Analysis of aberrant behaviour associated with Rett syndrome

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Rehabilitation therapies in Rett syndrome across the lifespan: A scoping review of human and animal studies

PURPOSE

To perform a scoping review of the evidence for therapeutic interventions to manage functional impairments associated with Rett syndrome (RTT) throughout the lifespan.

METHODS

MEDLINE, EMBASE, PsycINFO, CENTRAL, CINAHL, Scopus and Index to Chiropractic Literature were searched systematically up to December 2019. Two investigators independently reviewed all search results and extracted those that met the inclusion criteria. Human and animal model studies pertaining to therapies that increase functional ability or treat RTT-associated symptoms in all age groups were included. Relevant studies were grouped into intervention categories and rated using the Oxford Centre of Evidence Based Medicine Levels of Evidence. Demographics of participants, interventions, and outcomes were summarized.

RESULTS

Ninety-one articles representing 88 studies met the inclusion criteria, of which 80 were human clinical studies and eight were studies using animal models. Study designs were primarily case series and only six studies involved participants above the age of 40.

CONCLUSION

A small number of rigorously studied rehabilitation interventions have been published. Published studies aim to address a wide variety of functional impairments. Research regarding implementation of therapies for older patients with RTT is lacking and requires further exploration.

Rehabilitation interventions in Rett syndrome: a scoping review

AIM

To summarize existing interventions and their outcomes in Rett syndrome (RTT) rehabilitation and identify gaps in the literature.

METHOD

Five databases (Ovid MEDLINE, Ovid Embase Classic, Ovid PsycINFO, EBSCO CINAHL Plus, and ProQuest ERIC) were systematically searched up to 23rd July 2018 for studies describing rehabilitation interventions. Data on study participants, design, and outcomes were extracted.

RESULTS

Sixty-two articles were included in the final review. Evidence consistently demonstrated that females with RTT can improve their gross motor, fine motor, and communicative skills with rehabilitation. All 11 interventions targeting gross motor function, namely ambulation, achieved functional improvements. Twenty of 24 articles describing fine motor rehabilitation studies succeeded in decreasing stereotypies, improving functional hand use, and/or reducing self-injurious behaviors. Twenty-one of 22 studies describing communication interventions succeeded in training choice-making, communicative language, or socialization behavior. Other key findings include the positive interplay between physical and communicative rehabilitation outcomes, and the ability of females with RTT to improve their cognitive abilities during intervention.

INTERPRETATION

Rehabilitation can impact the daily lives of females with RTT and their caregivers in clinically meaningful ways.

Direct Observation of the Behaviour of Females with Rett Syndrome

The aim was to observe the behaviour of a sample of females with RTT and explore how it was organized in relation to environmental events. Ten participants, all with a less severe form of classic (n = 9) or atypical (n = 1) Rett syndrome (RTT), were filmed at home and at school or day centre. Analysis used real-time data capture software. Observational categories distinguished engagement in social and non-social pursuits, hand stereotypies, self-injury and the receipt of attention from a parent, teacher or carer. Associations between participant behaviour and intake variables and receipt of attention were explored. Concurrent and lagged conditional probabilities between behavioural categories and receipt of attention were calculated. Receipt of adult attention was high. Engagement in activity using the hands was associated with a less severe condition and greater developmental age. Engagement in activity, whether using the hands or not, and social engagement were positively associated with receipt of support. The extent of hand stereotypies varied greatly across participants but was independent of environmental events. Six participants self-injured. There was some evidence that self-injury was related to adult attention. Participants appeared to experience a carer and attention rich environment and their levels of engagement seemed high as a result. As in the more general literature, engagement in activity was related to personal development and to social support. Self-injury contrasted with hand stereotypies in having possible environmental function.

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.

Recognizing and treating Rett syndrome in schools

A review of the literature on Rett syndrome (RS) for school-based professionals is presented from a behavioral perspective. A description of RS is provided, including distinctive physical, behavioral, and emotional features, diagnostic criteria for classic and formes frustes forms of RS, and stages of the disorder. The similarities and differences between RS and autism are reviewed. Controversies regarding the classification of RS are presented, including whether RS should be classified as a neurological or psychiatric condition and whether RS should remain classified as a pervasive developmental disorder. Last, a variety of options for the treatment of RS are discussed.

Phenotype-environment interactions in genetic syndromes associated with severe or profound intellectual disability

The research literature notes both biological and operant theories of behavior disorder in individuals with intellectual disabilities. These two theories of genetic predisposition and operant reinforcement remain quite distinct; neither theory on its own is sufficient to explain challenging behavior in genetic syndromes and an integrated approach is required. This literature review integrates the two approaches by exploring how environmental factors can influence problem behavior in genetic syndromes associated with intellectual disability. Particular attention is paid to studies that describe evidence that problem behaviors in syndromes that are considered to be phenotypic are associated with other aspects of an established behavioral phenotype. The review highlights how the study of phenotype-environment interactions within syndromes can promote understanding of the aetiology of problem behaviors both within genetic syndromes and, ultimately, the wider population of individuals with severe intellectual disabilities. The review also evaluates the current status of research and the methods typically employed. Implications for intervention, future research and extending existing causal models of challenging behavior are discussed.

