Transcript How Vision impacts Memory:

How Vision impacts Memory:
The visual connection in the adult
neurological population
Alicia M. Reiser, MS OTR/L
Physical Therapy at St. Luke’s
Vision and Visual Perception
• Rowe et al (2009) up to 92% stroke survivors had some visual
impairment
• Visual Deficits can be mistaken as cognitive or physical deficits
• Vision
– Primary way we acquire information
Alerts us to danger, pleasure
Enables anticipatory actions
Plans for situations and reactions
• Visual Perception
– “Applying cognitive concepts of space and form to understand the visual world by
transforming raw data form the retina into cognitive concepts”
Eye Sight vs. Vision: What’s the Difference?
Mary Warren’s visual hierarchy and
the 4 circles of vision
Visual cognition
Visual memory
Pattern recognition
Scanning
Visual attention
Oculomotor control,
visual fields, visual
acuity
Magnacellular
Parvocellular
Ambient (peripheral) vision
Focal vision
Doesn’t go to occipital lobe
Visual language processing
Directs motor movement of eyes/hands
Gross Motor
occipital/temporal lobes
visual spatial processing
object identification
fine motor
Identify:
What is it?
Centering:
Where is it?
VISION
Antigravity:
Where am I?
Speech/auditory:
What do I
know about it?
(Hillier and Kawar, 2013)
(Warren, 1993)
What does the hierarchy mean?
• Visual cognition: ability to mentally manipulate visual info and
integrate it with other sensory info to solve problems, form plans and
make decisions (executive functioning)
• Visual memory: store and retrieve a mental image of object in the
mind’s eye, apply new patterns to solve problems by comparison
• Pattern recognition: identify the salient features of an object in order
to visually remember it (shape, color, texture). This determines if
the memory is laid down. Frontal Lobe looks for as many attractors
as possible- what makes an object different. CVA and TBIs tend to
use more generic attractors.
• Scanning: the ability of the fovea to fixate and take in the
environment in a sequential pattern by using saccades automatically
by the brain stem and voluntarily by the frontal lobes. Reading is
usually linear, non structured shape is circular.
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Visual attention: 3 step cognitive process (disengage, move and compare). Critical
step in visual processing using both global and focal attentions
Oculomotor control, visual fields, visual acuity: together allows for efficient conjugate
movement, registering the entire scene and eyesight, including contrast. Oculomotor
control provides perceptual stability, acuity provides clarity of detail and color, and
field allows for awareness of objects in environment (Warren, 1993)
Hierarchy: works together at all levels- think developmentally
Following brain injury:
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Visual field, acuity, control and visual attention impacted
OT screens for this deficits and identifies limitations in occupational performance (Warren, 2014)
Oculomotor control affected by disruption of CN function or disruption of CNS control
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Exotropia, high exophoria, accommodative dysfunction (Blurry vision), convergence insufficiency (diploplia),
low blink rate, spatial disorientation (the inability of a person to determine his true body position, motion, and
altitude relative to his surroundings), poor fixation, irregular eye pursuit movements and unstable ambient
vision
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Diploplia, illusion that objects are moving in the environment, poor concentration and attention, staring, poor visual
memory, eye pain, neuromotor deficits including balance, coordination and postural control (Kane)
Team Introduction
• Neuro opthomologist: diagnose and
prognose- what caused the impairment?
