Communication in Individuals with Rett Syndrome: an Assessment of Forms and Functions

Insights into Rett Syndrome girls' receptive vocabulary through eye movements and parental perception

OBJECTIVE

This study evaluated the receptive vocabulary of girls diagnosed with Rett Syndrome (RS) by employing eye-tracking technology and examined how these objective measures compared with parents' perceptions of their daughters' language abilities.

METHOD

Fourteen girls with RS and eleven typically developing peers participated. Instruments included the Kerr Scale, a parental questionnaire on communication skills, the Peabody Picture Vocabulary Test - PPVT-4, and eye-tracking equipment. The PPVT-4's initial 12 cards, each displaying four images, were presented on screen for 5 s for the child's initial inspection. Subsequently, the same card was shown for 5 s with instructions to identify the picture matching the word, repeated three times in a randomized order.

RESULTS

Eye-tracking assessments revealed that girls with RS with less severe symptoms, performed below typically developing peers with aged 3-4 years. The number of eye fixations emerged as a reliable metric for assessing their performance. A positive correlation was found between parental reports of their daughters' vocabulary knowledge and their ability to identify the correct stimulus, suggesting comprehension and active engagement in the testing process.

CONCLUSION

This study presents a pioneering approach by combining parental perceptions with eye-tracking measures to assess receptive vocabulary in girls diagnosed with Rett Syndrome. Despite showing lower performance levels compared to significantly younger peers, the findings suggest that these individuals use less effectively eye contact as a mode of communication.

Atypical brain responses to 40-Hz click trains in girls with Rett syndrome: Auditory steady-state response and sustained wave

AIM

The current study aimed to infer neurophysiological mechanisms of auditory processing in children with Rett syndrome (RTT)-rare neurodevelopmental disorders caused by MECP2 mutations. We examined two brain responses elicited by 40-Hz click trains: auditory steady-state response (ASSR), which reflects fine temporal analysis of auditory input, and sustained wave (SW), which is associated with integral processing of the auditory signal.

METHODS

We recorded electroencephalogram findings in 43 patients with RTT (aged 2.92-17.1 years) and 43 typically developing children of the same age during 40-Hz click train auditory stimulation, which lasted for 500 ms and was presented with interstimulus intervals of 500 to 800 ms. Mixed-model ancova with age as a covariate was used to compare amplitude of ASSR and SW between groups, taking into account the temporal dynamics and topography of the responses.

RESULTS

Amplitude of SW was atypically small in children with RTT starting from early childhood, with the difference from typically developing children decreasing with age. ASSR showed a different pattern of developmental changes: the between-group difference was negligible in early childhood but increased with age as ASSR increased in the typically developing group, but not in those with RTT. Moreover, ASSR was associated with expressive speech development in patients, so that children who could use words had more pronounced ASSR.

CONCLUSION

ASSR and SW show promise as noninvasive electrophysiological biomarkers of auditory processing that have clinical relevance and can shed light onto the link between genetic impairment and the RTT phenotype.

Trofinetide Treatment Demonstrates a Benefit Over Placebo for the Ability to Communicate in Rett Syndrome

BACKGROUND

Trofinetide was approved by the US Food and Drug Administration for the treatment of Rett syndrome (RTT) in March 2023. Benefiting the ability to communicate in RTT is often identified as the most important caregiver goal for new therapies. This analysis reports the communication-related end points from the phase 3 LAVENDER study of trofinetide in RTT.

METHODS

Females with RTT, aged five to 20 years, were randomized 1:1 to trofinetide or placebo for 12 weeks. Secondary efficacy end points related to communication were based on change from baseline to week 12 and included the caregiver-rated Communication and Symbolic Behavior Scales Developmental Profile™ Infant-Toddler Checklist (CSBS-DP-IT) Social Composite score (key secondary end point; scores ranged from 0 to 26 [higher scores indicated better communication]) and novel clinician rating scales (0 [normal] to 7 [severe impairment]) measuring the ability to communicate choices nonverbally (RTT-COMC) and verbally (RTT-VCOM).

RESULTS

Trofinetide demonstrated a statistically significant difference versus placebo for the CSBS-DP-IT Social Composite score (least squares mean [LSM] difference = 1.0; 95% confidence interval [CI], 0.3 to 1.7; P = 0.0064; Cohen's d effect size = 0.43) and a nominally significant difference for the RTT-COMC (LSM difference: -0.3; 95% CI, -0.6 to -0.0; P = 0.0257; Cohen's d effect size = 0.36). As expected, there was no difference for the RTT-VCOM.

CONCLUSIONS

Significant treatment benefit for trofinetide versus placebo was observed in scales measuring the ability to communicate. These scales may be appropriate for future clinical studies in RTT and other neurodevelopmental disorders.

Development of trofinetide for the treatment of Rett syndrome: from bench to bedside

Rett syndrome (RTT) is rare neurodevelopmental disorder caused by mutations in the MECP2 gene that encodes methyl-CpG-binding protein 2 (MeCP2), a DNA-binding protein with roles in epigenetic regulation of gene expression. Functional loss of MeCP2 results in abnormal neuronal maturation and plasticity, characterized by loss of verbal communication and loss of fine and gross motor function, among others. Trofinetide, a synthetic analog of glycine-proline-glutamate, was approved by the US Food and Drug Administration for the treatment of RTT in adult and pediatric patients aged 2 years and older. Here, we present the development of trofinetide from bench research to clinical studies and emphasize how the collaboration between academia, the pharmaceutical industry, and patient advocacy led to the recent approval. The bench-to-bedside development of trofinetide underscores the value of collaboration between these groups in the development and approval of treatments for rare diseases.

