Stroke cognitive deficits and rehabilitation dr venugopal kochiyil
1. Cognitive rehabilitation in stroke
Venugopal Kochiyil
Medical Head of the Unit - Northern Adelaide
Rehabilitation Service
Modbury Hospital
South Australia, Australia
3. Post stroke cognitive impairment
• Common but underdiagnosed
• Poor prognosis
• 40 – 70% of stroke patients
• Inadequately assessed, not diagnosed and not treated
www.ebsr.com
Shigaki CL, Frey SH. Semin Neurol 2014;34(5):496-503
5. Cognition
• Not a unitary concept
• Domains are not independent
• Affect of different states of physiology and mood
• Only 50% of vascular cognitive impairments shows
amnestic signs
• What is the gold standard in assessment
6. Cognitive problems after stroke
• Not being aware of one’s surroundings
• Poor attention and concentration to tasks
• Memory difficulties especially short term memory
• Poor problem solving and reasoning
• Poor executive functioning
• Slower processing of new information
7. Profile of cognitive deficits and stroke
• Most frequent after cerebral artery stroke than
vertebrobasilar strokes
• Cortical strokes (74 % v/s 50%)
• Cardioembolic stroke vs vessel disease
• Haemorrhagic strokes (larger)
• Left hemispheric strokes (language issues)
• Stroke recurrence
• Lesion location and volume
8. Profile of cognitive impairments after
stroke
• Does this affect all domains?
• Probably greater effect in attention and executive
functions
• Marked deficits in attention, abstract thinking and
processing speed
• Higher risk of non amnestic cognitive impairments
associated with history of stroke (especially lacunar
strokes)
9. Focal v/s diffuse damage
• Focal v/s diffuse problems
• Genu of IC
• Underlying subclinical cerebrovascular disease
• Higher white matter hyper intensities and dementia
• Slowed processing, attentional and executive deficits –
Internal capsule, caudate and thalamic lesions – disrupt
fronto-striato-thalamic circuits
Cumming TB, Marshal RS. Int Journal of Stroke2013;8:38-45
10. Characteristics Vascular dementia Alzheimer’s dementia
Onset Sudden or gradual Gradual
Progression Slow and stepwise Constant insidious decline
Neurological findings Focal deficits Subtle
Memory Mildly affected Early and severe
Executive functions Early and severe Late
Neuroimaging Infarct or white matter
lesions
Hippocampal atrophy
Gait Affected early Normal
Cardiovascular history TIA, stroke, CCF Nil
11. Speed of processing
• Cognitive slowing is a main issue with stroke
• It is an independent contributor of functional outcome
and dependency
• Effect on cognitive performance (time sensitive tasks)
14. Functional memory
• Information storage, retrieval
• Related to attention and executive functions
• Related to speech
• Integration of contextual information with memory
content
• Intrusions
• Overestimating performance accuracy
• Barrier for independence
Shigaki CL, Frey SH. Semin Neurol 2014;34(5):496-503
15. Memory function
• Vascular dementia – superior long term memory but
significant frontal executive function deficits
• Memory deficits present over time
• Subcortical infarcts – lower memory performances
(episodic, semantic and working memory)
• ? More executive than memory
Cumming TB, Marshal RS. Int Journal of Stroke2013;8:38-45
17. Perceptual issues - Neglect
• Three components for hemispatial neglect
visuospatial – right inf parietal lobule
visuomotor component – right dorsolateral prefrontal
object centred component – deep temporal gyrus
• Egocentric neglect and allocentric neglect
(peripersonal and extrapersonal)
• Visual and or sensory
• Network of areas/focal areas
20. Neglect
• Seen in approx 30 % strokes
• Significant functional deficits
• Predictor of functional recovery and returning home
• Sometimes seen only with high levels of activity
• Tend to recover during first six months.
