Cognitive performance in Rett syndrome girls: a pilot study using eyetracking technology

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.

Use of a low-tech tool in the improvement of social interaction of patients with Rett Syndrome: an observational study

Introduction

The main aim of the present study was to examine whether the use of a low-tech tool, called click4all, inserted into cognitive and motor training can increase social interaction of patients with Rett Syndrome (RTT) with classmates in a school setting.

Methods

Twenty-seven participants with RTT were randomly assigned to two groups: the experimental group received treatment with click4all, and the control group received traditional treatment without click4all. Parameters were measured before treatment (T1), 6 months after treatment (T2), 6 months after the second treatment phase (T3) and at the end of the third treatment phase (T4).

Results

The results demonstrated an increase in levels of social interaction among classmates and patients with RTT in the experimental group, over time, compared to the control group, 95% CI [5.20-15.30]. Classmates also showed a higher level of knowledge related to participants of the experimental group, and this increased over time, 95% CI [24.98-63.52]. The level of knowledge related to the control group was stable over time and lower than the experimental group.

Discussion

This study demonstrated that the use of a low-tech tool can increase social interactions of patients with RTT in a school setting. This is important, as patients with RTT are often restricted in an isolation condition.

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.

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.

Cognitive stimulation has potential for brain activation in individuals with Rett syndrome

BACKGROUND

Knowledge regarding neuropsychological training in Rett syndrome (RS) is scarce. The aim of this study was to assess the outcome and the duration of the effect of cognitive stimulation on topographic electroencephalography (EEG) data in RS.

METHODS

Twenty female children diagnosed with RS were included in the analysis. Girls with RS conducted a cognitive task using an eye-tracker designed to evaluate access and choice skills. EEG data were acquired during the experimental procedure including two 10-min baseline stages before and after the task. Topographical changes of several EEG spectral markers including absolute and relative powers, Brain Symmetry Index and entropy were assessed.

RESULTS

Topographic significance probability maps suggested statistical decreases on delta activity and increases on beta rhythm associated with the cognitive task. Entropy increased during and after the task, likely related to more complex brain activity. A significant positive interaction was obtained between Brain Symmetry Index and age showing that the improvement of interhemispheric symmetry was higher in younger girls (5-10 years).

CONCLUSIONS

According to our findings, significant alterations of brain rhythms were observed during and after cognitive stimulation, suggesting that cognitive stimulation may have effects on brain activity beyond the stimulation period. Finally, our promising results also showed an increase brain symmetry that was especially relevant for the younger group. This could suggest an interaction of the eye-tracking cognitive task; however, further studies in this field are needed to assess the relation between brain asymmetries and age.

Preliminary testing of eye gaze interfaces for controlling a haptic system intended to support play in children with physical impairments: Attentive versus explicit interfaces

Introduction

Children with physical impairments may face challenges to play because of their motor impairments, which could lead to negative impacts in their development. The objective of this article was to compare two eye gaze interfaces that identified the desired toy a user wanted to reach with a haptic-enabled telerobotic system in a play activity.

Methods

One of the interfaces was an attentive user interface predicted the toy that children wanted to reach by observing where they incidentally focused their gaze. The other was an explicit eye input interface determined the toy after the child dwelled for 500 ms on a selection point. Five typically developing children, an adult with cerebral palsy (CP) and a child with CP participated in this study. They controlled the robotic system to play a whack-a-mole game.

Results

The prediction accuracy of the attentive interface was higher than 89% in average, for all participants. All participants did the activity faster with the attentive interface than with the explicit interface.

Conclusions

Overall, the attentive interface was faster and easier to use, especially for children. Children needed constant prompting and were not 100% successful at using the explicit interface.

Cognitive Assessment in GNAO1 Neurodevelopmental Disorder Using an Eye Tracking System

GNAO1 gene mutations are associated with a neurodevelopmental disorder characterized by developmental delay, epilepsy, and movement disorder. Eye tracking and eye movement analysis are an intriguing method to assess cognitive and language function and, to the best of our knowledge, it has never been tested in a standardized way in GNAO1. GNAO1 children are usually wheelchair-bound and with numerous motor constrains, including dystonic movements and postures, heterotropia, and hypotonia, making the cognitive assessment arduous. These contribute to the burden and disability, with a high level of frustration of caregivers and patients. We have herein demonstrated that, through an eye tracking system, six GNAO1 patients evaluated showed variable degrees of communicative intent through intentionally directed gaze. Moreover, three of these were able to complete a cognitive evaluation, and showed normal fluid intelligence and lexical comprehension. In conclusion, in GNAO1-related disorders, the degree of cognitive development is underestimated; eye tracking technologies may help in overcome these boundaries.