Stereotypical hand movements in 144 subjects with Rett syndrome from the population-based Australian database

Stereotypic hand movements are a feature of Rett Syndrome but few studies have observed their nature systematically. Video data in familiar settings were obtained on subjects (n = 144) identified from an Australian population-based database. Hand stereotypies were demonstrated by most subjects (94.4%), 15 categories were observed and midline wringing was seen in approximately 60% of subjects. There was a median of two stereotypies per subject but this number decreased with age. Clapping and mouthing of hands were more prevalent in girls younger than 8 years and wringing was more prevalent in women 19 years or older. Clapping was commoner in those with p.R306C and early truncating mutations, and much rarer in those with p.R106W, p.R270X, p.R168X, and p.R255X. Stereotypies tended to be less frequent in those with more severe mutations. Otherwise, there were no clear relationships between our categories of stereotypies and mutation. Approximately a quarter each had predominantly right and left handed stereotypies and for the remaining half, no clear laterality was seen. Results were similar for all cases and when restricted to those with a pathogenic mutation. Hand stereotypies changed with increasing age but limited relationships with MECP2 mutations were identified.

Incorporating "motivation" into the functional analysis of challenging behavior: on the interactive and integrative potential of the motivating operation

Sensitivity theory attempts to account for the variability often observed in challenging behavior by recourse to the "aberrant motivation" of people with intellectual and developmental disabilities. In this article, we suggest that a functional analysis based on environmental (challenging environments) and biological (challenging needs) motivating operations provides a more parsimonious and empirically grounded account of challenging behavior than that proposed by sensitivity theory. It is argued that the concept of the motivating operation provides a means of integrating diverse strands of research without the undue inference of mentalistic constructs. An integrated model of challenging behavior is proposed, one that remains compatible with the central tenets of functional analysis.

Treatment of hand mouthing in individuals with severe to profound developmental disabilities: a review of the literature

This paper reviews studies investigating the assessment and treatment of hand mouthing in individuals with severe to profound developmental disabilities. A literature search identified 101 studies carried out between 1969 and 2004. The trend in the studies indicated a shift away from aversive interventions in the last 10 years, so this review included studies conducted from 1995. Twenty-three studies were identified within this period and were included in this review. The 23 studies were sorted into seven intervention categories and one assessment category. The seven intervention categories included (a) antecedent interventions, (b) multicomponent interventions (e.g., differential reinforcement and response effort), (c) pharmacological interventions, (d) interventions that utilized reinforcement, (e) response blocking interventions, (f) response effort interventions, and (g) sensory stimulation interventions. The one assessment category included studies that investigated the function of hand mouthing. One main finding in these studies was that the various intervention strategies led to decreases in hand mouthing in individuals with severe to profound developmental disabilities. This finding is discussed in relation to its effect on issues of health, adaptive behavior, and social functioning. A second finding indicated that hand mouthing is often maintained by automatic reinforcement (i.e., non-social contingencies). The implications of this finding are discussed in terms of how assessments and treatments associated with automatically maintained challenging behavior might be more effectively linked. Potential issues for future research are also examined.

An analogue assessment of repetitive hand behaviours in girls and young women with Rett syndrome

BACKGROUND

Rett syndrome is a neurodevelopmental disorder that almost exclusively affects females. In addition to neurodevelopmental regression and loss of hand skills, apraxia, deceleration of head growth, and increasing spasticity and scoliosis, a number of behavioural features are also seen, including stereotypic hand movements, hyperventilation and breath holding. The aim of the study was to investigate the extent to which analogue environmental conditions affected the frequency of repetitive hand behaviour in eight girls and young women with Rett syndrome.

METHOD

The frequency of repetitive hand movements was observed every 10 s for four 4-min sessions under the following conditions: Continuous Adult Attention, Adult Demands, Stimulation and No Stimulation.

RESULTS

The frequency of repetitive hand movements was high -- they occurred in above 60% of all intervals in all conditions for all participants and at nearly 100% for some participants in some conditions. For one participant the frequency of repetitive hand movements was somewhat reduced in the Stimulation condition; for another it was relatively increased in the No Stimulation condition.

CONCLUSIONS

Overall, environmental manipulations had relatively limited effects on repetitive hand behaviours. Repetitive hand behaviour in Rett syndrome may be maintained by automatic reinforcement or neurochemical processes and may not be primarily influenced by contingent reinforcement.