The science behind Nextherapy
Different types of brain changes that occur after exercise. Adapted from Yau et al 2016
Nextherapy’s interventions have a strong focus on intensity and specificity and often include the use of robotics and technologies in order to best activate the brain’s activity-dependent plasticity, which can have significant positive implications for recovery from brain damage (Alvaro Pascual-Leone et al. 2011)(Ganguly and Poo 2013)(Ganguly and Poo 2013).
Activity-dependent plasticity is a form of functional and structural neuroplasticity that arises from the use of cognitive functions and personal experience. Every time we move, we think or have a new experience, our neurons trigger a wide variety of changes that alter the brain connectivity. They go from gene expression to changes in the structure of the nervous system. They allow our brain to remodel itself and recover lost function, enhance comprehension and speech amongst other things.
To reach activity dependent plasticity, the practice and experience must follow certain principles such as intensity, repetition, specificity, transference and salience or motivation (Maier, Ballester, and Verschure 2019).
Intensity and repetition
- Intensive programs delivering 25 to 30 hours of therapy a week have demonstrated improvements that are double those of other interventions tested so far with lower intensities(Daly et al. 2019) (Lang, Lohse, and Birkenmeier 2015) (Lohse, Lang, and Boyd 2014).
- Intensity is a major factor for recovery(Van Peppen et al. 2004)(Veerbeek et al. 2014)(Spiess and Colombo 2017)(Schneider et al. 2016) and there is sufficient evidence that clinically significant improvements months or years after the injury are possible if enough therapy is provided by increasing plasticity, and therefore opening a new window for recovery(Daly et al. 2019)(Ward, Brander, and Kelly 2019).
- One hypothesis for this is the ability to trigger structural plastic changes (Maier, Ballester, and Verschure 2019). That means, pushing our brain to reorganize neural networks , increase or normalize our cortical excitability in order to have durable changes on our brain(Maier, Ballester, and Verschure 2019).
- In studies, patients have perceived no barriers regarding the implementation of higher intensity programs and were positive to work harder (Janssen et al. 2020). Initial objective assessments and the use of sensors and technology supports therapists to push patients harder(Connell et al. 2018)
Chronic patients, training 300 hours in 3 months have shown 9.8 points of improvement on FMS, more than double the clinical significant value.
Improvement on arm and hand function on stroke patients >1 year after stroke
Daly et al 2019
A meta analysis study at least an extra 240% rehabilitation was needed for significant likelihood to achieve recovery.
Schneider E et al 2016
Specificity
Task performed during therapy needs to be as similar as possible to task to be achieved (Schmidt R.A, 2018). Task specific training induces plastic changes in our brain and improves motor learning and retention (A. Pascual-Leone et al. 1995)(Hubbard et al. 2009) (Merabet et al. 2005)
Changes in the brain area representing the fingers after 5 days of practice show that has the ability to change our brain and improve function.
Extracted from Pascual-Leone et al 2005
Transference
- Changes in functions of one skill can facilitate the learning of other skills. Research has found that trainings that targeted one specific finger, increased the plasticity and circuits of the whole hand, allowing learning of other hand movements faster(Kleim and Jones 2008) .
- Transference is related to one of the motor learning key factors, transfer, which speaks about the ability to transfer what has been learned to a new task variant or conditions (Seidler 2010).
- Transfer is key in order to sustain the improvements since it enables our systems to learn how to learn.
Salience or Motivation
- Tasks or actions that have a bigger impact for the individual, induce bigger plastic changes on the brain. This is why the individualization of the therapy program is key for the success. Taking the patient goals and preferences as the base to determine the activities will lead to increase motivation and attention, which are critical for the acquisition of new movements or functions(Conte et al. 2007).
- Activities that are action-oriented have a different representation in our brain than simple movements and produce higher activity, being critical for the transfer of learning(Maier, Ballester, and Verschure 2019).
The excitability of the brain area corresponding to the hand increases when the person is paying attention to the target hand (blue line) vs no attention (grey line) or attention to the opposite hand (orange line)
Image adapted from Conte A et al 2007
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