Pedretti Ch. 25 - Assessment of Perceptual Dysfunction Flashcards
Perception is the gateway to __
cognition
Optimal battery of standardized assessments include:
Tools that require a verbal response or a motor response or have flexible response requirements of either mode (should be in specific context of occupation being performed)
Also, observation of occupational performance in context and the analysis of perceptual-motor demands of functional activities
The OT is able to gather info to discriminate between an impairment in the reception of information and an impairment in the verbal or motor output
Performance on global perceptual tests may be affected by:
Performance on global perceptual tests may be affected by deficits in cognitive areas (attention, memory, cognitive function)
Assessing neurobehavioral dysfunction (perceptual dysfunction)
Arnadottir recommends the use of ADLs to assess neurobehavioral dysfunction (perceptual dysfunction) and its effect on the performance of tasks essential to functional independence
- Preferred for OTs to assess neurobehavioral deficits directly from ADL evaluation
- Arnadottir OT-ADL Neurobehavioral Evaluation (A-ONE): evaluates perceptual and perceptual motor dysfunction in the context of ADL and functional mobility tasks
Toglia’s Multicontext Treatment Approach
Focuses on remediating and compensating for perceptual and cognitive impairments by promoting generalization of functional skills across multiple contexts
- Visual processing strategies, task analysis, incorporation of specific learning needs of the client establishment of criteria for the transfer of learning, metacognitive training and practice in multiple settings
Toglia’s Dynamic Object Search Test
assessment that can be utilized to assess visual processing, visual scanning and visual attention
Assessment of Motor and Process Skills (AMPS)
Evaluates the performance skills necessary for engagement in areas of occupations
- 16 motor skills; 20 process skills
- each performance skill is evaluated in the context of client-identified and culturally relevant IADLs from a list of standardized activities at various levels of difficulty
Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) and Rivermead Perceptual Assessment Battery
Comprehensive profile of visual perceptual and motor skills and involve both motor free and constructional functions
Motor-Free Visual Perceptual Test-Revised (MVPT-R)
assesses basic visual perceptual abilities
Motor-Free Visual Perceptual Test-Verbal (MVPT-V)
reduce the interference of hemianopsia or visual inattention; Identify persons who would not be safe drivers
Test of Visual Perceptual Skills-Upper Level (TVPS-UL)
provides a multiple-choice formant and has been normed for adults; untimed; higher level of visual analysis than MVPT
Hooper Visual Organization Test
requires that the individual mentally assemble fragmented drawing of common objects
Minnesota Paper Form Board Test
high-level assessment of visual organization, requiring mental rotation of fragmented geographic shapes
Visual Perception Disorder
Impairs the person’s ability to recognize and identify familiar objects and people
May have intact visual anatomic structures; but objects and people may appear distorted or larger or smaller
Difficulty interpreting the meaning of objects in their environment (signs and maps)
Difficulty recognizing, identifying or remembering the names of colors in their environment
Can lead to safety problems and may affect social skills
Agnosia
Impairment in visual object recognition (the ability to verbally identify objects via visual input)
Caused by lesions in the right occipital lobe or posterior multimodal association area
Can demonstrate normal foundation skills
Inability to name objects is not caused by a language deficit
Only unable to recognize objects using a visual means (ex: if touching can use tactile to recognize)
Assessment: asking them to name 5 common objects by sight (if needed can offer choice of three answers); if not able to name 4/5 object visual agnosia may be indicated
Adaptive Methods: keeping frequently used objects in consistent locations; relying more on other sensory modalities (stereognosis)
Remediative Methods: having client practice identifying objects needed
Color Agnosia
Color Agnosia: client’s inability to remember and recognize the specific colors for common objects in the environment (ex: paint sky green)
Assessment: present client with two common objects that are accurately colored; and two that are not → client is asked to pick the ones not accurately colored
Color Anomia
Client’s inability to name the color of objects; can understand the differences between the different colors of objects but not able to name object correctly (ex: can separate colors into categories but cannot name them)
Assessment: Ask client to name the color of various objects in their environment.
