Changes in Bone Markers in Youth with PWS.

Bone mineral density (BMD) is of concern in Prader-Willi syndrome (PWS). This study compared responses to a physical activity intervention in bone parameters and remodeling markers in youth with PWS (n = 45) and youth with non-syndromic obesity (NSO; n = 66). Measurements occurred at baseline (PRE) and after 24 weeks (POST) of a home-based active games intervention with strengthening and jumping exercises (intervention group = I) or after a no-intervention period (control group = C). Dual x-ray absorptiometry scans of the hip and lumbar spine (L1-L4) determined BMD and bone mineral content (BMC). Bone markers included fasting bone-specific alkaline phosphatase (BAP) and C-terminal telopeptide of type I collagen (CTx). Both I and C groups increased their hip BMD and BMC (p < 0.001). Youth with PWS-I increased their spine BMC from PRE to POST (p < 0.001) but not youth with PWS-C (p = 1.000). Youth with NSO (I and C) increased their spine BMC between PRE and POST (all p < 0.001). Youth with PWS showed lower BAP (108.28 ± 9.19 vs. 139.07 ± 6.41 U/L; p = 0.006) and similar CTx (2.07 ± 0.11 vs.1.84 ± 0.14 ng/dL; p = 0.193) than those with NSO regardless of time. Likely, the novelty of the intervention exercises for those with PWS contributed to gains in spine BMC beyond growth. Bone remodeling markers were unaltered by the intervention.

Increasing physical activity in adult women with Prader-Willi syndrome: A transferability study.

BACKGROUND: The present authors aimed (a) to objectively quantify spontaneous physical activity (PA) in adult patients with Prader-Willi syndrome (PWS) and (b) to evaluate the transferability of a home-based exercise training programme in these patients. METHOD: Physical activity was compared between 10 adult women with PWS (PWS group) and 20 adult women with non-syndromic obesity (CON group, for cross-sectional comparison). In the PWS group, PA, body composition, walking capacity, quality of life and eating behaviour were then compared before and after a 16-week supervised exercise programme. RESULTS: The PWS group displayed lower PA and higher sedentary time compared to the CON group. Median attendance to exercise sessions reached 100% (Q1-Q3: 97%-100%) sessions. Moderate-to-vigorous PA and walking capacity increased after the programme without significant effect on body composition. CONCLUSION: Supervised home-based exercise sessions are an effective strategy to improve PA in women with PWS who are less active than women matched for adiposity.

Cognitive Training Targeting Planning Dysfunction in Adults with Prader-Willi Syndrome: Brief Report of a Study Protocol.

Background: Prader-Willi syndrome (PWS) is a neurodevelopmental genetic disorder involving executive deficits notably with planning. The main objective of the study is to assess the effectiveness of cognitive training on daily life planning difficulties in PWS patients. Methods/design: The study is a double-blind randomized controlled trial which will compare the effectiveness of a metacognitive strategy intervention designed to improve planning difficulties for PWS patients to usual occupational therapy. Sixty adults will be included over 20 months. The main outcome measure will be the performance on the Modified Six Elements Test from the BADS; secondary outcome measures will be computerized executive tasks and questionnaires. Daily life planning difficulties will be identified and transformed into measurable goals using Goal Attainment Scaling. Discussion: The project will provide knowledge on the difficulties experienced by PWS patients, in relation to their executive functioning in order to implement effective intervention for planning in daily life.

Physical exercise and Prader-Willi syndrome: A systematic review.

OBJECTIVE: The aim of this systematic review was to summarize evidence on the acute responses of individuals with Prader-Willi syndrome (PWS) to physical exercise, and on the effectiveness of long-term exercise interventions to improve the clinical manifestations of this syndrome. DESIGN/METHODS: Relevant articles were identified in the electronic databases PubMed, Medline, CINAHL and SPORTDiscus (from inception to December 2018). Twenty-two studies including a total of 356 patients with PWS met all inclusion criteria and were included in the review. RESULTS: Patients with PWS present with a decreased physical performance and impaired cardiorespiratory (maximal oxygen consumption, heart rate recovery after exercise) and hormonal (growth hormone release) responses to exercise. Most long-term exercise interventions have proven to decrease body mass while improving physical performance. Some benefits have also been reported in biochemical (glucose homeostasis, lipid profile) and biomechanical (gait pattern) variables, although there is controversy regarding the effects on body composition. No exercise-related adverse events have been reported in patients with PWS. CONCLUSION: Physical exercise seems to be safe and effective for improving several phenotypes in PWS, notably physical fitness. However, further research is needed to confirm these results and especially to corroborate whether exercise per se or combined with dietary intervention is an effective coadjuvant treatment for reducing body mass in these patients.

