Equine-Assisted Physiotherapy for Spinal Muscular Atrophy

Spinal muscular atrophy is rare neuromuscular disease, it is caused by gene mutation survival motor neuron 1 (SMN1). This gene encodes survival motor neuron (SMN) protein. This protein is most important to survive alfa-motoric neurons in spinal cord. When this protein doesn´t work, no signals go from brain to skeletal muscles and fazic muscles of body. In the end weakening breathing muscles and internal organs muscles.

Disease-modifying therapies have substantially changed the natural history of SMA. In the Czech Republic, currently available pharmacological treatment includes nusinersen (Spinraza), onasemnogene abeparvovec (Zolgensma) and risdiplam (Evrysdi). As survival and motor abilities of children with SMA improve, rehabilitation has become an increasingly important part of comprehensive care. Physiotherapy is one of the recommended rehabilitation types.

The use of rehabilitation procedures is common in clinical practice. In a 2016 study, 105 adults with SMA were asked how many of them used physiotherapy. A total of 86% of respondents received these services, yet the authors of the article conclude that further research is needed to understand the impact of physiotherapy in SMA.

Nevertheless, there is a lot of discussion if physiotherapy is really good for people and children with SMA. Some research shows us, that physiotherapy doesn´t worsen this disease. Researchers showed that strength training 3 times a week does not show side effects in children under 10 years of age, in some cases trends in improving muscle strength and motor functions have been observed.

Because in physiotherapy therapists work primarily with muscles, and a lot of activity can cause fatigue of skeletal muscles and worsen their function. But from clinical work scientists know that the effect of physiotherapy is extensive. There is a research on mice which shows the effect of physiotherapy on the strength activities and the aerobic activities.

Research to better elucidate the intensity of physiotherapy has not yet been published. Motes et al. monitored a total of 16 patients with SMA aged 10 - 55 years, who regularly underwent home autotherapy for 16 months - cycling and strengthening. The authors did not find any side effects of exercise on strength, function or fatigue during the study. However, the oxidation capacity has been reduced and according to the authors, further research is needed in this area.

In the United States, the "Standard of Care" (SMA-SOC) has been developed for SMA, which regulates the rehabilitation care of children and adults with SMA according to the degree of mobility. In the framework of the said directive, the stretching of contractures, swimming, water therapy, light strength exercises and a verticalization stand are recommended within the framework of physiotherapy, and horse riding is also mentioned - but without more detailed information. Vibration techniques and positioning are recommended to improve breathing. Recommended exercises for seated persons also include concentric and eccentric exercises and aerobic and general fitness exercises with and without resistance. According to the directive, the duration of therapy should be adapted to the individual patient. For walkers, the exercise program may include some forms of balance exercises, dynamic and static.

In a study from 2021, physiotherapists were asked about their knowledge of SMA-SOC and its use in practice. Most of them stated that after individuals with SMA started disease-modifying pharmacotherapy, they would recommend increasing the frequency and duration of therapeutic interventions. The authors agree that in practice there are differences in the care of people with SMA, especially in the frequency and duration of specific interventions. At the same time, they state that these findings can identify future research needs and thus extend SMA-SOC to rehabilitation management best practices.

The aim of this study is to evaluate the effects of intensive rehabilitation in children with spinal muscular atrophy receiving disease-modifying therapy. The study evaluates changes in motor function, postural control, respiratory function, movement quality, neuromuscular activity, quality of life and selected molecular biomarkers following intensive rehabilitation.

The secondary intention of the research is to determine an appropriate intensity of rehabilitation so that unwanted muscle fatigue does not occur.

Investigators will therefore investigate the neurophysiological mechanisms of rehabilitation that investigators will monitor using long non-coding RNAs (lncRNAs) involved in important cellular regulation, including regulation of genomic imprinting, epigenetic chromatin modification, transcriptional interference, and nuclear export. The lncRNA, SMN-antisense 1 (SMN-AS1), has been shown to repress the expression of the duplicate survival motor neuron 2 (SMN2) gene by binding Polycomb repressive complex 2 (PRC2) to its locus. Increasing the transcriptional activity of an almost identical SMN2 gene can functionally compensate for the loss of SMN1, increase the amount of SMN protein and thus improve the prognosis of the disease. Chemically modified oligonucleotides have been proposed that disrupt the interaction between SMN-AS1 and PRC2, which inhibits the action of PRC2 and thus leads to increased SMN2 expression.

Investigation of lncRNAs involved in the processes of gene regulation of these genes may help to understand the neurophysiological effects of rehabilitation of children with SMA.

Inclusion criteria

• clinic diagnosis SMA (I, II, and III types)
• no changing medicine 6 months at least
• without another grave diseases

Exclusion criteria

• hip luxation
• allergies to horses and the environment of horse stables
• insurmountable fear of the horse