A Severity Comparison between Italian and Israeli Rett Syndrome Cohorts

Rett syndrome (RTT) is a neurodevelopmental disorder marked by profound cognitive, communication, and motor impairments. Despite identified genotype/phenotype connections, the extent of clinical severity varies even among individuals sharing the same genetic mutation. Diverse sociocultural environments, such as the level of inclusivity of the scholar system, the time spent with family, and the intensity of the rehabilitative intervention provided, might influence their development diversely. This study examines the severity of RTT in people in Italy and Israel, countries with distinct contradictory approaches to caring for those with intricate disabilities, across two age groups. Data from 136 Italian and 59 Israeli girls and women with RTT were assessed and divided into two age categories: above and below 12 years. The RARS, a standardized RTT-specific clinical severity tool, was administered. Despite no differences in age and genetic characteristics, the Italian group showed better scores in the RARS motor and disease-related characteristics areas in both age groups. Moreover, the young Italian participants gathered better total RARS scores and emotional and behavioral characteristics area scores. Furthermore, the young group showed significantly less scoliosis, foot problems, and epilepsy than the older group. These findings endorse the inclusion of girls with RTT in the regular schooling system for a limited daily period, investing in high activity levels within the home and community environments, and suggest continuously providing the person with daily occasions of physical activity and socialization.

Aided language modelling, responsive communication and eye-gaze technology as communication intervention for adults with Rett syndrome: three experimental single case studies

PURPOSE

To examine the effect of a communication intervention package on expressive communication and visual attention in individuals with Rett syndrome.

MATERIALS AND METHODS

A modified withdrawal (A-B1-A1-B2-A2) single case experimental design with a direct inter-subject replication across three participants was applied. Three women with Rett syndrome participated. The study took place over a six-week period and comprised 32 sessions with each participant. All sessions were video recorded. During the intervention the communication partner used aided language modelling on a gaze-controlled device in combination with using responsive partner strategies. Expressive communication was assessed as synthesised words per minute and unique synthesised words per minute. Visual attention was assessed as rate of focused gazes (1 s or longer) in interaction.

RESULTS

An intervention effect was found on the rate of unique words for all participants. The rate of words increased for two participants when the intervention was introduced but no withdrawal effect could be seen. An intervention effect on visual attention could be seen for one participant. The intervention appeared to have social validity as reported by caregivers.

CONCLUSION

Aided language modelling (ALM), while using responsive partner strategies and a gaze-controlled device may be used with adult individuals with Rett syndrome to increase their rate of expressive communication. Detailed observational measures revealed individual learning patterns, which may provide clinically valuable insights.Implications for RehabilitationAdults with Rett syndrome may benefit from access to gaze-controlled devices in combination with responsive partner strategies.Responsive partner communication may be effective for some individuals with Rett syndrome to increase their rate of synthesised utterances.Rate of focused gazes may be considered as an outcome measure for individuals with oculomotor difficulties when introducing aided language modelling.

Validation of the Observer-Reported Communication Ability (ORCA) measure for individuals with Rett syndrome

PURPOSE

The study goal was to validate the Observer-Reported Communication Ability (ORCA) measure for use with females with Rett Syndrome (RTT).

METHODS

Qualitative interviews, including concept elicitation and cognitive interviewing methods, were conducted with 19 caregivers of individuals with RTT ages 2 and older. A quantitative study was then conducted in 279 caregivers to evaluate construct validity and reliability.

RESULTS

After minor modifications were made, the modified ORCA measure was well understood and captured key communication concepts. Quantitative data showed evidence for reliable scores (α = 0.90, test-retest intraclass correlation = 0.88), minimal floor and no ceiling effects, and strong correlation with the Communication and Symbolic Behaviors Scale (r = 0.73).

CONCLUSIONS

This study provided initial support that the modified ORCA measure is an acceptable caregiver-reported measure of communication ability for females with RTT. Future work should include evaluation of longitudinal validity of the measure and its associations with clinician- and performance-based measures in diverse samples.

Inhibitory Synaptic Influences on Developmental Motor Disorders

During development, GABA and glycine play major trophic and synaptic roles in the establishment of the neuromotor system. In this review, we summarise the formation, function and maturation of GABAergic and glycinergic synapses within neuromotor circuits during development. We take special care to discuss the differences in limb and respiratory neuromotor control. We then investigate the influences that GABAergic and glycinergic neurotransmission has on two major developmental neuromotor disorders: Rett syndrome and spastic cerebral palsy. We present these two syndromes in order to contrast the approaches to disease mechanism and therapy. While both conditions have motor dysfunctions at their core, one condition Rett syndrome, despite having myriad symptoms, has scientists focused on the breathing abnormalities and their alleviation-to great clinical advances. By contrast, cerebral palsy remains a scientific quagmire or poor definitions, no widely adopted model and a lack of therapeutic focus. We conclude that the sheer abundance of diversity of inhibitory neurotransmitter targets should provide hope for intractable conditions, particularly those that exhibit broad spectra of dysfunction-such as spastic cerebral palsy and Rett syndrome.

Documentación de habilidades comunicativas y de lenguaje receptivo en un caso de Síndrome de Rett

Las dificultades de las personas con síndrome de Rett (SR) para hablar y producir respuestas motoras hace de la valoración un proceso difícil, resultando necesario combinar métodos informales y adaptaciones en los instrumentos formales para obtener información sobre los niveles de competencia. El objetivo de este estudio es documentar el proceso de valoración de las habilidades comunicativo-lingüísticas seguido con una niña con SR combinando métodos de evaluación y realizando adaptaciones en los tests estandarizados. Se llevaron a cabo observaciones informales en entornos naturales, los compañeros de comunicación cubrieron la Matriz de Comunicación, y se realizaron adaptaciones en los tests Vocabulario en Imágenes Peabody y TSA de desarrollo de la morfosintaxis, y en el Test of Aided Communication Performance, consistentes en reducir el número de alternativas, presentarlas en una disposición accesible a la señalización con la mirada, y en dar tiempo de espera para la respuesta de la participante con SR. Los resultados obtenidos mediante las adaptaciones utilizando la mirada como método de acceso mostraron niveles de dominio de comunicación preintencional y de comunicación no convencional, junto con destrezas emergentes en comunicación convencional y simbólica para funciones de petición e interacción social y una comprensión de estructuras gramaticales sencillas. La conclusión que se desprende es que es imperativo que las evaluaciones se adapten a las limitaciones físicas y orales de las personas con SR, de modo que puedan descubrirse capacidades ocultas, se establezcan objetivos para la intervención basados en sus niveles reales de competencia para apoyar al máximo la comunicación.