• Neuro or behavioral optomotrist: diagnose,
prognose and interventions to improve
• Certified Vision Rehab Therapist: if vision
is significantly impaired to teach blind tech
• Occupational Therapist: screen and
identify strategies to improve occupational
performance
Primary changes after brain injury:
Visual field, visual acuity,
oculomotor control, visual attention
ADL performance affected
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Reading
Writing
Employment
Role of parent, child, spouse, worker
Functional Directional Skills
– Driving
– Topographical orientation
– Personal space
Vision Screen Performed by OT
Screen for Acuity
• Deficits due to optic nerve damage or
bilateral damage to the occipital lobe
• High Contrast Acuity: distance and near,
low contrast
– Distance Snellen Chart
– Reading acuity chart
– Mars Chart, LeaNumbers Chart or Glass Test
Treating acuity dysfunction
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Clean glasses
Check med side effects: seizure, spasticity
Refer to optometrist/opthomologist for refraction update
Improve accommodation
Use contrast on stairs, with meals, in bathroom,
minimize patterns and clutter, increase lighting, LED
lighting, enlarged adaptive equipment, organize
environment, simplify tasks, manage glare
• Electronic Magnifiers
Visual
pathway to
the brain
Left honomonous hemianopsia
Right hemianopsia
Binasal occlusion
Tunnel vision
Screen for Visual Field
• Deficits due to MCA, PCA (75% result in homonymous
hemianopsia) or occipital lobe brain injury
• Diagnosed by opthamologist or optometrist, usually after 5 months
• Perimetry testing: central and peripheral, manual or computerized
• Confrontation test: shown unreliable
• Tangent Screen: results given in isopter, absolute scale or gray
scale diagrams
• Visual Skills for Reading Test (Pepper), Telephone number copy
• Trail making test, clock drawing test, single letter cancellation test,
line bisection test
Behaviors seen with HH
• Don’t cross visual midline therefore filling in the blanks with previous
visual memories, safety imparied
• Scan slowly to affected side impacting rate of ADL completion
• Miss detail on blind side with reading, small detail tasks
• Reduced hand monitoring with function
• Decreased mobility: slowed, looks down, stops to search, gets lost
• Writing: drifts
• ADLS: driving, shopping, yard work, meal prep, money mgmt,
communication, homemaking, self-care
• Reading: word recognition due to limited fovea previously 19
characters, unable to preplan saccade
– Right: affects saccade, can’t preplan next word
– Left: omits words, skips lines
Treating Hemianopsia
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Recovery rare after 6 months (Zhang, et al, 2006): Compensation is Key
Computerized Light boards: Dynavision, Wii
Laser pointer: flashlight tag
Reading: Pre-Reading tasks to increase saccade length, large print familiar text,
occupation based text. Maybe not bifocals
Writing: illumination, contrast, bold lines and black pen
“Scan the environment” tasks
– Wider head turns
– Increased head movement for scanning
– Faster rate of head movement
– Improved search pattern
– Wide scanning tasks
Approach from the affected side during divided attention tasks
Modify the environment
Prisms from neuro optomotrist
Visual Attention
• Skills to attend: filter out, balance all
perceptions, become salient, termination
• Monitor central field (cones- what is it?)
and peripheral field (rods-where am I?)
• Constant communication through cortex,
brainstem and cerebellum orchestrated by
the frontal lobe
• Mass practice , experience and context
can all improve recovery
Types of Attention
• Focused attention: responding to specific
element
• Sustained attention: maintaining response over
period of time
• Selective attention: free from distraction of
environment
• Alternating attention: shift from one task to
another
• Divided attention: simultaneous engagement in
more than one task, multitasking
Neglect
• Due to deviation in normal search pattern
• Disorder in:
– spatial cognition
• No concept of space….no insight
– spatial orientation
• Left sided space doesn’t exist
– spatial exploration
• Difficulty crossing visual midline
• Difficult disengaging search pattern from right
• 80% result from damage in right parieto-temporal-frontal circuitry
(Warren)
• If vestibular cortex: pusher syndrome
Behaviors
• Decreased ADLS: reading, WC mobs,
driving
• Limited insight
• Decreased task initiation
• Decreased sustained attention
• Decreased working memory
• Perseverates
• Decreased alternating attention
Evaluation for Visual Attention
• Why is there inattention?
