Co-occurrence of Dystonic and Dyskinetic Tongue Movements with Oral Apraxia in Post-regression Dysphagia in Classical Rett Syndrome Years of Life 1 Through 5

Parkinsonism and Dystonia Are Prevalent and Concomitant Movement Disorders in a Cohort of Patients with Rett Syndrome

BACKGROUND

Rett syndrome (RTT) is a rare neurodevelopmental disorder linked with MECP2 variants, frequently presenting with movement disorders (MDs).

OBJECTIVES

This study examined the frequency, types, and associations of MDs with RTT characteristics and severity.

METHODS

Twenty female patients (median age 11 years, range 3-40) with MECP2 variants were recruited and assessed using disease severity and MD scales, alongside videotaped neurological examinations.

RESULTS

Prevalent MD was hypokinetic in 55% of the patients and hyperkinetic in 45%. Parkinsonism and dystonia were the most common, coexisting in 75% of patients. Higher Movement Disorders-Childhood Rating Scale (MD-CRS) scores correlated with greater severity on the Rett Assessment Rating Scale (RARS) (P = 0.04). Dystonia was significantly associated with respiratory (P < 0.05) and gastrointestinal problems (P = 0.02).

CONCLUSIONS

The study identified parkinsonism and dystonia as the prevalent MDs in RTT, emphasizing the association between dystonia and gastrointestinal/respiratory problems and reflecting the complex nature of MDs in RTT.

Recommendations for the management of gastrointestinal comorbidities with or without trofinetide use in Rett syndrome

INTRODUCTION

Although gastrointestinal (GI) comorbidities are experienced by over 90% of individuals with Rett syndrome (RTT), a neurodevelopmental disorder associated with mutations in the MECP2 gene, many neurologists and pediatricians do not rank the management of these comorbidities among the most important treatment goals for RTT. Trofinetide, the first approved pharmacologic treatment for RTT, confers improvements in RTT symptoms but is associated with adverse GI events, primarily diarrhea and vomiting. Treatment strategies for GI comorbidities and drug-associated symptoms in RTT represent an unmet clinical need.

AREAS COVERED

This perspective covers GI comorbidities experienced by those with RTT, either with or without trofinetide treatment. PubMed literature searches were undertaken on treatment recommendations for the following conditions: constipation, diarrhea, vomiting, aspiration, dysphagia, gastroesophageal reflux, nausea, gastroparesis, gastritis, and abdominal bloating.

EXPERT OPINION

The authors recommend a proactive approach to management of symptomatic GI comorbidities and drug-associated symptoms in RTT to enhance drug tolerance and improve the quality of life of affected individuals. Management strategies for common GI comorbidities associated with RTT are reviewed based on authors' clinical experience and augmented by recommendations from the literature.

Fiberoptic Endoscopic Evaluation of Swallowing Findings in Children With Rett Syndrome

Feeding abnormalities, swallowing dysfunction, and gastrointestinal issues cause poor weight gain, oral motor dysfunction, and air swallowing in children with Rett syndrome (RTT). Pneumonia is the leading cause of death. Our study describes fiberoptic endoscopic swallowing findings in 11 female RTT children. Each patient was evaluated using the 8-point Penetration/Aspiration Scale (PAS). The average age was 7 years. All patients had tongue dyskinesis and prolonged oral stage. Eight girls exhibited liquid entering the airway without coughing, whereas 6 did well with pureed meal. Three girls had pneumonia. Age was not correlated with pneumonia episodes (P = .18). Pureed material was related with pneumonia (P = .006), whereas liquids were not. Pureed PAS was positively correlated with Liquid PAS (P = .008) and age (P = .004). All aspiration/penetration incidents occurred before the pharyngeal phase. No patient under 7 years experienced pneumonia episodes. Silent aspiration can occur early in infancy, although pneumonia episodes can occur later.