The GAIRS Checklist: a useful global assessment tool in patients with Rett syndrome

Background

Rett Syndrome is a severe, neurodevelopmental disorder mainly caused by mutations in the MECP2 gene, affecting around 1 in 10,000 female births. Severe physical, language, and social impairments impose a wide range of limitations in the assessment of the abilities of Rett patients. This study proposes an analysis and first validation of a Global Assessment and Intervention in Rett syndrome (GAIRS) Checklist for assessing behavioral, intellectual, academic, neuropsychological and psychosocial manifestations in patients with Rett Syndrome. We administered the GAIRS Checklist to 113 Italian patients with Rett Syndrome aged 4–42.

Aims of this study

To examine the psychometric characteristics of the GAIRS Checklist. Moreover, the aim is also to examine the validity of GAIRS with test–retest correlation, convergent validity with similar functional measurements, such as the Vineland scales, and divergent validity with severity of disease scale, such as the RARS scale and severity of neuropsychiatric evaluations.

Results

All 10 subscales of GAIRS were positively and significantly related to each other and to the total GAIRS score, and the subscales showed high levels of Cronbach’s alpha values (from .77 to .95). Principal axis factoring suggested two factors that explain 60% of the variance. Test–retest reliability is 0.82. This means that psychometric properties are reliable. Correlation for Concurrent validity with Vineland score was high and Divergent Validity with RARS was also high.

Conclusion

The GAIRS Checklist used for Rett syndrome is acceptable and feasible to complete assessment in a clinical setting. Moreover, it can detect the complexity of this disease and may suggest the next step in terms of specific training in Rett syndrome.

Design and outcome measures of LAVENDER, a phase 3 study of trofinetide for Rett syndrome

INTRODUCTION

Rett syndrome (RTT) is a debilitating neurodevelopmental disorder with no approved treatments. Trofinetide is a synthetic analog of glycine-proline-glutamate, the N-terminal tripeptide of insulin-like growth factor 1. In a phase 2, placebo-controlled trial in 82 females with RTT aged 5-15 years, a significant (p ≤ 0.042) improvement over placebo was observed with the highest trofinetide dose (200 mg/kg twice daily [BID]) on three measures: Rett Syndrome Behavior Questionnaire (RSBQ), Clinical Global Impression-Improvement (CGI-I), and RTT-Clinician Domain Specific Concerns-Visual Analog Scale (RTT-DSC-VAS). Trofinetide was well tolerated at all doses (50, 100, and 200 mg/kg BID). A phase 3 trial utilizing disease-specific and novel scales was designed to investigate the efficacy and safety of trofinetide in girls and women with RTT.

METHODS

This 12-week, double-blind, randomized, placebo-controlled study (LAVENDER; NCT04181723) will evaluate trofinetide in 187 females, aged 5-20 years, with RTT. Co-primary endpoints are the RSBQ and CGI-I scales. Clinical domains of the CGI-I include communication, ambulation, hand use, seizures, attentiveness, and social (eye contact) and autonomic (breathing) aspects. Secondary endpoints will leverage four novel RTT-specific clinician ratings (derived from the RTT-DSC-VAS) of hand function, ambulation, ability to communicate, and verbal communication, and existing scales, to evaluate other core symptoms of RTT, quality of life and caregiver burden. A 40-week, open-label extension study will follow.

DISCUSSION

This study was designed using disease-specific scales optimized to demonstrate changes in core symptoms of RTT and may provide the first phase 3 data demonstrating drug efficacy in individuals with RTT.

TRIAL REGISTRATION

Clinicaltrials.govNCT04181723.

A comparison of formal and informal methods for assessing language and cognition in children with Rett syndrome

BACKGROUND

Opinions about the cognitive and receptive language skills of people with Rett syndrome (RTT) range from severe intellectual impairment to near-normal development. Assessment is challenging because most are non-verbal, with no purposeful hand use. Clarkson et al. (2017) adapted the Mullen Scales of Early Learning for use with eye gaze technology (MSEL-A/ET) for people with RTT.

AIMS

To investigate and compare the performance of children with RTT on formal and newly-designed informal assessments of language and cognition using eye gaze/tracking technology.

METHODS AND PROCEDURES

Ten children with RTT aged 4:0-6:8 were assessed on the MSEL-A/ET for Visual Reception (VR) and Receptive Language (RL), and standard MSEL for Expressive Language (EL). Informal assessments of the same skills were embedded in activities such as reading and cake-decorating.

OUTCOMES AND RESULTS

Standard scores on MSEL-A/ET VR and RL subtests ranged from 'very low' to 'above average'. All children scored 'very low' on standard EL assessment. Informal assessments added information about EL, with children producing 1-3 word utterances and a range of communicative functions through an eye gaze device.

CONCLUSIONS AND IMPLICATIONS

Combining low-tech augmentative and alternative communication, eye gaze technology, informal activities and formal assessment, yields greater insight into children's abilities. This is important in informing suitable support and education for the individual.

Participation and engagement in family activities among girls and young women with Rett syndrome living at home with their parents - a cross-sectional study

PURPOSE

To describe the extent of participation and engagement in family activities and explore variables potentially impacting on these factors in family activities among girls and young women with Rett syndrome (RTT) under the age of 21.

MATERIALS AND METHODS

The Child Participation in Family Activities (Child-PFA) questionnaire was sent to parents in the target group (n = 42). Additionally, age, number of siblings at home, ambulation level, clinical severity and level of hand function were recorded to explore possible impact. Data were analyzed using descriptive statistics, Fishers exact test and cross-tables.

