Cognitive-Perceptual Disorders in Stroke PDF

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COGNITIVE-PERCEPTUAL DISORDERS IN STROKE

Question to the class- What you cognitive-perceptual deficits would you expect post stroke?    

Short term/long term memory problems Neglect Mood changes – depression, apathy Visual changes

Cognitive-Perceptual Deficits:    

Can greatly reduce effectiveness of rehab treatment Limits ability for functional return and independence Important for PTs to understand how these deficits may present and the implications for treatment Necessity to adapt standard treatment techniques as well as utilize some newer approaches to maximize outcomes

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Must differentiate from o Sensory loss o Language impairment o Hearing loss o Motor loss (weakness, spasticity, incoordination) o Level of fatigue o Visual disturbances o Disorientation o Lack of comprehension o Depression, apathy

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Before patient examination: Need to consider medications patient is taking o Some of these change level of arousal especially anti-spasmodic and anti convulsants  Cause drowsiness  Processing information is slowed down – especially with anti convulsants Can affect pt. state of arousal resulting in poor performance during testing Many meds have drowsiness as a side effect

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Must rule out pure sensory deficits prior to testing for cognitive/perceptual problems if not, therapist may attribute poor performance to cognitive/perceptual problems treatment approach will then be inappropriate OT will be the primary discipline involved

Somatosensory impairment   

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Pt’s ability to integrate sensory info is related to pt’s state of alertness Somatosensation is important for executing and guiding movement o Continual feedback Somatosensory impairments o Can contribute to poor control of movement o Can occur together with motor deficits, compounding problems  Strength and sensory impairments – lead to problems with motor control Will also impact on effectiveness of rehab treatment

Sensory Testing 

Rule out disturbances, test: o Superficial sensation o Deep sensation o Cortical sensation o Hearing: does the patient where a hearing aid?  They may appear to be receptively aphasic but they just don’t have their hearing aid in

Visual Impairments  

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Visual impairments are one of the most common forms of sensory loss affecting pts with hemiplegia Stroke lesions can affect o Optic radiation –in the occipital lobe o Visual cortex o Cranial nerves Looking at the picture to the right: o Left and Right field of vision o What visual cuts would you expect at 2,3,4 and 5 (fyi: he used a different picture, so the numbers he is saying in the recording will not match these numbers)

o 2(optic nerve)- total right eye o 3 (optic chiasm)- peripheral vison in both eyes  bitemporal hemianopsia  information from the right visual field hits the retina on the left and vice versa  all of the information from your right visual field gets processed in the left occipital lobe  in your right eye, the information has to cross over  in the left eye it doesn’t have to cross because it is already on the left  (both still have to cross initially to hit the left retina)

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this visual field cut can often occur in those with pituitary tumors or have had them removed o 4 (right optic tract)- left visual field of both eyes  homonymous hemianopsia o 5- quadrinopsia (he doesn’t expect us to know this – focus on the others) Visual system is the primary source of info about our environment Vision plays a crucial role in postural control Visual info guides us in all motor activity Integration of sensory input, including vision, allows for adaptation to our environment Can impair a pt’s ability to engage in rehab and function in daily life Results in a decreased ability of the CNS to use vision in environmental adaptations o Vison in used a lot for motor learning (feedback)  Vision impairments might impair their ability to learn or relearn movements Be aware of any pre-existing visual problems prior to tx. (e.g., decreased visual acuity, cataracts, macular degeneration) o Example: Do they have their glasses with them? 

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2 Types of Visual Impairments  

Low vision (peripheral disorders) o Glaucoma, diabetic retinopathy, macular degeneration Neurologically based o Diplopia – often times occurs d/t cranial nerve involvement (3,4,6) o Hemianopsia o cranial nerve involvement

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Acuity: o Does the pt. wear or need glasses? Oculomotor control o Diplopia: double vision o Convergence/divergence: maintain focus on an object as it is moved nearer or farther away o Ocular pursuits (smooth pursuit): eyes follow a moving object and visually scan the environment o Oculomotor dysfunction usually accompanies visual-perceptual dysfunction Visual field o Homonymous hemianopsia o Close correlation between visual field deficits and visual neglect

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You do not always need to have visual field impairments in order to have neglect

Other o Cortical blindness: secondary to damage/lesion to visual cortex o Retinal damage

