Perceptual Disorders ppt .pptx

This presentation was prepared for the physiotherapy students to discuss on the perceptual disorders in stroke patients.

1. Perceptual Disorders Moderator : Mr. Sydney Roshan Rebello Presenter : Ashik Dhakal

2. Content Introduction to perceptual disorders Types Clinical implication, Testing and treatment References

3. Sensation Cognition Perception Sensation may be defined as the appreciation of stimuli through the organs of special senses. Cognition is the act or process of knowing, including awareness, reasoning, judgment and memory. Perception is defined as the integration of sensory impressions into information that is psychologically meaningful.

4. Perceptual disorders occur following Brain damage,(> on Stroke and TBI) Stroke can produce visual- perceptual deficits with a reported incidence ranging from 32 to 41 % These may include perceptual deficits such as Body scheme/body image , disorders of Spatial relations , Agnosias and Apraxia

5. Body image is the visual and mental image of one’s body that includes feeling of one’s own body Body scheme refers to a postural model of the body including the relationships of body parts to each and the environment. Both may be distorted following stroke

6. Specific impairments of Body scheme and Body images Unilateral neglect Anosognosia Somatoagnosia Right- Left discrimination Finger agnosia

7. Unilateral neglect Unilateral neglect is defined as the inability to register and integrate stimuli and perceptions from one side of the body and environment or hemispace, which is not due to sensory loss. Synonyms : unilateral spatial neglect, hemi- inattention, hemi- neglect, and unilateral visual inattention Is the most common perceptual disorder

8. If a patient has unilateral neglect, he or she seems to ignore the one side of the body and stimuli occurring in the same hemispace. This may occur despite intact visual fields. Site of lesion — parietal lobe or temporo-parietal junction.

9. Unilateral neglect may express itself as a disorder of attention and goal directed behaviour in : Contralesional personal space : shaving only the right half of the face, or failing to wash the left side of the body Contralesional peri-personal space (area of space within arm distance) failing to use objects on the contralesional side of the meal tray. Contralesional extrapersonal space (area of space beyond arm length) failing to negotiate obstacles, doorways and so forth during locomotion.

10. Some patients neglect half of the environment

11. Neglect half of objects in the total environment

12. Hemi-lateral neglect and hemianopia left sided hemianopia —actual loss of vision from the left visual field of both eyes, —may be aware of the problem and compensate automatically or learn to compensate by turning the head. A patient with visual neglect has intact vision but seems unaware of the problem and does not attempt to compensate by turning the head.

13. Clinical example Patient may ignore the left half of the body when dressing and forget to put on the left sleeve or left pants Often a male patient might forget to shave the left half of his face Patient may start reading a news paper from the middle of the line Assessments : Line bisection tests, cancellation test, copying and drawing tests, Behavioural inattention test, Catherine bergego scale.

14. Treatment approach Stimulus enhancing right side of the brain — shapes and blocks Inhibit left brain activation — letters and numbers should be minimized . Simple verbal instructions — to turn the head to the left to lead his attention to that side of space. Research suggests that conducting motor activities with the left side of the body such as simply clenching and unclenching the fist can improve attention to left hemispace .

15. Treatment : Weinberg et al — scanning to the left. An initial target that served as an anchoring point was placed in the left hemispace of a reading task . Robertson et al — auditory reminder consisted of unpredictable loud knocking on the desk and a loud verbal command to “ Attend ” Smania et al — Visual imagery exercises - describing the position of objects in a room of their home and visualizing a word and then spelling it backwards. visualize moving through the sequence and to verbalize their visual representations.

16. Rossi et al — used prisms that were attached bilaterally to the left half of eyeglasses of patients with left-sided USN. The prisms shifted peripheral images to a more central position on the retina. The patients showed improvement after 4 weeks of wearing the prisms.

17. Eye patch : In an individual with an intact nervous system, retinal input from the eye is strongest to the contralateral superior colliculus . Visual stimuli to the right superior colliculus generates leftward saccades , whereas visual stimuli to the left superior colliculus generates rightward saccades. This method is thought to control the intention and direction of gaze, generating leftward saccades.