– Spatial bias
– Impaired conceptualization
– Non lateralized inattention
• Tests: Cancellation tests (assesses
search pattern), Telephone number copy,
Reading performance, Design Copy, Scan
Board, ScanCourse, Dynavision, ADL
observation
Search Patterns (Warren)
Left Hemianopsia
• Abbreviated search
pattern- omissions on left
• Pattern is organized
• Re-scanning to check
accuracy
• Sustained attention
measured by completion
time appropriate
• Improves with cuing
Hemi- inattention
• Abbreviated search
pattern- omissions on left
• Pattern is random
• Revisitng on right
• Reduced sustained
attention, shorter
completion time
• Cue meaningless
Interventions for Visual
Attention
• Modify Environment to support
participation
– Decrease pattern, increase contrast, reduce
glare, lighting
• Improve attention through language to
assess performance, activity based
• Visual Scanning Training
– Focus on: Left to right, symmetrical scanning,
completing search to left, observe detail,
anticipate, rapidly shifting R v L
Treating Visual Attention
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Multimatrix tasks: categorization, spelling
Shapes and grid tasks
Pencil and Marsden ball tasks with patch
Cognitive load tasks
– Go-no-go: flash pen light a number of times,
hold fingers up how many seconds to wait,
then pt taps table equal to amount of flashes
Treatment
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Meaningful occupations
Salient tasks: babies, pets, family
Multimatrix Game, Tracking Tube
Refer to developmental or neuro
optometrist for prisms, lenses
• Sensory Input: Incorporate auditory,
visual (prisms or partial occlusion) and
vestibular treatment with cognitive load
Oculomotor Impairment
• Caused by closed head injury, facial
trauma, Cranial nerve trauma or Brainstem
injury; damage to cortical areas that use
eye movements to shift attention (Warren),
PD, MS
• Saccades: bring taret to fovea after activated by
attention, uses scan and search with quick movements
• Smooth pursuits: triggered by movement and hold a
moving image on the fovea
• Cervical VOR
Accomodative dysfunction
• Convergence insufficiency
• Treated by optometrist
• OT uses larger print or magnifiers
• Binocular insufficiency
• Convergence excess
• Divergence excess
• Divergence insufficiency
• 23 kinds of nystagmus
• Ocular dysmetria: over/under shoots with saccades,
slows down identification
• 3 steps to accommodate
– Converge to target and stimulate
photoreceptors
– Lens thickens to refract light
– Pupils constrict to reduce scatter of light
Behaviors
• Difficulty focusing, altered perception,
disruption of balance
• OT cannot fix oculomotor dysfunction
– Modify and Adapt
– Manage condition until resolves
– Eliminate stress for improved ADLS
• Most clears up within 6 months (Park, Hwang, Yu,
2008)
Altered Perception
• Diploplia
– Doubled images
– Blurred images
– Ghosting images
– Distorted images
• Acquired paralytic strabismus
– Due to paralysis or weakness of CN 3,4,6
Cranial Nerve Review:
• CN 3 (Oculomotor nerve) lesion:
exotropia, vertical or medial movements
difficult, lateral diploplia, ptosis, dilated
pupil, due to severe TBI
• CN 4 (Trochlear Nerve) lesion: bilateral
lesions common, vertical diploplia near
vision, head tilt contralateral side
• CN 5 (Abducens Nerve) lesion: esotropia,
lateral diploplia for far vision
Screening for binocularity
What and how to screen:
What does it mean?
• Unilateral Cover test:
phorias near and far
• Broch string:
convergence,
suppression near vs far,
alignment,
accommodation
• Red/Green Fusion test:
suppression right vs left
eye
• Near point of
convergence
• Behaviors with phorias:
headache, blurred vision
• Convergence
insufficiency: poor recall
of what read, decreased
reading, look out window
• Convergence excess:
love to read, get close to
notes to write
• Suppression: poor sports
skills
• Accommodative infacility:
poor concentration, poor
sustained attention
Screen for diploplia
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Screen if binocular or monocular
diploplia
– Only when both eyes open:
binocular diploplia
– Patching can be useful
– Even when one eye shut:
Monocular diploplia
– patching doesn’t help: requires
sx, vision rehab or prisms
Screen where the diploplia is?
– Move eyes around from 12 to
6 to 12
– Where is the double vision
worse? Better?
– Tilt head right, left. Worse,
better?
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Patching: complete occlusion
– Can lead to monocular vision,
eye fatigue and strain
– Must alternate patch- poor pt
compliance
– Decreased depth perception /
increase fall risk
– Strengthen the oculomotor
deficit
Occlusion:
– Binasal occlusion forcing
peripheral vision
– Nasal portion of dominant eye
– Need MD consent
Diploplia cont….
• Prisms from optomotrist when peripheral or central nerve
injury (Hilliar, 2014) Used with phorias to achieve fusion.