Choosing Strategies to Deal with Artifactual EEG Data in Children with Cognitive Impairment

Rett syndrome is a disease that involves acute cognitive impairment and, consequently, a complex and varied symptomatology. This study evaluates the EEG signals of twenty-nine patients and classify them according to the level of movement artifact. The main goal is to achieve an artifact rejection strategy that performs well in all signals, regardless of the artifact level. Two different methods have been studied: one based on the data distribution and the other based on the energy function, with entropy as its main component. The method based on the data distribution shows poor performance with signals containing high amplitude outliers. On the contrary, the method based on the energy function is more robust to outliers. As it does not depend on the data distribution, it is not affected by artifactual events. A double rejection strategy has been chosen, first on a motion signal (accelerometer or EEG low-pass filtered between 1 and 10 Hz) and then on the EEG signal. The results showed a higher performance when working combining both artifact rejection methods. The energy-based method, to isolate motion artifacts, and the data-distribution-based method, to eliminate the remaining lower amplitude artifacts were used. In conclusion, a new method that proves to be robust for all types of signals is designed.

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.

Eye-trackers, digital-libraries, and print-referencing: A single case study in CDKL5

BACKGROUND

Providing emergent literacy intervention and assessing outcomes for children with low-incidence, complex disabilities with concomitant physical, cognitive, sensory, and communication impairments presents a significant challenge to researchers, educators, clinicians, and families alike.

AIMS

This study aimed to leverage advancements in commercially available eyetracking technologies to measure visual attention to print before and after a parentmediated print referencing intervention with a child with a severe, low incidence, congenital disability. Print referencing means drawing attention to the print on the page while reading.

METHODS AND PROCEDURES

The single case study investigated a mother-daughter dyad who completed the protocol using eye-gaze technology, digital children's books, and a computer configured with software for observing and recording interactions that were shipped to the family's home and set up by the mother with remote support from a researcher.

OUTCOMES AND RESULTS

Results demonstrate that the eye-tracker successfully captured the participant's eye-gaze. Furthermore, mean-level shifts in frequency of fixations demonstrates changes in visual attention to print after the parent introduced the print referencing strategy during reading.

CONCLUSIONS AND IMPLICATIONS

Commercially available eye-trackers and digital libraries were successfully used by the parent-child dyad to record visual attention. Furthermore, remote support from a trained researcher was sufficient to support the parent through set-up, calibration, intervention, and implementation.

Longitudinal cognitive rehabilitation applied with eye-tracker for patients with Rett Syndrome

BACKGROUND

longitudinal effects of cognitive rehabilitation in Rett Syndrome (RTT) have been poorly investigated and the mechanisms do not appear to have been described in detail.

AIMS

the aim of this study was to examine the effects of cognitive rehabilitation with eye-tracker technology on attention, choice behaviours and language over a 2-year period in patients with RTT.

METHODS AND PROCEDURES

28 participants with RTT, ranging from age 4-22 years old (M = 13.85 years, SD = 5.89), received 30 min of cognitive rehabilitation with eye-tracker for 3 days a week over a 1-month for 2 years. They then underwent cognitive assessment to evaluate attention, choice, language and global functioning in four specific times: before cognitive rehabilitation (T1), after six months of cognitive rehabilitation (T2), six months after the second cognitive rehabilitation phase (T3) and at the end of the third cognitive rehabilitation phase (T4).

OUTCOME AND RESULTS

patients with RTT show long-term improvements in seconds of attention and number of choice behaviours, with barely any improvement in global functioning. No improvement in language was found.

CONCLUSIONS AND IMPLICATIONS

this is the first study aimed at examining longitudinal effects of cognitive rehabilitation in patients with RTT, demonstrating a linear improvement across time in attention and choice.

Differentiating social preference and social anxiety phenotypes in fragile X syndrome using an eye gaze analysis: a pilot study

Background

Fragile X syndrome (FXS) is the leading inherited cause of autism spectrum disorder, but there remains debate regarding the clinical presentation of social deficits in FXS. The aim of this study was to compare individuals with FXS to typically developing controls (TDC) and individuals with idiopathic autism spectrum disorder (ASD) across two social eye tracking paradigms.