18. Ramchandra and colleagues Mirrors : to facilitate attention to the neglected side. Placed a mirror in the right parasagittal plane of patients with left neglect so that the left hemispace was visible to the patient. When the patients were asked to reach for an object in the left hemispace that was visible in the mirror on the right, some patients were able to locate the object in the left hemispace. Other patients attempted to reach for the mirror image of the object, named this behavior mirror agnosia .

19. Anosognosia A severe condition including denial and lack of awareness of the presence or severity of one’s paralysis or illness. Clinical examples : patient says there is nothing wrong and may disown the paralysed limbs and refuse to accept responsibility for them. e.g The patient may claim that the limb has a mind of its own or that it was left at home, or it may belong to someone else, or changes the topic.

20. Site of lesion — supramarginal gyrus, pathogenesis remains unclear. Testing : identified by talking to the patient , by asking what happened to the arm or leg, whether he is paralysed, how the limb feels and why it cannot be moved. Treatment : Anosognosia often resolves spontaneously in the first 3 months following stroke. Until resolved, it seriously hampers rehabilitation Safety is most important in the treatment and discharge planning for patient , as they typically do not acknowledge their disability and will therefore refuse to be careful.

21. Somatoagnosia Also known as impairment in body scheme , is a lack of awareness of the body structure and the relationship of body parts to oneself or to others. Patients with this deficit may display difficulty following instructions that require distinguishing body parts and may be unable to imitate movements . Also referred to as Autopagnosia or simply body agnosia.

22. Clinical examples : May have hard time participating in exercises that require some body parts to be moved in relation to other body parts. Eg: bring your arm across your chest and touch your shoulder. The lesion site— dominant parietal lobe, seen primarily with right hemiplegia.

23. Testing : The patient is asked to answer questions about the relationship of body parts. Eg :which is on top of your head, your hair or your feet ? The words right and left should not be used because they may lead to an inaccurate diagnosis in patients who have difficulty with right- left discrimination. For patients with aphasia , questions should be phrased to require a yes or no response

24. Treatment approaches Facilitation of body awareness is accomplished through sensory stimulation to the body part affected. Eg; patient is asked to rub the appropriate body part with a rough cloth as the therapist names or points to it.

25. Right- Left Discrimination Inability to identify the right and left sides of one’s own body or of that of the examiner. This includes inability to execute movements in response to verbal commands that include the terms right and left.

26. Clinical examples Patient cannot tell the examiner which is the right arm and which is the left. The right shoe cannot be discerned from the left shoe and unable to follow instructions using the concept of right left such as turn right . The lesion site is the parietal lobe of either hemisphere

27. Testing Patient is asked to point to body parts on command such as right ear, left foot etc. 6 responses should be elicited on either the patient’s own body or examiner or picture of a human body.

28. Treatment approaches If using compensatory approach when giving instructions to the patient, the words right and left should be avoided . Pointing or providing cues using distinguishing features of the limb may be more effective. Eg : the arm with the watch. The rt side of all common objects such as shoes and clothing should be marked (red tape).

29. Finger Agnosia Inability to identify the fingers of one’s own hands or of the hands of the examiner. Clinical examples : Characterised by difficulty in naming the fingers on command, identifying which finger was touched. This deficit usually occurs bilaterally and is more common in the middle 3 fingers.

30. Finger agnosia correlates highly with poor dexterity (typing, buttoning). Result of a lesion located in either parietal lobe often in the region of the angular gyrus of the left hemisphere Often found in conjunction with an aphasic disorder

31. Testing Sauguet’s test includes asking the patient to move or point to his finger when named by the therapist. The patient is asked to name the fingers touched by the examiner with the eyes open 5 times, if successful, with vision occluded, 5 times.

32. Treatment approches : Patient’s discriminative tactile systems ( touch and pressure ) are to be stimulated. A rough cloth can be used to rub the dorsal surface of the more affected arm, hand and fingers. Pressure can be applied to the ventral surface of the hand.

