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

Fine touch and proprioception Affects ipsilateral side

Ventral Spinothalamic Tract Crude Touch Affects contralateral side 2-3 segments below level of

lesion

Lateral Spinothalamic Tract 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. Continuous low pressure

2. Concentrated high pressure

3. Excessive heat or cold

4. Repetitive mechanical stress

5. Pressure on infected tissue

Compensation Techniques Use other senses

Vision - observe motion and location of body parts; check skin condition Hearing – rubbing sounds

Use less affected part In checking temperature Handling sharp objects

Use of adapted devices Built up handles for tools – distribute pressure

Frequent position change 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. Dellon

2. Wynn Parry

3. Turner

4. La Croix and Helman

5. Callahan

6. Nakada and Uchida

SR Protocols - PNI1. 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

2. 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 phasea. Place block in affected hand with vision occluded – feel block,

describe shape, compare weight with block in UAb. Look at the block and repeat manipulation if incorrect/differentc. Compare sensory experience with UA handd. Continue until various shaped blocks have been masterede. Differentiate textured from wooden surfaces – blocks with

sandpaper or velvet

SR Protocols - PNI

Next phasea. Identification of several textures with vision occludedb. 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 Localization1. Vision occluded2. OT touches several places on volar surface3. Patient locates each stimulus with index finger of UA hand

Incorrect response – patient is directed to look and relate

SR Protocols - PNI

3. Turner (Pedretti, 5th Ed., p.441) 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 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

4. La Croix and Helman (Pedretti, 5th Ed., p.441) 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

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

5. Callahan (Trombly, 5th Ed., p. 588)

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:

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

5. 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. Object recognition - feature detection strategies

2. Prehension of various objects – grasping

3. Control of prehension force while holding objects

4. Maintenance of prehension force during transport of objects

5. 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. with vision => vision occluded => use of padded surface2. gross discrimination => fine3. estimate quantities through touch4. discriminate large and small objects hidden in sand5. discriminate between 2-3 dimensional objects6. 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 dailyStructured 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

2. 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

3. Diabetic – in her 50’s; primary income earner - cooks for a living (cart), always up and about

4. Amputee – motor cycle accident; radial 3 digits, wounds healing but c/o phantom pain; late 30’s teacher

5. Hand burn contractures – skin grafting over digits, wounds healing; diminished sensation

6. 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!