Methods

Individuals with FXS and age- and gender-matched TDC and individuals with idiopathic ASD completed emotional face and social preference eye tracking tasks to evaluate gaze aversion and social interest, respectively. Participants completed a battery of cognitive testing and caregiver-reported measures for neurobehavioral characterization.

Results

Individuals with FXS exhibited reduced eye and increased mouth gaze to emotional faces compared to TDC. Gaze aversive findings were found to correlate with measures of anxiety, social communication deficits, and behavioral problems. In the social interest task, while individuals with idiopathic ASD showed significantly less social preference, individuals with FXS displayed social preference similar to TDC.

Conclusions

These findings suggest fragile X syndrome social deficits center on social anxiety without the prominent reduction in social interest associated with autism spectrum disorder. Specifically designed eye tracking techniques clarify the nature of social deficits in fragile X syndrome and may have applications to improve phenotyping and evaluate interventions targeting social functioning impairments.

Oculomotor Function in Individuals With Rett Syndrome

BACKGROUND

Individuals with Rett syndrome (RTT) are notoriously reliant on the use of eye gaze as a primary means of communication. Underlying an ability to communicate successfully via eye gaze is a complex matrix of requirements, with an intact oculomotor system being just one element. To date, the underlying neural and motor pathways associated with eye gaze are relatively under-researched in RTT.

PURPOSE

This study was undertaken to plug this gap in knowledge and to further the understanding of RTT in one specific area of development and function, namely oculomotor function.

MATERIAL AND METHODS

The eye movements of 18 girls and young women with RTT were assessed by electronystagmography (ENG). This tested their horizontal saccadic and smooth pursuit eye movements as well as optokinetic nystagmus and vestibulo-ocular reflex. Their results were compared with normative data collected from 16 typically developing children and teenagers.

RESULTS

Overall, the individuals with RTT demonstrated a range of eye movements on a par with their typically developing peers. However, there were a number of difficulties in executing the ENG testing with the RTT cohort which made quantitative analysis tricky, such as reduced motivation and attention to test materials and low-quality electrode signals.

CONCLUSIONS

This study suggests that individuals with RTT have an intact oculomotor system. However, modifications should be made to the ENG assessment procedure to combat problems in testing and add strength to the results. Further investigation into these testing difficulties is warranted in order to inform such modifications.

Assessing cognitive functioning in females with Rett syndrome by eye-tracking methodology

BACKGROUND

While many individuals with severe developmental impairments learn to communicate with augmentative and alternative communication (AAC) devices, a significant number of individuals show major difficulties in the effective use of AAC. Recent technological innovations, i.e., eye-tracking technology (ETT), aim to improve the transparency of communication and may also enable a more valid cognitive assessment.

OBJECTIVES

To investigate whether ETT in forced-choice tasks can enable children with very severe motor and speech impairments to respond consistently, allowing a more reliable evaluation of their language comprehension.

METHODS

Participants were 17 girls with Rett syndrome (M = 6:06 years). Their ability to respond by eye gaze was first practiced with computer games using ETT. Afterwards, their receptive vocabulary was assessed using the Peabody Picture Vocabulary Test-4 (PPVT-4). Target words were orally presented and participants responded by focusing their eyes on the preferred picture.

RESULTS

Remarkable differences between the participants in receptive vocabulary were demonstrated using ETT. The verbal comprehension abilities of 32% of the participants ranged from low-average to mild cognitive impairment, and the other 68% of the participants showed moderate to severe impairment. Young age at the time of assessment was positively correlated with higher receptive vocabulary.

CONCLUSIONS

The use of ETT seems to make the communicational signals of children with severe motor and communication impairments more easily understood. Early practice of ETT may improve the quality of communication and enable more reliable conclusions in learning and assessment sessions.