33. Disorders of Spatial relations/ complex perception Disorders of Spatial relations refers to a collection of impairments that have in common a difficulty in perceiving the relationship between self and 2 or more objects in the environment. It includes specific impairments in figure –ground discrimination, spatial relations, position in space, topographical disorientation, form discrimination, depth and distance perception, vertical disorientation.

34. 1. Figure ground discrimination Inability to visually distinguish a figure from the background in which it is embeded. Functionally interferes with the patient’s ability to locate important objects. Increased distractability — Difficulty in ignoring irrelevant stimuli and cannot select the appropriate cue to which to respond.

35. Clinical examples : The patient cannot locate buttons on a shirt. May not be able to tell when one step ends and another begins on a flight of stairs Site of lesion — Parieto-occipital lesion of the right hemisphere and less frequently the left hemisphere commonly produce this disorder

36. Testing The Ayres Figure Ground Test : requires the subject to distinguish the three objects in an embedded test picture, from a possible selection of six items. Functional tests: a white towel can be placed on a white sheet and ask the patient to find the towel , can be asked to point out the sleeve buttons or collar of a white shirt

37. Treatment Remedial approach : the therapist should arrange for practice in visually locating objects in a simple form and progress to more difficult ones. Compensatory approach : Patient is taught to become aware of the existence and nature of the deficit. Patient should be cautioned to examine groups of objects slowly and systematically and should be instructed to use other intact senses eg: touch

38. 2. Spatial relations disorders aka spatial disorientation, is the inability to perceive the relationship of object in space to the other or to oneself. The patient might find it difficult to place the plate and spoon in proper position Problems in constructional tasks and dressing. Spatial relation skills are required to manage most activities of daily living

39. Testing River mead Perceptual Assessment battery Includes 16 subtypes : picture matching, object matching, size recognition, series, missing article, sequencing pictures, right/left copying words, color matching, cube matching, figure ground discrimination, copying shapes, three dimensional copying, cancellation, animal halves, body-image self identification, and body image. Site of lesion — inferior parietal lobe or parieto-occipital –temporal junction usually of the right side Treatment : Patient’s ability to orient to other objects can be improved by giving the patient instructions to position himself in relation to another object . Eg: step over the line.

40. 3. Position in space Position in space impairment is the inability to perceive and to interpret spatial concepts such as up, down, under, over in , out, infront of, and behind. Eg : If asked to raise the arm above the head or if asked to place the feet on the footrests the patient may behave as if he or she does not know what to do. Site of lesion— non dominant parietal lobe .

41. Testing 2 objects are used such as shoe and a shoe box Asked to place the shoe in different positions in relation to the shoe box eg : In the box, on top of the box, or next to the box Treatment 3 or 4 identical objects are placed in the same orientation, an additional object is placed in a different orientation. The patient is asked to identify the odd one .

42. 4. Topographic disorientation Difficulty in understanding and remembering the relation of one location to the another. Patient is unable to get from one place to another with or without a map. This disorder is frequently seen in conjunction with other difficulties in spatial relationships.

43. Clinical examples Patient cannot find the way from his room to the therapy clinic despite being shown repeatedly. Site of lesion — right retrosplenial cortex (behind splenium of the corpus callosum) with Brodmann’s area 30 compromised in most patients. Bilateral parietal lesions and more rarely left side parietal lesions can produce this problem.

44. Testing Ask to describe or draw a familiar route, such as the block on which he lives. An impaired patient will be unable to succeed in this task Treatment This deficit usually resolves 8 weeks post –onset. Patient practices going from one place to another following verbal instructions. Initially simple roots should be used, and then more complicated ones

45. Form Discrimination Inability to perceive or attend to differences in form and shape , patient is likely to confuse objects of similar shape. Clinical Examples . The patient may confuse a pen with a toothbrush, a vase with a water pitcher, a cane with a crutch, and so forth. Site of lesion : lesion site is the parieto-temporo- occipital region (posterior association areas) of the nondominant lobe.

46. Testing A number of items similar in shape and different in size are gathered, patient is asked to identify them. Eg pencil, pen, straw, toothbrush, and watch, and the other might be a key, paper clip, coins, and ring. Each object is presented several times in different positions (e.g., upside down).

