Recent Study Shows Clinical Benefit of Environmental Enrichment in Rett Syndrome

Results from a study recently published in the Orphanet Journal of Rare Diseases report that behavioral interventions, like environmental enrichment, can reduce the functional deficit experienced by patients with Rett syndrome.

The study, led by Jenny Downs of the Telethon Kids Institute at the University of Western Australia, concluded that environmental enrichment can contribute to the evidence-base for management of the treatment and further understanding of epigenetic mechanisms. Because of effects for support of synapses and improved functioning, environmental enrichment serves as a significant aide in the assessment of new drug therapies that use BDNF pathways.

Rett syndrome is a rare neurological, non-inherited genetic disorder that occurs almost exclusively in girls, and can lead to life-threatening physical and cognitive impairments. It is the result of mutations that spontaneously occur along the MECP2 gene, and most symptoms observed in patients are likely to be related to where that mutation occurs. One of the effects of impaired MECP2 function is reduced production of Brain Derived Neurotrophic Factor (BDNF), a protein required for normal neuronal development.

Typical symptoms experienced by patients with Rett syndrome often include a regression of previously learned skills. As the disease progresses, purposeful hand movements and speech deteriorate and other physical and cognitive symptoms begin to appear. Symptoms vary from patient to patient, but most commonly include growth retardation, seizures, autistic-like behaviors, and difficulties swallowing and breathing.

Symptoms can be alleviated with help from medications, speech and physical therapies, and nutritional support, however, while these remedies improve the patient’s quality of life, they do not slow or stop progression of the disease.

The study, which enrolled a genetically variable group of 12 girls with a MECP2 mutation and younger than 6 years, investigated the effects of environmental enrichment on gross motor skills and blood BDNF levels in girls with Rett syndrome. The baseline period was either 1, 2, or 3 months as determined randomly and thereafter the intervention period was 6 months. The intervention provided a rich sensori-motor environment and included multiple supported activities, focused particularly on balance and walking, selected to target individual goals in the development of motor skills and endurance and increase BDNF production.

The primary outcome of the study was gross motor skill measured using the Rett Syndrome Gross Motor Scale, comprising 15 items for sitting, standing, walking and transition activities rated according to the observed level of assistance and using a 0-to-3 scale with 3 representing better function. Secondary outcomes included blood levels of the BDNF protein, growth, sleep quality and behavior.

For the 10 girls in the study with post intervention BDNF data, there was a 10.3-point increase in RSGMS score after 6 months of treatment adjusting for the effects of age at regression, current age and BDNF levels. In comparison to baseline, BDNF levels increased by 321.4 ng/ml after 6 months of treatment. BDNF levels increased an additional 39.0 ng/ml for each additional year in age, adjusting for age at regression and the RSGMS score.

After reviewing the results of the data, it was concluded that motor learning and exercise added with rich social, cognitive and other sensory experiences had constructive effects on motor functioning in patients with Rett syndrome. It was established that children with a later age at regression gained slightly more gross motor skill over the treatment period.

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