OT intervention (both): focus on providing the client with opportunities to recognize, identify and name various colors of objects in their environment → best in familiar context
Metamorphopsia
Visual distortion of objects, such as the physical properties of size and weight (ex: not able to distinguish between basketball, volleyball, baseball)
Assessment: presenting client with various objects of different weights and sizes; ask client to place each object in order according to size or weight through observation alone
OT intervention: providing the client with opportunities to practice distinguishing objects in the natural environment through intact sensory modalities
- Functional use of objects will provide the client with feedback about the size and shape of different objects
- OT should provide specific verbal descriptors of object
- Other modalities: puzzles, board games, computer games… etc
Prosopagnosia
Inability to recognize and identify familiar faces (own or family/friends)
- Cannot recognize the unique facial expressions that make each face different
- Caused by lesions in the right posterior hemisphere
Compensate by relying on auditory cues or distinctive features
Brain lesions can also impair the ability to interpret facial expressions
Standardized Test of Facial Recognition: multiple choice matching of faces presented in front and side views under various lighting conditions
Informal functional assessments: have client identify names of people in photographs (family members at the dinner table)
Prosopagnosia OT interventions
OT interventions:
- Remedial: providing face matching exercises
- Adaptive: providing pictures of family and famous people with names; assisting client to associate family member’s face with other unique characteristics (hairstyle, weight, height)
Simultanognosia
Refers to the inability to recognize and interpret a visual array as a whole (able to recognize individual components of the visual array)
- Caused by lesions to the right hemisphere
Assessment: presenting the client with a photograph with detailed visual array; asking them to describe the scene in detail
Simultanognosia OT intervention
OT intervention: help the client construct meaning of a visual array through verbal cues and therapeutic questions to facilitate abstract reasoning; best in familiar contexts
Visual Spatial Perception Disorders
- Refers to the capacity to appreciate the spatial arrangement of one’s body, objects in relationship to oneself and relationships between objects in space
- Spatial skills cannot be isolated easily from one another
- Right hemisphere (controls spatial) functions as a whole
- Left hemisphere focuses on discrete details
- Visual spatial perception occurs instantaneously and is not limited to the visual domain (ex: sounds can be localized in space)
Figure-Ground Discrimination Dysfunction
Allows a person to perceive the foreground from the background in a visual array
Assessment: can be assessed functionally in a variety of contexts (ex: finding a white shirt on white sheets)
Remedial approach: focus on challenging the client to localize objects of similar color in a disorganized visual array
Adaptive approach: focus on modifying the environment to increase the organization of common functional objects
Toglia’s multicontextual approach: help client gain self-awareness of their figure-ground discrimination dysfunction and develop effective organizational and visual scanning strategies for discriminating foreground and background
- Also focuses on generalization of skill to multiple functional contexts
Form-Constancy Dysfunction
Recognition of various forms, shapes and objects, regardless of their position, location or size
Assessment: ask client to identify familiar objects in their environment through observation alone when those objects are placed upside down or on their side
Intervention: using tactile cues to feel objects in various positions so that the client learns their constancy despite position, size or location
Best when used with common objects familiar to client
Right-Left Discrimination Dysfunction
Ability to accurately use the concepts of right and left (could be of their body or directionally)
Assessment: ask the client to point to various body parts (e.g. left ear) or assess the client’s ability to navigate the environment through verbal commands using left and right
Intervention: focus on assisting client to practice reciting right and left while interacting with their body or environment
Remediation of right-left discrim can significantly improve topographic organization (better navigate home and community)
Stereopsis
Inability to perceive depth in relation to the self or in relation to various objects in the environment (critical for function in 3D world)
Visual input from both eyes is required to perceive depth
Assessment: place a variety of common objects on a table surface and ask the client to identify which object is closer and which is farther
Computer-assisted software has been developed – help with developing depth perception by judging the relative distance of objects in relation to one another on a computer screen
Tactile-kinesthetic approaches – help client judge distances through the use of tactile input
Tactile discriminative skills
Tactile discriminative skills: second somatosensory area of parietal lobes
Higher level of synthesis than basic tactile sensory function of light touch and pressure
Astereognosis
Stereognosis: integration of touch, pressure, position, motion, texture, weight and temperature and is dependent on intact parietal cortical fx
Astereognosis – visually compensate, slow and purposeful movements (less active)
Assessment: Test of stereognosis (review)
Graded intervention program: Egggers
- Client manipulates object while looking and makes noise with object (taps on table) – intersensory facilitation
- Vision occluded, auditory cues eliminated; person relies on tactile-kinesthetic input alone
Farber (with CNS dysfunction):
- Allowed to examine object visually, no touch
