Stereotypies in Rett syndrome: Analysis of 83 patients with and without detected MECP2 mutations

Virtual Reality as a Tool for Upper Limb Rehabilitation in Rett Syndrome: Reducing Stereotypies and Improving Motor Skills

BACKGROUND/OBJECTIVES

Rett Syndrome (RTT) is a rare neurodevelopmental disorder that causes the loss of motor, communicative, and cognitive skills. While no cure exists, rehabilitation plays a crucial role in improving quality of life. Virtual Reality (VR) has shown promise in enhancing motor function and reducing stereotypic behaviors in RTT. This study aims to assess the impact of VR training on upper limb motor skills in RTT patients, focusing on reaching and hand-opening tasks, as well as examining its role in motivation and engagement during rehabilitation.

METHODS

Twenty RTT patients (aged 5-33) were randomly assigned to an experimental group (VR training) and a control group (standard rehabilitation). Pre- and post-tests evaluated motor skills and motivation in both VR and real-world contexts. The VR training involved 40 sessions over 8 weeks, focusing on fine motor tasks. Non-parametric statistical methods were used to analyze the data.

RESULTS

Results indicated significant improvements in the experimental group for motor parameters, including reduced stereotypy intensity and frequency, faster response times, and increased correct performance. These improvements were consistent across VR and ecological conditions. Moreover, attention time increased, while the number of aids required decreased, highlighting enhanced engagement and independence. However, motivation levels remained stable throughout the sessions.

CONCLUSIONS

This study demonstrates the potential of VR as a tool for RTT rehabilitation, addressing both motor and engagement challenges. Future research should explore the customization of VR environments to maximize the generalization of skills and sustain motivation over extended training periods.

Motor actions across psychiatric disorders: A research domain criteria (RDoC) perspective

The motor system is critical for understanding the pathophysiology and treatment of mental illness. Abnormalities in the processes that allow us to plan and execute movement in a goal-directed, context-appropriate manner (i.e., motor actions) are especially central to clinical motor research. Within this context, the NIMH Research Domain Criteria (RDoC) framework now includes a Motor Actions construct within the recently incorporated Sensorimotor Systems Domain, providing a useful framework for conducting research on motor action processes. However, there is limited available resources for understanding or implementing this framework. We address this gap by providing a comprehensive critical review and conceptual integration of the current clinical literature on the subconstructs comprising the Motor Actions construct. This includes a detailed discussion of each Motor Action subconstruct (e.g., action planning/execution) and its measurement across different units of analysis (e.g., molecules to behavior), the temporal and conceptual relationships among the Motor Action subconstructs (and other relevant RDoC domain constructs), and how abnormalities in these Motor Action subconstructs manifest in mental illness. Together, the review illustrates how motor system dysfunction is implicated in the pathophysiology of many psychiatric conditions and demonstrates shared and distinct mechanisms that may account for similar manifestations of motor abnormalities across disorders.

Genetic polymorphisms and bruxism: A scoping review

BACKGROUND

Recent studies have highlighted the multifactorial nature of bruxism, with behavioral, psychosocial, and physiological factors, including genetic predisposition, contributing to its development. However, the role of genetic markers in determining susceptibility to bruxism remains poorly understood, with limited studies offering significant findings.

OBJECTIVES

To identify the current knowledge to investigate the susceptibility of genetic markers for sleep (SB) and/or awake bruxism (AB).

MATERIALS AND METHODS

Seven electronic databases and two grey literature platforms were searched up to January 2024. We included studies that related different types of genes and/or genetic polymorphisms with different types of bruxism, regardless of age or sex of the participants. To be included the study must have described the form of detection of bruxism.

RESULTS

A total of 21 reports were included. Of these, 16 were primary research reports. The remaining five articles consisted of four systematic reviews and a literature review incorporating a systematic mapping process, and network visualization. Within the pool of 16 primary study reports, seven focused on the association of genetic polymorphisms with both SB and AB, while seven concentrated solely on the association with SB. One primary study reported results related to probable AB and one article did not specify the bruxism type. Regarding all the studied genes and polymorphisms, significant association results were obtained for 15 polymorphisms from 11 different genes. Self-reported SB was associated with genes from the serotonergic (5HTR2A) and dopaminergic pathways (DRD2, DRD3, and ANKK1), as well as genes encoding enzymes (COMT and MMP9) and proteins (ACTN3 and ANKK1). Instrumentally reported SB was linked only to the reverse telomerase gene (TERT). Self-reported AB was associated with the ACTN3 and ANKK1 genes.

CONCLUSION

This review identified 30 genes and 56 polymorphisms variations potentially associated with either SB or AB. However, few presented significant results regarding positive associations, mostly acting at neurotransmitter pathways. The authors recommend further studies to determine the susceptibility of genetic markers as a risk factor for bruxism.

The use of botulinum toxin for grinding in patients with Rett syndrome-Case report

AIMS

Rett syndrome (RTT) is a neurodevelopmental disorder caused by a mutation in the methyl-CpG-binding protein 2 (MECP2) gene. It is characterized by profound and severe motor disability. Patients with RTT grind their teeth, causing damage to their permanent teeth. This article aims to describe the case of an 8-year-old child with RTT and the methods of botulinum toxin-based treatment for teeth grinding.

METHODS AND RESULTS

Surface electromyography (sEMG) was used to monitor the effects of treatment. The masseter and temporal muscles, responsible for the elevation of the mandible, were injected with botulinum toxin. The results of the sEMG examination performed 1 week, 1 month and 4 months after toxin administration were compared to the sEMG conducted before treatment. The research demonstrates a significant reduction in both grinding frequency and tension of the masseter and temporal muscles.

CONCLUSION

Possible adverse effects after chronic use of botulinum toxin were discussed. The article also emphasizes the need for masticatory muscle rehabilitation during botulinum toxin therapy. However, it is necessary to repeat this procedure on a larger group of children with RTT to establish our efforts' efficacy.

Relationship between hand stereotypies and purposeful hand use and factors causing skin injuries and joint contractures in individuals with Rett syndrome

BACKGROUND

Skin injuries and joint contractures in the upper limbs are observed in approximately 50 % of individuals with Rett syndrome, respectively.

AIMS

To investigate the relationship between stereotypic hand movements and purposeful hand skills, items related to these, and factors that cause upper extremity skin injuries and joint contractures in individuals with Rett syndrome.

STUDY DESIGN

We conducted a cross-sectional observational study in 2020 with families belonging to either of the two largest Rett syndrome organizations in Japan.

SUBJECTS

In 2020, we sent a questionnaire to 194 Japanese families.

OUTCOME MEASURES

We used descriptive statistics to indicate frequency in each question. We analysed the association between hand stereotypies and purposeful hand use, their associations with each questionnaire item, and the relationship between the occurrence of skin injuries and joint contractures.

RESULTS

We acquired information from 72 cases. We found correlations between stereotypy frequency with reaching and between purposeful hand use with intellectual development grade and hand function. Hand and finger skin injuries and elbow and finger joint contractures were associated with wringing/washing, grasping, locomotion, reaching, and intellectual development grade. We identified cut-off points for the occurrence of elbow and finger joint contractures of 10 years 6 months, ability to roll over, finger feeds only, and understanding of simple words.

