Sensory Re-education

Introduction, principles of sensory re-education hypersensitivity and hyposensitivity, stages of training after nerve repair, uses and benefits, sensory reeducation in stroke - its principle. Actve and passive Sensory reeducation in stroke, orofacial sensory retraining

1. SENSORY RE-EDUCATION MRS.M.PRADEEPA MPT (NEURO) VICE PRINCIPAL PPG COLLEGE OF PHYSIOTHERAPY COMIBATORE, TAMILNADU, INDIA

2. INTRODUCTION Sensory re-training or sensory re-education is a cognitive behavioural therapy technique that helps the patient with a nerve injury to meaningfully interpret the altered profile or neural impulses reaching his conscious level after the altered sensation area has been stimulated. The repetitive neural input from sensory re-training exercises can produce plastic changes(plasticity) in the somatosensory cortex via the same mechanisms underlying those evoked by altered input from the nerve damage. Sensory re-training does not alter the course of nerve regeneration or the absolute thresholds to touch but does improve both the patient’s cognitive and adaptive response to stimulation of the affected skin region

3. After Surgery… After a nerve repair sensibility and muscle function in parts of the hand are lost, and intolerance to cold is common. After the surgery when the nerve sheath is repaired new nerve axons grow into the skin and the muscles. Hypersensitivity to light touch is normal during this growth period but can be influenced by so-called desensitisation when the skin gradually gets used to normal touch again.

4. Nerve grows, approximately 1 mm per day. The result is a new sensibility that you have to learn to interpret - the hand ”speaks a new language to the brain”. The brain has a detailed map of the body where touch is registered and interpreted. Touch from the right hand is mainly processed in the left part of the brain, but both halves of the brain are active during perception of touch. All our senses cooperate when we touch something, and vision and hearing for example can help to strengthen touch.

5. Phases Phase 1: A repaired nerve means that the brain programme for interpretation of touch input for a period of time is silent since there is no or very little sensibility in the hand. During this period the hand map in the brain is also rapidly ”occupied” by adjacent areas and is changed. Phase 2: When the new axons have grown to the skin, and to the muscles, the map is again changed since the axons don´t grow in exactly the same paths as before the injury. The hand map becomes unstructured, and the sensibility during this time is not very useful. You need to use vision to understand what the hand is touching.

6. This functional reorganisation of the brain is a natural process and depends on the brain´s capacity to adapt when the body sends new signals.

7. PRINCIPLES OF SENSORY REEDUCATION The exercises should be done for a few minutes several times per day. Performing sensory re-education exercises for a short period of time, 4 to 6 times per day on a daily basis, is more effective than a longer, less frequent protocol Start the training soon after an injury or surgery when the patient is stable enough to receive therapy Patient should be in a quiet and comfortable place for better concentration, lower response and fewer results occur with delayed training

8. The effectiveness of sensory re education depends on several factors: Age Learning capacity Cognitive skills Motivation Reinforcement Incorporating meaningful and graded stimuli Active participation Accurate feedback from a therapist

9. USES/BENEFITS Sensory retraining teaches the patient to ignore or blot out post-injury unpleasant sensations to optimally tune into and decipher the weakened and damaged signals from the tissues. Sensory retraining is a simple, inexpensive, non-invasive exercise program, which initiated shortly after injury, can lessen the objectionable impression of altered sensations. Sensory retraining exercises are most effective on decreasing the perceived burden associated with hypoesthetic altered sensations.

10. STAGES OF RETRAINING Stage 1: Localization The intent is to re-educate constant vs moving touch perceptions.   A greater stimulus intensity may be necessary for the patient to differentiate constant from moving touch but the intensity should never be so great as to evoke pain Stage II: Texture and shape discrimination The intent is to re-educate the directionality of movement perceptions of the patient.

