Introduction to OT 689

1
Introduction to OT 689

• Foundations in Evaluation and Treatment of Visual
  Impairment from Brain Injury

2
Instructors Information

• Email address warrenm_at_uab.edu
• Phone number 934-1800
• Office Hours by appointment
• Office 340

3
Class Materials

• biVABA Test Manual
• Copy of chapter 24 in 2001 Pedretti
• Copy of assessment forms for biVABA
• Penlight
• 1 inch craft sticks (2)
• Eye patch
• Each person needs a have a partner with whom they
  will practice evaluations and take the practical
  exam

4
Lectures/Reading Materials

• PPP will be posted in WebCT at least one day
  before the class
• Copies of Pedretti Chapter, required readings and
  evaluation forms will be in the resources file in
  WebCT
• Information will be addressed on tests

5
Case Applications

• 4 case applications will be completed on a pt
  with visual impairment from brain injury
• Topic
• acuity deficits
• oculomotor impairment
• visual field deficit
• visual inattention
• Will be completed in two parts, submitted
  sequentially
• Part 1, test through webCT part 2 tx application
• Each worth 50 points
• Occulsion exercise-50 points

6
Class Assignments

• Must be type written and submitted in the
  required format
• .5 deduction for all mis-spellings, grammatical
  errors
• 10 point deduction for turning in a late
  assignment

7
Student Evaluation

• Four written exams 60
• Short answer, multiple choice
• Will include required readings
• Two application exams 20
• Demonstrate correct test procedure
• Demonstrate understanding of test mechanics
• Demonstrate understanding of test modifications
• In class assignments and 20
• case applications

8
Tentative Test Dates

• Test One January 27th
• Application Test February 17th
• Test Two February 24th
• Test Three March 16th
• Application Test April 13th
• Test Four April 20th

9
Absences

• Notify me by phone or email if you will need to
  miss a class. Because this class relies on class
  lecture and demonstration with little outside
  reading, attendance is very important.
• One excused absence is allowed
• Additional absences result in 15 pt deduction
  from test grade
• No class on March 23rd (spring break)
• In the case of bad weather (ice, snow) class will
  be cancelled-( I will send an email out to the
  class via WebCT) although the information you
  will be taught is very important it doesnt
  warrant risking life, limb and car.

10
Communication

• I will send written communications to you either
  through webCt or by sending a mass email through
  the class distribution system at UAB
• If your current email address differs from the
  the email address in the electronic address book
  for UAB you will not receive these emails
• Its your responsibility to update the directory

11
The Adaptation Process
12
Lecture Objectives

• Understands the role of vision in occupational
  performance and adaptation
• Able to apply the concept of the visual
  perceptual hierarchy as a framework for
  evaluation and treatment
• Able to describe the purpose of occupational
  therapy evaluation
• Able to describe the general approach to
  treatment intervention

13

• The overall function of the brain is to filter,
  organize and integrate sensory information to
  make an adaptive response to the environment.
• Jean Ayres

14
Adaptation is built on theintegration of sensory
information

• We are sensory-motor-sensory beings
• Sensory input triggers motor response that
  produces new sensory input that modifies the
  motor response and so on.
• The trigger is awareness of the incoming sensory
  input
• If you dont see the ball coming at you, you
  dont make an attempt to catch it

15
Adaptation is Context Dependent

• Incoming sensory information creates the context
• Bits and pieces of sensory information are
  integrated to create a complete and continuously
  updated picture of the environment which is then
  used to make decisions, formulate plans etc.
• The context of the situation determines the
  response

16
Adaptation is Dependent on Anticipation

• Anticipation allows person to plan for an
  upcoming situation which in turn increases
  chances of successfully handling the event
• Anticipation is driven by sensory context
• It looks like rain.Id better take an umbrella
• For anticipation and planning to occur, incoming
  sensory input must be of sufficient quantity and
  quality to build an accurate complete context
• When incoming sensory input is altered by
  disease, trauma, age etc, ability to adapt lessens

17
Role of Vision in the Adaptation Process
18
Vision is our most far reaching sensory system

• First to alert to danger or pleasure
• Enables us to be anticipatory
• Provides early warning of what is about to happen
• And plan for situations
• Have time to plan how to respond

19
Vision can instantly convey an immense amount of
information

• The power of television is that is conveys a
  tremendous amount of information within seconds
• World trade towers
• JFK assassination
• Challenger explosion
• You can instantly identify an object with vision,
  you can also identify objects using your other
  senses but it will take longer