CONCLUSIONS

Direct interventions can reduce hand stereotypies and increase purposeful hand use, while related items can be addressed with indirect interventions. Evaluations of factors that cause skin injuries and joint contractures can prevent their occurrence.

Interprofessional Collaboration Improves Quality of Life of a Young Adult With Rett Syndrome

Rett syndrome (RTT) is a genetic neurodevelopmental disease characterized by early normal development followed by regression in motor and language skills. Patients with RTT often exhibit seizure disorders, growth failure, heart and lung disorders, bruxism, and dental caries. We report on a female patient in her 20s with Rett syndrome who presented to her primary care clinic with increasing agitation and pain. This case reports describes a collaborative, interprofessional approach between medical and dental providers who work in an integrated outpatient setting. It demonstrates that interprofessional collaboration, goals of care discussions, and attention to social drivers of health can improve quality of life for a medically and socially complex patient.

Motor stereotypies in autism spectrum disorder: Clinical randomized study and classification proposal

LAY ABSTRACT

Motor stereotypies are one of the most frequent features in children with a diagnosis of autism spectrum disorder. They may disrupt children's functioning and development and be a potential source of stress for families. Several factors, including sex, age, cognitive ability, and severity of autism spectrum disorder, may influence the presence and intensity of stereotypies. The present study aimed to identify the prevalence of motor stereotypies in a group of children with autism spectrum disorder. In addition, it sought to investigate whether sex, age, cognitive ability, verbal language, neurological comorbidities, and severity of autism spectrum disorder were associated with an increased probability and higher number, duration, and variability of stereotypies. A total of 134 participants aged 2.3-17.6 years underwent a clinical protocol with standardized video-recorded sessions. Stereotypies were identified and classified by two independent evaluators. The prevalence of stereotypies was 56.7%, and a total of 1198 motor stereotypies were captured. Children who were younger, nonverbal, and had higher severity of autism spectrum disorder had an increased probability of presenting stereotypies. Being nonverbal or having higher severity of autism spectrum disorder was also associated with presenting a higher number of stereotypies. Children with developmental delay, intellectual disability, or epilepsy displayed longer stereotypies, and children with developmental delay or intellectual disability additionally presented more diverse stereotypies. As part of the study, the authors present a clinical classification model, a glossary, and video samples of motor stereotypies. The findings of this study suggest that children who are younger, nonverbal, have lower cognitive ability, and have higher severity of autism spectrum disorder may have a higher burden of stereotypies. Earlier intervention and monitoring of these children have the potential to improve their long-term outcomes.

Feasibility of wearable devices and machine learning for sleep classification in children with Rett syndrome: A pilot study

Sleep is vital to many processes involved in the well-being and health of children; however, it is estimated that 80% of children with Rett syndrome suffer from sleep disorders. Caregiver reports and questionnaires, which are the current method of studying sleep, are prone to observer bias and missed information. Polysomnography is considered the gold standard for sleep analysis but is labor and cost-intensive and limits the frequency of data collection for sleep disorder studies. Wearable digital health technologies, such as actigraphy devices, have shown potential and feasibility as a method for sleep analysis in Rett syndrome, but have not been validated against polysomnography. Furthermore, the collected accelerometer data has limitations due to the rigidity, periodic limb movement, and involuntary muscle contractions prevalent in Rett syndrome. Heart rate and electrodermal activity, along with other physiological signals, have been linked to sleep stages and can be utilized with machine learning to provide better resistance to noise and false positives than actigraphy. This research aims to address the gap in Rett syndrome sleep analysis by comparing the performance of a machine learning model utilizing both accelerometer data and physiological data features to the gold-standard polysomnography for sleep analysis in Rett syndrome. Our analytical validation pilot study (n = 7) found that using physiological and accelerometer features, our machine learning models can differentiate between awake, non-rapid eye movement sleep, and rapid eye movement sleep in Rett syndrome children with an accuracy of 85.1% when using an individual model. Additionally, this work demonstrates that it is feasible to use digital health technologies in Rett syndrome, even at a young age, without data loss or interference from repetitive movements that are characteristic of Rett syndrome.

Multidimensional Development and Adaptive Behavioral Functioning in Younger and Older Children With Rett Syndrome

OBJECTIVE

The purpose of this study was to examine clinical severity, multidimensional development, and adaptive behavioral functioning in younger and older children with Rett syndrome (RTT) in the pseudostationary stage (stage III).

METHODS

Fourteen younger (≤10 years of age) and 15 older (11-18 years of age) children with confirmed stage III RTT (assigned to young-RTT and old-RTT groups, respectively) participated in this study. Clinical severity was determined using the Clinical Severity Score (CSS) scale for RTT. The children's cognitive, language, motor, and sociocommunicative development was assessed using the Mullen Scales of Early Learning (MSEL) and the Early Social Communication Scale (ESCS). Their adaptive behavioral and daily functional skills were assessed using the Vineland Adaptive Behavior Scales-Chinese version (VABS-C) and Pediatric Evaluation of Disability Inventory-Chinese version (PEDI-C).

RESULTS

Compared with the young-RTT group, the old-RTT group had higher severity of scoliosis on the CSS scale, poorer fine motor scores on the MSEL, reduced eye contact, reduced alternating eye gaze, and reduced turn-taking during social interaction on the ESCS. However, none of the VABS-C or PEDI-C subscale scores differed significantly between the groups. Higher CSSs were significantly correlated with lower scores in several subscales of MSEL, ESCS, VABS-C, and PEDI-C, especially for gross motor, mobility, and socialization functioning in all children with RTT.

CONCLUSION

Age-related differences in fine motor and sociocommunicative skills were observed between the young-RTT and old-RTT group, as measured using standardized assessments. Greater severity of RTT was correlated with poor motor, sociocommunicative, adaptive behavioral, and daily functional skills in stage III RTT.

IMPACT

Practitioners should be aware of clinical severity and the differences of developmental and adaptive behavioral functioning between younger and older children in the pseudostationary stage of RTT to provide specific age-related treatments.

LAY SUMMARY

With an understanding of severity and differences of developmental and adaptive behavioral functioning between younger and older children, clinical professionals can provide specific age-related treatments.

Cognitive, Behavioral, and Sensory Profile of Pallister–Killian Syndrome: A Prospective Study of 22 Individuals

Background: Developmental delay and intellectual disability are two pivotal elements of the phenotype of Pallister–Killian Syndrome (PKS). Our study aims to define the cognitive, adaptive, behavioral, and sensory profile of these patients and to evaluate possible correlations between the different aspects investigated and with the main clinical and demographic variables. Methods: Individuals of any age with genetically confirmed PKS were recruited. Those ≤ 42 months were administered the Bayley Scales of Infant and Toddler Development Third Edition (Bayley-III), and those > 42 months the Vineland Adaptive Behavior Scales—Second Edition (Vineland-II). Stereotyped behaviors (Stereotypy Severity Scale, SSS) and aggressive behaviors (Behavior Problems Inventory—Short Version, BPIs) were assessed in all subjects > 1 year; sensory profile (Child Sensory Profile 2, C-SP2) in all aged 2–18 years. Results: Twenty-two subjects were enrolled (11 F/11 M; age 9 months to 28 years). All subjects ≤ 42 months had psychomotor developmental delay. Of the subjects > 42 months, 15 had low IQ deviation, and 1 in the normal range. Stereotypies were frequent (median SSS-total score 25/68). Lower Vineland-II values corresponded to greater intensity and frequency of stereotypies (p = 0.004 and p = 0.003), and self-injurious behaviors (p = 0.002 and p = 0.002). Patients with severe low vision had greater interference of stereotypies (p = 0.027), and frequency and severity of aggressive behaviors (p = 0.026; p = 0.032). The C-SP2, while not homogeneous across subjects, showed prevalence of low registration and sensory seeking profiles and hypersensitivity to tactile and auditory stimuli. Lower Vineland-II scores correlated with higher Registration scores (p = 0.041), while stereotypies were more frequent and severe in case of high auditory sensitivity (p = 0.019; p = 0.007). Finally, greater sleep impairment correlated with stereotypies and self-injurious behaviors, and lower Vineland-II scores. Conclusions: The present study provides a further step in the investigation of the etiopathogenesis of the syndrome. Furthermore, these aspects could guide rehabilitation therapy through the identification of targeted protocols.

