Sensory Reeducation & Desensitization
SENSATIONS… Moberg
– “Hands without sensation is like eyes without vision”
The
Disembodied Lady
- from the book, “The Man Who Mistook His Wife for a Hat” – by Oliver Sachs (Sachs 1985, p.43-54)
Sensation…
Entails the ability to transduce, encode, and ultimately perceive information generated by stimuli arising from both internal and external environments
Five
Basic Senses:
Somatic Vision Vestibular Auditory Chemical Senses
The
Sixth Sense - proprioception
A Little Review of Neuro…
In a patient with a specific sensory deficit can one determine which spinal segment is affected? And where the lesion might occur? – Yes. By using dermatomal maps. – Especially pain and temperature rather than touch, pressure and vibration. The dermatomal maps for pain and temperature do not overlap as much.
Are these maps the same in each person. – No.
Do proprioceptors follow the dermatomal maps. – No, they follow muscle innervation patterns.
A Little Review of Neuro…
The Somatic Sensory System has 2 Major Components: 1. Subsystem for mechanical stimuli - light touch, vibration, pressure, cutaneous tension (mechanoceptors) 2. Subsystem for painful stimuli (nociceptors) and temperature
Mechanosensory processing of external stimuli initiated by a diverse population of cutaneous and subcutaneous mechanoreceptors at the body surface.
Additional receptors are located in muscles, joints, and other deep structures and monitor mechanical forces generated by the musculoskeletal system called proprioceptors (spindles, GTOs, joint receptors).
Neuro pa rin…
Medial Lemniscal Tract/Dorsal column
Ventral Spinothalamic Tract
Crude Touch Affects contralateral side 2-3 segments below level of lesion
Lateral Spinothalamic Tract
Fine touch and proprioception Affects ipsilateral side
Pain and Temperature Affects contralateral side
Dorsal Horn
“the gate” Lamina I-VI - Substantia gelatinosa – lamina 2 (what gives it distinction?)
3 Types of Primary Afferent Fibers: 1. Large Myelinated A β fibers -
Mechanoceptors - Touch, pressure
2. Small Myelinated A δ fibers -
Mechanoceptors, Nociceptors (fast pain), Cold receptors
3. Small Unmyelinated C fibers -
Nociceptors (slow pain), Warm and Cold receptors, Mechanoceptors
Types of Somatic Sensations
Protective sensations
Pressure – warns of deep pressure or repetitive pressure that can lead to injury; if touch sensation is impaired, pressure sensation can aid in performance of ADL and substitute for touch feedback in some activities
Thermal sensation
Superficial Pain
Discriminative sensations – fine motor functions
Touch sensation
2-pt discrimination – static and moving (measures innervation densities)
Stereognosis
Movement and posture sensations
Proprioception
Kinesthesia
Sensory Evaluation & Testing
Light touch Pressure Position/Motion Sense Thermal Superficial Pain Functional Tests
Functional Implications?????
Two-Fold Objective Sensory acuity – potential to function Function with acuity – actual ability to function
Principles of Treatment
Treatment is always based on Learning Principles
Tailored to interest and ability of the patient.
Activities are graded to ensure success for improved performance The patient must find relevance and importance of treatment – motivation!!! Attention, concentration, judgment
Good assessment and reassessment is crucial
Clear picture of the diagnosis
CNS or PNS dysfunction? Prognosis? Hypersensitive? Diminished sensation? Loss of Sensation? Pain syndromes? Presence of paresthesias?
Intervention Strategies Loss of Sensation Compensation Techniques Diminished Sensory Re-Ed/Retraining Hypersensitive Desensitization
COMPENSATION TECHNIQUES
Compensation Techniques
Loss or impairment of protective sensation
Goal:
PREVENT INJURY
safety first! increase awareness of deficit minimize risks of tissue damage (Brand 1979) 1. 2. 3. 4. 5.
Continuous low pressure Concentrated high pressure Excessive heat or cold Repetitive mechanical stress Pressure on infected tissue
Compensation Techniques
Use other senses
Use less affected part
Built up handles for tools – distribute pressure
Frequent position change
In checking temperature Handling sharp objects
Use of adapted devices
Vision - observe motion and location of body parts; check skin condition Hearing – rubbing sounds
rest or relieve pressure over affected area
Skin care
prevention – cushions, in-soles, straps, protective mitts wound care
Methods of Compensation Brand (1979) Avoid exposure of the involved area to heat, cold, and sharp objects.
When gripping a tool or object, be conscious of not applying more force than necessary
Beware that the smaller the handle, the less distribution of pressure over the gripping surfaces. Avoid small handles by building up the handle or by using a different tool whenever possible.
Avoid tasks that require use of one tool for long periods of time, especially if the hand is unable to adapt by changing the manner of grip.
Methods of Compensation Brand (cont’d) Change tools frequently at work to rest tissue areas.
Observe the skin for signs of stress, that is, redness, edema, and warmth, from excessive force or repetitive pressure, and rest the hand if these signs occur.
If blisters, lacerations, or other wounds occur, treat them with the utmost care to avoid further injury to the skin and possible infection.
