Week 1 Flashcards
Perception:
the ability to process and interpret sensory
information
Perceptual Impairments
Classification
- Unilateral Neglect
- Inattention/extinction
- Agnosias
- Other impairments of visuospatial awareness
- Pushing Behaviour
Unilateral Neglect
Definition:
– The failure to report, respond or orient
– To novel or meaningful stimuli
– Presented to the side opposite a brain lesion
– When this failure cannot be attributed to either
sensory or motor impairments
Unilateral Neglect
Incidence:
– 11–82 % following stroke in the right side of the brain
Unilateral Neglect
• Neglect associated with
– longer length of stay in rehabilitation
– poorer functional outcome following stroke
Unilateral Neglect
• Synonyms
– Unilateral spatial neglect – Inattention (X) – Hemi‐neglect – Hemi‐spatial neglect – Neglect syndrome – Contralesional neglect – Visual spatial neglect
What side is neglect more common on and why?
• Left neglect following right sided stroke is most common • Right hemisphere directs attention to both right and left hemispaces • Left hemisphere directs attention primarily to right hemispace -– does not usually result in UN – intact right hemisphere can direct attention to both hemispaces
Types of unilateral neglect
– sensory neglect
– motor neglect
– representational neglect
Unilateral Neglect
• Sensory neglect
• Sensory neglect
– decreased awareness of sensory stimulation in
the contralesional hemispace
– despite intact primary sensory cortical area and
sensory pathways
Unilateral Neglect
• Motor neglect
– Decreased ability to move in the contralesional
hemispace
– Despite being aware of a stimulus in that space
– Not a deficit of the motor pathway
Unilateral Neglect
• Representational neglect
• Representational neglect
– person ignores the contralesional half of
internally generated images
– Internally generated images are mental
representations or visualizations of a task, action,
or environment
Unilateral Neglect
Distribution of neglect
• Personal
– contralesional ½ of body
• Spatial:
– Peripersonal • contralesional near space within reaching distance
– Extrapersonal • space beyond reaching distance
Looking for neglect during functional assessment
• Note failure to use or attend to one side of body or
environment
• Note any mismatch between:
– Strength observed during assessment in chair/on
bed
– Functional use of limbs during STS or gait etc.
Possible observations UN physio assessment neglect
Possible observations during Functional Assessment
• Gaze to the lesion side (often right)
• May slump or lean to lesion side
• Ignore objects in the contra‐lesional visual field
• Run into objects and doorways on contra‐lesional side
• May leave hemiplegic arm behind when rolling
• Difficulty crossing midline
Unilateral neglect impairment measures
Line bisection
Cancellation Tasks
The Bells Test
Star cancellation test
Behavioural assessment of neglect
- Catherine Bergego Scale
* The Behavioural Inattention Test
Most sensistive neglect measure
• Behavioural assessment of neglect in daily life was more
sensitive than any other single measure of neglect. (Catherine Bergego Scale)
Agnosias
Agnosias
• The inability to recognise objects or symbols in
the absence of impairments of the primary
senses
• Visual, auditory, tactile or proprioceptive
Astereognosis (tactile agnosia)
• The inability to recognise objects
by touch even though tactile,
thermal and proprioceptive
functions are intact
Autotopagnosia
- Disturbed perception of the patient’s own body parts
- May be unaware of existence of one side of body
- May be unable to distinguish right from left (laterality)
Anosognosia
• Failure to recognise the presence or severity of paralysis
• In subjective examination ‐ observe if patient is unrealistic
about their condition
Verticality perception
- Subjective postural vertical
* Subjective visual vertical
Before assessing visual perception, must first test
- Acuity
- Eye movements
- Visual fields
Subjective postural vertical
• Perception of own body orientation • Observe posture • Move person into various positions – ask if they feel ‘straight’ or ‘falling/leaning to one side’ – do they have a fear of falling?
Subjective Visual Vertical
Perception of position of objects in environment
– Hold a stick against a background with no cues
– Slowly rotate stick
– Ask person to
Distance perception
Difficulty determining the relative
distance between objects and oneself
• May present as difficulty with stairs or
curbs or negotiating obstacles
Size, colour or shape perception
• Functionally patient may show
inappropriate fear
– e.g. fear of rolling off edge of
bed when there is ample space
Figure‐ground perception
– Inability to distinguish a specific stimulus
from its background
– Visual or auditory systems may be involved
Direction sense
• Patient may have difficulty perceiving directions despite having intact language skills: – up – down – left – right – forwards – backwards
• Route finding impairment
• Inability to find one’s way in
familiar surroundings or to
learn the way in a new situation
Pushing Behaviour
• Characterised by: • an asymmetrical trunk posture towards the hemiplegic side • active pushing towards the hemiplegic side
Pushing Behaviour
• Other terms in literature include:
– Pusher syndrome
– Contraversive pushing
– Ipsilateral pushing
– Lateropulsion
PB Clinical Features
• Overactivity of the nonparetic ipsilesional arm and leg – extend the unaffected arm and leg and actively push away from the nonparetic side
• Resistance to attempts at passive correction of posture towards the ipsilesional side • Falling towards hemiplegic side • Fear of falling towards the ipsilesional side
PB Clinical Features ‐ Severity
• Severity of PB appears to: – Vary between individuals – Vary within individuals over time – Become more obvious when the base of support is reduced
Mechanism for Pushing Behaviour
Theories:
1. Disturbed perception of verticality: – ? SVV – ? SPV – ? BOTH 2. Graviceptive Neglect – Disrupted processing of graviceptive information 3. Right hemisphere syndrome – PB is frequently associated with unilateral neglect but not always
Management of Unilateral Neglect
• Approaches are classified into Top Down or Bottom Up
Management of Unilateral Neglect
Top Down Approaches
• Aimed at cognitive level • Train the person to voluntarily compensate for their neglect during activity • Require awareness of the impairment • Interventions train clients to direct attention to the neglected side
• Increase the person’s awareness and understanding of their
impairments using their intact verbal and cognitive ability
– e.g. if they have a disturbance of subjective postural
vertical:
• Point out that they are mistaken about the nature of
vertical
• Encourage them to align themselves with known
vertically oriented objects (e.g. a door frame)
Visual scanning training
• Initially train scanning to side of neglect
• Later train to scan to neglected side then back to other side
• Use bright objects, cards, numbers on wall