Enablers and barriers in dental attendance in Rett syndrome: an international observational study

AIMS

Intellectual and developmental disabilities are heterogeneous in aetiology and presentation, and one cannot make assumptions about the oral health barriers of those with Rett syndrome (RTT) based on findings from generic studies. This study investigated caregivers' perceptions regarding access to dental care for those with (RTT), and associations of dental treatments received by those with RTT with their caregivers' perceived value of oral health and perception of their own as well as their daughter's dental anxiety.

METHODS AND RESULTS

Retrospective observational data of a subset of individuals with confirmed MECP2 mutations in the InterRett database (n = 216) were used to explore caregiver-related factors and their relationships with longitudinal data on dental service utilisation, using negative binomial regression. The main reported barriers to dental care access for individuals with RTT were primarily dentist-related in nature, regardless of dental service history. Those with reported dental nonattendance were of older age. Increasing levels of caregiver-reported dental fear were associated with less frequent dental check-ups or for any appointments for affected individuals.

CONCLUSIONS

Dentist-related barriers and caregiver-reported anxiety may both adversely affect dental attendance for those with RTT. Future research should explore caregivers' beliefs and oral health literacy.

A semi-standardized music therapy intervention for girls with Rett syndrome: A descriptive essay

Rett syndrome (RTT) is a severe neurodevelopmental disorder resulting in a wide range of functional impairments and therefore greatly impacts the lives of both patients and their families. While genetic and medical aspects have been studied for several decades, rehabilitation intervention research is still in its infancy. In this study, the investigating researchers have presented a rehabilitative framework by using music therapy for girls with RTT. This model is founded upon the use of music therapy in light of Stern's proposal of subjective experience and affect attunement; it also refers to Rosenbaum's family-centered rehabilitation medicine perspective. This study both describes the theory behind this intervention and presents a newly developed outcome measure. This novel tool may have future clinical and research applications. Music therapy for patients with RTT has not been well researched yet, and, as a result, is not universally recommended. However this study's findings suggest that music therapy is an important component of multidisciplinary therapy. Further collaborative research should be encouraged in order to study and implement the use of music therapy in the treatment of severe disabilities. Projects such as the Enablin+ program with the support from the European Commission constitute fundamental tools in promoting integrative medical research and international networks.

Comparison of the presence and absence of an intervention to reduce hand stereotypies in individuals with Rett syndrome

BACKGROUND

We investigated how many individuals with Rett syndrome were undergoing interventions to reduce stereotypic hand movements and the factors determining the presence or absence of an intervention.

METHOD

A questionnaire was sent to 194 families. Each survey item was compared between the intervention and non-intervention groups according to the presence or absence of interventions to reduce hand stereotypies.

RESULTS

Information was acquired from 72 cases; 72.1% of individuals had received an intervention to reduce stereotypies at some point in their lives. An upper limb splint was the most common intervention. Age, locomotor and reaching function, diagnostic age, frequency and type of stereotypy, joint contractures and stereotypy-associated problems separated the presence or absence of a current or past intervention.

CONCLUSIONS

Interventions for stereotypy-associated problems are important and there are several variables related to whether an intervention is received.

Movement disorders in patients with Rett syndrome: A systematic review of evidence and associated clinical considerations

AIM

This systematic review identified and thematically appraised clinical evidence of movement disorders in patients with Rett syndrome (RTT).

METHOD

Using PRISMA criteria, six electronic databases were searched from inception to April 2021. A thematic analysis was then undertaken on the extracted data to identify potential themes.

RESULTS

Following the thematic analysis, six themes emerged: (i) clinical features of abnormal movement behaviors; (ii) mutational profile and its impact on movement disorders; (iii) symptoms and stressors that impact on movement disorders; (iv) possible underlying neurobiological mechanisms; (v) quality of life and movement disorders; and (vi) treatment of movement disorders. Current guidelines for managing movement disorders in general were then reviewed to provide possible treatment recommendations for RTT.

CONCLUSION

Our study offers an enriched data set for clinical investigations and treatment of fine and gross motor issues in RTT. A detailed understanding of genotype-phenotype relationships of movement disorders allows for more robust genetic counseling for families but can also assist healthcare professionals in terms of monitoring disease progression in RTT. The synthesis also showed that environmental enrichment would be beneficial for improving some aspects of movement disorders. The cerebellum, basal ganglia, alongside dysregulation of the cortico-basal ganglia-thalamo-cortical loop, are likely anatomical targets. A review of treatments for movement disorders also helped to provide recommendations for treating and managing movement disorders in patients with RTT.

Putative neural consequences of captivity for elephants and cetaceans

The present review assesses the potential neural impact of impoverished, captive environments on large-brained mammals, with a focus on elephants and cetaceans. These species share several characteristics, including being large, wide-ranging, long-lived, cognitively sophisticated, highly social, and large-brained mammals. Although the impact of the captive environment on physical and behavioral health has been well-documented, relatively little attention has been paid to the brain itself. Here, we explore the potential neural consequences of living in captive environments, with a focus on three levels: (1) The effects of environmental impoverishment/enrichment on the brain, emphasizing the negative neural consequences of the captive/impoverished environment; (2) the neural consequences of stress on the brain, with an emphasis on corticolimbic structures; and (3) the neural underpinnings of stereotypies, often observed in captive animals, underscoring dysregulation of the basal ganglia and associated circuitry. To this end, we provide a substantive hypothesis about the negative impact of captivity on the brains of large mammals (e.g., cetaceans and elephants) and how these neural consequences are related to documented evidence for compromised physical and psychological well-being.

Rett Syndrome Spectrum in Monogenic Developmental-Epileptic Encephalopathies and Epilepsies: A Review

INTRODUCTION

Progress in the clinical application of next-generation-sequencing-based techniques has resulted in a dramatic increase in the recognized genetic heterogeneity of the Rett syndrome spectrum (RSS). Our awareness of the considerable overlap with pediatric-onset epilepsies and epileptic/developmental encephalopathies (EE/DE) genes is also growing, and the presence of variable clinical features inside a general frame of commonalities has drawn renewed attention into deep phenotyping.

METHODS

We decided to review the medical literature on atypical Rett syndrome and "Rett-like" phenotypes, with special emphasis on described cases with pediatric-onset epilepsies and/or EE-DE, evaluating Neul's criteria for Rett syndrome and associated movement disorders and notable stereotypies.