Decreasing Food Stealing of Child with Prader-Willi Syndrome Through Function-Based Differential Reinforcement.

Challenging behaviors involving food are common for individuals with Prader-Willi syndrome (PWS) and often lead to obesity and other chronic health conditions. Efforts to decrease these behaviors, such as isolation during meals and strict monitoring of food consumption, can be stigmatizing. To decrease the food stealing of a 7 year-old girl with PWS, therapists conducted a latency-based functional analysis in a clinic setting before implementing a function-based intervention to facilitate her inclusion at the family dinner table. Intervention components entailed differential reinforcement procedures which incorporated a token board and schedule thinning. The intervention successfully generalized to the home setting and across food preferences and implementers.

Dynamic balance assessment during gait in children with Down and Prader-Willi syndromes using inertial sensors.

Down (DS) and Prader-Willi (PWS) syndromes are chromosomal disorders both characterized by obesity, ligament laxity, and hypotonia, the latter associated with gait instability. Although these shared features may justify a common rehabilitation approach, evidence exists that adults with DS and PWS adopt different postural and walking strategies. The development of an instrumented protocol able to describe these strategies and quantify patients' gait stability in the current clinical routine would be of great benefit for health professionals, allowing them to design personalized rehabilitation programs. This is particularly true for children with DS and PWS, where motor development is dramatically constrained by severe hypotonia and muscle weakness. The aim of this study was, thus, to propose an instrumented protocol, integrated with the clinical routine and based on the use of wearable inertial sensors, to assess gait stability in DS and PWS children. Fifteen children with DS, 11 children with PWS, and 12 typically developing children (CG) were involved in the study. Participants performed a 10-meter walking test while wearing four inertial sensors located at pelvis, sternum, and both distal tibiae levels. Spatiotemporal parameters (walking speed, stride frequency, and stride length) and a set of indices related to gait symmetry and upper-body stability (Root Mean Square, Attenuation Coefficient and Improved Harmonic Ratio) were estimated from pelvis and sternum accelerations. The Gross Motor Functional Measures (GMFM-88) and Intelligence Quotient (IQ Wechsler) were also assessed for each patient. A correlation analysis among the GMFM-88 and IQ scales and the estimated parameters was then performed. Children with DS and PWS exhibit reduced gait symmetry and higher accelerations at pelvis level than CG. While these accelerations are attenuated by about 40% at sternum level in CG and DS, PWS children display significant smaller attenuations, thus reporting reduced gait stability, most likely due to their typical "Trendelenburg gait". Significant correlations were found between the estimated parameters and the GMFM-88 scale when considering the whole PWS and DS group and the PWS group alone. These results promote the adoption of wearable technology in clinical routines to monitor gait patterns in children with DS and PWS: the proposed protocol allows to markedly characterize patient-specific motor limitations even when clinical assessment scores provide similar results in terms of pathology severity. This protocol could be adopted to support health professionals in designing personalized treatments that, in turn, could help improving patients' quality of life in terms of both physical and social perspectives.

The PRETEND Program: Evaluating the Feasibility of a Remote Parent-Training Intervention for Children With Prader-Willi Syndrome.

Research has shown that children with Prader-Willi syndrome (PWS) have social-cognitive challenges and decreased quality parent-child interactions. However, given the low prevalence rate, developing interventions for children with PWS is faced with the significant challenge of enrolling enough participants for local studies. To better understand the feasibility and acceptability of telehealth, the current study delivered a 6-week remote parent training intervention to 15 primary caregivers of a child with PWS (ages 3-6). Behavioral Intervention Rating Scale results indicate good acceptability (5.64/6.00) and satisfaction (4.75/5.00) with the intervention. These results are one of the first to support the use of telehealth in conducting parent training in rare disorders, such as PWS.