Eye gaze performance for children with severe physical impairments using gaze-based assistive technology-A longitudinal study

Gaze-based assistive technology (gaze-based AT) has the potential to provide children affected by severe physical impairments with opportunities for communication and activities. This study aimed to examine changes in eye gaze performance over time (time on task and accuracy) in children with severe physical impairments, without speaking ability, using gaze-based AT. A longitudinal study with a before and after design was conducted on 10 children (aged 1–15 years) with severe physical impairments, who were beginners to gaze-based AT at baseline. Thereafter, all children used the gaze-based AT in daily activities over the course of the study. Compass computer software was used to measure time on task and accuracy with eye selection of targets on screen, and tests were performed with the children at baseline, after 5 months, 9–11 months, and after 15–20 months. Findings showed that the children improved in time on task after 5 months and became more accurate in selecting targets after 15–20 months. This study indicates that these children with severe physical impairments, who were unable to speak, could improve in eye gaze performance. However, the children needed time to practice on a long-term basis to acquire skills needed to develop fast and accurate eye gaze performance.

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.

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.

Automatic cortical representation of auditory pitch changes in Rett syndrome

Background

Over the typical course of Rett syndrome, initial language and communication abilities deteriorate dramatically between the ages of 1 and 4 years, and a majority of these children go on to lose all oral communication abilities. It becomes extremely difficult for clinicians and caretakers to accurately assess the level of preserved auditory functioning in these children, an issue of obvious clinical import. Non-invasive electrophysiological techniques allow for the interrogation of auditory cortical processing without the need for overt behavioral responses. In particular, the mismatch negativity (MMN) component of the auditory evoked potential (AEP) provides an excellent and robust dependent measure of change detection and auditory sensory memory. Here, we asked whether females with Rett syndrome would produce the MMN to occasional changes in pitch in a regularly occurring stream of auditory tones.

Methods

Fourteen girls with genetically confirmed Rett syndrome and 22 age-matched neurotypical controls participated (ages 3.9–21.1 years). High-density electrophysiological recordings from 64 scalp electrodes were made while participants passively listened to a regularly occurring stream of 503-Hz auditory tone pips that was occasionally (15 % of presentations) interrupted by a higher-pitched deviant tone of 996 Hz. The MMN was derived by subtracting the AEP to these deviants from the AEP produced to the standard.

Results

Despite clearly anomalous morphology and latency of the AEP to simple pure-tone inputs in Rett syndrome, the MMN response was evident in both neurotypicals and Rett patients. However, we found that the pitch-evoked MMN was both delayed and protracted in duration in Rett, pointing to slowing of auditory responsiveness.

Conclusions

The presence of the MMN in Rett patients suggests preserved abilities to process pitch changes in auditory sensory memory. This work represents a beginning step in an effort to comprehensively map the extent of auditory cortical functioning in Rett syndrome. These easily obtained objective brain measures of auditory processing have promise as biomarkers against which future therapeutic efforts can be assayed.

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.

Cognitive training modifies frequency EEG bands and neuropsychological measures in Rett syndrome

Rett syndrome (RS) is a childhood neurodevelopmental disorder characterized by a primary disturbance in neuronal development. Neurological abnormalities in RS are reflected in several behavioral and cognitive impairments such as stereotypies, loss of speech and hand skills, gait apraxia, irregular breathing with hyperventilation while awake, and frequent seizures. Cognitive training can enhance both neuropsychological and neurophysiological parameters. The aim of this study was to investigate whether behaviors and brain activity were modified by training in RS. The modifications were assessed in two phases: (a) after a short-term training (STT) session, i.e., after 30 min of training and (b) after long-term training (LTT), i.e., after 5 days of training. Thirty-four girls with RS were divided into two groups: a training group (21 girls) who underwent the LTT and a control group (13 girls) that did not undergo LTT. The gaze and quantitative EEG (QEEG) data were recorded during the administration of the tasks. A gold-standard eye-tracker and a wearable EEG equipment were used. Results suggest that the participants in the STT task showed a habituation effect, decreased beta activity and increased right asymmetry. The participants in the LTT task looked faster and longer at the target, and show increased beta activity and decreased theta activity, while a leftward asymmetry was re-established. The overall result of this study indicates a positive effect of long-term cognitive training on brain and behavioral parameters in subject with RS.