RESULTS

"Rett-like" features were described in syndromic and non-syndromic monogenic epilepsy- and DE/EE-related genes, in "intellectual disability plus epilepsy"-related genes and in neurodegenerative disorders. Additionally, prominent stereotypies can be observed in monogenic complex neurodevelopmental disorders featuring epilepsy with or without autistic features outside of the RSS.

CONCLUSIONS

Patients share a complex neurodevelopmental and neurological phenotype (developmental delay, movement disorder) with impaired gait, abnormal tone and hand stereotypies. However, the presence and characteristics of regression and loss of language and functional hand use can differ. Finally, the frequency of additional supportive criteria and their distribution also vary widely.

Oral health care and service utilisation in individuals with Rett syndrome: an international cross-sectional study

BACKGROUND

There is a dearth of literature available on the comparative oral health status of those with Rett syndrome (RTT) despite diurnal bruxism being a supportive diagnostic criterion for the disorder. This study was designed to investigate the dental experiences of individuals with RTT in terms of perceived at-home and professional dental care.

METHODS

Using data in the InterRett database, provided by English-speaking families of individuals with a confirmed MECP2 genetic mutation, the study investigated relationships between dental problems, oral care, child factors including bruxism and use of gastrostomy, and socioeconomic indicators. The study also explored relationships between dental presentations and socioeconomic, child, and family-related factors.

RESULTS

Individuals with RTT exhibiting bruxism were more likely to access dental treatment. Those who had full oral feeding had a higher incidence rate of dental treatment than those with full tube feeding. A conservative (under) estimation of the overall dental caries progression rate revealed that this may be similar to that of the normal population.

CONCLUSIONS

Drivers for dental treatment in RTT include bruxism as well as dental caries. Those who have full oral feeding experience more dental treatment than those with full tube feeding. A higher maternal education level may confer a protective effect for oral health outcomes in those with RTT. Nevertheless, families generally tended to value the importance of oral health despite reported difficulties in day-to-day mouth care.

Oral parafunction and bruxism in Rett syndrome and associated factors: An observational study

OBJECTIVES

To explore patterns of parafunction, and bruxism, and its relationships with genotype and snoring in individuals with Rett syndrome (RTT).

METHODS

Retrospective observational data of those with confirmed MECP2 mutations in the InterRett database (n = 216) were used to investigate experience of parafunctional habits, and bruxism and their relationships with genotype and snoring using multivariable linear regression.

RESULTS

The prevalence of parafunction was 98.2%. Bruxism was reported (66.2%) with the patterns mostly both diurnal and nocturnal (44.1%) and exclusively diurnal (42.7%). Compared to individuals with C-terminal deletion, individuals with p.Arg106Trp mutations were less likely to have bruxism reported (aOR = 0.15; 95% CI 0.02-0.98, p = 0.05) and those with p.Arg168* mutation were more likely to have frequent bruxism than none or occasional bruxism reported (aROR 3.4; 95% CI 1.1-10.7 p = 0.04). The relative odds of having nocturnal bruxism constantly, compared to none/occasionally, were higher among those 'always' snoring (aROR 6.24; 95% CI 2.1-18.2, p = 0.001) than those with no snoring.

CONCLUSIONS

There appeared to be genotypic association with bruxism in p.Arg168* and p.Arg106Trp mutations and association between nocturnal bruxism and frequent snoring in an international sample of individuals with RTT. Clinical significance of the high prevalence of bruxism should be highlighted in relation to difficulty communicating pain and increased dental treatment need in RTT.

Phonic and Motor Stereotypies in Autism Spectrum Disorder: Video Analysis and Neurological Characterization

Stereotypies are among the core symptoms of Autism spectrum disorder (ASD) and can cause significant clinical impairment. At present, phonic stereotypies in ASD have been scarcely explored. This study investigates the frequency, variability, and typologies of phonic and motor stereotypies in children with ASD and their association with clinical neurological variables. We examined 35 patients by recording standardized video sessions and administering the Autism Diagnostic Observation Schedule-Second Edition (ADOS-2). Phonic stereotypies were present in 83.0% of the patients. The most prevalent subtypes were noncommunicative vocalizations (60.0%), single syllables (37.1%), and echolalic stereotypies (22.9%). Noncommunicative vocalizations were more frequent in nonverbal patients (OR = 4.629, p = 0.008), while echolalic stereotypies were more represented in verbal patients (OR = 0.279, p = 0.028). Patients with intellectual disability (ID) showed a higher number (F(1,26) = 9.406, p = 0.005) and variability (F(1,25) = 7.174, p = 0.013) of motor stereotypies, with a higher number (F(1,26) = 13.268, p = 0.005) and variability (F(1,26) = 9.490, p = 0.005) of stereotypies involving the head/trunk/shoulders category. Patients with guttural stereotypies showed a higher variability of total motor stereotypies (OR = 1.487, p = 0.032) and self-directed motor stereotypies (OR = 4.389, p = 0.042). These results, combined with a standardized video-analysis, document the frequency and variability of phonic stereotypies among children with ASD. Correlations between specific phonic stereotypies and verbal abilities should be investigated further.

Oral Manifestations of Rett Syndrome-A Systematic Review

Rett Syndrome is an x linked developmental disorder which becomes apparent in females after 6 to 18 months of age. It leads to severe impairments including loss of speech, loss of hand movements/manual dexterity, characteristic hand movements such as hang wringing and intellectual disability/learning problems. This systematic review was carried out to identify the dental manifestation of Rett syndrome and to shed light on treatment options available for oral health problems associated with Rett syndrome. A systematic literature search was conducted on the PubMed, Scopus, Biomed, Web of Science, Embase, Google Scholars, Cochrane and CINAHL using the following entries: Rett syndrome (n = 3790), Oral health and Rett syndrome (n = 17), dental health of Rett syndrome patients (n = 13), and the MeSH terms listed below: Rett syndrome and Oral Health (n = 17), Rett syndrome and dentistry (n = 29). The final review included 22 search articles. The most common oral findings was bruxism. Masseteric hypertrophy was also reported. Anterior open bite and non-physiological tooth wear was observed. Other oral manifestations of Rett syndrome included mouth breathing, tongue thrusting, digit/thumb sucking, high arch palate. Increased awareness and dental education amongst dentists and assistants regarding the dental manifestations of Rett syndrome and similar neurodevelopmental disorders is required to improve the level of care and empathy they can provide to these differently able patients. Research on dental aspects of Rett is scarce and this remains a neglected topic.

Correlation of dystonia severity and iron accumulation in Rett syndrome

Individuals with Rett syndrome (RTT) commonly demonstrate Parkinsonian features and dystonia at teen age; however, the pathological reason remains unclear. Abnormal iron accumulation in deep gray matter were reported in some Parkinsonian-related disorders. In this study, we investigated the iron accumulation in deep gray matter of RTT and its correlation with dystonia severity. We recruited 18 RTT-diagnosed participants with MECP2 mutations, from age 4 to 28, and 28 age-gender matched controls and investigated the iron accumulation by susceptibility weighted image (SWI) in substantia nigra (SN), globus pallidus (GP), putamen, caudate nucleus, and thalamus. Pearson's correlation was applied for the relation between iron accumulation and dystonia severity. In RTT, the severity of dystonia scales showed significant increase in subjects older than 10 years, and the contrast ratios of SWI also showed significant differences in putamen, caudate nucleus and the average values of SN, putamen, and GP between RTT and controls. The age demonstrated moderate to high negative correlations with contrast ratios. The dystonia scales were correlated with the average contrast ratio of SN, putamen and GP, indicating iron accumulation in dopaminergic system and related grey matter. As the first SWI study for RTT individuals, we found increased iron deposition in dopaminergic system and related grey matter, which may partly explain the gradually increased dystonia.

