Cognitive deficits following stroke Flashcards
cognitive domains affected following stroke?
5 categories
1) attention - focus attention, sustained/ selective/ divided attention
2) memory - visual/ auditory/ working memory/ episodic/ semantic/ procedural (non-cued recall more affected than recognition = suggest its more executive problem than amnestic - cumming, 2012)
3) executive function - imitation/ processing speed/ problem solving/ planning
4) perception/ praxis - visuo-spatial/ visuo-perceptual/ unitlateral neglect/ inattention/ dyspraxia/ apraxia/ agnosia/ prosopagnosia
5) language - aphasias, brocas/ Wernicke’s/ transcortical motor or sensory or mixed/ conductive/ global
- - left hemisphere associated with more cognitive deficits
- - not necessarily all features in one domain will be affected
- - there will be overlaps in these cognitive function eg. selective attention may affect processing speed
Definitions
praxis
agnosia
prospoagnosia
- praxis= process of getting an idea, initiating, and completing new motor tasks. It is an end product of input from all the necessary systems and the brain
- integrated info from the sense of touch, balance and movement, vestibular, vision and hearing, may be necessary for good motor planning
- individuals with motor planning problems have to think harder to complete motor tasks than other people because of poor info from sensory systems
- agnosia= inability to interpret sensations or recognise info from sensory input
- prosopagnosia = inability to recognise faces (fusiform gyrus)
General assessment for cognitive impairments following stroke (3)
1) mini mental state examination
2) montreal cognitive assessment
3) neuropsychological test
1) mini mental state examination
tasks? (6)
scores that represent deficits?
strengths/ limitations
a practical method for grading the cognitive state of patients for the clinician
- a brief screening tool that provides a quantitative assessment of cognitive impairment of multiple domains
- orientation (spatial and temporal): what year, date, time, month etc
- registration: name 3 objects and then ask the patient to recall them all after you have said them
- attention and calculation: ask the patient to count backwards in 7s from 100. Ask them to spell words backwards
-recall = ask the patient to recall the 3 objects from registration task
-language = show patients a pencil and watch - ask them to name objects
- follow a 3 stage command = take paper in you hand, fold it and put it on the floor. write a sentence. copy the design shown
- patients given a score out of 30
24-30 = no cognitive impairment
18-24 = mild cognitive impairment
0-17 = severe cognitive impairment
strengths:
- easy to complete
- quick
- inexpensive
- used widely
- doesn’t require training
- easy to interpret
Limitations: - lacks sensitivity (particularly with mild cognitive impairment individuals and patients with right- sided strokes) - lacks evaluation of exec function -confounded by age - confounded by level of education - confounded by sociocultural background = could lead to misclassification
Montreal cognitive assessment
tasks used?
to assess?
strengths/ limitations
use tasks such as: - clock drawing -picture naming -recall -abstraction (similarity between 2 objects) Used to assess the following domains: - attention and concentration - executive functions - memory -language - visuoconstructional skills - conceptual thinking, calculations, and orientation
Strengths:
- more sensitive than the MMSE (detects impairments that score in normal range on MMSE)
- availability of alternate MoCA eg. multiple languages
- freely accessible
Limitations:
- relatively new = reliability and validity may not be thoroughly tested
Neuropsychological test
tests?
strengths/ limitations
- visuospatial memory tests
- verbal learning tests
- weschler memory scale
- Dells-Kaplan executive function system
- number/ letter sequencing
- boston naming test
- Weschler Adult intelligence scale (WAIS)
- phonetic/ category fluency
= a comprehensive battery of neuropsychological tests to assess a wide range of cognitive functions
such as: - attention
-memory
-language
-executive function
strengths:
- very comprehensive
limitations:
- time consuming and can be tiring for patients (could be tiredness causing poorer performance, rather than stroke)
Unilateral neglect
which part of brain damaged? Type of issue?