47. Treatment Suggestions Remedial Approach: The patient should practice describing, identifying, and demonstrating the use of similarly shaped and sized objects. The patient should be assisted to focus on differentiating object cues. Compensatory Approach. The patient must be made aware of the specific deficit. If the patient can read, frequently used and confused objects can be labeled. Encouraged to use vision, touch, and self-verbalization in combination when objects are confused.

48. Depth and Distance Perception The patient with a disorder of depth and distance perception experiences inaccurate judgment of direction, distance, and depth. Clinical Examples . The patient may have difficulty navigating stairs, may miss the chair when attempting to sit, or may continue pouring juice once a glass is filled. Site of lesion : posterior right hemisphere in the superior visual association cortices, it may be evident with right-sided or bilateral lesions.

49. Testing a. For a functional test of distance perception, The patient is asked to take or to grasp an object that has been placed on a table. The object may also be held in front of the patient, in the air, and the patient is again asked to grasp it. The patient with impaired distance perception will overshoot or undershoot. However, the movements look purposeful and smooth, which distinguishes this problem from a coordination deficit. b. To determine depth perception functionally, the patient can be asked to fill a glass of water. A patient with a depth perception deficit may continue pouring once the glass is filled.

50. Treatment Suggestions The patient should be assisted in becoming aware of the deficit. Emphasis should be placed on the importance of walking carefully on uneven surfaces, particularly the stairs. a. Remedial Approach : The patient is requested to place the feet on designated spots during gait training. Blocks can be arranged in piles 5 to 8 cm high. The patient is asked to touch the top of the piles with the foot, to reestablish a sense of depth and distance. b. Compensatory Approach. Practice in compensating for disturbances in depth and distance perception occurs intrinsically in many ADL skills, both those involving moving through space and those that involve manipulation.

51. Vertical Disorientation Vertical disorientation refers to a distorted perception of what is vertical. Displacement of the vertical position can contribute to disturbance of motor performance, both in posture and in gait. Clinical Example . A person with distorted verticality views the world differently and this may affect upright posture. lesion site is in the nondominant parietal lobe .

52. T esting The therapist holds a cane vertically and then turns it sideways to a horizontal plane. Researchers use a luminous rod with patients seated in a darkened room The patient is handed the cane and asked to turn it back to the original position. If the patient’s perception of the vertical position is distorted, the cane will most likely be placed at an angle , representing the patient’s conception of the world around himself or herself. Treatment Suggestions . The patient must be made aware of the deficit, should be instructed to compensate by using touch (tactile cues) for proper self-orientation, especially when going through door-ways, in and out of elevators, and on the stairs.

53. Agnosias/simple perception Agnosia is the inability to recognise incoming information despite intact sensory system. Types : Visual agnosias Auditory agnosias Tactile agnosia or Astereognosia

54. Visual Agnosia Defined as inability to recognize familiar objects despite normal function of the eyes and optic tracts Visual object agnosia is the most common form of agnosia. The patient may not recognise people, possessions and common object.

55. Simultanagnosia aka, Balint’s syndrome is the inability to perceive a visual stimulus as a whole. Colour agnosia is the inability to recognize colors, it is not color blindness. Unable to identify or name colors on command although color chips can be correctly paired. Prosopagnosia also called face blindness, is a cognitive disorder of face perception in which the ability to recognize familiar faces, including one's own face (self-recognition), is impaired.

56. Lesion area : occipito-temporo-parietal association areas of either hemisphere. Testing : several common objects are placed in front Asked to name the objects , to point to an object named by the therapist.

57. Treatment Practice discrimination between faces, colors and common objects. Examiner should assist the patient in picking out salient visual cues for relating names to faces. The patient can be instructed to use intact sensory system such as touch or audition to distinguish people and objects.

58. Auditory agnosia Inability to recognize non speech sounds or to discriminate between them. Rarely occurs in the absence of other communication disorders. Patient cannot tell, eg: the difference between the ring of a doorbell and that of a telephone or between a dog barking and thunder.

