With the Dextrain Manipulandum, the result of his work at the Institut de psychiatrie et neurosciences in Paris, Påvel Lindberg and his colleagues enrich the rehabilitation of fine motor skills: hitherto purely functional, it is now equipped with a quantitative measure to assess and exercise the five key components of the skill. In addition, the latest advances in neurology and neuroimaging allow you to get the most out of it brain plasticity patients.
An article you will find in the next issue of Inserm magazine
Stroke is the leading cause of physical disability in Europe and affects more than 140,000 people in France each year. “It is caused by an occlusion or bleeding of the vessels in the brainremembers Isabelle Loubinoux *, head of the Idream team at the joint neuroimaging center in Toulouse (Tonic). Immediately after the accident, in the acute phase, it is necessary to act as quickly as possible to limit the extent of the injury.. Time is brainsays the finger! Thanks to public awareness, the deployment of Samu and accelerated hospital care, between 10 and 15% of affected patients benefit from thrombolysis, a technique that dissolves a blood clot, or thrombectomy, for remove it.
But the acute phase lasts only 6 to 24 hours in some patients. The lesion then stabilizes, first in the subacute phase, then in the chronic phase from 6 months. By then, half of patients suffer from long-term fine motor disorders: they can no longer button a shirt or manipulate an object, for example. ” 20% of these people are under 65 years oldpoints out Påvel Lindberg **. And everyone wants an active life! If there is rehabilitation of the upper limbs, specific solutions for fine finger control are lacking. This is where Dextrain Manipulandum, winner of the Innovation handicap Sofmer 2021 competition, comes in.
Measurement of dexterity
” Finger dexterity is often the hardest thing to recover from a stroke “We certainly have functional motor scales, but the associated tests are qualitative: can the patient grab or drop an object? The Dextrain Manipulandum offers a quantitative assessment of the five components of the skill: strength, independence of the fingers, timing of the movement, speed of execution of the gesture and learning of movement sequences.Connected to a tablet, it can detect and control these different indicators from the instructions given to the patient.Thus, the latter can observe directly the quantitative translation of the gesture made in this instrument which, with its five pistons, is somewhat reminiscent of a trumpet.To measure the fine gesture, the inventors of this apparatus have combined the skills of engineers, including those of the Sensix, a company specializing in force detectors, also aims to better identify the specifics of each: Stroke patients are never the same, which tends to obscure the use of broad diagnostic categories.says Påvel Lindberg. Monitoring these patients over time allows them to better plan and guide the rehabilitation of their own deficits. »
Because the Dextrain Manipulandum is not only a measuring and evaluation device, it is also a valuable clinical tool, dedicated to completing the panoply of motor rehabilitation devices. To this end, Påvel Lindberg co-founded the start-up Dextrain in February 2021. ” Beyond what engineering makes possibletempera, clinical relevance should prevail. In physiotherapy and occupational therapy, the tool will only be adopted if, scientifically validated, it is also compatible with gestures, limitations, and clinical goals. Many hospital doctors have already indicated to the scientific director of Dextrain, Maxime Térémetz **, that they wanted to try it. However, he tested the first prototype during his thesis! The development of the instrument was supported by SATT Erganeo from 2016, in collaboration with the University of Paris-Descartes. »

Closer to the brain
This success is at the same time a new clinical orientation of rehabilitation, supported by neuroimaging. ” Along with brain imagesexplains the neuroscientist, Dextrain Manipulandum data can tell us about brain structures affected by certain motor deficits, whether or not they are caused by a stroke. We can locate the affected areas, but also see the neurological effect of rehabilitation exercises. Brain plasticity is at the heart of these questions! This tendency of the brain to reshape its own connections is manifested in two ways, sums up Isabelle Loubinoux. In first place, ” there is intense competition in the brain between territories: if an organ stops sending information to the brain, the brain ends up losing interest and the brain regions recover for other uses. Therefore, it is vital that this organ is “made known” to the brain, through motor or even sensory rehabilitation. “With rehabilitation, redundant but latent neural pathways can be awakened, for example to form an alternative motor network. And areas of the brain can learn a new function to replace damaged areas. »
In regenerative medicine, these discoveries will identify new approaches to revive and guide this plasticity: pharmacological therapies, stem cell transplants, non-invasive transcranial stimulation … ” At the momentacknowledges Påvel Lindberg, we seek to better measure and understand the neurological effects of rehabilitation and treatments. But in the future, with neuroimaging, I think we are moving towards an individualized and predictive analysis. Fine skills deficits could also be a harbinger of a neurological disease, such as Alzheimer’s disease, which we could control as soon as possible. »
Note :
* Unit 1214 Inserm / Toulouse III University – Paul-Sabatier, Toulouse Neuroimaging Center (Tonic), iDream equipment
** Unit 1266 Inserm / Cité University of Paris, Paris Institute of Psychiatry and Neurosciences (IPNP), Stroke team: prognostic determinants, translational research and personalized medicine
Sources :
- L.Carment et al. Manual dexterity and aging: a pilot study that decouples the sensorimotor from cognitive decline. Frontal neurol., October 29, 2018; doi: 10.3389 / fneur.2018.00910
- J.Birchenall et al. Individual recovery profiles of manual dexterity and relationship to cortical spinal injury load and post-stroke excitability: a longitudinal pilot study. Neurophysiol Clin., October 31, 2018; doi: 10.1016 / j.neucli.2018.10.065
- Mr. Teremetz et al. A new method for quantifying the key components of manual dexterity after a stroke. J NeuroEng Rehabil., August 2, 2015; doi: 10.1186 / s12984-015-0054-0
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