"Over time it just becomes easier ": parents of people with Angelman syndrome and Prader-Willi syndrome speak about their carer role.

PURPOSE: This study investigated two of the stresses experienced by parents caring for offspring with Angelman syndrome (AS) and Prader-Willi syndrome (PWS) in Western Australia, and identified their coping strategies. METHODS: Parents of 19 offspring with AS and PWS participated in the Family Stress and Coping Interview which provides a stress level score, and a discussion of stressors and coping methods associated with 24 life situations, two of which are reported. All text was examined using directed content analysis. RESULTS: Family carers (14/19) reported high stress associated with the initial diagnosis of AS or PWS in their offspring; and finding time for themselves. Stressors identified included lack of quality information about the disorder, time constraints and physical and emotional tiredness. Parents adopted a variety of coping strategies, including learning about the disorder, accepting the situation, seeking instrumental and social supports and dealing with problems. CONCLUSIONS: No specific coping strategy was associated with reduced stress. However, parents felt that accurate and timely information during the diagnostic period helped. Parents used family and community support although there were difficulties accessing respite care. It is advised that government agencies, service providers, family members and peer support associations should provide practical and emotional support to assist the parents of offspring with AS and PWS, and indeed any form of intellectual disability, across the lifespan. Implications for Rehabilitation Long-term caring for offspring with AS or PWS can involve considerable stress for parents. Stress has been associated with poorer health outcomes for parental carers. Parents need a variety of practical and emotional supports to cope with stress, including timely access to information.

A mindfulness-based intervention for self-management of verbal and physical aggression by adolescents with Prader-Willi syndrome.

PURPOSE: There is a dearth of clinical and research literature on the treatment of maladaptive behaviors in adolescents with Prader-Willi syndrome (PWS). The purpose of this study was to evaluate the effectiveness of a mindfulness-based intervention, Meditation on the Soles of the Feet (SoF), to facilitate self-management of verbal and physical aggression. METHOD: We utilized a multiple-baseline design across participants to test the intervention with three adolescents diagnosed with PWS. RESULTS: Relative to baseline, verbal aggression decreased to minimal levels following mindfulness-based practice and physical aggression was nearly eliminated. Intervention effects were maintained at 12-month follow-up. Quantitative analytics confirmed statistically significant outcomes. CONCLUSIONS: The SoF mindfulness intervention was effective in reducing verbal and physical aggression in three adolescents with PWS. Future research should test the SoF intervention with this clinical population in a larger clinical trial, and the SoF intervention may be applicable to other pediatric populations.

Using the iPad to facilitate interaction between preschool children who use AAC and their peers.

Social interaction is one of the key components of education, yet children with complex communication needs often face social isolation in the classroom, rarely interacting with same-age peers. This study investigated the impact of the provision of an iPad(®) (1) with an AAC app with visual scene displays and a dyadic turn taking training on the number of communicative turns taken by children with complex communication needs in interaction with same-age peers. Two preschool children with complex communication needs and six peers without disabilities participated in this research. A single-subject, multiple probe across partners design with one replication was used to evaluate the effectiveness of the intervention on the frequency of communicative turns expressed by the children with complex communication needs. Parents, teachers, speech-language pathologists, and the children participated in social validation measures. As a result of intervention, Participant 1 showed immediate gains in the frequency of symbolic communicative turns after the first training session across all three partners (average gains of 30-46 symbolic communicative turns per 10-min session across peer partners). Participant 2 showed some initial gains, but they were not maintained over time (average gains of 11-24 turns across partners). Classroom implications and future research directions are discussed.

Weight control and behavior rehabilitation in a patient suffering from Prader Willi syndrome.

