Vision and Perceptual Dysfunction- EXAM 1- ADULT NEURO

Visual function components

• visual acuity

• Oculomotor abilities

• Contrast sensitivity

• Pupillary function

• Visual fields

Warren’s hierarchy

Each skill level builds upon itself, bottom 3 needed for the rest above (foundational)

Types of visual acuity

• myopia

• Hyperopia

• Astigmatism

• Presbyopia

Types of Oculomotor Components

• fixation

• ROM

• Tracking/pursuits

• Convergence

• Saccades

Visual acuity

The level of clear central vision

Oculomotor

Ability to purposefully contract the muscles of eyes to do coordinated movement

Myopia

Nearsightedness (can’t see far)

Hyperopia

Farsightedness (can’t see near)

Astigmatism

Asymmetrical or distorted vision as any distance, caused by curvature of eye or lens that bends light

Presbyopia

Loss of accommodation of lens and shortening of the eye caused by loss of aqueous fluid, results in hyperopia (age 40)

Fixation

Ability to maintain focus on an object in the central vision

Tracking/pursuits

Ability to smoothly follow a moving target

Convergence

Ability to move two eyes nasally simultaneously

Saccades

Ability to shift the area of clearest vision back and forth using quick eye movements

Homonymous Hemianopia

Left side of each eye loss of visual field

Results from stroke and TBI

Use of compensatory strategies

Perception

Dominant sene to gather info form peri-personal and extra-personal environment

Can choose to respond to stimuli w/ motor act or verbal expression

Visual perceptual dysfunction

Compromises w/ safety and independence

Remedial approaches for Perceptual Dysfunctions

• practicing skill

• Similar activities requiring same perceptual skill

• Engage in meaningful occupation

Adaptive/compensatory approach for Perceptual dysfunction

• strategies to compensate for skills

• Reduce demand for skill in daily activities

• Adapt task

• Change environment

Visual spatial dysfunction

• inability to recognize specific characteristics of objects, or position in space

• Needed for successful interaction with environment

Visual spatial dysfunction cause

Diffuse or focal leasions to temporal and parietal lobes

Form constancy

• distinguish objects through visual cues- color, shape, orientation, motion

• Missing difference in object details

Occupational performance difficulties in Form Constancy

• Reading

• Identifying common objects

• Locating objects in personal environment

Assessments for Form Constancy

during functional tasks, note if person has diff distinguishing between objects of similar shape and size (silverware)

Form constancy remedial approach

• sort objects in personal env

• Puzzle designs

• Identifying shapes or letters in design

Form constancy adaptive approach

• organize objects by size, shape, and in proper orientation

• Label objects

• Tactile input to reinforce visual input

Figure ground

• Inability to distinguish foreground from background

• Diff distinguishing objects from similarly colored or cluttered background

Assessments for Figure ground

• figure ground sub tests

• Functional tasks- ask a person to locate items in a junk drawer with many objects

Remediation approach for Fiigure Ground

Practice locating items from cluttered field- silverware, coins, puzzles

Adaptive approach for Figure Ground

• organize visual areas

• Toiletries, drawers, tools, silverware

Visual closure

Visualize a complete whole when provided with fragmented pictures or incomplete info

Visual closure difficulties

• writing

• Selecting objects for a task

• Identifying objects if obscured

Assessments for Visual Closure

• growing completion tasks

• Object identification from fragmented picture

Remediation approach for visual closure

• practice identifyingincomplete objects

• Puzzles to practice skills

Adaptation approach for Visual Closure

• rely on other cues

• Reduce occlusion of objects

Stereoposis/Depth perception

Difficulty perceiving depth in relation t self or objects within the environment

Safety issues for Stereopsis/Depth perception

• running into things

• Dropping items

Stereopsis/Depth perception requires…

Integration of monocular and binocular vision

Assessments for Stereopsis/Depth Perception

• standardized measures

• Observing client can determine how far or near an object or item is in the environment

• Observe overshooting or undershooting when reaching for things

• Stepping signs

Remedial approach for Stereopsis

• practice judging distances, tactile kinesthetic approach to help client judge or confirm

Adaptive approach for Stereopsis

• environmental modifications/safety

• Provide visual cues for steps

Topographical Orientation

Relationship of one location to another

Conceptualice a “mind’s eye” view

Difficulties with Topographical orientation

Can’t describe directions or draw maps for familiar places

Assessment for Topographical orientation

• observe patient finding their way around hospital

• Take memory deficits into consideration

Remedial approach for topographical orientation

• Practice locating places based on written or verbal directions

• Scavenger hunts

• Virtual games

Adaptive approach for topographical organization

• signs

• Landmarks to navigate

• Provide guidance or assistance as needed

Right left discrimination

Understanding and using concepts of right and left consistently

Assessments for R/L discrimination

• ask client to point to various body parts or objects using R and L directions

• Assess clients ability to navigate the env. Through verbal commands using R and L

Remedial approach for R/L discrimination

• tactile and visual input

• Practice activities with commands using specific body parts

Adaptive approach for R/L discrimination

• identify strategies so client canidentify R and L through cues

• Use of colors to indicate R and L

Visual Perceptual skills

Ability to conceptually interpret visual info.

