Although the brain has a basic structure and a given shape, the reality is that each human brain is unique and behaves in a very different way to the rest. This difference is due, principally, to the fact that our brain changes how it interacts with its surroundings, a phenomenon that is named neuroplasticity.
One of the most well-known studies about this subject, which shows that neuroplasticity also occurs in adults, is the study that was done of taxi drivers in London in 2000 [Ref] where the brains of a group of taxi drivers were analysed against the brains of a control group. You must keep in mind that London taxi drivers are required to pass a demanding exam, The Knowledge, which consists of learning more than 320 routes through more than 25,000 streets. The results of this study demonstrated that there were significant differences in the size of the rear part of the hippocampus, the area of the brain which, amongst other things, plays an important role in spatial memory and orientation. Therefore, the taxi drivers, above all those that had driven for longer, presented a larger hippocampus than the rest of the participants.
Just as this and many other similar studies show, the words of Santiago Ramón y Cajal “Any man could, if he were so inclined, be the sculptor of his own brain” are a real fact. Our brain is plastic, and it is changing its structure and functioning throughout your life. The plasticity allows the neurons to regenerate as much anatomically as functionally, forming new synaptic connections and helping the nervous system to reorganise, restructure and even recover in some cases of brain damage including stroke and traumatic brain injury.
Many other diseases, such as brain haemorrhages, dementia, ADHD, major depression, ageing or neurological injuries, cause damage in the brain that can bring associated changes in its structure, activity and functioning. Usually, this brings a loss or decrease in some function of our body with it, which could be the loss of movement of an arm or the loss of our ability to keep attention. However, this extraordinary ability to reorganise that the brain has, allows new neural connections to be made, which in many cases can support the recovery of the lost functions through programmes of neurorehabilitation.
What is neurorehabilitation and what types are there?
Rehabilitation is a group of techniques and methods that are used to recover a function or activity of the body that has been decreased or lost because of an accident or illness. The most common are motor rehabilitation (lost motor ability), cognitive rehabilitation (lost cognitive ability and executive actions), and visual, emotional or neurologic rehabilitation. Neurorehabilitation is a process we refer exclusively to for rehabilitation that is used when the illness has happened in the nervous system. Rehabilitation is carried out by a team of health professionals including occupational therapy.
The objective of neurorehabilitation is to take advantage, appropriately, of neural plasticity, in order to achieve a recovery from an injury, neurological disorders or neurological disabilities. The type of neurorehabilitation can be motor, cognitive, visual or emotional, amongst other types, depending on the type of decrease of function that it is trying to recover.
In recent years, and thanks to new neuroimaging techniques, it has been possible to study neurorehabilitation programmes in much greater detail, better understanding why they work and evaluating their results. All this has been done as well as it being possible to inspire new motor, cognitive and emotional rehabilitation therapies with emerging technology such as neurotechnology or virtual reality.
These new therapies and scientific research projects around neurorehabilitation are based in the following theoretical outline:
- Producing neuroplastic changes by methods of exogenous cerebral stimulation (caused by external measures) or endogenous stimulation (caused by the person themselves).
- Measuring in real time the cerebral response to be able to generate feedback processes (by means of a sensory method), in order to direct these neuroplastic changes, used in a passive form to give information, or active to direct changes by learning.
Leading research projects on motor rehabilitation in Europe
The objective of motor rehabilitation is to recover the functionality and mobility of a limb, which has been lost or decreased by an injury to the nervous system caused by a stroke, brain injury or spinal cord injury, amongst others. This type of cerebral motor rehabilitation tries to regenerate the deteriorated neural pathways, combining systems of measuring the neural activity (brain-computer interface), neuroprosthetics, exoskeletons, and neurorobots that mobilize limbs and systems that provide both visual (e.g. virtual reality) as much as somatosensory (e.g. tactile stimulation) feedback. The central idea is to mobilise the affected limbs at the precise moment in which the registered brain activity indicates that it is trying to make the movement, maintaining the temporal consistency of the information that goes by the afferent and efferent routes as much as possible in order to maximize the probability of achieving a neural reorganization that recovers the functionality.
The European project CORBYS for motor neurorehabilitation with neurorobots
The European project CORBYS (2011-2015) had the objective of neurorehabilitation of inferior limbs by recovering mobility in patients who had suffered a stroke or brain injury. The project entailed an important advance in knowledge with the following developments:
1. A brain-computer interface to identify in real-time the intention of movement and the attention of the patient’s movement.
2. An electric walking frame connected to an inferior limb exoskeleton capable of dynamically adapting the movement of each extremity.
3. An artificial intelligence motor capable of adapting the patient’s movement as much as the residual abilities on a cerebral level such as the level of movement of their feet.
The basic principle that the technology controls, consisted of making the movement of the lower body only when the patient had the motor cortex activated sufficiently and that a total adhesion to the movement was being detected. In addition, the technology carried out the mobilization in a completely adaptive way. Currently, a part of the final prototype is operational in Univerzitetni Rehabilitacijski Institut Republike Slovenije-Soca in Slovenia and it is used for routine clinical practice.