To keep skin soft and pliant, follow a daily routine of skin care, including soaking and oil massage to lock in moisture.
SENSORY REEDUCATION FOR PERIPHERAL NERVE INJURIES (PNI)
Sensory Reeducation for PNI
FOCUS: the HAND esp. fingertips
Cortical maps - reorganization Reinnervation (nerve repair and recovery) Time Limited by scar tissue Atrophy of sensory receptors Malalignment of axonal fibers
PURPOSE: help learn to recognize the distorted cortical impression
Outcome dependent on:
cognitive capacities – learning abilities and visuospatial cognition motivation compliance
General Principles of SR
Implementation before adequate regeneration
No benefit, causes frustration Semmes-Weinstein 4.56-6.65
Active exploration is encouraged
General sequence: Eyes closed – eyes open – eyes closed
May begin when the patient first can appreciate deep, moving touch
Matching sensory perception with visual perception
Perception of light non moving touch with good touch localization
Functional tasks of object identification through touch Semmes-Weinstein 4.31 or lower
The better return of touch perception, the better the prognosis for retraining in fine discrimination.
General Principles of SR
Localization:
Use of grid May be graded – dull to light Proximal to distal strokes or transverse Constant touch is at the center of each zone
Discrimination:
Gross to fine discrimination Moving/exploring Use of grid Progression: Matching - Same or different? In what way? Identify texture, object, etc…
Sensory Modalities Used
Eraser end of pencil - graphesthesia
Dowels with different textures
Fabrics
Objects with different rough/smooth edges
Objects embedded in Putty
Games and Puzzles
Containers with different background mediums
ADL with Vision Occluded
Work simulated tasks
Sensory Modalities Used
SR Protocols - PNI
Different protocols for different facilities Principles are generally similar 1. 2. 3. 4. 5. 6.
Dellon Wynn Parry Turner La Croix and Helman Callahan Nakada and Uchida
SR Protocols - PNI
Dellon (Pedretti, 5th ed, p.440; Trombly, 5th Ed, p.589)
Early phase
Reeducation of moving touch, constant touch, pressure, and touch localization Use of pencil eraser 4x a day at least 5 mins each Procedure: 1. Patient observes the stimulus 2. Vision occluded (verbalizes sensation felt) 3. Eyes open to verify
Late phase
Initiated when moving and constant touch are perceived at the fingertips with good localization Usually 6-8 months after nerve repair at the wrist Goal: recovery of tactile gnosis Procedure: Same as above Progression: 1. Large objects different from one another (common household items) 2. Objects with more subtle differences 3. Different textures 4. Smaller objects requiring discrete discriminations 5. Incorporate activities that simulate occupational roles
SR Protocols - PNI Wynn Parry
(Pedretti, 5th Ed., p.441)
Begins approximately 6-8 months after a nerve suture at the wrist 2-4x a day for 10 minutes Reevaluation done 1,3,6 months after IE Time to recognize objects Time to recognize textures Time for correct localization
Initial phase a. Place block in affected hand with vision occluded – feel block, describe shape, compare weight with block in UA b. Look at the block and repeat manipulation if incorrect/different c. Compare sensory experience with UA hand d. Continue until various shaped blocks have been mastered e. Differentiate textured from wooden surfaces – blocks with sandpaper or velvet
SR Protocols - PNI
Next phase a. Identification of several textures with vision occluded b. Identification of common objects with vision occluded
Incorrect responses: allow to perform manipulations while looking at the objects - relate what is felt to what is seen
Progression: large to small objects
Variations: burying objects in bowl of sand form boards identifying wooden letters
Training of Touch Localization 1. Vision occluded 2. OT touches several places on volar surface 3. Patient locates each stimulus with index finger of UA hand Incorrect response – patient is directed to look and relate
SR Protocols - PNI Turner
Peripheral Nerve Lesions Retraining begins with return of protective sensation (deep pressure, pinprick) and touch perception Same principles of identifying objects, shapes, textures with vision occluded
(Pedretti, 5th Ed., p.441)
If incorrect – look at the object and compare sensation for integration Use different textured dominoes or checkers, finding large to small sized objects in rice or lentils
3-4x a day for 45 minutes Encourage bilateral activities in functional tasks
Pottery, bread-kneading, weaving, macrame Compare the feelings of the tools and materials – A vs. UA
SR Protocols - PNI
La Croix and Helman
Purpose is to help patient to correctly interpret different sensory impulses Sessions are done several times a day for short periods UA => A Vision => vision occluded Graded stimuli are used in treatment
(Pedretti, 5th Ed., p.441)
Least stressful stimuli are presented first Constant pressure, movement, light touch, vibration
Hypersensitive areas are noted
Stroking, deep pressure, rubbing, maintained touch with different textures and shapes
SR Protocols - PNI Callahan
Moving and constant touch sequence
eyes closed =>open => close again
Use of smaller and lighter stimulus as patient improves Goal: localization of a touch that is near the light-touch threshold Progression:
(Trombly, 5th Ed., p. 588)
Discrimination of similar and different textures using sandpaper, fabrics, and edges of coins – introduced early Practice graphesthesia, Identify shapes or letter blocks Later stages: pick objects from containers filled with sand or rice and practice identification of common objects Recommends practice of daily living activities with vision occluded
Variety of tasks – games, puzzles are more beneficial
SR Protocols - PNI Nakada and Uchida
(Trombly, 5th Ed., p. 588)
5 stage Sensory Reeducation program Patient had total impairment of vision and very limited sensation in her left hand Good functional outcome (ADL performance) – drying dishes, putting on socks, and holding dentures while brushing Stages: 1. 2. 3. 4. 5.