11. The principles of sensory re-education after median nerve repair.

12. Training in phase 1- Localization In phase 1 the hand is without sensibility and the hand map in the brain has disappeared. This phase lasts up to three months after an injury at wrist level and encompasses the period direct after surgery until some growing axons have reached the palm of the hand. During this phase you have no protective sensibility and it is important to carefully watch the hand when you use it to prevent skin injuries. Aim: The sensory re-learning in this early phase, in combination with training of the mobility of the hand, is aimed at activating and maintaining the hand map in the brain to make the sensory re-learning easier once the axons have re-grown. This is done by giving the brain an illusion of sensibility in the hand.

13. The training: When you see someone else touch things, think about how such touch normally feels. By touching the areas in the hand that have no sensibility in combination with concentrated watching, the hand map in the brain is activated. This is repeated several times per day. Eg ., ask someone else to touch the fingers without sensibility and corresponding fingers on the other hand simultaneously while you watch carefully You can also touch the fingers without sensibility yourself using the corresponding fingers of the other hand

14. Another way is to use a mirror positioned so you can see your uninjured hand in the mirror looking like the injured hand. In this way you create an illusion that means that the brain thinks there is activity in the injured hand. You can also use other senses to substitute for sensibility in phase 1, for example hearing using a so called Sensor Glove with small microphones that pick up the friction-sounds during touch.

15. Training in phase 2 – Texture and Shape discrimination In phase 2 the axons have reached the hand and the hand map in the brain has a changed pattern. This is approximately three months after a repair at wrist level and you have some sensibility in the palm. This means that it is time to start training with phase 2 exercises.

16. The training: To localise touch, touch your skin in one of the areas marked in the picture on the next page with a blunt object e.g. a pen. Press or move the object hard enough for you to perceive the touch. Compare to an area where you have normal sensibility Concentrate on WHERE, WHAT and HOW you feel the touch. Repeat the touch, first with your eyes open and then with your eyes closed until you feel you know the location and character of the touch. Work on a few areas first until you are sure that you can localize the touch correctly. Then move to adjacent areas. Get someone else to apply the stimulus to ensure that you really are able to identify where and what you feel.

17. When Patients have some protective sensibility in the fingertips it is time to start exercises to relearn to differentiate between different textures and shapes and to identify objects. Use the same principles as for the localisation exercises. Repeat the touch, first with your eyes open and then with your eyes closed until you feel you know what kind of stimulus it is.

18. Examples of how the training can be performed: 1. Touch a hidden texture/shape/object and try to identify it. 2. Touch a copy of the texture/shape/object with the uninjured hand and the hidden object with the injured hand at the same time and compare the feeling. 3. Was it correct? If not or if it was too difficult - touch and watch at the same time 4. Using a modified Rubik´s cube several different patterns can be created as you turn the elements of the cube. 5. Combine identical shapes/textures/objects. 6. Carry a few objects in your pocket and try to identify them – and think about their shape, texture, weight and which object you are touching.

19. Use all your senses to strengthen the feeling of touch. For example when you eat a fruit think not only about its taste, but also the smell, colour and how the structure feels. “The tactile meal!”

20. It will help you re-educate the sensibility in your hand if you make it a rule to try to feel the structure and shape of everyday objects. Concentrate on what you feel, and e.g. soft or hard object, sharp or blunt edges, shape, size and texture?

21. SRE FOR STROKE PATIENTS

22. SRE Therapy techniques to re-train sensory pathways Made possible by Neuroplasticity Dynamic potential of the central and peripheral nervous systems to reorganize during development, learning, or after being damaged

23. 50-85% of patients present with sensory deficits after stroke Re-training sensation can permit normal cortical representations to be maintained. Down-side to neuroplasticity : When input is eliminated, adjacent cortical regions take over the unused areas Sensation impacts function

24. How Sensation Impacts Function Safety concerns (e.g., detecting hot temperatures, stereognosis, proprioception) Impaired spontaneous use Inability to sustain grasp and manipulate objects; pinch grip Impaired ability to reacquire skilled movements for activities of daily living

25. SRE Principles in Stroke Graded progression of discriminations from easy to difficult Attentive exploration of stimuli with vision occluded Use of anticipation trials Feedback on salient sensory features of the stimuli, accuracy of judgments, and method of exploration Summary feedback and intensive training Use of vision to facilitate intermodal calibration of sensory information