Communication Intervention to Teach Requesting Through Aided AAC for Two Learners With Rett Syndrome

Evidence on effective communication interventions for persons with Rett syndrome is needed to drive the standard of care with this population. This study examined the effectiveness of an intervention package to teach multiple, aided communication requests for two persons with Rett syndrome (ages 27 and 7) through within participant, adapted multiple baseline designs across items/activities. Participants were taught graphic mode requests on speech generating devices, with access methods based on motor ability; one participant responded by pressing a touch screen, and one participant responded by fixed eye-gaze. Results are discussed in relation to the effectiveness of the intervention packages on increasing the accuracy of independent request selection responses emitted and the number of sessions required to reach an a priori performance criterion for both participants. Difficulties during initial prompting and during prompt fading with the eye-gaze response are considered. The findings suggest implications related to emerging evidence on the intervention methods to teach requesting skills to this population, and future research directions for communication intervention options for persons with severe communication impairment and limited motor repertoires.

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.

The eye-tracking of social stimuli in patients with Rett syndrome and autism spectrum disorders: a pilot study

OBJECTIVE

To compare visual fixation at social stimuli in Rett syndrome (RT) and autism spectrum disorders (ASD) patients.

METHOD

Visual fixation at social stimuli was analyzed in 14 RS female patients (age range 4-30 years), 11 ASD male patients (age range 4-20 years), and 17 children with typical development (TD). Patients were exposed to three different pictures (two of human faces and one with social and non-social stimuli) presented for 8 seconds each on the screen of a computer attached to an eye-tracker equipment.

RESULTS

Percentage of visual fixation at social stimuli was significantly higher in the RS group compared to ASD and even to TD groups.

CONCLUSION

Visual fixation at social stimuli seems to be one more endophenotype making RS to be very different from ASD.

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].

Rett Syndrome: Coming to Terms with Treatment

Rett syndrome (RTT) has experienced remarkable progress over the past three decades since emerging as a disorder of worldwide proportions, particularly with discovery of the linkage of RTT to MECP2 mutations. The advances in clinical research and the increasing pace of basic science investigations have accelerated the pattern of discovery and understanding. Clinical trials are ongoing and others are planned. A review of these events and the prospects for continued success are highlighted below. The girls and women encountered today with RTT are, overall, in better general, neurologic, and behavioral health than those encountered earlier. This represents important progress worldwide from the concerted efforts of a broadly based and diverse clinical and basic research consortium as well as the efforts of parents, family, and friends.

Quantification of functional abilities in Rett syndrome: a comparison between stages III and IV

We aimed to evaluate the functional abilities of persons with Rett syndrome (RTT) in stages III and IV. The group consisted of 60 females who had been diagnosed with RTT: 38 in stage III, mean age (years) of 9.14, with a standard deviation of 5.84 (minimum 2.2/maximum 26.4); and 22 in stage IV, mean age of 12.45, with a standard deviation of 6.17 (minimum 5.3/maximum 26.9). The evaluation was made using the Pediatric Evaluation of Disability Inventory, which has 197 items in the areas of self-care, mobility, and social function. The results showed that in the area of self-care, stage III and stage IV RTT persons had a level of 24.12 and 18.36 (P=0.002), respectively. In the area of mobility, stage III had 37.22 and stage IV had 14.64 (P<0.001), while in the area of social function, stage III had 17.72 and stage IV had 12.14 (P=0.016). In conclusion, although persons with stage III RTT have better functional abilities when compared with stage IV, the areas of mobility, self-care, and social function are quite affected, which shows a great functional dependency and need for help in basic activities of daily life.

Training communication abilities in Rett Syndrome through reading and writing

The goal of this clinical case study is to investigate the possibility of training communication abilities in people with Rett Syndrome (RS). Usually, girls with RS never exceed the sensorimotor stage of development, but the inter-individual variability typical of RS may lead us to doubt the irrevocability of that developmental limit, especially for those girls who are engaged in cognitive rehabilitation. The case study reported here concerns a 21-year-old girl with RS who was engaged in cognitive rehabilitation training based upon the principles of Feuerstein's modificability and mediated learning theory. The training aimed to teach her basic concepts and enhance reading-writing abilities. Statistical analyses showed that the girl reached adequate reading-writing abilities, proving the validity of the cognitive intervention which allowed her to communicate by composing words with her forefinger on an alphabetic table. Although these results need to be cautiously considered as they derive from a single case study, they have implications for future cognitive rehabilitation for deeply impaired clinical conditions as in the case of RS.