20
Speed supplied by vision is critical to
adaptation to dynamic environments

• Operate in two types of environments
• Static
• Dynamic
• Static
• Nothing moves but the person
• Spatial adaptation is required but not temporal
  adaptation
• Person decides when to start and stop movement
• Vision is nice to have but not critical to
  performance

21

• Dynamic environments
• Objects are in motion independent of the person
• Requires both spatial and temporal adaptation
• Timing is critical
• Only vision provides sufficient advanced warning
  to coordinate body movement with movement of
  other objects

22
Vision is the primary sensory system used to
acquire information about the environment

• 80-90 of all learning occurs through the visual
  channel
• 90 of all sensory information supplied to the
  CNS is visual

23
Vision plays a powerful role in learning and
decision making

• Supplies information needed for cognitive
  functions of problem solving and decision making
• Supplies information needed to interpret social
  interactions
• 90 of social communication is non verbal, cued
  by vision
• You see someone and you smile at them
• Supplies input for motor and postural control
• Impetus for movement
• See the diet coke, go get the diet coke
• Warns of upcoming challenges to postural control
• Gives us 100 feet of planning time before we
  encounter an obstacle

24
Dominance of Vision

• Vision has been such a reliable, fast, precise
  source of input that over the years we have built
  our culture around visual input
• Primary way we acquire information
• Newspapers
• Labels
• Instructions
• Telephones
• Watches
• Computers

25
Dominance of Vision

• Dominates recreational activities
• Sewing
• Handcrafts
• Sports
• Movies, television, plays
• Card games
• Provides us with the ability to participate in
  dynamic unpredictable activities
• 1 - driving

26
Visual Impairment

• Can occur secondary to
• Disease/conditions
• Acquired or congenital
• Trauma
• Stroke, traumatic brain injury, brain tumor,
  infection
• Age
• Impairment begins in 40s becomes significant in
  90s
• Often occurs due to a combination
• Example stroke causing hemianopsia in a patient
  who already has diabetic retinopathy

27
When visual impairment occurs

• Can alter the quality and amount of visual input
  into the brain
• Or alter the way the brain is able to process
  normal visual input
• Or both
• Regardless
• Results in a decrease in the ability to use
  vision for occupational performance

28
Visual impairment

• Will observe changes in the performances
  dependent on vision
• Driving or reading for example
• Observe a decrease in the speed of information
  processing
• Reduced reaction time, slowed response
• Observe changes in decision making
• Errors occur because person doesnt get enough
  information or faulty information

29
Resulting changes in behavior

• Frequently observe
• Anxiousness and uncertainty in responding to the
  environment
• Decreased confidence in ability to compete
  activities
• Increased passiveness in decision making
• Can affect persons performance in a variety of
  daily activities

30
In general

• Persons will have the most difficulty completing
  activities that must be done in dynamic
  environments
• Daily activities affected the most are those that
  occur in the community
• Driving
• Shopping
• Working
• Participating in sports

31
Biggest Challenge

• One of greatest concerns among persons working in
  the field
• Person with visual impairment will refrain from
  engaging in activities in community and dynamic
  environments
• Not only eliminates very enjoyable activities but
  prolongs the adjustment to disability

32
Neurological Framework for Evaluation and
Treatment
33
Visual Perception

• Integration of visual input within CNS to turn
  the raw data supplied by the retina into
  cognitive concepts of the perception of objects
  and space that can be manipulated and used for
  decision making

34
Visual Perceptual Hierarchy

• Visual perceptual function can be conceptualized
  as being organized into a hierarchy of processes
  that interact and sub-serve each other to
  provide integration of visual information

35
Processes comprising visual perceptual processing

• Visual cognition
• Visual memory
• Pattern recognition
• Visual search and scanning
• Visual attention
• Oculomotor control
• Visual field
• Visual acuity

36
Visual Cognition

• Apply cognitive concepts of space and form
  developed through vision to decision making and
  problem solving
• Size constancy as an example
• Forms basis of all academics
• Ability to read and complete mathematics
• Foundation for many vocations
• Surgeons, architects, engineers
• Cannot alter vision without altering cognition

37
Visual Memory

• Supports visuo-cognition
• To understand and mentally manipulate visual
  input you must have visual memories of objects to
  compare and contrast

38
Example Visual Memory
Can you see the silhouette of both the hawk and
the goose ?
To see either requires recall of the silhouette
of the bird from visual memory
39
Pattern Recognition

• Whether a memory is initially laid down and how
  accurate and useful the memory is depends on
  pattern recognition
• Pattern recognition requires identification of
  salient features of objects
• A salient feature is one that distinguishes the
  object and defines it as what it is

