Walking on treadmill with Rett syndrome-Effects on the autonomic nervous system.

People with Rett syndrome have deficient central autonomic control, which may interfere with walking. We have limited knowledge regarding the effects of exertion during physical activity in Rett syndrome. The aim was to investigate the autonomic responses during walking on a treadmill in Rett syndrome. Twenty-six females, 12 with Rett syndrome and 14 healthy females were included. All individuals started on the treadmill by standing still, followed by walking slowly with progressive speed until reaching maximum individual speed, which they kept for 6 min. Heart rate (HR), systolic (SBP), diastolic (DBP), mean arterial blood pressures (MAP), cardiac vagal tone (CVT), cardiac sensitivity to baroreflex (CSB), transcutaneous partial pressures of oxygen (pO2), carbon dioxide (pCO2), and breathing movements were recorded simultaneously and continuously. Autonomic responses were assessed by MAP, CSB and CVT during walking at 3 and 6 min. The changes in CSB and CVT in people with Rett syndrome compared to controls indicated more arousal, but only when the treadmill was started; as they continued walking, the arousal dropped to control level. People with Rett syndrome exhibited little changes in pCO2 whereas the controls showed increased values during walking. This suggests poor aerobic respiration in people with Rett syndrome during walking. Five people with Rett syndrome had Valsalva type of breathing at rest, three of those had normal breathing while walking on the treadmill while the remaining two started but soon stopped the Valsalva breathing during the walk. Our results show that individuals with Rett syndrome can walk for up to 6 min at their own maximum sustainable speed on a treadmill. Energy production may be low during walking in Rett syndrome, which could cause early tiredness. A treadmill can be used in people with Rett syndrome, but must be introduced slowly and should be individually tailored. We propose that walking promotes regular breathing in Rett syndrome.

Activities that girls and women with Rett syndrome liked or did not like to do.

OBJECTIVE: Activities occur in all people's lives. This study investigated over a period of time, 15 years, what activities were enjoyed or not enjoyed and what activities parents and staff liked to do with girls/women with Rett syndrome. METHOD: A descriptive study was conducted using secondary data from three earlier questionnaires at the Swedish National Rett Center. The first questionnaire provided data on 123 girls/women with Rett syndrome, the second on 52 and the third questionnaire, on 39. Informants were parents and/or staff, in total 365. Open-ended questions were analysed using a content analysis approach. RESULTS: Three categories appeared: Being in motion, receiving impressions and having contact. Bathing/swimming, listening to music and being outdoors/walking were the most enjoyed activities over the years. Of the few activities that were reported as being unenjoyable, most were daily care activities. The activities that the parents/staff enjoyed doing with the girls/women were similar to those the girls/women themselves liked to do. CONCLUSION: A preliminary overview for both liked and disliked activities of girls/women with Rett syndrome was presented. This knowledge could facilitate the choice and use of activities.

Neurophysiology versus clinical genetics in Rett syndrome: A multicenter study.

Many studies have attempted to establish the genotype-phenotype correlation in Rett syndrome (RTT). Cardiorespiratory measurements provide robust objective data, to correlate with each of the different clinical phenotypes. It has important implications for the management and treatment of this syndrome. The aim of this study was to correlate the genotype with the quantitative cardiorespiratory data obtained by neurophysiological measurement combined with a clinical severity score. This international multicenter study was conducted in four European countries from 1999 to 2012. The study cohort consisted of a group of 132 well-defined RTT females aged between 2 and 43 years with extended clinical, molecular, and neurophysiological assessments. Diagnosis of RTT was based on the consensus criteria for RTT and molecular confirmation. Genotype-phenotype analyses of clinical features and cardiorespiratory data were performed after grouping mutations by the same type and localization or having the same putative biological effect on the MeCP2 protein, and subsequently on eight single recurrent mutations. A less severe phenotype was seen in females with CTS, p.R133C, and p.R294X mutations. Autonomic disturbances were present in all females, and not restricted to nor influenced by one specific group or any single recurrent mutation. The objective information from non-invasive neurophysiological evaluation of the disturbed central autonomic control is of great importance in helping to organize the lifelong care for females with RTT. Further research is needed to provide insights into the pathogenesis of autonomic dysfunction, and to develop evidence-based management in RTT. © 2016 Wiley Periodicals, Inc.

Clinical Guidelines for Management of Bone Health in Rett Syndrome Based on Expert Consensus and Available Evidence.