Preclinical research in Rett syndrome: setting the foundation for translational success

In September of 2011, the National Institute of Neurological Disorders and Stroke (NINDS), the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the International Rett Syndrome Foundation (IRSF) and the Rett Syndrome Research Trust (RSRT) convened a workshop involving a broad cross-section of basic scientists, clinicians and representatives from the National Institutes of Health (NIH), the US Food and Drug Administration (FDA), the pharmaceutical industry and private foundations to assess the state of the art in animal studies of Rett syndrome (RTT). The aim of the workshop was to identify crucial knowledge gaps and to suggest scientific priorities and best practices for the use of animal models in preclinical evaluation of potential new RTT therapeutics. This review summarizes outcomes from the workshop and extensive follow-up discussions among participants, and includes: (1) a comprehensive summary of the physiological and behavioral phenotypes of RTT mouse models to date, and areas in which further phenotypic analyses are required to enhance the utility of these models for translational studies; (2) discussion of the impact of genetic differences among mouse models, and methodological differences among laboratories, on the expression and analysis, respectively, of phenotypic traits; and (3) definitions of the standards that the community of RTT researchers can implement for rigorous preclinical study design and transparent reporting to ensure that decisions to initiate costly clinical trials are grounded in reliable preclinical data.

Rett syndrome: an eye-tracking study of attention and recognition memory

AIM

The aim of this study was to examine attention and recognition memory for faces and patterns in Rett syndrome, a severely disabling neurodevelopmental disorder caused by mutations in the X-linked MECP2 gene.

METHOD

Because Rett syndrome impairs speech and hand use, precluding most neuropsychological testing, the visual paired-comparison paradigm (VPC) was used, together with eye tracking. In the VPC, two identical stimuli are presented for familiarization. On test, the familiar stimulus and a new one are paired, and recognition inferred from preferential looking to the novel target. Attention is measured by looking time, gaze dispersion, and number/length of fixations. Twenty-seven female patients with Rett syndrome (mean age 10y 6mo; SD 6y 8mo, age range 2-22y) from the Rett clinic at a children's hospital were assessed in this study, along with 30 age- and sex-matched typically developing participants (outpatients from the same hospital).

RESULTS

Although patients with Rett syndrome showed recognition of both faces and patterns, with novelty scores greater than chance (50%), their performance was significantly poorer than that of the typically developing comparison group. Their attention to both was less mature and marked by a more narrowly focused gaze, with fewer and longer fixations. When inspecting faces, attention to the eyes was similar in both groups; however, patients with Rett syndrome tended to ignore the nose and mouth.

INTERPRETATION

This is one of the first studies to characterize attention and memory in individuals with Rett syndrome. Visually based techniques, such as the VPC, open a new avenue for quantifying the cognitive phenotype associated with this syndrome.

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.

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.

Network hyperexcitability in hippocampal slices from Mecp2 mutant mice revealed by voltage-sensitive dye imaging

Dysfunctions of neuronal and network excitability have emerged as common features in disorders associated with intellectual disabilities, autism, and seizure activity, all common clinical manifestations of Rett syndrome (RTT), a neurodevelopmental disorder caused by loss-of-function mutations in the transcriptional regulator methyl-CpG-binding protein 2 (MeCP2). Here, we evaluated the consequences of Mecp2 mutation on hippocampal network excitability, as well as synapse structure and function using a combination of imaging and electrophysiological approaches in acute slices. Imaging the amplitude and spatiotemporal spread of neuronal depolarizations with voltage-sensitive dyes (VSD) revealed that the CA1 and CA3 regions of hippocampal slices from symptomatic male Mecp2 mutant mice are highly hyperexcitable. However, only the density of docked synaptic vesicles and the rate of release from the readily releasable pool are impaired in Mecp2 mutant mice, while synapse density and morphology are unaffected. The differences in network excitability were not observed in surgically isolated CA1 minislices, and blockade of GABAergic inhibition enhanced VSD signals to the same extent in Mecp2 mutant and wild-type mice, suggesting that network excitability originates in area CA3. Indeed, extracellular multiunit recordings revealed a higher level of spontaneous firing of CA3 pyramidal neurons in slices from symptomatic Mecp2 mutant mice. The neuromodulator adenosine reduced the amplitude and spatiotemporal spread of VSD signals evoked in CA1 of Mecp2 mutant slices to wild-type levels, suggesting its potential use as an anticonvulsant in RTT individuals. The present results suggest that hyperactive CA3 pyramidal neurons contribute to hippocampal dysfunction and possibly to limbic seizures observed in Mecp2 mutant mice and RTT individuals.