40
Example Pattern Recognition
What feature distinguishes the E from the F? A
the lower horizontal bar
41
Pattern Recognition is Comprised of Two Abilities

• Ability to see the pattern holistically as a
  single entity or gestalt
• See the forest
• Ability to go into the pattern and see the
  details
• See the trees

42
Example

• Viewed as a single gestalt
• The observer sees a tree in winter
• When the details of the
• illustration are viewed
• The observer becomes
• aware that the tree is actually a bird with
  a bird perched within its branches

43
Visual Search and Scanning

• Sub-serves pattern recognition
• To see gestalt and detail requires thorough
  scanning/search of the visual array
• Occurs on two levels
• Automatic reflexive
• Mediated through brainstem for survival
• Automatically turn head toward appearance of any
  light/object moving into the periphery
• Voluntary purposeful
• Mediated through the cortex driven by cognition
• Purposefully scan a visual array in order to
  locate and identify a target

44
Visual Search and Scanning

• Completed in an organized efficient and
  predictable pattern
• Prevalent scanning pattern
• Left to right
• Top to bottom
• Linear pattern is used to view a structured array
  
• Example searching for a friend sitting on
  bleachers at a game
• Circular pattern is used to view a non structured
  array
• Example searching a landscape

45
Reading Left to right top to bottom
search strategy
Landscape Left to right, circular search strategy
46
Visual Attention

• Sub-serves visual search/scanning
• Visual search is an expression of visual
  attention
• Critical component for complex visual processing
• Attention to a target determines the level of
  assimilation
• Varies from global to focal depending on type of
  visual analysis needed
• Global attention is required for awareness that
  there is a chair in a room
• Focal attention is needed to identify the type of
  chair

47
Visual Attention

• Simultaneously employ at least 2 types of visual
  attention at all times
• Global awareness of objects in environment so one
  can navigate the environment
• Focal attention to the target so it can be
  identified
• Example locating a friend in a crowd and walking
  towards him
• Requires global attention to negotiate the crowd
  and focal attention to be sure that your friend
  doesnt move off before you reach him

48
Visual Attention

• Requires all of CNS to complete visual attention
• Structures in the brainstem, cerebral cortex and
  cerebellum are all involved

49
Foundation Functions

• Three visual functions form the foundation for
  all higher level visual perceptual processing
• Oculomotor control
• Provides perceptual stability
• Visual acuity
• Provides visual clarity-ability to see details
• Visual field
• Provides awareness of objects
• Without these visual functions no image would be
  generated within the CNS

50
All levels must work together

• Like parts of a car, loss or impairment of one
  level affects the functioning of all other levels
• Especially if a lower level function has been
  impaired

51
Example

• Patient with a left homonymous hemianopsia is
  blind in the left half of each eye
• Because of the blindness, the brain does not
  register objects on the left side
• Because brain does not register objects on the
  left, visual attention is not engaged towards the
  left
• Because visual attention is not engaged towards
  the left, pattern recognition is not completed
  for objects on the left side

52
Example continued

• Because pattern recognition is not completed,
  visual memory of the visual array on the left is
  not laid down
• Because visual memory is not laid down, the
  patient displays topographical disorientation, a
  cognitive inability to map out and navigate space

53
Changes in Visual PerceptionFollowing Brain
Injury

• Occur primarily as result of changes in 4 areas
  of visual function
• Visual field
• Visual acuity/focusing
• Oculomotor control
• Visual attention
• Impairment in each area runs along a continuum
  from mild to severe
• Persons ability to adapt depends on severity of
  the impairment and persons other strengths and
  weaknesses

54
Challenges Addressing Visual Impairment from
Brain Injury
55
Challenges

• Disability picture is very complex
• Many factors contribute to persons inability to
  complete daily activities
• Motor
• Language
• Cognitive
• Visual
• Psychological

56
Challenges

• Patient often presents ambiguous picture
• Visual impairment often looks like cognitive or
  motor impairment because it sub-serves both
• Very difficult to tease out the visual impairment
• Requires careful observation and a thorough
  understanding of the specific characteristics of
  visual impairment
• Aided by good understanding of neuroanatomy
• Correlate functional performance with location of
  brain injury

57
Challenges

• Critical to collaborate with other professionals
• Must have good communication with ophthalmologist
  or optometrist
• Not part of the standard of care yet
• Requires OT to facilitate referral
• Means that OT must be able to complete a good
  screening and justify request for referral
• Critical that OT, PT, Speech and Nursing
  communicate and work together
• OT must be able to communicate how vision affects
  functional performance