Parkinsonism in children: Clinical classification and etiological spectrum

Infantile- and childhood-onset parkinsonism is mainly due to genetic alterations and is an exceedingly rare condition, unlike Parkinson's disease (PD), which is one of the most common neurologic disorders in adulthood. The clinical characterization of parkinsonism during early stages of neuromotor development is controversial due to the lack of consensus regarding the clinical criteria of PD or parkinsonism in the immature brain. The classification here proposed is based on a review of conditions that emerge during infancy and childhood, with key symptoms evocative of adult parkinsonism. The proposed nosography is based on age at presentation, clinical features, outcome, and etiological background. It includes developmental parkinsonism, infantile degenerative parkinsonism, parkinsonism in the setting of neurodevelopmental disorders, parkinsonism in the setting of multisystem brain diseases, juvenile parkinsonism and dystonia-parkinsonism, and acquired parkinsonism. The subgroups denoting peculiar clinical presentations as a consequence of disease impact on the immature brain are developmental parkinsonism due to monoamine metabolic disorders and infantile degenerative parkinsonism caused by DAT and WASR2 defects. More tardive parkinsonisms occur in genetic conditions that cause a generalized derangement of neurodevelopmental processes, such as those due to MECP2, NR4A2, SCN1A, and RAB39B. Some conditions presenting with neurodevelopmental disorder can progress later, disclosing their neurodegenerative nature (i.e. WDR45 and KCND3). Finally, new emerging conditions with childhood-onset parkinsonism arise from the cumulative effect of multiple genetic lesions.

Gratification Disorder as an Early Marker of Rett Syndrome: Two Pediatric Case Reports

Gratification disorder (GD) is a form of stereotyped posturing with mechanical pressure applied to the genitalia without manual manipulation and is generally considered benign. Here, we describe two patients who exhibited GD. Both were later diagnosed with Rett syndrome via genetic sequencing. In both patients, GD preceded the onset of the hallmark hand stereotypies of Rett syndrome. We therefore conclude that GD is not as benign as previously assumed and in fact can be an early sign of Rett syndrome. Further studies are needed to evaluate the prevalence of GD in Rett girls with the MECP2 genotype.

Rett Syndrome as a movement and motor disorder - A narrative review

Rett syndrome (RTT) is neurodevelopmental disorder affecting approximately 1:10000-15000 live female births, commonly associated with MECP2 gene mutations. Hand stereotypies and gait disturbance, as well as spasticity and dystonia, were noted in RTT since first descriptions. This review aimed to explore the prevalence of reported movement disorders in RTT.

DATA SOURCES AND EXTRACTION

Pubmed and Embase databases for papers describing features of movement disorders in RTT. Papers were selected if included description of case report, cohort or case-series of patients with RTT including descriptions of clinical features of their movement disorder. Papers were divided into 3 epochs - i) Pre-1999,ii) 2000-2009, and iii) 2010 onwards.

RESULTS

32 studies (13 in the first, 10 in the second and 9 in the third epochs) reported on movement disorders in RTT. Hand stereotypies were almost universal, diminishing but not disappearing over time. Gait disturbance and ataxia/tremor were also very common (>50% cases). Hypertonia was also often reported, increasing with age. In earlier descriptions spasticity was commonly described, with greater reference to dystonia/rigidity in more recent reports. Myoclonus and choreoathetosis were uncommonly reported.

CONCLUSIONS

Movement disorders beyond hand stereotypies are common in RTT, most notably tremor. Hypertonia is frequently seen in RTT, increasing in prevalence with age, with apparent changes in nomenclature over time, (i.e early epoch spasticity, late epoch dystonia). Dystonia was specifically reported in 229/417 cases. Further work is required to explore the relative contribution of dystonia and rigidity to hypertonia in RTT, as well as the impact of these impairments when present.

Consensus guidelines on managing Rett syndrome across the lifespan

BACKGROUND

Rett syndrome (RTT) is a severe neurodevelopmental disorder with complex medical comorbidities extending beyond the nervous system requiring the attention of health professionals. There is no peer-reviewed, consensus-based therapeutic guidance to care in RTT. The objective was to provide consensus on guidance of best practice for addressing these concerns.

METHODS

Informed by the literature and using a modified Delphi approach, a consensus process was used to develop guidance for care in RTT by health professionals.

RESULTS

Typical RTT presents early in childhood in a clinically recognisable fashion. Multisystem comorbidities evolve throughout the lifespan requiring coordination of care between primary care and often multiple subspecialty providers. To assist health professionals and families in seeking best practice, a checklist and detailed references for guidance were developed by consensus.

CONCLUSIONS

The overall multisystem issues of RTT require primary care providers and other health professionals to manage complex medical comorbidities within the context of the whole individual and family. Given the median life expectancy well into the sixth decade, guidance is provided to health professionals to achieve current best possible outcomes for these special-needs individuals.

The spectrum of involuntary vocalizations in humans: A video atlas

In clinical practice, involuntary vocalizing behaviors are typically associated with Tourette syndrome and other tic disorders. However, they may also be encountered throughout the entire tenor of neuropsychiatry, movement disorders, and neurodevelopmental syndromes. Importantly, involuntary vocalizing behaviors may often constitute a predominant clinical sign, and, therefore, their early recognition and appropriate classification are necessary to guide diagnosis and treatment. Clinical literature and video-documented cases on the topic are surprisingly scarce. Here, we pooled data from 5 expert centers of movement disorders, with instructive video material to cover the entire range of involuntary vocalizations in humans. Medical literature was also reviewed to document the range of possible etiologies associated with the different types of vocalizing behaviors and to explore treatment options. We propose a phenomenological classification of involuntary vocalizations within different categorical domains, including (1) tics and tic-like vocalizations, (2) vocalizations as part of stereotypies, (3) vocalizations as part of dystonia or chorea, (4) continuous vocalizing behaviors such as groaning or grunting, (5) pathological laughter and crying, (6) vocalizations resembling physiological reflexes, and (7) other vocalizations, for example, those associated with exaggerated startle responses, as part of epilepsy and sleep-related phenomena. We provide comprehensive lists of their associated etiologies, including neurodevelopmental, neurodegenerative, neuroimmunological, and structural causes and clinical clues. We then expand on the pathophysiology of the different vocalizing behaviors and comment on available treatment options. Finally, we present an algorithmic approach that covers the wide range of involuntary vocalizations in humans, with the ultimate goal of improving diagnostic accuracy and guiding appropriate treatment. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Sensory Integration and Functional Reaching in Children With Rett Syndrome/Rett-Related Disorders

Background

The loss of functional hand skills is a primary characteristic of Rett syndrome. Stereotypies, dyspraxia, and other sensory processing issues severely limit the individual's ability to reach toward and sustain grasp on objects. This loss of functional reach and grasp severely limits their ability to participate in self-help, play, and school-related activities. We proposed that Ayres Sensory Integration (ASI) treatment would improve sensory processing and motor planning, which would lay the sensory-motor groundwork for improving grasp of objects, an important first step in developing functional hand use.