Being able to see the whole of an object and know what it is

Visual object agnosia

Unable to identify objects using only vision despite adequate visual function

• can using TOUCH and SMELL

• Describe details but not WHOOLE

Cause of visual object agnosia

Temporal lobe dysfunction

Difficulties with reading

Visual object agnosia assessments

• Identify 5 common objects (unable to do 4/5 is +)

• Rule out language deficits and visual dysfunction

• LOTCA- visual identification of objects subtlest

Remedial approach for visual object agnosia

Practice identifying and naming objects that are familiar

Adaptive approach for visual object agnosia

• placing frequently used objects in consistent locations

• Teach pt. To rely on intact sensory modalities to find items

• Establish routine for ADL tasks and maintain consistency

Prosopagnosia

• inability to recognize and identify familiar faces

• Inability to recognize unique facial expressions that make each face diff

Assessment for prosopagnosia

• identify names of ppl in photo, family

• Identify their own face in mirror

Remedial approach for prosopagnosia

• face matching exercises

• Practice identifying familiar people such as family or close friends

Adaptive approach for prosopagnosia

• client identify ppl by voice

• Client associate specific characteristics with person height, weight, hair, voice

Color agnosia

Inability to remember and recognize the specific colors for common objects in the env

Assessment for color agnosia

• provide client with two common objects that are accurately colored and two objects that are not, ask client t identify

Color anomia

Unable to name the color of objects

Assessment for color anomia

Ask patient to name the color of various objects in the env

Interventions for color agnosia and anomia

Provide opportunity to recognize, identify, and name various colors of objects in the env

Remedial approach for color anomia and agnosia

Identifying colors of objects

Adaptive approach for color agnosia and anomia

• labeling objects

• Teach client to use alternative characteristics to describe objects

Tactile perception

Parietal lobe functions

Astereognosis or tactile agnosia

Cannot identify familiar objects placed in hand with vision occluded

Remedial approach for astereognosis or tactile agnosia

Practice identifying objects

Sensory input to hands

Adaptive approach for astereognosis or tactile agnosia

Safety edu and training on visual input

Agraphesthesia

Unable to decipher letters drawn on skin

May or may not be present if astereognosis is present

Body scheme disorders

Impairment in representation of the spatial relation among the parts of the body

Perception of body position and relationship of body is affected

Foundation for perception of env

Cause of body scheme disorders

Right hemisphere lesions

Somatognosia

Lack of awareness of body structure and failure to recognize body parts and relationship to each other

Difficulties with somatognosia

• person confuse sides of the body

• May not differentiate their body from another person’s bod

Assessment for somatognosia

• draw a person- scoring 10 parts

• Human figure or face puzzle (6 piece puzzle)

• Follow instruction to point to specific body part

Intervention For somatognosia

• bilateral activities

• Tactile input

Unilateral in attention

• awareness and representation of 1 hemisphere is lost- self and env

• Absence of awareness, not often distressed

• Inability to perceive or integrate 1 side of the body

• May or may not occur w/ visual cut

Assessment for unilateral attention

• drawing clock

• Human figure

• Parts on side will be distorted

• Functional tasks

Remedial approach for unilateral attention

• input to that side with visual attention

• Bilateral activities

• Weight bearing

• Use of neglected side in ADL tasks

Adaptive approach for unilateral inattention

• emphasize safety concerns w/ family

• Env. Modifications to keep objects in hemisphere to which they can attend

Which side has the most severe unilateral in attention

LEFT

Apraxia

Difficulty performing skilled motor movement

Most in left hemisphere dysfunction

Idea of motor tasks + execution of motor task

Ideational apraxia/conceptual apraxia

• dysfunction is kinesthetic execution of motor task

• Inability use real ovbjects appropriately

• May substitute objects and attempt to use

• Diff sequencing acts in proper order

Ideo motor apraxia

Cannot imitate gestures

Assessment for apraxia

Done through observations of performance of functional tasks

• brush teeth

• Comb hair

• Dressing

Remedial approach for apraxia

Determine which type of commands are most effective, carry out activities in th appropriate context or env

Adaptive approach for apraxia

Hand over hand to initiate tasks

Constructional disorder

Inability to organize or assemble parts into a whole (2-3D)

Assessment for constructional disorder

• copying tasks

• Design tasks

  • Peg designs

  • Sticks

  • Blocks

Remedial approach for constructional disorder

Paper and pencil activities, puzzles, 2-3D designs

Adaptive approach for constructional disorder

Meal prep

Best strategies for visual perceptual challenges

Routines and habits

Remediation approach for Visual Closrue

• practice identifyingincomplete objects

• Puzzles