58
Challenges

• Visual impairment manifests over a long period of
  time
• Difficult to complete standardized evaluations in
  acute phases of recovery
• Must rely on observations
• Some visual impairments only become identifiable
  after other impairments have resolved
• Visual impairment persists after other
  impairments have resolved
• If you miss it initially, you still have time to
  identify the impairment

59
Challenges

• More visual impairments will occur with traumatic
  brain injury and it will be more difficult to
  identify the impairment
• Brainstem plays a major role in coordinating
  visual function and is very vulnerable in head
  trauma
• Damaged in 90 of cases
• Diffuse axonal injury causes disruption of visual
  processing on many levels
• Extent of permanent impairment may not be known
  immediately

60
Challenges

• Patients with stroke often show a mixture of
  neuro-related and age related impairment
• Conditions such as diabetes, atherosclerosis,
  cardiac disease, hypertension contribute to
  stroke and also cause retinal damage
• Older patients will have normal age related
  impairment in addition to acquired conditions
• Although stroke and head trauma are the major
  causes of visual impairment they are not the only
  causes
• Neurological diseases also cause impairment
• Parkinsons, multiple sclerosis, Huntingtons, etc.

61
Evaluation and Treatment Approach
62
General Approach

• In working with patients, vision must be viewed
  as part of a unified process used by the CNS to
  adapt to the environment and circumstances
• Not a singular, simple modality
• Ability to see the letter on an eye chart
• Not a series of discrete skills
• Little compartments in brain for position in
  space, visual closure, figure ground perception

63
Viewed as part of a unified process

• A patients visual performance is not significant
  in terms of how it deviates from the norm but how
  it interferes with occupational performance
• Whether or not a patient has a visual deficit
  that requires remediation depends on his/her life
  demands

64

• A patient has a visual deficit if his/her ability
  to obtain and/or process visual information has
  been altered to the extent it prevents completion
  of a necessary activity of daily living
• Viewing it from this perspective helps determine
  medical necessity
• Determine if treatment intervention is required
  and justified

65
OT Evaluation has 4 purposes

• Identify the limitation in occupational
  performance
• Link the performance limitation to the presence
  of an impairment
• Determine if treatment is necessary
• Identify most appropriate treatment intervention

66
Criteria for Treatment Intervention

• A person has a visual impairment that merits
  treatment intervention ONLY if it interferes with
  completion of a necessary activity of daily
  living
• Therefore observation of the patients functional
  performance is the cornerstone of evaluation

67
Two Treatment Approaches

• Person centered approach
• Emphasis is on changing the person
• Improving ability to take in and process visual
  information
• Environment centered approach
• Emphasis is on altering the environment to
  achieve a better person-environment fit
• Enable the person to respond with remaining
  capabilities

68
Education is a Critical Component of Treatment

• Education is critical to success because insight
  is critical to persons ability to adapt
• Education is particularly important for persons
  with visual impairment because we dont typically
  question the accuracy of our vision
• One reason why it takes a long time for 40
  somethings to realize that they need reading
  glasses for presbyopia

69
Goal never changes.

• Goal is always occupational performance
• Same as for any disability
• Only the method changes
• Instead of treating a patient with function
  limitations from a motor deficit, youre treating
  limitations from a visual deficit
• You will continue to provide occupational therapy
• This is NOT vision therapy and you are NOT a
  vision therapist

70
Professionals Involved in TX

• Ophthalmologist
• Neuro-ophthalmologist
• Board certified in dx/management of visual
  conditions caused by neurological impairment
• Optometrist
• Neuro or behavioral
• Orientation Mobility Specialist
• Addresses travel impairments
• Rehabilitation Teacher
• Involved if visual acuity is significantly
  affected
• Vision Teachers
• Involved in patient is K-12

71
Case Application

• Billy Ray Bottlerocket
• 19 yr old
• Sustained a closed head injury after being thrown
  from a 4 wheeler while off-roading with friends

72
Billy Ray

• Lives with his parents
• Buddy and Eulaha
• Older sister, Buffy attends Jefferson State

73
Billy Ray

• Works as a grounds keeper at the Hoover Country
  Club
• Prized possession
• An Alabama red Ford 150 4x4

74
Billy Ray

• 6 weeks post injury
• Comatose for 3 weeks after his injury
• Sustained a severely crushed right ankle in
  addition to the head injury
• Casted and non weight bearing at this time
• Cognitive Status
• Rancho Level IV-V
• Motor Status
• Limited ROM left UE/LE with residual increased
  tone
• Mild ataxia right UE/LE