Objective

We examined effects of ASI treatment on rate of reaching and grasping for children with Rett syndrome/Rett-related disorders.

Methods

We used an interrupted time series design to measure changes in outcome variables occurring after intervention initiation and cessation. We analyzed daily video observations during baseline, intervention, and post-intervention periods, over a span of 7 months.

Results

During baseline, rate of grasping declined moderately. There was a 15% increase in grasping from the end of baseline to end of the post-intervention period. There was no significant change in rate of reaching.

Conclusions

This study provides preliminary data showing very small improvements in hand grasp of children with Rett syndrome following ASI treatment; larger studies in diverse settings are needed to establish the effectiveness of this approach. This study shows that an interrupted time series research design provides a valid template for evaluating interventions for children with rare disorders.

Variation factors of stereotypical hand movements in subjects with Rett syndrome

Background: Stereotypical hand movements have been observed in most individuals diagnosed with Rett syndrome. Objectives: To investigate factors that increase or decrease hand stereotypies in individuals with Rett syndrome. Methods: A questionnaire regarding hand stereotypies or purposeful hand behaviours was sent to 1016 schools for special needs education and 204 facilities in Japan. Results: Information was acquired from 216 cases (3-53 years old) with Rett syndrome; 81.9% and 87.6% of individuals had factors that increased and decreased stereotypical hand movements, respectively. Stereotypies were mainly increased by displeasure (63.8%) or pleasure (48.5%), and decreased by somnolence (43.5%), pleasure (30.0%), or food (24.1%). Conclusion: Emotion was the main factor increasing stereotypical hand movements, whereas there were a large number of factors that decreased these movements. The factors that decrease stereotypies could be useful to prevent the skin problems or joint contracture observed in patients with Rett syndrome.

Hand stereotypies: Lessons from the Rett Syndrome Natural History Study

OBJECTIVE

To characterize hand stereotypies (HS) in a large cohort of participants with Rett syndrome (RTT).

METHODS

Data from 1,123 girls and women enrolled in the RTT Natural History Study were gathered. Standard tests for continuous and categorical variables were used at baseline. For longitudinal data, we used repeated-measures linear and logistic regression models and nonparametric tests.

RESULTS

HS were reported in 922 participants with classic RTT (100%), 73 with atypical severe RTT (97.3%), 74 with atypical mild RTT (96.1%), and 17 females with MECP2 mutations without RTT (34.7%). Individuals with RTT who had classic presentation or severe MECP2 mutations had higher frequency and earlier onset of HS. Heterogeneity of HS types was confirmed, but variety decreased over time. At baseline, almost half of the participants with RTT had hand mouthing, which like clapping/tapping, decreased over time. These 2 HS types were more frequently reported than wringing/washing. Increased HS severity (prevalence and frequency) was associated with worsened measures of hand function. Number and type of HS were not related to hand function. Overall clinical severity was worse with decreased hand function but only weakly related to any HS characteristic. While hand function decreased over time, prevalence and frequency of HS remained relatively unchanged and high.

CONCLUSIONS

Nearly all individuals with RTT have severe and multiple types of HS, with mouthing and clapping/tapping decreasing over time. Interaction between HS frequency and hand function is complex. Understanding the natural history of HS in RTT could assist in clinical care and evaluation of new interventions.

Analysis of the Phenotypes in the Rett Networked Database

Rett spectrum disorder is a progressive neurological disease and the most common genetic cause of intellectual disability in females. MECP2 is the major causative gene. In addition, CDKL5 and FOXG1 mutations have been reported in Rett patients, especially with the atypical presentation. Each gene and different mutations within each gene contribute to variability in clinical presentation, and several groups worldwide performed genotype-phenotype correlation studies using cohorts of patients with classic and atypical forms of Rett spectrum disorder. The Rett Networked Database is a unified registry of clinical and molecular data of Rett patients, and it is currently one of the largest Rett registries worldwide with several hundred records provided by Rett expert clinicians from 13 countries. Collected data revealed that the majority of MECP2-mutated patients present with the classic form, the majority of CDKL5-mutated patients with the early-onset seizure variant, and the majority of FOXG1-mutated patients with the congenital form. A computation of severity scores further revealed significant differences between groups of patients and correlation with mutation types. The highly detailed phenotypic information contained in the Rett Networked Database allows the grouping of patients presenting specific clinical and genetic characteristics for studies by the Rett community and beyond. These data will also serve for the development of clinical trials involving homogeneous groups of patients.

Oral health experiences of individuals with Rett syndrome: a retrospective study

Background

There is relatively little literature on the oral health experiences of individuals with Rett syndrome. This study described the incidence of dental extractions and restorations in a population-based cohort, according to a range of demographic and clinical factors. The association between bruxism and age was also investigated.

Methods

Existing questionnaire data in the population-based Australian Rett Syndrome Database for the years 2004, 2006, 2009 or 2011 on genetically confirmed female cases (n = 242) were analysed.

Results

The incidence rate of restorations and extractions were 6.8 per 100 person years (py) and 9.3 per 100 py respectively. The incidence of extractions decreased with increasing levels of income. Compared to those with a C-terminal mutation, the incidence rate of extraction was higher for those with large deletions (Incidence Rate Ratio (IRR) 4.93; 95% CI 1.46–16.7, p = 0.01). There was a 5% decrease in the risk of frequent bruxism for every one-year increase in age (Risk Ratio 0.95; 95% CI 0.94–0.97).

Conclusions

Social advantage may provide some protection for dental health in individuals with Rett syndrome. Those with more severe genotypes seemed to have poorer oral health outcomes.

Further delineation of the MECP2 duplication syndrome phenotype in 59 French male patients, with a particular focus on morphological and neurological features

The Xq28 duplication involving the MECP2 gene (MECP2 duplication) has been mainly described in male patients with severe developmental delay (DD) associated with spasticity, stereotypic movements and recurrent infections. Nevertheless, only a few series have been published. We aimed to better describe the phenotype of this condition, with a focus on morphological and neurological features. Through a national collaborative study, we report a large French series of 59 affected males with interstitial MECP2 duplication. Most of the patients (93%) shared similar facial features, which evolved with age (midface hypoplasia, narrow and prominent nasal bridge, thick lower lip, large prominent ears), thick hair, livedo of the limbs, tapered fingers, small feet and vasomotor troubles. Early hypotonia and global DD were constant, with 21% of patients unable to walk. In patients able to stand, lower limbs weakness and spasticity led to a singular standing habitus: flexion of the knees, broad-based stance with pseudo-ataxic gait. Scoliosis was frequent (53%), such as divergent strabismus (76%) and hypermetropia (54%), stereotypic movements (89%), without obvious social withdrawal and decreased pain sensitivity (78%). Most of the patients did not develop expressive language, 35% saying few words. Epilepsy was frequent (59%), with a mean onset around 7.4 years of age, and often (62%) drug-resistant. Other medical issues were frequent: constipation (78%), and recurrent infections (89%), mainly lung. We delineate the clinical phenotype of MECP2 duplication syndrome in a large series of 59 males. Pulmonary hypertension appeared as a cause of early death in these patients, advocating its screening early in life.