• Multimatrix games
• Fusion tasks with scanning
• Convergence activities
– Reading
– Broch string
– Pencil push ups
– Add an auditory component with a metronome
– Add a cognitive load by converging on every 3rd beat
Other Disturbances in
Visual Perception
• Visual discrimination:
ability to discriminate one
thing from another
allowing for pattern
recognition
• Pattern recognition:
spatial patterns (shape of
the letter), sequential
patterns (q is a spatial
pattern in a sequence of
letters to form a word)
and movement patterns
(magnocellular through
gestures, expression)
• Behaviors include not
recognizing patterns,
sequences, difficulty with
symbolic literacy, difficulty
organizing space and
time
Visual Memory
• Semantic Declarative Memory: info heard or
read
• Episodic Declarative Memory: remembering
what did or what happened
• Implicit Procedural Memory: long term memory
for motor learning task (tying shoe, handwriting)
• Working Memory: metacognition…think while we
are thinking! Reading, writing, lecture
Visual Imagery
• Manipulating images in minds eye
Perceptual Midline Shift
• Perceived midline of body is not the actual
midline of the body
– Auditory
– Visual
– Vestibular
– Due to dysynchrony of sensory integration at midbrain with major
contributions from ambient visual pathway causing poor sports
performance, social insecurity and difficulty driving (Hillier and
Kawar)
– Benefit from yoked prisms
Treating Tunnel Vision
• Bimanual circles
• Mimicking gross motor
movements while fixated straight
ahead
• Flashlight tag
• Scarf juggling
Therapeutic strategies after trauma
• Adapt: make plastic changes in the cerebellum and brainstem
neuronal responses to head movement
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Decrease retinal slip/oscillopsia
Improve postural control and gaze
Decrease vertigo
Use for those with unilateral lesions with high velocity head movement
or central lesion
• Habituate: minimize sensitivity to aggravating stimuli
• Use for those with unilateral lesions causing asymmetry and visual
vestibular mismatch
• Substitute: enhance visual and somatosensory cues to compensate
• Use for those with bilateral lesions and high velocity unilateral lesions
with gaze stability and somatosensory training
References
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Hillier, Carl and Kawar, Mary. (continuing education PDP, 2013). Eyesight
to Insight: Visual/Vestibular Assessment and Treatment. Pittsburgh, PA.
Hillier, Rita and Tarbutton, Natalie. Vision Deficits following Stroke:
Implications for Occupational Therapy Practice. OT Practice, 19 (21), 13-16
Lane, Kenneth (2012). Visual Attention in Children: Theories and Activities.
SLACK Publishers, New York.
Park, UC; Kim S. J.; Hwang, J. M. & Yu, Y. S. (2008). Clinical features and
natural history of acquired third, fourth, and sixth cranial nerve palsy. Eye
(Lond). 2008 May;22(5):691-6. Epub 2007 Feb 9.
Rowe, F., Brand, D., Jackson, C. A., Price, A., ….Freeman, C. (2009).
Visual impairment following stroke: Do stroke patients require visual
assessments? Age and Ageing, 38, 188-193.
Rummell, Errol. (2012, September 17). Vision Rehab for Hemianopsia:
How VRT can improve vision loss from a neurological origin. Advance for
Occupational Therapy Practitioners
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Warren, Mary. (1993). A Hierarchical Model for Evaluation and Treatment
of visual Perceptual Dysfunction in Adult Acquired Brain Injury, Part 1.
AJOT, 47, 42-54.
Warren, Mary. (continuing education vis ABILITIES Rehab Services, inc.
2014). Visual Processing Impairment I: Evaluation and Intervention for
Adult Acquired Brain Injury. JFK Johnson Rehabilitation Institute, Edison,
New Jersey.
Zhang, X., Kadar, S., Lynn, M. J., Newman, N. J. & Bouisse, V. (2006).
Homonymous he,ianopsia in strole. Journal of Neuro-opthomology, 26, 180183.
Appendix
Eye Terms
• Mobility: the ability to move eyes full range
• Motility: skill with which the eyes move (smooth,
slightly jerky, jerky)
• Pursuits: tracking of moving object with body
still or stationary object with body moving
• Steady fixation: ability to keep eyes from moving
off moving target
• Saccades: quick eye movement for scanning
environment, reading (visual memory,
comprehension based here)
Eye Terms
• Binocularity (teaming or alignment)
– Phoria “the tendency to” or weakness
• Orthophoria: tendency to stay in alignment
• Exophoria: tendency to drift out, therefore a shift
inward when contralateral eye occluded
• Esophoria: tendency to drift in, therefore a shift
outward when contralateral eye occluded
• Hyperphoria: tendency to drift upward, therefore a
shift downward when contralateral eye occluded
• Results in intermittent diploplia
• REFERRAL to Dev/Neuro Optomotrist if eso or
hyperphoric
• Binocularity
– Tropia “is out of alignment” or
paralyzed/ Strabismus
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Exotropia: eye is turned out
Esotropia: eye turned in
Hypertropia: eye turned up
Cyclotropia: eye is rotated
Results in constant diploplia of gaze
• Strabismus is acquired from TBI or developmental