• Variable at times
23. Pusher syndrome
• Seen in about 10% of stroke patients
• Impaired control in vertical and horizontal body
postures
• Leaning towards weaker side
24. Apraxia
• Inability to execute a purposeful activity despite
presence of adequate strength, sensation, coordination
• Related to parietal or frontal premotor involvement
• Ideomotor
• Ideational
• Constructional
• Dressing
• Single step/mutlistep
• Conceptual
25. Assessment of Praxis
• Tasks like gesturing
• Mimicking an object use
• Motor sequencing (Luria sequence)
• Actual use of an object
26. Praxis
• Affect ability to use objects
• Affect grooming
• Affect motor training
• Only limited information on natural recovery
• Severe ideomotor apraxia is associated with
incomplete recovery
27. Hypoperfusion
• Ischemia and hypoperfusion
• Aphasia and neglect are more closely associated with
hypoperfusion
• Reduction in brain volume (esp gray matter)
• CCF and cognitive issues
28. Subcortical strokes
• Cerebellum has a role in cognition
• Multiple cognitive issues – visuospatial, verbal
working memory, executive functions
• Basal ganglia/thalamus – multiple cognitive
issues
29. Assessing cognitive impairments post stroke
• Mini Mental screening evaluation (MMSE) – unable
to identify milder cognitive impairments and fronto -
temporal impairments
• Clock drawing test (CDT) – visuospatial, praxis,
attention and executive areas
• Montreal cognitive assessment – screening for mild
cognitive impairments, score of less than 26/30 is
significant, available in multiple languages
31. Cognitive assessment
• Addenbrooke’s cognitive assessment
• Instrumental activities of daily living – ability to
travel, manage finances, medication management,
independent use of telephone
32. Cognitive rehabilitation
• Retraining
• Correcting deficits
• Enhances the capacity/improve ability
• We can use all kind of technologies – low tech to high
tech
33. Rehab and cognitive deficits post stroke
• Issues with cognitive impairments –
discharge/recovery/participation
• Capacity of the person to make decisions
• Good at identifying but not so good at providing
solutions
• Generic treatments
34. Compensatory v/s restorative strategies
• Compensatory or restorative (cognitive skill training)
rehab
• KPI pressures
• Restorative rehab is resource intense
• Externally generated or internally generated
compensatory strategies
36. Interventions for functional memory
• Reduce distractions
• Memory tools
• External structure
• Internalised mnemonic strategies
• Routines
• Repeated practice – unfortunately do not generalise
• What do we do when patient has limited insight?
• Errorless learning for implicit memory
37. Interventions for apraxia
• Very difficult to treat
• Compensatory training like strategy training – verbal
cueing during action initiation and execution
• Restorative training like sensory stimulation and
perceptuo-motor control
38. Therapy for neglect
• Visual scanning for “where” neglect
• Prism adaptation for “aiming” defects – do visual-
manual exercises while wearing a prism lenses
Shigaki CL, Frey SH. Semin Neurol 2014;34(5):496-503
39. Assistive technology in cognitive rehab
• External aids can improve independence
• Cognitive orthoses, cognitive prosthesis
• Mainly compensatory
• Patient factors to consider
• Evidence is still limited
40. Recovery
• In many, cognitive decline continue post stroke
• Recovery in about 20% patients
• Most improvements in first three months but recovery
can continue for an year
• Deficits in language and memory improves more than
that of attention
Marin AG, Berteanu M. Int J Pharm Med Biol Sci 2015;4(2):146-150
41. Summary
• Common problem after stroke
• Impact functional recovery and independence
• Needs detailed assessment
• Gap between diagnosis and treatment approaches
• Limited evidence for therapeutic approaches
Editor's Notes
Cognition refers to thinking skills. Cognitive difficulties depend on area and severity
Executive functioning means goal setting, planning, initiating, self awareness, self inhibition, self monitoring and self evaluation, flexibility of thinking
Trouble of concentration when there is internal or external distractions
Short term memory affecting learning