OBJECTIVES: We developed clinical guidelines for the management of bone health in Rett syndrome through evidence review and the consensus of an expert panel of clinicians. METHODS: An initial guidelines draft was created which included statements based upon literature review and 11 open-ended questions where literature was lacking. The international expert panel reviewed the draft online using a 2-stage Delphi process to reach consensus agreement. Items describe the clinical assessment of bone health, bone mineral density assessment and technique, and pharmacological and non-pharmacological interventions. RESULTS: Agreement was reached on 39 statements which were formulated from 41 statements and 11 questions. When assessing bone health in Rett syndrome a comprehensive assessment of fracture history, mutation type, prescribed medication, pubertal development, mobility level, dietary intake and biochemical bone markers is recommended. A baseline densitometry assessment should be performed with accommodations made for size, with the frequency of surveillance determined according to individual risk. Lateral spine x-rays are also suggested. Increasing physical activity and initiating calcium and vitamin D supplementation when low are the first approaches to optimizing bone health in Rett syndrome. If individuals with Rett syndrome meet the ISCD criterion for osteoporosis in children, the use of bisphosphonates is recommended. CONCLUSION: A clinically significant history of fracture in combination with low bone densitometry findings is necessary for a diagnosis of osteoporosis. These evidence and consensus-based guidelines have the potential to improve bone health in those with Rett syndrome, reduce the frequency of fractures, and stimulate further research that aims to ameliorate the impacts of this serious comorbidity.

Normal reactions to orthostatic stress in Rett syndrome.

The aim of this study was to investigate orthostatic reactions in females with Rett syndrome (RTT), and also whether the severity of the syndrome had an impact on autonomic reactions. Based on signs of impaired function of the central autonomic system found in RTT, it could be suspected that orthostatic reactions were affected. The orthostatic reactions in 21 females with RTT and 14 normally developed females matched by age were investigated when they rose from a sitting position, and during standing for 3 min. Reactions of the heart, the blood pressure and the time for recovery of systolic blood pressure, were studied in real time, heartbeat by heartbeat, simultaneously. There was no difference between participants with RTT and the normally developed controls regarding general orthostatic reactions (heart rate, systolic and diastolic blood pressure, and mean arterial pressure) when getting up from a sitting position, and when standing erect for 3 min. In the specific immediate response by the heart to standing up, the 30:15 ratio, significantly lower values were found for females with RTT. In the RTT group, the maximum fall of systolic blood pressure showed a tendency to a larger decrease, and the initial decrease in systolic blood pressure was significantly faster. The time for recovery of systolic blood pressure from standing erect did not differ between groups. At baseline the females with RTT had significantly lower systolic blood pressure and a tendency to a higher heart rate. The results do not indicate any autonomic limitations for people with RTT in getting up from a sitting position and standing. The participants with RTT had normal orthostatic reactions indicated by the heart and blood pressure responses when standing erect for 3min. A faster initial drop in systolic blood pressure in people with RTT was notable.

Treating hypoxia in a feeble breather with Rett syndrome.

Rett syndrome (RS) is a unique X-linked dominant neurodevelopmental disorder affecting 1 in 10,000 females. Mutations in the MECP2 gene located on Xq28 have been identified. Many of the characteristic features evolve due to immaturity of the brain in RS. Cardiorespiratory function should be investigated early to characterise the clinical phenotype of the person with RS because each of the three cardiorespiratory phenotypes; apneustic, feeble and forceful breathers have unique and different management strategies. We report a case of a feeble breather showing a correlation between cortical function and tissue pO(2) and pCO(2). We conclude that subtle changes in the levels of blood gases significantly affect cortical function in RS.

Assessment of the maturity-related brainstem functions reveals the heterogeneous phenotypes and facilitates clinical management of Rett syndrome.

We have investigated whether brainstem assessment using the Neuro Scope could be used for objective and quantitative monitoring of early development and later progress in Rett syndrome. Brainstem features can be seen on bedside examination of Rett patients and are included in the International Scoring system. The following cardiovascular vital signs were recorded simultaneously in real-time: cardiac vagal tone (CVT), cardiac sensitivity to baroreflex (CSB), heart rate (HR), and mean arterial blood pressure (MAP) and respiratory vital signs: breathing rate and pattern, transcutaneous partial pressures of oxygen (pO(2)) and carbon dioxide (pCO(2)). We assessed the occipito-frontal head circumference (OFHC), height and body mass index (BMI). Results are from 72 patients with classical Rett syndrome studied at the Swedish National Rett Centre. Three cardiorespiratory phenotypes, designated Forceful, Feeble and Apneustic breathers were present in similar proportions in the Rett population but early development measured by OFHC and BMI differed. Height was not affected. Baseline levels of CVT and CSB also differed within the phenotypes indicating differences in parasympathetic activities. However, parasympathetic activity in the whole population was similar to that previously reported in Rett. Baseline levels of MAP and HR were similar across the phenotypes, consistent with previous reports of little effect of Rett disorder on baseline sympathetic tone. Adverse responses to opiate analgesics and hypocapnoeic attacks were unique to specific phenotypes. We recommend early characterisation of these phenotypes in the management of Rett syndrome. We conclude that classical Rett syndrome consists of heterogeneous clinical phenotypes with distinct cardiorespiratory states. Brainstem functions can be used to identify these and to monitor development and treatment, thereby facilitating clinical management.