RESULTS

23 families participated. Highest degrees of participation and engagement were seen in social and stationary family activities. Indoor activities were frequent and showed high levels of participation and engagement, Outdoor activities were infrequent and showed low levels of participation despite a high degree of engagement. Routine activities were frequent but showed moderate to low participation and engagement. A negative association was found between participation in watching a movie and number of siblings living at home, and positive associations between engagement and age in three family activities.

CONCLUSION

Therapists working with this target group may benefit from focusing on engagement in routine activities and modification of family activities.IMPLICATIONS FOR REHABILITATIONTherapists may benefit from focusing on engagement in routine activities in the goal setting process and intervention as they occur on a daily basis, giving the opportunity for development of new skills.Therapists may benefit from focusing on assistive devices or other compensatory strategies for outdoor activities and activities that require a certain amount of hand function.Therapists may benefit from modifying the family's activities so that they require more social and mental participation and focus on experiencing different types of sensory input e.g., sound, tactile, visual or vestibular input rather than taking part in the activity by using their hands.

Development of a tool to assess visual attention in Rett syndrome: a pilot study

This was a two-phase study that aimed to (a) develop a tool for assessing visual attention in individuals with Rett syndrome using AAC with a communication partner during naturalistic interactions in clinical settings; and (b) explore aspects of the tool's reliability, validity, and utility. The Assessment of Visual Attention in Interaction (AVAI) tool was developed to assess visual attention operationalized as focused gazes (1 s or longer) at the communication partner, an object, and a symbol set. For the study, six video-recorded interactions with nine female participants diagnosed with Rett syndrome (range: 15-52-years-old) were used to calculate intra- and inter-rater agreement, and 18 recorded interactions were analyzed to examine sensitivity to change and acceptability. There was a significant difference in the AVAI results between two conditions (with and without aided-language modeling). Inter-rater agreement ranged from moderate and strong. There was a range in scores, indicating that the AVAI could differentiate between participants. The AVAI was found to be reliable, able to detect change, and acceptable to the participants. This tool could potentially be used for evaluating interventions that utilize aided AAC.

Development of consensus-based guidelines for managing communication of individuals with Rett syndrome

Difficulties with communication have a profound impact on the lives of individuals with Rett syndrome and their caregivers. Globally, many families report difficulty accessing appropriate and timely information and services from professionals with expertise in augmentative and alternative communication (AAC) as it pertains to Rett syndrome. To address this need, international consensus-based guidelines for managing the communication of individuals with Rett syndrome were developed by combining available evidence and lived experience with expert opinion. A two-phase Delphi survey was built on statements and recommendations extracted from a review of over 300 pieces of literature combined with survey responses from communication professionals and caregivers. All statements that reached a pre-determined threshold of ≥70% agreement were incorporated into guidelines that consist of 268 statements and recommendations relating to (a) rights of the individual; (b) beliefs and attitudes of communication partners; (c) professional knowledge and team work; (d) strategies to optimize engagement; (e) assessment; and (f) intervention (targets and goals, techniques), including the use of AAC. To date, this project is the largest of its kind, with 650 participants from 43 countries contributing to development of consensus-based guidelines for Rett syndrome.

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.

Experimental Examination and Social Validation of a Microswitch Intervention to Improve Choice-Making and Activity Engagement for Six Girls with Rett Syndrome

Background: The use of assistive technology, specifically microswitches, with children with RTT has been shown to effectively moderate the impact of their disability on their quality of life^- by facilitating access to meaningful leisure and other activities. Objectives: This study aimed to evaluate the effectiveness of a microswitch intervention on increased choice making, engagement in a targeted sorting activity, and indices of happiness, and decreased stereotypic behaviors for six girls with Rett syndrome. Targeted dependent variables were also assessed at six months post-intervention. Following the intervention study, 90 external raters completed a social validation procedure. Method: An ABABAB experimental sequence was implemented for each participant with a cross-over effect. A social validation assessment involving 90 external raters was carried out. Results: Data emphasized an improved performance for each participants involved (i.e., adaptive responses). Five participants showed a capacity of independent choice. One participant seemed to be closely linked to the position of the container. Social raters favorably endorsed the use of the program since they positively evaluated the use of the technology on all the dimensions investigated. Conclusion: A microswitch intervention may improve choice making and activity engagement for children with Rett syndrome. Further research is needed on the development of more sophisticated forms of individualized technological options to improve opportunities for enhanced engagement and choice-making for individuals with RTT.

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.

Neurophysiological and cognitive effects of Transcranial Direct Current Stimulation in three girls with Rett Syndrome with chronic language impairments

BACKGROUND

this study was based on both neurophysiological decelerated activity and communication deficits in Rett Syndrome (RTT).

AIMS

the aim was to examine the neurophysiological and cognitive effects of Transcranial Direct Current Stimulation (tDCS) in three girls with RTT with chronic language impairments.

METHODS AND PROCEDURES

we proposed an integrated intervention: tDCS and cognitive empowerment applied to language in order to enhance speech production (new functional sounds and new words). Because maximal gains usually are achieved when tDCS is coupled with behavioral training, we applied tDCS stimulation on Broca's area together with linguistic training.

OUTCOMES AND RESULTS

the results indicated a general enhancement in language abilities (an increase in the number of vowel/consonant sounds and words and the production and comprehension through discrimination), motor coordination (functional movements), and neurophysiological parameters (an increase in the frequency and power of alpha, beta and theta bands).

CONCLUSION AND IMPLICATIONS

we assume that tDCS stimulation combined with the cognitive empowerment applied to language can significantly influence a chronic impairment even in genetic syndromes. Our results provide data that support the role of tDCS in fostering brain plasticity and in particular in empowering speech production and comprehension in girls with RTT.

