Date
July 12, 2022
Auteur
Franz Gayet, Occupational therapist
Catégorie
Scientific article
The “sensitive” consequences of an amputation range from unpleasant sensations (tingling, tingling, water running down the skin, etc.) which are more or less persistent, to the pain felt (burns, stings, electric shocks, etc.). We are talking about phantom limb pain(s).
Two theories confront and complement each other: “peripheral” and central. If muscular, vascular and nervous damage seems obvious, the same is not true for the functioning of the brain and the cortex in particular. The cortical area (somatotopic maps) corresponding to the sensory inputs of the amputated limb interprets the absence of sensory stimuli as pain while the motor inputs persist.
The pain control system is disrupted by the lack of consistent information. Probably the central integrative system records discrepancies between motor intention, proprioception and/or visual representation and translates these discrepancies into a more or less clear painful type feeling. Different strategies for combating pain exist and the management burden of phantom limb pain is more complex due to the variability of clinical pictures.
Among the “classic” or known therapies, cold, heat, desensitization, vibrations, analgesics and related drugs, behavioral and cognitive therapies including relaxation, hypnosis and sophrology. Additional psychological support helps prevent the person from focusing on their pain. Other solutions are being studied and may be effective, such as transcranial magnetic stimulation or spinal cord stimulation in certain specific cases.
We know the alternative to both cognitive and functional with mirror therapy.
To understand the mirror therapy technique: the two limbs are placed on either side of a mirror and the amputated segment is hidden from vision. The person observes the image of an entire limb in the mirror and has the illusion of seeing their limb moving. The support of Therapists (Occupational Therapists, Physiotherapists, etc.) helps guide the patient in carrying out certain movements in order to correlate their sensory and motor perceptions.
Mirror therapy is in fact based on vision, illusion, observation, imagination, motor pattern, movement and body image via central and cortical processes. And we know that the onset and management of pain involves the central nervous system.
However, the brain is constantly evolving. For example, we speak of cerebral plasticity and/or cortical “reorganizations” when we observe functional recovery following a stroke when an area of the cortex has been necrotic. In the case of stroke, the two cerebral hemispheres allow a functional redundancy that must be stimulated. Mirror therapy proves to be one of the effective treatments in the management of hemiplegia, CRPS (Syndrome Complex Regional Pain or algodystrophy) and phantom limb pain.
Case studies (Ramachandran 1993, Mac Lachlan 2004 & al., Chan et al. 2004, Darnall et al. 2009) have thereby shown that mirror therapy significantly reduces the pain of the phantom limb for sessions of 10 minutes per day. In all these applications, it is a question of training the brain to function differently through vision.
New technologies have opened up new perspectives of treatment charge with the development of immersive three-dimensional virtual reality mirror therapy
Immersive 3D virtual reality allows you to avoid the sometimes difficult installation with a real or average quality mirror. In addition, the patient is fully immersed in a controlled environment where his attention and concentration are dedicated to his rehabilitation or rehabilitation session.
Patients and users of this technology speak of effectiveness and therapeutic objectives achieved more quickly. It simply involves having patients wear a virtual reality mask and exposing them to an immersive environment where they will visualize their members.The virtual reality software used is therapeutic software and fully adjustable in real time to adapt to each patient.The effectiveness of the immersive 3D virtual reality illusion causes an action of progressive reduction of pain as “reversed learning” at the sensory level. Visual feedback of a “whole” limb reduces discordance between sensations, movements and vision. This feedback makes it possible to reorganize and “normalize” the central somatic representations.
Virtualis, a French company developing rehabilitation equipment and therapeutic software, is developing these mirror therapy solutions for the upper limbs and lower limbs. The results can be spectacular and rapid.
This system is also used by the Laveran Military Hospital in Marseille which takes care of amputee patients and where Christophe, a patient with a left arm amputee, testifies: “It’s quite surprising. It’s a kind of lure for the brain and the spirit. We feel a lightness in the amputated limb. To the phantom limb. » (source: Emission France 5, the Health magazine of 09/23/2020).
Immersive therapeutic virtual reality in 3 dimensions opens up new perspectives for patients and is already available in many Rehabilitation Services - Rehabilitation, in Neurology and in Liberal Practice. The brain is capable of therapeutic feats provided that it is guided in this direction. Virtualis technology helps patients control and reduce their phantom limb pain.