BACKGROUND: This study reports a case of Prader Willi syndrome (PWS), a genomic imprinting disease related to chromosome regions 15q11.2-q13 15, which includes hypothalamic dysfunction leading to hyperphagia, obesity, shortness, sleep abnormalities. Our case is extremely severe, in comparison to other PWS cases described in literature, due to the association with severe emotional and psychiatric symptoms: oppositional behaviour, rigidity of thought, skin picking and pathological hoarding. CASE PRESENTATION: We described the case of a Caucasian male patient suffering from PWS, treated in outpatient care by local Mental Health Centre and supported by Social Service, who was admitted to a residential rehabilitative facility. After a 2-year follow-up, the patient showed a global improvement in symptoms and functioning, as registered by the rating scales administered. At the end of observation period, we also reported an important improvement in weight control, reducing the risk of obesity and related diseases, therefore improving the prognosis of life. CONCLUSION: This case highlights the need for long-term, individualized and multi-professional treatment in patients suffering from a complex genetic syndrome with both organic and psychological alterations, for which medical care setting and pharmacological treatments are not sufficient. Clinical observation of this case leads us to compare PWS to drug addiction and indirectly endorse the neurophysiological hypothesis that food and drugs stimulate the same brain circuits in the limbic system.

Beneficial Effects of Long-Term Growth Hormone Treatment on Adaptive Functioning in Infants With Prader-Willi Syndrome.

The aim of this study was to investigate the effect of growth hormone treatment on adaptive functioning in children with Prader-Willi syndrome. Vineland Adaptive Behavior Scale (VABS) was assessed during a randomized controlled trial (RCT) and after 7 years of growth hormone treatment. In the RCT, 75 children (42 infants and 33 prepubertal children) with Prader-Willi syndrome were included. Subsequently, 53 children were treated with long-term growth hormone. Our study demonstrates a marked delay in adaptive functioning in infants and children with Prader-Willi syndrome, which was associated with older age and lower intelligence. Results of the repeated measurements show that the earlier growth hormone treatment was started during infancy, the better the adaptive skills were on the long-term.

Hormonal and metabolic responses to endurance exercise in children with Prader-Willi syndrome and non-syndromic obesity.

OBJECTIVE: Excess adiposity affects endocrine and metabolic function at rest and during exercise. This study evaluated the endocrine and metabolic responses to exercise in syndromic (Prader-Willi syndrome) and non-syndromic pediatric obesity. MATERIALS/METHODS: Eleven PWS (10.9±1.6 y, 45.4±9.5% body fat), 12 lean (9.4±1.2 y, 17.5±4.6% body fat), and 12 obese (9.2±1.2 y, 39.9±6.8% body fat) children completed ten two-minute cycling exercise bouts, separated by one-minute rest. Blood samples were obtained at rest pre-exercise (PRE), immediately post-exercise (IP), and 15, 30 and 60 minutes into recovery. Samples were analyzed for hormones and metabolites. RESULTS: Growth hormone increased in response to exercise in lean and obese but not PWS (IP>PRE; IP: lean>obese). Epinephrine increased with exercise in lean (IP>PRE), while norepinephrine increased in lean and obese (IP>PRE) but not PWS; no differences were observed between lean and obese groups at IP. No other significant hormonal group interactions existed. Glucose, lactate, free fatty acid, glycerol and ketone responses were similar among groups. CONCLUSION: PWS children exhibited altered stress hormone responses to exercise. However, glucose-regulating hormones and metabolic responses to exercise appeared normal.

A comparative study of educational provision for children with neurogenetic syndromes: parent and teacher survey.