perception deficit
= failure to report, respond or orient to sensory stimuli presented to the side contralateral to the stroke lesion
-USN is found in about 23% of stroke patients
-more common in patients with Right sided lesions(42%) than left (8%)
- sensory issue = parietal lobe affected in someone with USN (not a visual deficit = sensory processing issue)
–> parietal damage not occipital
Unilateral spatial neglect
Assessed by? (3)
1) line bisection test
2) clock drawing test
3) behavioural inattention test
line bisection test
strengths
limitations
assessed by:
- line bisection test = consists of 18 horizontal lines drawn on paper. Patients have to put a mark on each line that bisects it into equal parts (scored by measuring deviation of line from centre. 6mm or more = indicates USN, also if patient misses 2 or more lines on one side of the paper)
- -> can be performed using pen and paper and by behavioural activity or a combo
- -> using a battery of tests are often more sensitive than a single test
strengths = simple, inexpensive and doesn’t require training
limitations = lack of sensitivity
clock drawing test (CDT)
provides a quick assessment of visuospatial and praxis abilities and may detect deficits in both attention and executive dysfunction
- involves having patient draw a clock, place the numbers on the clock in their proper positioning and then placing the arms at the requested time
- -> task itself is viewed as highly complex involving a number of neuropsychological abilities (Suhr et al)
- scoring system (many suggestions) - all evaluate errors and/ or distortions in the form of omissions of numbers and errors in their placement such as perseveration, transpositions and spacing
strengths:
- brief, inexpensive and easy to administer
- may help to complete a picture of cognitive function when it is used with other assessment tools
- acceptable levels of reliability and has been shown to correlate highly with other cognitive screening measures
limitations:
- negatively influenced by increasing age, reduced education
- may also be affected by visual neglect, hemiparesis (Weakness/ paralysis in one side of the body) and motor discoordination
(most effective use for CDT may be a supplement to other cognitive assessments, rather than an independent screening tool)
Behavioural inattention test (Wilson et al, 1987) BITC BITB strengths limitations
screens for unilateral visual neglect and provides information relevant to its treatment (Halligan et al ,1991)
scoring: BIT yields a total score of 227 with higher scores indicating greater degrees of neglect
-cutoff for BIT:
BIT: 196/227
BITC: 129/ 146
BITB: 67/81
BITC = behavioural inattention test - conventional section eg. line crossing, letter cancellation, star cancellation, shape copying, line bisection, representational drawing
BITB = behavioural section - picture screening, phone dialling, article reading, telling and setting the time, coin sorting, address and sentence copying, map negotiating, card sorting
strengths:
- BIT is a comprehensive battery that provides a detailed and ecologically valid assessment of patient functioning (Halligan et al, 1991)
- a parallel form of the test is available, which allows for re-testing with minimal concern for practice effects
- the behavioural subtests can be used to help therapists target tasks that should be given particular attention during treatment
limitations:
- more time consuming and expensive than most non-battery tests of neglect
- 40 mins for completion is quite taxing on patients
Remedial treatments for USN: (3)
remedial training aims for direct restoration of function
- focuses on training the patient to voluntarily compensate for their deficits
- require full cooperation from the patient, the patient must be aware of deficit
1) visual scanning - patients with visual neglect often don’t scan their whole environment = no attention to one side of space
- visual scanning teaches patients to look to both sides in a consistent manner (eg. left side)
- strong evidence that treatment using visual scanning improves visual neglect with associated improvement in function
2) computer-based scanning - computer versions of tasks associated with visual scanning have been developed
- offers a means to supplement costly treatments/ therpay with massed practice
- moderate evidence (based on 1 RCT) computer-based visual scanning doesn’t remediate visual neglect
- can be done at home
3) virtual reality therapy for neglect - several studies have been promising but has been very expensive
- Nintendo wii and other games offer potentially cheap alternative and is gaining popularity in rehab unit
- limited evidence virtual reality training may help to improve awareness of neglected space
Compensatory treatments (4) and evidence for them?
1) prisms adaptation for neglect
- prisms affect spatial representation by calling on optical deviation of the visual field
- prisms tend to shift the visual field input and increase visual fields by 5-10 degrees
- outside of the visual field when looking straight ahead but when gaze is shifted to the side = increases visual field
- strong evidence prism treatment associated with increases in visual perception scores in stroke patients with hemianopsia and visual neglect; however, it was not associated with improvement in ADL scores (Rossi et al)
2) Limb activation strategies
- intended to increase orientation and attention to neglected hemi-space
- motor or externally-applied sensory stimulus to the affected side attempts to ‘activate’ the right hemisphere
- includes limb activation(well studied) as well as application of a sensory stimulus (less well studied)
- strong evidence that limb activation therapies improve neglect (Robertson, 2002)
- however, little info with regard to duration of effect or effect of treatment on functional ability
3) sensory feedback strategies for neglect
- intended to improve awareness and attention to neglected space
- include audity and visual feedback
- make patient aware of neglect behaviours and may assist in learning new ways to remediate neglect
- strong evidence feedback strategies are beneficial in treatment of neglect
- more study needed to establish generlisability to other behaviours and to determine durability of effects
4) Eye patching and hemispatial glasses
- eye patching of the eye ipsilateral to lesions causes the patient to attend to unpatched side
- moderate evidence that monocular, opaque patching to improve neglect works (inconsistent results)
- moderate evidence that bilateral half-field eye patches improve visual neglect and functional ability
Dyspraxia/ Apraxia
-damage where?