Overview of Social Cognitive Dysfunctions in Rare Developmental Syndromes With Psychiatric Phenotype

Rare neurodevelopmental syndromes often present social cognitive deficits that may underlie difficulties in social interactions and increase the risk of psychosis or autism spectrum disorders. However, little is known regarding the specificities of social cognitive impairment across syndromes while it remains a major challenge for the care. Our review provides an overview of social cognitive dysfunctions in rare diseases associated with psychiatric symptoms (with a prevalence estimated between 1 in 1,200 and 1 in 25,000 live births: 22q11.2 deletion syndrome, Angelman syndrome, Fragile X syndrome, Klinefelter syndrome, Prader-Willi syndrome, Rett syndrome, Smith-Magenis syndrome, Turner syndrome, and Williams syndrome) and shed some light on the specific mechanisms that may underlie these skills in each clinical presentation. We first detail the different processes included in the generic expression "social cognition" before summarizing the genotype, psychiatric phenotype, and non-social cognitive profile in each syndrome. Then, we offer a systematic review of the social cognitive abilities and the disturbed mechanisms they are likely associated with. We followed the PRISMA process, including the definition of the relevant search terms, the selection of studies based on clear inclusion, and exclusion criteria and the quality appraisal of papers. We finally provide insights that may have considerable influence on the development of adapted therapeutic interventions such as social cognitive training (SCT) therapies specifically designed to target the psychiatric phenotype. The results of this review suggest that social cognition impairments share some similarities across syndromes. We propose that social cognitive impairments are strongly involved in behavioral symptoms regardless of the overall cognitive level measured by intelligence quotient. Better understanding the mechanisms underlying impaired social cognition may lead to adapt therapeutic interventions. The studies targeting social cognition processes offer new thoughts about the development of specific cognitive training programs, as they highlight the importance of connecting neurocognitive and SCT techniques.

Adapting the Mullen Scales of Early Learning for a Standardized Measure of Development in Children With Rett Syndrome

Rett Syndrome (RTT) is characterized by severe impairment in fine motor (FM) and expressive language (EL) function, making accurate evaluations of development difficult with standardized assessm ents. In this study, the administration and scoring of the Mullen Scales of Early Learning (MSEL) were adapted to eliminate the confounding effects of FM and EL impairments in assessing development. Forty-seven girls with RTT were assessed with the Adapted-MSEL (MSEL-A), a subset (n = 30) was also assessed using the Vineland Adaptive Behavior Scales-Second Edition (Vineland-II) and a further subset (n = 17) was assessed using an eye-tracking version of the MSEL (MSEL-ET). Participants performed better on the visual reception (VR) and receptive language (RL) domains compared to the FM and EL domains on the MSEL-A. Individual performance on each domain was independent of other domains. Corresponding MSEL-A and Vineland-II domains were significantly correlated. The MSEL-ET was as accurate as the MSEL-A in assessing VR and RL, yet took a 44% less time. Results suggested that the MSEL-A and the MSEL-ET could be viable measures for accurately assessing developmental domains in children with RTT.

Choice making in Rett syndrome: a descriptive study using video data

PURPOSE

To describe the choice-making abilities of girls and women with Rett syndrome.

METHOD

Females with Rett syndrome registered with the Australian Rett Syndrome Database with a pathogenic MECP2 mutation were included in this study. Video clips showing choice making in 64 females at a median age of 11.6 years (range 2.3-35.6 years) were analysed. Video clips were coded for the location and nature of the choice-making interaction, and the actions of the communication partner and female with Rett syndrome.

RESULTS

The majority (82.8%, 53/64) of females made a choice, most using eye gaze. Just under half (24/53) used one modality to communicate their choice, 52.8% used two modalities and one used three modalities. Of those who made a choice, 50% did so within 8 s. The length of time to make a choice did not appear to vary with age. During choice making, 57.8% (37/64) of communication partners used language and gestures, 39.1% (25/64) used only language and two used language, gestures and symbols within the interaction.

CONCLUSIONS

The provision of adequate time allowing for a response and observation for the use of multiple modalities could promote effective choice making in females with Rett syndrome. Implications for Rehabilitation The provision of adequate time allowing for a response will promote effective choice making in girls and women with Rett syndrome. Although almost all girls and women with Rett syndrome used eye gaze to indicate their choice, communication partners also need to recognise and respond to other communication modalities that are sometimes used like body movements.

An Exploration of the Use of Eye Gaze and Gestures in Females With Rett Syndrome

PURPOSE

This study investigated the communicative use of eye gaze and gestures in females with Rett syndrome.

METHOD

Data on 151 females with Rett syndrome participating in the Australian Rett Syndrome Database was used in this study. Items from the Communication and Symbolic Behavior Scales Developmental Profile Infant-Toddler Checklist (Wetherby & Prizant, 2002) were used to measure communication. Relationships between the use of eye gaze and gestures for communication were investigated using logistic regression. The influences of MECP2 mutation type, age, and level of motor abilities on the use of eye gaze and gestures were investigated using multivariate linear regression.

RESULTS

Both eye gaze and the use of gestures predicted the ability to make requests. Women aged 19 years or older had the lowest scores for eye gaze. Females with better gross motor abilities had higher scores for the use of eye gaze and gestures. The use of eye gaze did not vary across mutation groups, but those with a C-terminal deletion had the highest scores for use of gestures.

CONCLUSIONS

Eye gaze is used more frequently than gestures for communication, and this is related to age, MECP2 mutation type, and gross motor abilities.

Parental perspectives on the communication abilities of their daughters with Rett syndrome

OBJECTIVE

This study describes, from the perspective of parents, how females with Rett syndrome communicate in everyday life and the barriers and facilitators to successful communication.

METHODS

Sixteen interviews were conducted with parents with a daughter with Rett syndrome with a pathogenic mutation in the methyl-CpG-binding protein 2 gene. Interviews were recorded and transcribed verbatim. Transcripts were analysed using directed content analysis.

RESULTS

All parents reported their daughters were able to express discomfort and pleasure, and make requests and choices using a variety of modalities including vocalisations, body movements and eye gaze. Parents also reported their daughters understood most of what they said and that the level of functional abilities, such as mobility, and environmental factors, such as characteristics of the communication partner, influenced successful communication.

CONCLUSIONS

The perspectives of parents are integral to the assessment of communication abilities and have the potential to inform communication interventions for girls and women with Rett syndrome.