The feasibility of using actigraphy to characterize sleep in Rett syndrome

BACKGROUND

Rett syndrome (RTT) is a neurodevelopmental disorder primarily caused by mutations in the MECP2 gene. Sleep problems are reported by the majority of caregivers of individuals with RTT.

METHODS

The present study aimed to replicate and extend previous work about the feasibility of measuring sleep with an actigraph device in a sample of girls with clinically diagnosed RTT (N = 13, mean age = 9 years, 5 months). Participants wore an actigraph device day and night for seven consecutive days. Materials also included a parent-completed sleep diary to measure bedtime, duration of nighttime sleep, and daytime sleep, and the Child Sleep Habit's Questionnaire (CSHQ).

RESULTS

The means for the sample as measured by actigraphy were 492.3 min (SD = 47.3) of total night sleep (TNS), 76.0% (SD = 6.7) sleep efficiency, 86.0 min (SD = 34.2) of wake after sleep onset, and 46.1 min (50.8) of sleep when parents reported a nap occurring. Parents reported 589.7 min (SD = 53.6) of TNS, 15.9 min (SD = 12.0) of WASO, and 93.6 min (SD = 66.8) of daytime sleep according to sleep diaries, with all parents reporting at least one nap during the week. Relations were found between sleep characteristics and seizure status and CSHQ total scores. No age-related changes were observed for any sleep characteristic, regardless of collection method. Five of nine participants above the cutoff score on the CSHQ indicate the need for further evaluation for a sleep disorder.

CONCLUSIONS

Overall, actigraphy was feasible in this community-based sample of girls with RTT. The results replicated some aspects of previous studies of sleep in RTT (e.g., no age-related changes in total nighttime sleep or efficiency). Some participants met the American Academy of Sleep Medicine guidelines for recommended total sleep time, with others showing too much or too little sleep. Each of the three methods for describing sleep presented its own advantages and challenges. Future work should be prospectively designed, validate the use of actigraphy in this population, and include a typically developing comparison sample to improve the precision of our understanding of sleep in RTT.

Skin injuries and joint contractures of the upper extremities in Rett syndrome

OBJECTIVES

The purpose of this study was to investigate the incidence and type of skin injuries and joint contractures of the upper extremities in individuals with Rett syndrome.

METHODS

In 2016, a questionnaire regarding skin injuries and joint contractures was sent to 1016 directors of schools for special needs education and 204 directors of departments of rehabilitation [consisting of 130 facilities for persons with severe motor and intellectual disabilities (SMID), 73 wards for patients with SMID, and the National Hospital Organisation and National Centre Hospital, National Centre of Neurology and Psychiatry] in Japan. Descriptive statistics were used to indicate frequency in each question.

RESULTS

Information was acquired from 216 cases (3-53 years old) with Rett syndrome. Skin injuries and joint contractures of the upper extremities were observed in 41% and 49% of individuals with Rett syndrome, respectively. Most of the skin injuries were observed on the hands (19%) and fingers (29%). The incidence of skin injuries was not affected by age or disease severity. Many joint contractures were observed in the shoulder (33%) and elbow (29%) joints. Joint contractures tended to occur in individuals aged over 10 years or with severe locomotor impairment.

CONCLUSION

Almost half of the Rett syndrome subjects assessed in the present study had skin injuries and joint contractures. Especially, the incidence of joint contractures was affected by age and disease severity. Thus, it is important that medical staff attempt to prevent the occurrence of skin injuries and joint contractures in this patient population.

Defining Hand Stereotypies in Rett Syndrome: A Movement Disorders Perspective

INTRODUCTION

Hand stereotypies (HS) are a primary diagnostic criterion for Rett syndrome (RTT) but are difficult to characterize and quantify systematically.

METHODS

We collected video on 27 girls (2-12 years of age) with classic RTT who participated in a mecasermin trial. The present study focused exclusively on video analyses, by reviewing two five-minute windows per subject to identify the two most common HS. Three raters with expertise in movement disorders independently rated the five-minute windows using standardized terminology to determine the level of agreement. We iteratively refined the protocol in three stages to improve descriptive accuracy, categorizing HS as "central" or "peripheral," "simple" or "complex," scoring each hand separately. Inter-rater agreement was analyzed using Kappa statistics.

RESULTS

In the initial protocol evaluating HS by video, inter-rater agreement was 20.7%. In the final protocol, inter-rater agreement for the two most frequent HS was higher than the initial protocol at 50%.

CONCLUSION

Phenotypic variability makes standardized evaluation of HS in RTT a challenge; we achieved only 50% level of agreement and only for the most frequent HS. Therefore, objective measures are needed to evaluate HS.

Variations of stereotypies in individuals with Rett syndrome: A nationwide cross-sectional study in Taiwan

Individuals with Rett syndrome (RTT) can have variable manifestations of stereotypies. In this nation-wide cross-sectional study, we recruited all individuals with RTT in Taiwan diagnosed as RTT by neurologists based on genetic findings and diagnostic criteria. The data were collected using questionnaire. A total 43 cases of typical RTT and 15 cases of atypical RTT, aged from 2.1 to 40.1 years, were enrolled. They included 3 (5.2%) in stage II, 42 (72.4%) in stage III, and 13 (22.4%) in stage IV. All individuals presented with at least one stereotypy. Individuals with atypical RTT had more varied stereotypies (mean: 14 ± 6) compared to those with typical RTT (mean: 9 ± 5) (P = 0.003). Flapping (73.3%) and wringing (58.1%) were the most common hand stereotypies in atypical and typical RTT, respectively. Compared with typical RTT, hair pulling, bruxism, retropulsion, and protrusion of lips were more common in atypical RTT (P = 0.003, P = 0.006, P = 0.003 and <0.001, respectively). The number of stereotypies did not differ among different stages, clinical severities, and hand functions. Although there were no age-related changes in stereotypies in atypical RTT, flapping (P = 0.012), clapping (P = 0.044), and mouthing with single hand (P = 0.009) were significantly more prevalent in individuals aged <10 years with typical RTT, and they decreased after 10 years. In conclusion, our study showed that the stereotypical movements varied in typical and atypical RTT, implying the heterogeneous nature of the disease and the pathogenic mechanisms of RTT with atypical features. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1204-1214. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Oral health in a group of patients with Rett syndrome in the regions of Valencia and Murcia (Spain): a case-control study

Objectives: Rett syndrome (RS) is a rare disease with oral manifestations that have not been described in detail or in a standardized manner in the literature. The present study describes the oral health of the population with RS in two Spanish regions, following the protocol of the World Health Organization for conducting common oral health surveys. Study Design: A prospective, observational case-control study was carried out, involving a group of patients with RS (n1=41) and a mean age of 13.37±3.19 years, and an age- and gender-matched control group without RS (n0=82). The data referred to oral health and habits were recorded by means of a questionnaire and oral examination was used to document caries indicators (prevalence of caries, df(t), df(s), DMF(T), DMF(S) and indices referred to dental loss, morbidity, restoration), the Community Periodontal Index (CPI), and the most characteristic oral manifestations. Results: The most frequent oral habit in the patients with RS was diurnal bruxism, followed by stereotyped tongue movements and oral breathing. The caries scores were lower in the RS population than in the control group, but patients with RS showed greater periodontal alterations and a greater prevalence of drooling, dental wear, high-arched palate and anterior open bite. Conclusions: The population with RS exhibits characteristic and early oral habits and alterations, and periodontal problems that are more notorious than caries disease, so that our efforts should focus on the diagnosis and early correction of the parafunctional habits, promoting restorative treatment, and providing instructions on correct oral hygiene.