Correlations between neurophysiological, behavioral, and cognitive function in Rett syndrome

Rett syndrome, a neurodevelopmental disorder affecting mainly females, is caused by a mutation of the MeCP2 gene. Girls with Rett syndrome manifest diverse behavioral and cognitive phenotypes, and the reasons for this variability remain unknown. In addition, girls with Rett syndrome often have epileptic seizures and abnormal EEGs, the characteristics of which differ with the patient. The aim of the study was to verify if neurophysiological and epileptological characteristics could be correlated with cognitive measures, obtained using eye tracker technology, and behavioral scores (Vineland Adaptive Behavior Scales and Rett Assessment Rating Scale) in 18 patients with Rett syndrome (mean age 13.7 years) at clinical stages III and IV. Age at epilepsy onset and seizure frequency were strictly correlated with neuropsychological outcome, as were EEG stage and distribution of paroxysmal abnormalities. Our findings demonstrate that neurophysiological features should be considered prognostic of cognitive and behavioral outcome in the clinical management of Rett syndrome.

Caracterização das habilidades funcionais na síndrome de Rett

O objetivo deste estudo foi identificar as áreas de maior comprometimento nas habilidades funcionais na síndrome de Rett (SR). Foram avaliadas 64 pacientes que preenchiam os critérios para a forma clássica da doença, com idade entre 2 e 26 anos. Foi aplicado o Inventário de avaliação pediátrica de incapacidade (PEDI) que contém 197 itens nas áreas de autocuidado, mobilidade e função social. Dentre as 73 atividades da área de autocuidado, 52 (71,2%) não foram realizadas por qualquer paciente; na mobilidade, dentre as 59 atividades propostas, 8 (13,5%); e na área de função social, dentre as 65 atividades, 50 (76,9%) não foram realizadas por paciente alguma. O desempenho médio ajustado em escala de 0 a 100 para a área de autocuidado foi de 8,9/100, variando de 0 a 19; na área de mobilidade, foi de 30,2/100, variando de 1 a 44; e na de função social, 5,2/100, com variação de 0 a 14. Foi possível verificar fortes correlações entre a área de autocuidado e as de mobilidade e função social; no entanto, entre as áreas de mobilidade e função social não foi detectada correlação significativa. Infelizmente, devido à gravidade da síndrome, o menor comprometimento da mobilidade, comparado ao das áreas de autocuidado e função social, não traz vantagens adaptativas ou maior independência às pacientes com SR.

Concepts of color, shape, size and position in ten children with Rett syndrome

Individuals with Rett syndrome (RS) present severe motor, language and cognitive deficits, as well as spontaneous hand movement loss. On the other hand, there are strong evidence that these individuals use the eyes with intentional purpose. Ten girls aged 4y8m to 12y10m with RS were assessed with a computer system for visual tracking regarding their ability of indicating with eyes the recognition of concepts of color (red, yellow and blue), shape (circle, square and triangle), size (big and small) and spatial position (over and under) to which they were first exposed to. Results from comparing the time of eyes fixation on required and not required concepts did not differ significantly. Children did not show with eyes the recognition of the required concepts when assessed with eye tracking system.

Rett syndrome: recent research progress

Recent progress in our understanding of Rett syndrome has been dramatic. Against the background that the clinical features of Rett syndrome may be reversible, in part or in whole, substantial optimism has emerged regarding possible therapies. As such, it is timely to update recent research progress. This update summarizes research advances during the past 18 to 24 months in terms of clinical and translational research, as well as basic research.

Rett syndrome

Rett syndrome (RS) is an X-linked neurodevelopmental disorder and the second most common cause of genetic mental retardation in females. Different mutations in MECP2 are found in up to 95% of typical cases of RS. This mainly neuronal expressed gene functions as a major transcription repressor. Extensive studies on girls who have RS and mouse models are aimed at finding main gene targets for MeCP2 protein and defining neuropathologic changes caused by its defects. Studies comparing autistic features in RS with idiopathic autism and mentally retarded patients are presented. Decreased dendritic arborization is common to RS and autism, leading to further research on similarities in pathogenesis, including MeCP2 protein levels in autistic brains and MeCP2 effects on genes connected to autism, like DLX5 and genes on 15q11-13 region. This area also is involved in Angelman syndrome, which has many similarities to RS. Despite these connections, MECP2 mutations in nonspecific autistic and mentally retarded populations are rare.