Eye Gaze Technology as a Form of Augmentative and Alternative Communication for Individuals with Rett Syndrome: Experiences of Families in The Netherlands

This paper provides a brief report on families' experiences of eye gaze technology as one form of augmentative and alternative communication (AAC) for individuals with Rett syndrome (RTT), and the advice, training and support they receive in relation to this. An online survey exploring communication and AAC was circulated to 190 Dutch families; of the 67 questionnaires that were returned, 63 had answered questions relating to eye gaze technology. These 63 were analysed according to parameters including: experiences during trial periods and longer-term use; expert knowledge, advice and support; funding; communicative progress; and family satisfaction. 20 respondents were using or had previous experience of using an eye gaze system at the time of the survey, 28 of those with no prior experience wanted to try a system in the future. Following a trial period, 11 systems had been funded through health insurance for long-term use and two families had decided a system was not appropriate for them. Levels of support during trials and following long-term provision varied. Despite frustrations with the technology, satisfaction with the systems was higher than satisfaction with the support. The majority of families reported progress in their child's skills with longer term use. These findings suggest that although eye gaze technologies offer potential to individuals with RTT and their families, greater input from suppliers and knowledgeable AAC professionals is essential for individuals and families to benefit maximally. Higher levels of training and support should be part of the 'package' when an eye gaze system is provided.

Comparing social reciprocity in preserved speech variant and typical Rett syndrome during the early years of life

This study compared early markers of social reciprocity in children with typical Rett syndrome (RTT) and in those with the preserved speech variant (PSV) of RTT. Retrospective video analysis of 10 toddlers with typical RTT and five with PSV investigated participants' orientation to their name being called between the ages of 5 and 24 months, prior to their diagnosis. From analysis of the recordings two distinct profiles were apparent. Although response rate was higher in girls with typical RTT than PSV at 5 to 8 months this noticeably reversed from 9 to 12 months onwards. By two years of age there was a markedly higher rate and range of responses from girls with PSV. This study contributes to the delineation of different profiles for the variants of RTT.

Technological aids to support choice strategies by three girls with Rett syndrome

This study was aimed at extending the use of assistive technology (i.e., photocells, interface and personal computer) to support choice strategies by three girls with Rett syndrome and severe to profound developmental disabilities. A second purpose of the study was to reduce stereotypic behaviors exhibited by the participants involved (i.e., body rocking, hand washing and hand mouthing). Finally, a third goal of the study was to monitor the effects of such program on the participants' indices of happiness. The study was carried out according to a multiple probe design across responses for each participant. Results showed that the three girls increased the adaptive responses and decreased the stereotyped behaviors during intervention phases compared to baseline. Moreover, during intervention phases, the indices of happiness augmented for each girl as well. Clinical, psychological and rehabilitative implications of the findings are discussed.

Communication intervention in Rett syndrome: a survey of speech language pathologists in Swedish health services

PURPOSE

To investigate communication intervention that speech language pathologists (SLPs) provide to people with Rett syndrome.

METHODS

A web-based survey targeting all Swedish SLPs working with people currently receiving support from habilitation services.

RESULTS

The SLPs reportedly followed recommended practice in the following aspects: (1) Information on communicative function was collected from several sources, including observation in well-known settings and reports from the client s social network, (2) Multimodal communication was promoted and, (3) Responsive partner strategies were largely targeted in the intervention. However, few instruments or standard procedures were used and partner instruction was given informally. Most SLPs used communication aids in the intervention and their general impression of using communication aids was positive. Further, augmentative and alternative communication (AAC) was estimated to increase and clarify communicative contributions from the person.

CONCLUSIONS

Communication aids were reported to have a positive influence on communicative functions. Swedish SLP services followed best practice in several aspects, but there are areas with potential for development. Tools and best practice guidelines are needed to support SLPs in the AAC process for clients with Rett syndrome. [Box: see text].

Developmental profile of speech-language and communicative functions in an individual with the preserved speech variant of Rett syndrome

OBJECTIVE

We assessed various aspects of speech-language and communicative functions of an individual with the preserved speech variant of Rett syndrome (RTT) to describe her developmental profile over a period of 11 years.

METHODS

For this study, we incorporated the following data resources and methods to assess speech-language and communicative functions during pre-, peri- and post-regressional development: retrospective video analyses, medical history data, parental checklists and diaries, standardized tests on vocabulary and grammar, spontaneous speech samples and picture stories to elicit narrative competences.

RESULTS

Despite achieving speech-language milestones, atypical behaviours were present at all times. We observed a unique developmental speech-language trajectory (including the RTT typical regression) affecting all linguistic and socio-communicative sub-domains in the receptive as well as the expressive modality.

CONCLUSION

Future research should take into consideration a potentially considerable discordance between formal and functional language use by interpreting communicative acts on a more cautionary note.

Neurophysiological responses to music and vibroacoustic stimuli in Rett syndrome

People with Rett syndrome (RTT) have severe communicative difficulties. They have as well an immature brainstem that implies dysfunction of the autonomic nervous system. Music plays an important role in their life, is often used as a motivating tool in a variety of situations and activities, and caregivers are often clear about people with RTTs favourites. The aim of this study was to investigate physiological and emotional responses related to six different musical stimuli in people with RTT. The study included 29 participants with RTT who were referred to the Swedish Rett Center for medical brainstem assessment during the period 2006-2007. 11 children with a typical developmental pattern were used as comparison. A repeated measures design was used, and physiological data were collected from a neurophysiological brainstem assessment. The continuous dependent variables measured were Cardiac Vagal Tone (CVT), Cardiac Sensitivity to Baroreflex (CSB), Mean Arterial Blood Pressure (MAP) and the Coefficient of Variation of Mean Arterial Blood Pressure (MAP-CV). These parameters were used to categorise brainstem responses as parasympathetic (calming) response, sympathetic (activating) response, arousal (alerting) response and unclear response. The results showed that all participants responded to the musical stimuli, but not always in the expected way. It was noticeable that both people with and without RTT responded with an arousal to all musical stimuli to begin with. Even though the initial expressions sometimes changed after some time due to poor control functions of their brainstem, the present results are consistent with the possibility that the RTT participants' normal responses to music are intact. These findings may explain why music is so important for individuals with RTT throughout life.