The CORBYS project was funded by the European Commission’s FP7, led by the University of Bremen (Germany), and organizations such as Imperial College (UK), Otto Block Mobility and Bitbrain (Spain) participated in it.
The HYPER project for motor neurorehabilitation with neuroprosthetics and neurorobots
Hyper (2010-2014) was a Spanish project that had the goal of developing upper and lower limb neuroprosthetics and neurorobots for motor compensation and substitution in patients with a brain injury (stroke) and spinal cord injury. The project worked with advanced technology immediately after the injury or trauma happened, to try to maximize the possibility of recovery when the brain is most likely to reorganize by neuroplasticity mechanisms. Hyper brought an important advance in knowledge in the following areas:
- The design of brain-computer interfaces used in the pathological activity of this type of patient.
- In the design of exoskeletons and neurorobots for motor compensation and substitution.
- In the real implementation of these technologies for patients, measuring the results with new neuroimaging procedures.
- The real integration of these technologies in the clinic.
This project was funded as a Consolider project by the Spanish Ministry of Education and Science who acted as a great catalyst, placing Spanish research groups at the scientific forefront and carrying out a transfer of technology, merging Spanish spin-off companies such as Bitbrain, Techmed, etc. The Hyper project was led by CSIC and organizations such as the University of Zaragoza, the Toledo National Hospital for Paraplegics, or the Institute for Bioengineering of Catalonia, amongst others, participated in it.
The ROBIN project for motor neurorehabilitaion
The Spanish project Robin had the objective of developing intelligent neuroprosthetics capable of learning to adapt to the patient based on information from their brain, therefore achieving a better experience. In this project, they worked specifically with neuroprosthetics for upper body limbs in patients with a brain injury (stroke) and spinal cord injury.
The main result of the project was to demonstrate that, interacting with the patient’s brain, a robot can actually learn to operate. This was an extremely important milestone given that it opened the door for the design of intelligent neuroprosthetics that learned to adapt to the patient for the first time, leaving the classic prosthetic design behind, which worked in a standardized way for everyone. The magazine Scientific Reports by Nature discussed this scientific milestone.
This project was funded by the Spanish Ministry of Education and Science (CYCIT) and led by the University of Zaragoza, used as a consolidator of the spin-off Bitbrain.
Leading cognitive neurorehabilitation research projects in Europe
Recovering lost cognitive abilities such as working memory or sustained attention, which are decreased by illnesses such as dementia, ADHD, major depression or even ageing, is the objective of cognitive neurorehabilitation. In this context, at present new technologies like neurotechnology (brain-computer interfaces) to measure neuroplastic changes and virtual reality methods are being used to improve feedback to the patient.
Elevvo, innovation for cognitive neurorehabilitation
The Spanish project Elevvo (please, check this webpage for more info of cognitive neurorehabilitation and neural repair) has developed a new neurotechnology for cognitive stimulation to deal with the deterioration of cognitive abilities in patients that present various diseases such as major depression or attention deficit hyperactive disorder (ADHD).
The design of Elevvo for cognitive improvement is based on a modern method of neurofeedback implemented with brain-computer interfaces. During its development, various studies were carried out to confirm its impact, two of them were done on people with diseases that are associated with cognitive deterioration such as depression or ADHD.
Firstly, a non-randomised controlled study was carried out with people diagnosed with major depression. For this study, an experimental group (group of people who had been diagnosed with depression) that used the neurotechnology, were compared against a control group (who did not use the said method). Amongst the obtained results, the experimental group had a significant increase, on a cognitive level, in the variables of the PASAT test (attention, memory, processing speed) as well as a 24% decrease in the number of errors and a 15% decrease in the time needed to take the test. In addition, the cerebral changes that support these improvements were measured consistently. The prestigious magazine Frontiers in Behavioural Neuroscience (peer reviewed journal) discussed this advance. Currently, people can already access this neurotechnology developed by Bitbrain under the brand Elevvo Medical.
In the case of patients with attention deficit hyperactive disorder (ADHD), an exploratory study was done without a control group, in which the effects of cognitive stimulation neurotechnology was investigated in a group of children diagnosed with ADHD. On a cognitive level, the obtained results showed increases of 16% and 10% in the number of correct answers in the Digits and Letter-Number Sequencing tests (WISC-IV) respectively, suggesting an improvement, principally, in working memory and sustained attention. Furthermore, the parents of these children indicated an increase in attention and hyperactivity/impulsivity (approximately 9 points in both variables) measured with the Connors’ Parent rating Scales (CPRS-R). The cerebral changes that support these improvements were also measured consistently. The prestigious magazine Applied Psychophysiol Biofeedback discussed this advance, and currently Bitbrain is commercialising the technology under the brand Elevvo Medical.
The Elevvo project was funded by the Spanish Government’s Ministry of Economy and Finance with help from INNCORPORA 2011 and organisations such as the University of Zaragoza, Hospital Miguel Servet in Zaragoza and the Aragon Health Sciences Institute (IACS) participated in it.
The results of the innovation in neurorehabilitation are becoming an ally for millions of people in the world that suffer some sort of disease that affects their nervous system. Although many of these projects are in the investigation phase, accessible and specific solutions exist that are improving the quality of life of the people that live their daily lives with this reality.