26. Repeated presentation of target discrimination tasks Comparison of sensation with other hand Self-checking of accuracy A variety of stimuli within each sensory dimension trained Feedback on ability to identify distinctive features in novel stimuli Tuition of training principles

27. Accuracy in Sensory Evaluation Environment: background noise reduced, secluded room if possible Client: ability to concentrate, anxiety, skin calluses, Instrument: able to grade up/down or calibrate, quality Method: standard instructions, support/immobilize hand, varying timing & spacing of application Examiner: skill, experience, and concentration

28. SGT Transfer tasks selection: Same sensory-perceptual dimension Same body location Same tactile domain Same exploration technique (e.g., fingertips) Same limb-position discrimination

29. Active and Passive SRE Passive: when electrical stimulation is used to activate cutaneous nerves when no muscular contraction is available Active: participatory practice with exercises designed specifically to re-educate sensory function

30. Examples of Passive/Active SRE Passive Sensory Re-Training Sending constant message from peripheral nervous system (PNS) to central nervous system (CNS) re-builds the pathway for feeling into the limbs E- stim , pneumatic compression, thermal stimulation, massage and self-massage, and vibration Active Sensory Re-Training Practice of localization of sensations, discrimination, proprioception, stereognosis, graphesthesia , and kinesthesia.

31. Carey and Matyas (2005)  STIMULUS-SPECIFIC TRAINING: Designed to maximize improvement of specifically trained sensory discriminations (e.g., 1 specific texture) Success for trained texture and proprioceptive discriminations, but failed to show spontaneous transfer to related but untrained stimuli. STIMULUS-GENERALIZATION TRAINING: Designed to facilitate transfer of training to untrained/novel stimuli Success for intramodality transfer for texture discriminations. Most effective/efficient and practical for rehab after stroke.

32. OROFACIAL SENSORY RETRAINING An important component of the retraining exercises is the visual feedback provided by performing the exercises in front of a mirror. This elicits two different sensory events, the sensation of the brush on the facial skin and the sight of the brush on the face Retraining should with more repetition and less timing Perform exercises with a small handheld mirror for a short period of time, perhaps 1–2 minutes, 4 to 6 times per day would be as or more effective than a longer less frequent protocol.

33. After orofacial nerve repair WEEK EXERCISES 1 WEEK Alternate simple touch and stroke with cosmetic brush (Motion training). Feedback from mirror. Visualization with eyes closed 1 MONTH Alternate up/down and side/side strokes (Orientation training). Feedback from mirror. Visualization with eyes closed. 3 MONTHS Alternate up→down and down→up strokes (Directionality training). Feedback from mirror. Visualization with eyes closed.

34. HYPOSENSITIVIT: Points to consider…. Also known as anesthesia , hyposensitivity requires re-education (discriminative sensory re-education). Discriminative sensory re-education focuses on training to remind the system of how movement feels, using vision to see and provide feedback and compensation. This should be graded as progress develops with the ultimate goal of successful completion of activities with vision occluded, with gross-motor sensation returning first. Protective sensory re-education is vital, with an emphasis on safety training, avoiding repetitive activity for a long period of time, and built-up handles on objects such as forks, knives and other utensils when possible. Decreasing the amount of force used when gripping and proper skin care, including moisturizing to prevent drying and cracking, are also recommended.

35. Two phases: Early-phase sensory re-education should be initiated when the patient can feel vibration of 30 cycles per second (CPS) using a tuning fork, and will progress toward 256 CPS, which would be the highest level of sensation. Dellon describes two stages, the first state being “ submodality -specific perceptions, movement vs. constant-touch and pressure.” The second focuses on correction of misdirection, as well as localization limitations. Late phase should be initiated as moving-touch and constant-touch begins to be perceived with good localization at the fingertips. Dellon states that it’s never too late to begin late-phase sensory re-education, but starting too early leads to client failure and can have negative impacts. Generally this phase begins between week 6 and 8 months with injuries at the wrist. It’s also important that sensory re-education does not induce axonal regeneration, but facilitates maximum potential from nerve repairs.

36. THANK YOU