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.

Rett syndrome: a preliminary analysis of stereotypy, stress, and negative affect

Rett syndrome (RTT) is a neurodevelopmental disorder primarily affecting females. It is characterized by apparently normative development of motor and communicative abilities followed by deterioration in these domains. Stereotypic hand movements are one of the core diagnostic criteria for RTT. There is some anecdotal but limited scientific evidence that changes in hand stereotypy may be a sign of increased anxiety or arousal (i.e., a 'stress response') in RTT. Understanding stress responsivity is difficult in RTT because almost all individuals are nonverbal or otherwise severely communicatively impaired. This study used direct behavioral observation to quantify and compare the frequency of hand stereotypy and signs of negative affect during presumed periods of high and low stress associated with functional analysis conditions (negative reinforcement ['escape'] and control ['free play'], respectively) for 5 females with RTT (mean age=17.8; range 4-47). Negative affect was more likely to occur during negative reinforcement ('stress') conditions for each participant whereas hand stereotypies did not differ across conditions for any of the participants. Although preliminary, the results suggest that hand stereotypy may not be a valid behavioral 'stress-response' indicator in females with RTT. Alternatively, the approach we used may have been limited and not sufficient to evoke a stress response. Either way, more work with direct relevance to improving our understanding of hand stereotypy and anxiety in RTT in relation to social context appears warranted.

Development of socio-communicative skills in 9- to 12-month-old individuals with fragile X syndrome

We investigated the early socio-communicative development of individuals with fragile X syndrome (FXS) by undertaking a retrospective analysis of family videos. Videos were analyzed to identify existing communicative forms and functions. Analyses were undertaken on seven children who were later diagnosed with FXS. The children were filmed when they were 9-12 months old and before being diagnosed. Fourteen different communicative forms and six different communicative functions were observed. All participants were observed to express the functions of 'Attention to self' and 'Answering', but none indicated 'Requesting action', 'Requesting information', 'Choice making', or 'Imitating'. Results suggest that children with FXS may have a limited range of communicative forms and functions when they are from 9 to 12 months of age. However, further research is necessary to gain a specific developmental profile of socio-communicative forms and functions in FXS.

Three different profiles: early socio-communicative capacities in typical Rett syndrome, the preserved speech variant and normal development

BACKGROUND AND AIMS

This is the first study aiming to compare pre-diagnostic socio-communicative development of a female with typical Rett syndrome (RTT), a female with the preserved speech variant of RTT (PSV) and a control toddler.

METHODS

We analysed 1275 min of family videos at the participants' age between 9 and 24 months and used the Inventory of Potential Communicative Acts (IPCA) to delineate their repertoires of communicative forms and functions.

RESULTS

The results revealed different profiles for the three different conditions. The repertoire of communicative gestures and (pre)linguistic vocalizations was most comprehensive in the control toddler, followed by the female with PSV and the female with RTT.

CONCLUSION

These findings contribute to the growing knowledge about early developmental abnormalities in RTT. In order to define distinctive profiles for typical and atypical RTT and evaluate their specificity, a larger body of evidence is needed.

Early socio-communicative forms and functions in typical Rett syndrome

Rett syndrome (RTT) is a severe neurological disorder characterized by a developmental regression in motor and speech-language domains. There is, however, limited research on socio-communicative development of affected children before the onset of regression. We analyzed audio-video recordings made by parents of six 9- to 12-month old girls later diagnosed with typical RTT, applying the Inventory of Potential Communicative Acts (IPCA) to identify early communicative forms and functions. Each girl used at least one communicative form (e.g., body movement, eye gaze, or vocalizations) to gain attention and answer, but none were observed to make choices or request information. Varying numbers of children were observed to perform other communicative functions according to the IPCA including social convention, rejecting or requesting an object. Non-verbal forms (e.g., reaching, moving closer, eye contact, smiling) were more common than non-linguistic verbal forms (e.g., unspecified vocalizations, pleasure vocalizations, crying). (Pre-)linguistic verbal forms (e.g., canonical or variegated babbling, proto-words) were not used for communicative purposes. These data suggest that atypical developmental patterns in the socio-communicative domain are evident prior to regression in young individuals later diagnosed with RTT.

How facial expressions in a Rett syndrome population are recognised and interpreted by those around them as conveying emotions

Rett syndrome (RTT) is a neurodevelopmental disorder, including autonomic nervous system dysfunctions and severe communication impairment with an extremely limited ability to use verbal language. These individuals are therefore dependent on the capacity of caregivers to observe and interpret communicative signals, including emotional expressions. People in general, including therapists tend to focus on changes in facial expressions to interpret a person's emotional state or choices, but with this population it is difficult to know if the interpretations are correct. The aims of this study were to investigate if the Facial Action Coding System (FACS) could be used to identify facial expressions, and differentiate between those that expressed emotions and those that were elicited by abnormal brainstem activation in RTT. The sample comprised 29 participants with RTT and 11 children with a normal developmental pattern, exposed to six different musical stimuli during non-invasive registration of autonomic brainstem functions. The results indicate that FACS makes it possible both to identify facial expressions and to differentiate between those that stem from emotions and those caused by abnormal brainstem activation. This knowledge may be a great help to an uninitiated observer, who otherwise might incorrectly interpret the latter as an expression of emotion.