BACKGROUND: A number of neurogenetic syndromes have a high association with special educational needs including fragile X syndrome (FXS), Prader-Willi syndrome (PWS), Williams syndrome (WS) and Velo-Cardio-Facial syndrome (VCFS). There is a paucity of research on educational provision for children affected by these syndromes. METHOD: Parents (n = 381) and teachers (n = 204) of school-aged children with one of the four syndromes in the UK and Ireland were surveyed in a range of areas concerning the child's educational provision. Areas surveyed included school placement, views on the needs of children with the syndromes, desired changes to current provision and perceived teacher knowledge. RESULTS: School placement in mainstream settings decreased with age in all of the syndromes. Males with the syndromes were more likely to be in specialised educational settings with the exception of WS. Teachers reported limited input on initial or subsequent training for all of the syndromes. The majority of teachers did not view the needs of children with syndromes as different from other children with intellectual disability (ID) although there were significant differences between the syndromes. Changes deemed necessary to provision by parents and teachers differed between the syndromes indicating the existence of perceptions of syndrome specific needs. The lowest perceived level of teacher knowledge was in the VCFS group. CONCLUSION: The majority of teachers of children with neurogenetic syndromes report limited knowledge of the syndromes, but also a lack of belief that the children's needs are different from the majority of children with ID. Differences between the syndromes in some areas of provision suggest that a child's syndrome does impact on educational provision in some areas.

Gait strategy in genetically obese patients: a 7-year follow up.

The aim of this study was to quantitatively evaluate the change in gait and body weight in the long term in patients with Prader-Willi Syndrome (PWS). Eight adults with PWS were evaluated at baseline and after 7 years. During this period patient participated an in- and out-patient rehabilitation programs including nutritional and adapted physical activity interventions. Two different control groups were included: the first group included 14 non-genetically obese patients (OCG: obese control group) and the second group included 10 age-matched healthy individuals (HCG: healthy control group). All groups were quantitatively assessed during walking with 3D-GA. The results at the 7-year follow-up revealed significant weight loss in the PWS group and spatial-temporal changes in gait parameters (velocity, step length and cadence). With regard to the hip joint, there were significant changes in terms of hip position, which is less flexed. Knee flexion-extension showed a reduction of flexion in swing phase and of its excursion. No changes of the ankle position were evident. As for ankle kinetics, we observed in the second session higher values for the peak of ankle power in terminal stance in comparison to the first session. No changes were found in terms of ankle kinetics. The findings demonstrated improvements associated to long-term weight loss, especially in terms of spatial-temporal parameters and at hip level. Our results back the call for early weight loss interventions during childhood, which would allow the development of motor patterns under normal body weight conditions.

Rationale and design of active play @ home: a parent-led physical activity program for children with and without disability.

BACKGROUND: Compared to other children, those with disability have additional challenges to being physically active. Prader-Willi Syndrome is a genetic form of childhood obesity that is characterized by hypotonia, growth hormone deficiency, behavioral, and cognitive disability. In children, the low prevalence of this syndrome (1 in 10,000 to 15,000 live births) makes group-based physical activity interventions difficult. In contrast, the home environment presents a natural venue to establish a physical activity routine for this population. This manuscript describes the design of a parent-led physical activity intervention incorporating playground and interactive console-based games to increase physical activity participation in youth with and without Prader-Willi Syndrome. METHODS/DESIGN: The study participants will be 115 youth ages 8-15 y (45 with the syndrome and 70 without the syndrome but categorized as obese). The study will use a parallel design with the control group receiving the intervention after serving as control. Participants will be expected to complete a physical activity curriculum 4 days a week for 6 months including playground games 2 days a week and interactive console games 2 days a week. Parents will be trained at baseline and then provided with a curriculum and equipment to guide their implementation of the program. Tips related to scheduling and coping with barriers to daily program implementation will be provided. Throughout, parents will be contacted by phone once a week (weeks 1-4) and then every other week to receive support in between visits. Measurements of children and parents will be obtained at baseline, 12 weeks, and at the end (week 24) of the intervention. Children main outcomes include physical activity (accelerometry), body composition (dual x-ray absorptiometry), motor proficiency (Bruininks-Oseretsky Test of Motor Proficiency), quality of life and physical activity self-efficacy (questionnaires). Intervention compliance will be monitored using mail-in daily self-report checklists. DISCUSSION: This parent-guided physical activity intervention aims to increase physical activity by using a curriculum that builds physical activity related self-confidence through the development and/or enhancement of motor skill competency. Ultimately, helping children develop these skills as well as joy in being physically active will translate into sustained behavior change. TRIAL REGISTRATION: Current Controlled Trial: NCT02058342.