assessment?
treatment?
= a perceptual problem. It is the reduced ability to coordinate, perform, plan or carry out specific movements even when there is no paralysis
= mainly resulting from damage to areas within the frontal lobe which are involved in: motor coordination, judgement and tasks relating to exec function
- There may also be damage to the parietal area of the brain (sensory processing) which can feed in to the problems with coordination etc
(PARIETAL = SENSORY PROCESSING)
DYSPRAXIA = problems with motor coordination
APRAXIA = problems organising speech
80 % of patients who have apraxia may also have aphasia - these are closely related (one can exist without the other)
Assessment and therapy: - based on differential diagnosis of what it is not: -comprehension deficit -muscle weakness -sensory impairment - tone of abnormality - other movement disorder (diagnosis usually done by process of elimination)
Treatments:
1) strategy training = repetition of tasks and practice
2) sensory stimulation = stimulation of the nerve cells
3) proprioceptive stimulation = proprioceptive based training (PBT) is based on performing concurrent movements with both unaffected and affected arm, with the aim to foster motor recovery
4) cueing verbal and physical prompts
Aphasia
= loss of ability to communicate orally, through signs, or in writing, or in the ability to understand such communication
= impairment of language as a result of focal brain damage to the language dominant hemisphere
(Expression is most often affected)
- BROCAs aphasia = motor aphasia
- problems with verbal output; understanding remains intact
-non-fluent hesitant, laboured and paraphasic speaking vocab and confrontation naming is severely impaired
-writing is similarly affected
WERNICKEs aphasia= sensory aphasia
- problems with input or understanding of language
- fluent speech with severe comprehension deficit, poor repetition and often unintelligible jargon; reading similarly affected
- posterior part of superior temporal gyrus stroke characterised by fluent speech but poor comprehension
- associated with marked paraphasias and neologisms
GLOBAL aphasia = sensory and motor
- problem with input and output (writing and verbal)
- no communication even with gestures and no speech or only stereotypical repetitive noises
- reading and writing affected
- often no good rehab candidates due to difficulty understanding
- generally involve the entire MCA region, with moderate to severe impairment of language of all language function
Aphasia patients may struggle to express themselves through spoken word = use music/ art
Therapy for aphasias
many studies of speech and language therapy post-stroke
- Robey (1998) - meta analysis found SLT had a significant impact acutely and a lesser but still significant impact chronically
Limitaiton: many studies poor quality - small samples and not randomised trials
- SPEECH and LANGUAGE THERAPY (SLT)
Brogal et al (2003) - 4 RCTs showed a positive impact of SLT and 4 didn’t
- positive RCTs had: mean 8.8hrs a week, for around 11.2 weeks = total: 98.4 hrs therpay
- negative RCTs had: mean 2hrs a week, for around 22.9 weeks = 43.6hrs in total
= shows more intense therapy for shorter time = better
GROUP THERAPY:
- to maximise limited language resources ad encourage social interaction
- Elman and Bernstein-Ellis found: group therapy results in improvement of chronic aphasia
TRAINING conversation/ communication partners:
- social interaction to encourage sharing ideas, opinions and making plans
- can promote opportunity for restored access to convo
- Simmons-Mackie et al - found it was successful in improving communication activities and participation
COMPUTER based treatment:
- marked practive increasing intensity of therapy
CONSTRAINT - INDUCED (CI) aphasia therapy:
-chronic aphasia patients use most accessible communication channels eg. gestures/ drawing/ utterances
CI therapy based on 3 principles:
- intensive practice for short intentions
- constraints used to force patient to perform actions they are avoiding
- therapy focuses on action relevant to everyday life