Profiling early socio-communicative development in five young girls with the preserved speech variant of Rett syndrome

Rett syndrome (RTT) is a developmental disorder characterized by regression of purposeful hand skills and spoken language, although some affected children retain some ability to speech. We assessed the communicative abilities of five young girls, who were later diagnosed with the preserved speech variant of RTT, during the pre-regression period (aged 12-24 months). Videotapes, obtained by parents during routine family situations and celebrations, were analyzed to identify communicative forms and functions used by these toddlers. Non-verbal communicative forms dominated over verbal-communicative forms for six of the eight identified communication functions. Although the girls used various non-verbal forms to make requests, for example, none of the individuals were observed to make choices or request information. Early peculiarities in the speech-language domain during the first year of life became more prominent and evident during the second year of life as general differences between typical development and atypical development become more obvious in RTT. These findings highlight the importance of assessing socio-communicative forms and functions at early age in children with RTT. The results suggest that speech-language functions did not appear to play a major role in the children's communicative attempts. We conclude that, even among children with the preserved speech variant, socio-communicative deficits are present before regression and persist after this period.

Caring for a child with severe intellectual disability in China: the example of Rett syndrome

PURPOSE

Rett syndrome is one of several genetic disorders known to cause severe intellectual and physical disability, mostly in girls. Girls affected by Rett syndrome appear to develop normally in the first 6 months of life, after which the usual clinical presentation comprises regression of communication and hand skills, the appearance of hand stereotypies and impaired gait. Intellectual disability affects more than 1.5% of the population of children in developing countries yet we know little about the daily lives and support services available for them and their caregivers.

METHOD

This qualitative study explored the daily experiences of 14 mothers and one grandmother caring for a child with Rett syndrome in China via telephone interviews.

RESULTS

Participants reported a lack of education, rehabilitation and support services available to them. Limited access to information reduced families' capacity to adequately meet the needs of their child. These gaps were further exacerbated by discrimination and perceived stigma from some members of the community.

CONCLUSIONS

Additional support services and educational programs at the governmental level can improve the quality of life of persons with an intellectual disability and their families and programs involving community participation in the care of people with disabilities may help to address discrimination.

Rett syndrome: basic features of visual processing-a pilot study of eye-tracking

Consistently observed "strong eye gaze" has not been validated as a means of communication in girls with Rett syndrome, ubiquitously affected by apraxia, unable to reply either verbally or manually to questions during formal psychologic assessment. We examined nonverbal cognitive abilities and basic features of visual processing (visual discrimination attention/memory) by analyzing patterns of visual fixation in 44 girls with Rett syndrome, compared with typical control subjects. To determine features of visual fixation patterns, multiple pictures (with the location of the salient and presence/absence of novel stimuli as variables) were presented on the screen of a TS120 eye-tracker. Of the 44, 35 (80%) calibrated and exhibited meaningful patterns of visual fixation. They looked longer at salient stimuli (cartoon, 2.8 ± 2 seconds S.D., vs shape, 0.9 ± 1.2 seconds S.D.; P = 0.02), regardless of their position on the screen. They recognized novel stimuli, decreasing the fixation time on the central image when another image appeared on the periphery of the slide (2.7 ± 1 seconds S.D. vs 1.8 ± 1 seconds S.D., P = 0.002). Eye-tracking provides a feasible method for cognitive assessment and new insights into the "hidden" abilities of individuals with Rett syndrome.

Incontinence in Individuals with Rett Syndrome: A Comparative Study

Frequency and type of incontinence and its association with other variables were assessed in females with Rett Syndrome (RS) (n = 63), using an adapted Dutch version of the 'Parental Questionnaire: Enuresis/Urinary Incontinence' (Beetz et al. 1994). Also, incontinence in RS was compared to a control group consisting of females with non-specific (mixed) intellectual disability (n = 26). Urinary incontinence (UI) (i.e., daytime incontinence and nocturnal enuresis) and faecal incontinence (FI) were found to be common problems among females with RS that occur in a high frequency of days/nights. UI and FI were mostly primary in nature and occur independent of participants' age and level of adaptive functioning. Solid stool, lower urinary tract symptoms and urinary tract infections (UTI's) were also common problems in females with RS. No differences in incontinence between RS and the control group were found, except for solid stool that was more common in RS than in the control group. It is concluded that incontinence is not part of the behavioural phenotype of RS, but that there is an increased risk for solid stool in females with RS.

Early speech-language development in females with Rett syndrome: focusing on the preserved speech variant

AIM

Our aim was to contribute new findings related to the pre-regressional verbal development of females with a variant of Rett syndrome (RTT) as the loss of spoken language is one of the key clinical features of RTT, and it would be of particular interest to study the early speech-language development of females who are considered to have preserved some speech-language abilities.

METHOD

We analysed 461 minutes of audio-video recordings containing play situations and the daily routines of six females (aged 7 to 24 months; mean birthweight 3057g, SD 195g) with the preserved speech variant (PSV) of RTT. All videos were recorded by parents and analysed retrospectively after the diagnosis PSV was made.

RESULTS

From the age of 7 months onwards, we observed two types of vocalizations, appearing intermittently: (1) apparently normal sequences; and (2) atypical (i.e. inhalatory, pressed, or high-pitched crying-like) vocalizations. Some participants failed to reach the milestone of canonical babbling. We observed a limited phonological and lexical complexity and a restricted compositional variability. Volubility was reduced during the whole period under observation. Hand stereotypies with simultaneous atypical vocalizations appeared only during the second year of life.

INTERPRETATION

The intermittent character of normal versus abnormal verbal behaviours might contribute to an early identification of children with a possible genetic mutation, and provides evidence that speech-language functions are abnormal from the very beginning.

Social preferences in Rett syndrome

Children with Rett syndrome manifest profound impairments in their ability to speak and use their hands, and exhibit a very limited repertoire of abilities to express themselves, to be neuropsychologically tested, and consequently to be understood. This study examined nonverbal cognitive abilities and visual preferences by analyzing the pattern of visual fixation in 49 girls with Rett syndrome, compared with a group of typical control subjects. The girls with Rett syndrome demonstrated a tendency toward socially weighted stimuli/social preferences. They looked at people, and into people's eyes. Eye tracking represents a feasible method to assess cognition, and provide insights into the burden of isolation of these children and the mismatch between their social preferences and incompetence, caused by movement disorder and apraxia.