- Allowed to handle object in less affected hand
- Manipulates object with both hands while looking
- Placed in affected hand while looking
- Sequence is then repeated with vision occluded
Agraphesthesia
Graphesthesia: parietal lobe fx; ability to recognize letters, numbers, or forms written on the skin
Assessment: vision occluded; examiner traces letters, number or forms on the fingertips or palms with a dull pointed pencil
Intervention: focus on providing the client with opportunities for tactile discrimination through use of his or her hands
Praxis
ability to plan and perform purposeful movement
Motor Perception Disorders
Apraxia
Apraxia: deficit in the execution of learned movement which cannot be accounted for by either weakness, incoordination or sensory loss, or incomprehension of or inattention to commands
Results from damage to either side of the brain or corpus callosum
- *more frequently from left hemisphere damage
- TBI, CVA, or Alzheimer’s disease
often seen in people with aphasia; strongly correlated with dependence in areas of occupation
Motor Perception Disorders
Ideational (Conceptual) Apraxia
Inability to use real objects appropriately (ex: spoon to write with)
Also may have difficulty sequencing acts in a proper order
Significant functional implications in a variety of areas of occupations
Motor Perception Disorders
Ideomotor Apraxia
Inability to carry out a motor act on verbal command or imitation
Is able to perform the act correctly when asked to use the actual object
Impairments demonstrated only in the testing environment and appear to have little functional impact
Motor Perception Disorders
Dressing Apraxia
Inability to plan effective motor activities required during the complex perceptual task of dressing one’s upper and lower body
Assessment of Apraxia
Important to assess sensory fx, muscle strength and dexterity before test of praxis
Person with hemiplegia → use unaffected hand for testing
Often aphasia is associated with apraxia so it is important to consult with the SLP bc aphasia assessments include an apraxia section
Apraxia assessments: Florida Apraxia Screening Test (FAST), Movement Imitation test, Use of Objects Test, Loewenstein Occupational Therapy Cognitive Assessment (LOTCA), Rivermead Perceptual Assessment Battery
Developed by OTs: Santa Clara Valley Medical Center Praxis Test, Solet Test for Apraxia
Involves transitive movements (action involving both tool and use, such as writing with an imaginary pen)
And Intransitive movements (movements for communication, such as waving goodbye)
Treatment for Apraxia
Following a developmental sequence (starting with basic motor movements then more advanced)
Clinical reasoning process: beginning with spoken instruction for each sequence in the task, written or pictorial instructions, and visual monitoring of the limbs throughout each aspect of the task
Conductive education: breaking the task into smaller units and verbally guiding the sequence
OT interventions for dressing apraxia: problem solving with the client on effective dressing strategies (having the client position the garment the same way each time); labels, buttons or ribbons can be used as cues to differentiate front from back
Constructional Disorder
Visuoconstructional skills: ability to organize visual information into meaningful spatial representations
Deficits refer to the inability to organize or assemble parts into a whole 2D (drawing) and 3D (putting together block designs)
Results in significant dysfunction in occupations (dressing, organizing food in the fridge, loading a dishwasher… etc.)
Individual acts on his or her contextual environment based on the information he or she perceives → deficits in perception become more apparent when that person interacts with the environment in maladaptive ways
Tests of Constructional Abilities
2D mode: Test of Visual-Motor Skills for Adults; Benton Visual Retention Test; Rey Complex Figure assessment (quick screening of visual perceptual fx)
Three-Dimensional Block Construction involves the use of various blocks to copy a design from a 3-D model
Nonstandardized: drawing, conducting matchstick designs, assembling block designs, building a structure to match a model
- individual must have: integrated visual perception, motor planning and motor execution
Researchers found:
- The type of test administration affects scores
- In teaching persons with constructional disorders: models or demonstrations of desired performance are likely to produce better results than would photos or drawings (3-D vs. 2-D)
Constructional Disorder Interventions
Remedial: use of perceptual tasks such as paper and pencil activities, puzzles, and 3-D craft projects
Adaptive: participation in occupational performance and developing compensatory approaches to the functional performance skill impairments
Behavioral Aspects of Perceptual Dysfunction
Accurate self-awareness and recognition of the effect of the disability are needed if the person is to invest energy in therapy
Individual who is unaware of perceptual deficits may be a serious safety risk (attempt occupations beyond physical ability)
Denial is one of the early stages of recovery from CVA or TBI (protective coping mechanism; allows individual to gradually absorb the effect of injury)
OT needs to respect and be sensitive to the individual’s sense of self and be prepared to aid the client in understanding the changes in perceptual capacity and in reestablishing an accurate sense of self
Behavioral Aspects of Perceptual Dysfunction cont’d
Questionnaires: issued to the client as well as a family member or close friend
- Discrepancies are measured to see the accuracy of the individual’s insight and serve as a basis for intervention
An individual who has some degree of awareness of the disability is often depressed
- OT must recognize and appreciate the emotional response and assist the individual in achieving an emotional balance to reestablish QOL through celebrating progress in therapy while acknowledging the impact of perceptual impairment on participation in occupation
