Perceptual impairments

Unilateral neglect definition

Failure to report/ respond/ orient to novel/ meaningful stimuli → failure X attributed to sensory/ motor impairments 

Location: Side opposite to brain lesion

Presentation of unilateral neglect

Sensory: 

1. ↓ awareness of sensory stimulation in contralesional hemispace ( primary sensory cortical areas + pathways intact ) 

Action-intentional ( motor ): 

1. ↓ ability to move in the contralesional hemispace ( aware of stimulus in the space → X deficit in motor pathway ) 

Memory + representational deficits: 

Disorder of memory of 

1. Extra-personal space ( space beyond reach ) 

2. Peri-personal space ( space within reach of limbs’ length ) 

3. Personal space

Pusher definition

1. Asymmetrical trunk posture towards hemiplegic side 

2. Active pushing towards hemiplegic side 

3. Associated w/ right/ left hemis

Presentation of pusher behaviour

1. Overactivity of the non-paretic ipsilesional arm + leg 

2. Extend the unaffected arm + leg + active pushing away from non-paretic side 

3. Loss of midline orientation of head + trunk 

4. Resistance to attempts at passive correction of posture towards the ipsilesional side 

5. Falling towards hemiplegic side 

6. Fear of falling towards the ipsilesional side 

Severe: 

1. X transfer weight onto unaffected side 

2. In any position ( lying/ sitting/ standing ) 

Least severe: 

1. Typical post-stroke asymmetry in less challenging situations 

2. Only evident during walking/ more challenging environments

Definition of agnosia

Inability to recognise objects by touch even though tactile/ thermal/ proprioceptive functions are intact

Presentation of agnosia

Autotopagnosia: 

• Disturbed perception of own body parts 

→ unaware of existence of one side of body 

→ X distinguish right from left 

→ Ax: draw a man test

Definition of inattention

Failure to 

1. Recognise to a stimulus on affected side only when unaffected side is also being stimulated

2. Recognise objects/ symbols in absence of impairments of primary senses

Presentation of inattention

Commonly seen behaviour

1. Failure to use left side even when having suitable levels of sensation + motor output 

2. When 2 stimulus presented on both sides of the body → only responds to that on the right

Commonly present in right CVA

Aim of unilateral neglect Ax

Determine if neglect is 

1. Personal ( contralesional body ) 

2. Peripersonal ( contralesional near space within reaching distance ) 

3. Extrapersonal ( space beyond reaching distance ) 

4. type of neglect ( sensory/ motor/ representational / combination )

Components + expected results for unilateral neglect

Components: 

1. Functional Ax

2. Standardised impairment Ax 

What to look for in functional Ax 

1. Failure to attend to one side of the body 

2. Mismatch of quality of movement in on-bed v.s. functional Ax 

3. Functional use of limbs 

4. Inconsistencies of movement 

→ use of ORDER: 

R: Can you stand up

D: Can you place your left foot in line w/ your right 

E: let me help you 

R: I will do it for you

Ax for pusher + agnosia

Pusher	Scale for contraversive pushing ( quantifies presence + severity )  Ax of verticality perception  Neglect Ax
Agnosia	Is patient realistic about condition  Do they deny what happened  Standardised tests

Ax for inattention

Inattention

Bilateral simultaneous stimulation test  Procedure:  Make sure that primary sensation/ visual fields are intact  Present stimuli to affected side  Present stimuli to unaffected  Present to both sides simultaneously → only respond to unaffected side

Principles for Mx of perceptual disorders ( education + visual feedback/ cognitive checks/ somatosensory feedback )

Methods	Explanation
Education	Increase awareness + understanding of impairments  → point out behaviours → “ you have only eaten half of your meal/ not picked up all the objects from the table
Visual feedback	Encourage alignment with known vertically oriented objects
Cognitive checks	Advise to take their time + make frequent checks during activities requiring spatial judgments
Somatosensory feedback	Encourage patients to align w/ your body positions → bring shoulder to me/ align hip to the bar  → Use intact somatosensory system ( visual/ verbal/ tactile/ auditory )

Principles for Mx of perceptual disorders ( visual scanning + cognitive feedback )

Cognitive feedback

Point out success of alignments →” you are not falling/ in line w/ the mirror”  / “ you have managed to position left arm well in wheel chair”  Advise to take their time + make frequent checks during activities requiring spatial judgments

Visual scanning

Neglect:  Integrate into more complex functions w/ environment from peri-personal to extra-personal training ( progression)  Continual cognitive awareness strategies + feedback  Visual feedback: line on mirror/ table → good for pusher  Visual restrictions: drive attention to the opposite side ( e.g. neglect: tape on right visual field to drive attention to left / tape on steps/ left wheelchair brake[ inattention/ neglect ] / right side of wheel chair [ pusher ] )

Principles for Mx of perceptual disorders ( auditory feedback + proprioceptive )

Auditory feedback	Provide details to depth  Position self to left to draw attention  Auditory feedback to provide reinforcement for success of action/ verbal responses
Proprioceptive	Enhancement strategies/ compression bandages to draw attention to body part → only touch left side for provision of non-competing stimulus  FES triggered muscle activity  Weight bearing through joints

Principles for neglect Mx

1. Ipsilesional limb activation → use affected arm in affected sphere 

2. Prism adaptation theory 

3. Visual scanning 

4. Functional training 

5. Sensory targeting of ipsilesional side 

6. Awareness: perceptual/ attention training 

7. Trunk rotation 

8. Repeated neck muscle vibration 

9. Mental imagery training 

10. Video feedback training ( may not for inattention/ agnosias )

Principles for Mx of pusher behaviour

Avoid: 

1. Activities that make patients fearful 

2. Medio-lateral enhancements on affected side 

Antero-posterior for LL only; X trunk 

1. Ensure pushing arm/ leg relaxed → take away ability to push → set up 

2. Encourage understanding of mismatch bwt true visual vertical + own incorrect sense of body’s relation to gravity 

3. Set up patient w/ normal alignment even when out of therapy 

( wheelchair w/ optimal trunk + lateral support ) 

4. Starting: Large BoS → lower threat to pt 

5. Automatic activities/ facilitation techniques → promote weight transfer 

Principles for pusher behaviour 2

4. Progression: from relaxed/ supported positions → smaller base of support 

5. Training: 

• Reaching to pick up objects centrally → progression: pick objects up from unaffected side 

• Early walking w/ appropriate facilitation: stepping on + off block w/ affected leg → promote loading of unaffected leg 

• Stair training 

8. Set up of training space: 

• Encourage hand to slide along rail ( cue only ) 

• Extra person behind to assist manually w/ balance + weight transfer 

• X develop dependence on rail