Breathing disturbances in Rett syndrome

Rett Syndrome is an X-linked neurological disorder characterized by behavioral and neurological regression, seizures, motor deficits, and dysautonomia. A particularly prominent presentation includes breathing abnormalities characterized by breathing irregularities, hyperventilation, repetitive breathholding during wakefulness, obstructive and central apneas during sleep, and abnormal responses to hypoxia and hypercapnia. The condition and pathology of the respiratory system is further complicated by dysfunctions of breathing-motor coordination, which is reflected in dysphagia. The discovery of the X-linked mutations in the MECP2 gene has transformed our understanding of the cellular and molecular mechanisms that are at the root of various clinical phenotypes. However, the genotype-phenotype relationship is complicated by various factors which include not only X-inactivation but also consequences of the intermittent hypoxia and oxidative stress associated with the breathing abnormalities.

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

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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

Dietary intake and growth deficits in Rett syndrome-A cross-section study

Growth deficit is a common comorbidity and one of the supportive criteria in Rett syndrome (RTT). This study aimed to investigate the impact of dystonia, dietary intakes, and clinical severities on growth patterns in a Taiwanese cohort of RTT. We recruited 44 RTT patients with MECP2 mutation for analysis. For individuals ≤18 years of age, in comparison to the RTT-specific growth chart which comprised American RTT cohort, the body height was right-shifted to a higher percentile, whereas the body weight was left-shifted to a lower percentile. Furthermore, the body mass index was significantly decreased when compared to RTT-specific growth chart (p = 0.01). Higher degree of overall disease severity (odd ratio = 1.159; 95% CI = 1.063-1.264; p = 0.001) and hand use impairment (odd ratio = 2.017; 95% CI = 1.037, 3.921; p = 0.039) were associated with more severe growth patterns. All individuals had dystonia at certain variable degrees. The dystonia worsened with age (p < 0.001) but did not have significant impact on growth deficit. Most of our cohort had adequate protein (97.37%) and energy (58.97%) intakes. The fiber intakes were generally low, with about 38 (97.4%) individuals did not meet the daily reference intakes of fiber. The protein intake was significantly lower in individuals with severe growth deficit (p = 0.04). Our study shows that ethnicity should be considered when comparing RTT individuals' growth pattern to the RTT-specific growth chart. Further, disease severity, genotypes, and nutrition exert important impacts on RTT-growth pattern. LAY SUMMARY: Growth impairment is an important issue in Rett syndrome and the underlying patho-mechanism is multifactorial. Higher degree of overall disease severity and hand use impairment were associated with more severe growth pattern deficits. Although all individuals had dystonia at certain variable degrees and the dystonia worsened with age, but it did not have significant impact on growth deficit. Nutritional intakes may partially affect growth. Furthermore, ethnicity should be considered when comparing RTT individuals' growth pattern to the RTT-specific growth chart.

The Pathophysiology of Rett Syndrome With a Focus on Breathing Dysfunctions

Rett syndrome (RTT), an X-chromosome-linked neurological disorder, is characterized by serious pathophysiology, including breathing and feeding dysfunctions, and alteration of cardiorespiratory coupling, a consequence of multiple interrelated disturbances in the genetic and homeostatic regulation of central and peripheral neuronal networks, redox state, and control of inflammation. Characteristic breath-holds, obstructive sleep apnea, and aerophagia result in intermittent hypoxia, which, combined with mitochondrial dysfunction, causes oxidative stress-an important driver of the clinical presentation of RTT.

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

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

DATA SOURCES AND EXTRACTION

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

RESULTS

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

CONCLUSIONS

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

Prevalence of Dysphagia in People With Intellectual Disability: A Systematic Review

Dysphagia (feeding and swallowing disorder) is associated with serious health complications and psychosocial sequelae. This review summarizes international research relating to the prevalence of dysphagia in people with intellectual disability. Studies published from 1990 to July 2016 were identified using Medline, Cinahl, PsycINFO, Web of Science, email requests, and cross-citations. Twenty studies were identified. Dysphagia in people with intellectual disability appears to be associated with more severe levels of intellectual disability, comorbid cerebral palsy, and motor impairments. However, further research with representative samples of people with intellectual disability using adequate methods of assessment are required in order to provide more precise prevalence estimates and clarify factors that may be associated with dysphagia in this population.