Homonymous Hemianopsia   

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Loss of vison in ½ of the visual field in each eye contralateral to side of lesion Most common with MCA strokes MCA main stem syndrome secondary infarction of white matter of the optic radiation in the internal capsule o Can result in hemi-neglect (but you do not need visual impairments in order to have hemi neglect)  More common in the right hemisphere  Left neglect (right neglect is not common unless the dominant hemisphere of brain is switched) MCA inf. Div. syndrome- lesions involving either right or left hemisphere NOTE: VISUAL CUT I S NOT U SUALLY STRAIGHT DOW N THE MIDDL E Can also occur with lesions to primary visual cortex (PCA territory) o However, PCA strokes are not as common as MCA Greatly affects functional related outcomes Examination of visual field o Therapist sits directly in front of patient o Patient instructed to maintain gaze on therapist’s nose o Slowly bring target into patient’s field of view alternating each side o Patient is instructed to indicate when or where she/he sees it Other signs o Only recognizes objects on one side of a visual scene Compensation Training o Make patient aware of deficit (visual field cut or neglect) and frequently instruct to turn head to affected side  Example: put their television towards the affected side to make them more aware o Early in therapy, therapist and items should be placed on intact side o Progressively move to midline

o When appropriate, move to affected side o Gradually decrease reminders as patient is better able to compensate Cognition   

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Can also be impaired in patients with stroke, depending on what part of the brain is involved Ability to concentrate, learn and remember Relies on intact: o Memory- visual and verbal o Orientation o Language variability – verbal fluency and comprehension o Visuospatial reasoning o Attention Executive functions/higher order cognition Important component o Initiation/preservation – starting/stopping activities o Cognitive persistence and flexibility - task persistence or switching tasks o Self-monitoring- behavior selection based on situational context o Abstract thinking (includes planning) o Working memory – store and manipulate data during problem solving

Perception  

Ability to take sensory information and integrate it into a form that is meaningful o Putting senses into a meaningful form Perceptual deficits are not deficits in sensation but are deficits in the ability to interpret the sensation

Cognitive Perceptual Disorders 

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Cognition o Attention disorders o Memory disorders o Executive dysfunction (frontal lobe) Perception o Body scheme/image o Spatial relations o Agnosia o Apraxia

Cognition 

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Attention Disorders o Sustained attention o Focused or selective attention o Alternating attention

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o Divided attention Attention Disorder Treatment Suggestions: treat in closed environment with little visual or auditory stimulation. Cut out card for reading. o Example: Closed off environment with a curtain decreases visual feedback Memory Disorders o Immediate recall o Short-term memory o Long-term memory: rarely impacted in stroke Strategies: o Address attention deficits first o Simplify info and instructions to patient o Minimal distractions o Teach strategies to encode, memory book o Typically OT and Psych: however reinforce whatever techniques are given to them Executive Function Involves: o Volition: ability to determine what you want/need to do o Planning: organization of the steps needed to achieve a goal o Purposeful action: productivity and self-regulation o Effective performance: the ability to self-monitor and self-correct

Executive Dysfunction 

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May See: o Hypo or hyperactivity o Unable to formulate realistic goals – poor self awareness o Planning problems may say one thing and do another o May appear to have lack of initiation o May not perceive mistakes – poor self awareness o Poor judgement o May appear apathetic Cognitive Rehab Strategies o Provide:  Structure  Feedback (immediate)  Routine  Goal management therapy o Environmental Modification  Minimize distractions  Alarms for initiation o Also primarily OT and Psych, but we need to be aware of these strategies so that we can reinforce them

Perception: Body 

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Body image: visual and mental image; and feelings about one’s body

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Body scheme: postural model of one’s own body, including the relationship of body parts to each other and the environment Body awareness: derived from integration of tactile, proprioceptive and interoceptive sensations All are needed for purposeful motor behavior/learning

Perceptual Disorders    

Unilateral Neglect Anosoagnosia Somatoagnosia Right-left discrimination

Perceptual Disorders: Unilateral Neglect 

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Inability to register and integrate stimuli and perceptions from one side of the body (body neglect) and the environment (spatial neglect) o Can present as neglect of environment or own personal body. Can often me a little bit of both o For example: forget to groom that side of body Most common is left-sided neglect May occur despite intact visual fields May occur concomitantly with R or L homonymous hemianopsia however, not as a result of Secondary to lesions of inf/post regions of R parietal lobe Clinical Signs o May not put L sleeve or pant leg on o May not shave or apply makeup to L side o May not eat food on L side of plate

Perceptual Disorders: Anosognosia       

Lack of awareness or denial of deficits o Usually they lack the cognitive awareness/insight of what has happened to them Most troublesome when associated with hemiplegia o The more motor impairments, the harder it is to work with them May impair patient’s motivation to engage in rehab May not recognize need to compensate More frequent in R than L hemispheric stroke Usually resolves within 2 weeks, persist in...