Object recognition - feature detection strategies Prehension of various objects – grasping Control of prehension force while holding objects Maintenance of prehension force during transport of objects Object manipulation
SENSORY REEDUCATION FOR CNS Dysfunction
Sensory Reeducation - CNS Dys
Recovery of motor function depends on sensation (Dannenbaum & Jones, 1993)
Low priority - ranked 9th (Neistadt and Seymour, 1995) Less-defined than protocols for PNI – “still in infancy” Limited studies measuring outcomes in occupational performance
Concept of Neural Plasticity
Carr & Shepherd (1998) – reorganization appears to be related to frequency of use
Goal: gain larger cortical representation for the areas from which sensory feedback is crucial to performance of daily tasks
Functional use is possible but spontaneous use is limited
NO training => Learned non-use => further loss of sensory & motor fxns
recovery of pain and temperature perception usually precedes recovery of proprioception and light touch
Weight-bearing is used to increase proprioceptive feedback
Sensory Reeducation – CNS Dys
Eggers
Advocates integrating sensory retraining with motor retraining using NDT approach Focus on tactile and kinesthetic reeducation Stimulate sensation without increasing spasticity Repetition and variation is necessary Prerequisite: normalize muscle tone find optimal position Progression: 1. 2. 3. 4. 5. 6.
with vision => vision occluded => use of padded surface gross discrimination => fine estimate quantities through touch discriminate large and small objects hidden in sand discriminate between 2-3 dimensional objects pick a specific small object from among several objects
Sensory Reeducation – CNS Dys Dennenbaum
& Jones (1993)
Success = awareness of tactile stimulation + basic motor skills ES 100Hz With vision => eyes closed Identify finger that was stimulated Textured moving stimuli => stationary stimuli Early incorporation of hand into functional activities Textured surfaces, enlarged handles to help with tactile contact and tactile feedback
Sensory Reeducation – CNS Dys Yuketiel
& Guttman (1993)
Identification
of the number of touches Graphesthesia tests “Find your thumb” without looking Identification of shape, weight, and texture Passive drawing and writing OT
moves patient’s hand while holding a pencil and patient identifies a letter, number, or drawing made
Sensory Reeducation – CNS Dys Carr
& Shepherd (1998)
Sensory
relearning concurrent with motor relearning Advocate use of bimanual tasks Object identification without vision
DESENSITIZATION
Desensitization PNI,
crush injuries, wound/scar management, burns, amputations
Guarding = Learned non-use Phantom limb sensation vs. Phantom Pain Poor success – cumulative trauma and RSD
Progressive
stimulation => progressive
tolerance Begins at patient’s level of tolerance 3-4x daily Structured practice within the context of functional activities – better outcomes
Desensitization Goal:
Increasing the pain threshold of a nerve Decrease the discomfort Usually 7-8 weeks
Progression:
soft => coarse => rough Increase in force, duration, and frequency of application
Sensory Modalities Used
Massage Percussion/tapping or rolling/stroking with different textures Vibration Immersion in materials - styrofoam balls, rice, beans, popcorn and plastic squares Weight-bearing Pressure/Compression TENS Heat Fluidotherapy Therapy putty
Treatment Protocols
Hardy, Moran and Merritt Desensitization Protocol
Treatment Protocols
Three-Phase Desensitization Treatment Protocol
Sensory Modalities Used • Patients arrange dowel texture and immersion textures in the order of least to most irritating • Uncomfortable but tolerable for 10 minutes 3-4x daily
GROUP DISCUSSION
Skills Practice 6
groups Discuss different cases given (15 minutes) Presentation 15 minutes each
Principles of treatment - Suggest treatment intervention - progression? - possible functional activity/activities in outpatient clinic
Home program/instructions to be given to patient or caregivers – give 3-5.
Cases: 1.
Stroke – bedridden elderly overweight, requires positional splints for flaccid extremities, lethargic
3.
Peripheral Nerve Injury – car mechanic; median nerve repair; has loss of sensation on fingertips only of dominant hand; needs to go back to work in a week
5.
Diabetic – in her 50’s; primary income earner - cooks for a living (cart), always up and about
7.
Amputee – motor cycle accident; radial 3 digits, wounds healing but c/o phantom pain; late 30’s teacher
9.
Hand burn contractures – skin grafting over digits, wounds healing; diminished sensation
11.
Spinal Cord Injury – 30’s, wants to live independently in Baguio, incomplete hemi-section of spinal cord at C7 level
DO WELL ON YOUR EXAMS!!! God bless!