59. Lesion : dominant temporal lobe Testing : patient asked to close the eyes and identify the source of various sounds Treatment : generally drilling the patient on sounds but this has not been found to be particularly effective

60. Tactile agnosia Inability to recognise forms by handling them, although tactile , proprioceptive, and thermal sensations may be intact. If tactile agnosia is present in combination with unilateral neglect or sensory loss, performance in ADL may be severely hampered. If a patient is handed an object (key, comb, safety pin) with vision occluded, he will fail to recognize it.

61. Lesion area : parieto-temporo-occipital lobe of either hemisphere. Testing : asked to identify objects placed in the hand by examining them manually without visual cues. Treatment Practice feeling , various common objects , shapes, and textures with vision occluded. To improve cognitive awareness the patient is educated concerning the nature of the deficit and is instructed in visual compensation.

62. Apraxia Apraxia is an impairment of voluntary skilled learned movement It is characterised by an inability to perform purposeful movements , not because of inadequate strength, loss of co-ordination, impaired sensation, attentional difficulties, abnormal tone, movement disorders. Types : Ideomotor apraxia, Ideational apraxia and Buccofacial apraxia

63. 1. Ideomotor apraxia Refers to breakdown between concept and performance . There is disconnection between the idea of a movement and its motor execution Information cannot be transferred from the areas of the brain that conceptualize to the centers for motor execution. Habitual tasks : performs same movement over and over again

64. Clinical example : unable to blow on command , however if given a bubble wand, the patient will spontaneously blow bubbles. Lesion area : left dominant hemispheres, both frontal and posterior parietal lesions can result in apraxia Testing : comprises of universally known movements, such as blowing, brushing , shaving etc Treatment It is advised that the examiner speak slowly and use the shortest possible sentences. Divide the tasks and a great deal of repetition may be necessary, occupational therapy treatment program including strategy training.

65. Ideational apraxia Failure in the conceptualization of the task It is an inability to perform a purposeful motor act either automatically or on command. Patient no longer understands the overall concept of the act. Cannot retain the idea of the task or cannot formulate the motor patterns that are required

66. Clinical example : when given a toothbrush and toothpaste and told to brush the teeth, the patient put the tube of tooth paste in the mouth further he may be unable to describe verbally how tooth brushing is done. Lesion area : dominant parietal lobe. Testing : tests for ideational apraxia are similar to those for ideomotor apraxia Difference in the response is that with ideomotor patient can perform a motor act spontaneously at the appropriate time but in ideational is unable to do so. Treatment : techniques are same as ideomotor apraxia

67. Buccofacial apraxia Buccofacial or oral apraxia involves difficulties with performing purposeful movements with the lips , tongue , cheeks , larynx and pharynx on commands . Clinical example : patient may have difficulty in responding to the command, (pretend to blow out a candle) Lesion area : frontal and central opercula, anterior insula, and a small area of the first temporal gyrus.

68. Testing : The patient should be examined by a speech language pathologist. Treatment : the speech language pathologist can advice the health care team on strategies to communicate with patients who have buccofacial apraxia.

69. Pusher syndrome First described by Patricia Davies 1985 Pusher syndrome is a clinical disorder in which patients actively push away from the nonhemiparetic side, leading to a loss of postural balance.

70. In this, perception of body posture in relation to gravity is altered. In contrast, patients show no disturbed processing of visual and vestibular inputs determining visual vertical. left and right hemisphere damage occurs with equal frequency Site of lesion : left or right postero-lateral thalamus

71. Treatment : Follows following steps: Realise the disturbed perception of erect body position. Visually explore the surroundings and the body’s relation to the surroundings. Room containing many vertical structures , such as door frames, windows, pillars, and so on should be used Learn the movements necessary to reach a vertical body position. Maintain the vertical body position while performing other activities.

72. References Susan sullivan Assessment of unilateral neglect Unilateral spatial neglect Pusher Syndrome Physical Therapy, Volume 84, Issue 6, 1 June 2004, Pages 580–583 Perceptual disorder for adult with hemiplegia

73. Thank you