Key words:Rett syndrome, oral habits, bruxism, caries.

Perspectives on hand function in girls and women with Rett syndrome

OBJECTIVE

Rett syndrome is a rare neurodevelopmental disorder that is usually associated with a mutation on the X-linked MECP2 gene. Hand function is particularly affected and we discuss theoretical and practical perspectives for optimising hand function in Rett syndrome.

METHODS

We reviewed the literature pertaining to hand function and stereotypies in Rett syndrome and developed a toolkit for their assessment and treatment.

RESULTS

There is little published information on management of hand function in Rett syndrome. We suggest assessment and treatment strategies based on available literature, clinical experience and grounded in theories of motor control and motor learning.

CONCLUSION

Additional studies are needed to determine the best treatments for hand function in Rett syndrome. Meanwhile, clinical needs can be addressed by supplementing the evidence base with an understanding of the complexities of Rett syndrome, clinical experience, environmental enrichment animal studies and theories of motor control and motor learning.

Monozygotic twins with Rett syndrome: Phenotyping the first two years of life

The first two years of life for children with Rett syndrome (RTT) have previously been viewed as relatively asymptomatic. However, it is possible that subtle symptoms may be present in early development. To identify possible early indicators of RTT, we analysed videotapes of two twin girls with RTT. The videotapes were analysed to (a) describe the motor and communicative development of this twin pair with RTT; and to (b) explore whether early abnormalities and their age of onset differed between the twins and were related to their later clinical phenotypes. The results indicated several neurodevelopmental abnormalities present before the children exhibited any obvious signs of regression. Abnormalities were evident in the motor, speech-language and communicative domains. These data support an emerging evidence base showing the presence of developmental abnormalities in children with RTT during the first year of life. The results have implications for early screening and clinical assessment.

Unilateral rhythmic hand tapping in Rett syndrome: is this stereotypy?

Rett syndrome is a severe neurodevelopmental disorder, with hand stereotypies as a hallmark of the disease. Epilepsy is a frequent comorbidity and is accompanied by centrotemporal spikes on electroencephalogram, but stereotypic movements should not have epileptiform correlates. During routine video-electroencephalographic investigation in 5 Rett syndrome patients, we identified a peculiar type of unilateral, highly rhythmic hand tapping accompanied by contralateral synchronous centrotemporal spikes on electroencephalography. This phenomenon is not consistent with either reflex seizures or hand stereotypies and does not respond to antiepileptic drugs. The electroencephalographic activity probably represents evoked potentials, either somatosensory or motor, whereas the rhythmic activity raises the possibility of a subcortical pacemaker for a stereotypy variant. The phenomenon could be caused by abnormal circuitry among the hyperexcitable somatosensory cortex, motor cortex, and subcortical areas in Rett syndrome. Clinicians should be aware of the nonepileptic nature of this motor behavior and should not attempt to treat it.

Hand stereotypies distinguish Rett syndrome from autism disorder

BACKGROUND

Rett syndrome (RTT) and autism disorder (AD) are 2 neurodevelopmental disorders of early life that share phenotypic features, one being hand stereotypies. Distinguishing RTT from AD often represents a challenge, and given their distinct long-term prognoses, this issue may have far-reaching implications. With the advances in genetic testing, the contribution of clinical manifestations in distinguishing RTT from AD has been overlooked.

METHODS

A comparison of hand stereotypies in 20 children with RTT and 20 with AD was performed using detailed analyses of videotaped standardized observations.

RESULTS

Striking differences are observed between RTT and AD children. In RTT, hand stereotypies are predominantly complex, continuous, localized to the body midline, and involving mouthing. Conversely, in AD children, hand stereotypies are simple, bilateral, intermittent, and often involving objects.

CONCLUSIONS

These results provide important clinical signs useful to the differential diagnosis of RTT versus AD, especially when genetic testing for RTT is not an option.

Longitudinal hand function in Rett syndrome

Loss of hand function is a core feature of Rett syndrome. This article describes longitudinal hand function at 3 time points for 72 subjects participating in the Australian Rett Syndrome Database. Approximately 40% of subjects with some grasping abilities lost skill over the 3- to 4-year period between video assessments. In these subjects, a decrease in hand function was seen less frequently in girls 13 to 19 years old than in those younger than 8 years, in subjects with some mobility compared with those who were wheelchair bound, and in those who had previously been able to finger feed. Relationships with the magnitude of change reflected these findings. Change in hand function did not vary with clinical severity. The results for all subjects were similar to results obtained when analysis was restricted to those with a pathogenic mutation. Variability in the longitudinal course of hand function in Rett syndrome was observed.

Stereotypic movement disorders

Stereotypic movements are repetitive, rhythmic, fixed, patterned in form, amplitude, and localization, but purposeless (e.g., hand shaking, waving, body rocking, head nodding). They are commonly seen in children; both in normal children (primary stereotypy) and in individuals with additional behavioral or neurological signs and symptoms (secondary stereotypy). They should be differentiated from compulsions (OCD), tics (tic disorders), trichotillomania, skin picking disorder, or the direct physiological effect of a substance. There is increasing evidence to support a neurobiological mechanism. Response to behavioral and pharmacological therapies is variable.

Rett syndrome with and without detected MECP2 mutations: an attempt to redefine phenotypes

BACKGROUND

The diagnosis of Rett syndrome (RTT) is based on a set of clinical criteria, irrespective of mutation status. The aims of this study were (1) to define the clinical differences existing between patients with Rett syndrome with (Group I) and without a MECP2 mutation (Group II), and (2) to characterize the phenotypes associated with the more common MECP2 mutations.

PATIENTS AND METHODS

We analyzed 87 patients fulfilling the clinical criteria for RTT. All were observed and videotaped by the same paediatric neurologist. Seven common mutations were considered separately, and associated clinical features analysed.

RESULTS

Comparing Group I and II, we found differences concerning psychomotor development prior to onset, acquisition of propositive manipulation and language, and evolving autistic traits. Based on age at observation, we found differences in eye pointing, microcephaly, growth, number of stereotypies, rigidity, ataxia and ataxic-rigid gait, and severity score. Patients with truncating differed from those with missense mutations regarding acquisition of propositive words and independent gait, before the beginning of the disease, and microcephaly, growth, foot length, dystonia, rigidity and severity score, at the time of observation. Patients with the R168X mutation had a more severe phenotype, whereas those with R133C showed a less severe one. Patients with R294X had a hyperactive behaviour, and those with T158M seemed to be particularly ataxic and rigid.

CONCLUSION

A clear regressive period (with loss of prehension and language, deceleration of growth) and the presence of more than three different stereotypies, rigidity and ataxic-rigid gait seemed to be very helpful in differentiating Group I from Group II.