An analysis of the topography, severity, potential sources of reinforcement, and treatments utilized for skin picking in Prader-Willi syndrome.

We examined the topography, severity, potential sources of reinforcement, and treatments utilized for skin-picking behavior shown by individuals with Prader-Willi syndrome (PWS). The parents of 55 individuals with PWS, aged 6-25 years, were interviewed about their child's skin-picking behavior using the Self-Injury Trauma Scale (SIT; Iwata, Pace, Kissel, Nau, & Farber, 1990) and the Functional Analysis Screening Tool (FAST; Iwata, DeLeon, & Roscoe, 2013). Results showed that skin picking in PWS occurred on the extremities (i.e., arms, legs, hands, and feet) for 75% of cases and resulted in bodily injury for 83.7% cases. Skin picking posed a high risk to the individual concerned in 41.8% of cases. Automatic sensory stimulation was identified as a potential source of reinforcement in the majority of cases (52.7%) followed by access to social attention or preferred items (36.4%). Treatments utilized by parents were primarily behavioral strategies (56.3%) followed by basic first aid (54.5%). There were no differences in the topography, severity or potential source of reinforcement between those with the deletion (DEL) subtype and those with the uniparental disomy (UPD) subtype. Taken together, these data indicate that skin picking shown by individuals with PWS is a particularly severe and intractable behavioral issue that may be maintained by (as yet unknown) sensory consequences. Further studies to identify the determinants of skin picking in PWS are therefore needed. The implications for interventions are discussed.

The effect of vision on postural strategies in Prader-Willi patients.

The aim of this study was to quantify the role of visual contribution in patients with Prader-Willi syndrome (PWS) on balance maintenance using a force platform. We enrolled 14 individuals with PWS free from conditions associated with impaired balance, 44 obese (OG) and 20 healthy controls (CG). Postural sway was measured for 60s while standing on a force platform (Kistler, CH; acquisition frequency: 500 Hz) integrated with a video system. Patients maintained an upright standing position with Open Eyes (OE) and then with Closed Eyes (CE). The ratio between the value of the parameter under OE and CE conditions was measured. Under OE condition PWS and OG were characterized by higher postural instability than CG, with the PWS group showing poorer balance capacity than OG. The Romberg ratio showed that while OG and CG had lower balance without vision, PWS maintained the same performance changing from OE to CE. The integration of different sensory inputs appears similar in OG and CG with higher postural stability under OE than CE. Balance in PWS is not influenced by the elimination of visual input.

Postural adaptations to long-term training in Prader-Willi patients.

BACKGROUND: Improving balance and reducing risk of falls is a relevant issue in Prader-Willi Syndrome (PWS). The present study aims to quantify the effect of a mixed training program on balance in patients with PWS. METHODS: Eleven adult PWS patients (mean age: 33.8 ± 4.3 years; mean BMI: 43.3 ± 5.9 Kg/m2) attended a 2-week training program including balance exercises during their hospital stay. At discharge, Group 1 (6 patients) continued the same exercises at home for 6 months, while Group 2 (5 patients) quitted the program. In both groups, a low-calorie, well-balanced diet of 1.200 kcal/day was advised. They were assessed at admission (PRE), after 2 weeks (POST1) and at 6-month (POST2). The assessment consisted of a clinical examination, video recording and 60-second postural evaluation on a force platform. Range of center of pressure (CoP) displacement in the antero-posterior direction (RANGEAP index) and the medio-lateral direction (RANGEML index) and its total trajectory length were computed. RESULTS: At POST1, no significant changes in all of the postural parameters were observed. At completion of the home program (POST2), the postural assessment did not reveal significant modifications. No changes in BMI were observed in PWS at POST2. CONCLUSIONS: Our results showed that a long-term mixed, but predominantly home-based training on PWS individuals was not effective in improving balance capacity. Possible causes of the lack of effectiveness of our intervention include lack of training specificity, an inadequate dose of exercise, an underestimation of the neural and sensory component in planning rehabilitation exercise and failed body weight reduction during the training. Also, the physiology of balance instability in these patients may possibly compose a complex puzzle not affected by our exercise training, mainly targeting muscle weakness.