Stroke Syndromes Flashcards
Supplemental Motor Area (SMA) Location
- Part of motor association cortex (area 6)
- Medial surface of frontal lobe just in front of primary motor area
Supplemental Motor Area is strongly associated with
Basal ganglia - coordinates responses across brain regions and switches motor programs
Supplemental Motor Area Function
- Associated with internal initiated movements
- Associated with movements that were previously learned
- Assembles subroutines of complex movements
- Active during mental practice
Premotor Cortex (PMC) Location
- Area 6 - lateral hemisphere just in front of primary motor cortex
Premotor cortex (PMC) is strongly associated with
- Cerebellum - monitors & updates movement based on sensory feedback; error detection; optimizes movement plan
Premotor Cortex (PMC) Function
- Activated when movement initiation is dependent on external cue
- Associates with specific sensory cues with specific movements
- More active when movement is visually guided
- More active in early phases of learning
- Mirror neurons are found here
SMA v. PMC Activities
- PMC more active with early practice with explicit information
- SMA more active when sequence is more automatic
Primary Motor Cortex (Area 6) Function
- Movement initiation
- Fine motor control
- Novel movements
- Highly fractionated movements
- Good control over force and speed of movements
Primary Motor Cortex Afferents
- Supplemental motor cortex
- Premotor cortex
Inferior Parietal Lobule
- Generates spatial map of body and environment
- Codes parameters for movement between body and environmental targets and informs premotor cortex
- Mirror neurons located here
Apraxia
- Difficulty or inability in executing appropriate or purposeful movements despite absence of paresis, ataxia, or sensory loss, comprehension, attention, or willingness to perform movement
- Affects previously learned and new tasks
- Affects non-paretic side
Apraxia results from damage to
- Parietal lobe damage, especially inferior parietal lobule
- Sometimes frontal motor association areas
- Usually dominant (left) hemisphere
Types of apraxia
- Ideomotor apraxia
- Oral motor apraxia
- Ideational apraxia
- Constructional apraxia
- Dressing apraxia
Ideomotor Apraxia
- Has form of concept but cannot translate to execution
- Most common form of apraxia
- Associated with inferior parietal lobule
- Motor planning deficits
- Has difficulty performing movements on commands but can perform spontaneously
- Movement is clumsy and awkward
Oral Motor Apraxia
- Common in children and can happen in adults after stroke
- Affecting lips and face
- Affects purposeful movements associated with speaking and facial expression
Ideational Apraxia
- More severe motor planning deficit
- Associated with dominant parietal lobe
- Cannot conceptualize the motor task (no idea of what to do)
- With more severe involvement, cannot perform appropriately either automatically or on command
Constructional Apraxia
- Inability to construct or copy simple design or models
- Visual association cortex of non-dominant parietal lobe affected
- Aware of mistakes
- Inability to comprehend, interpret, and reproduce reciprocal relationships of objects in space
Dressing Apraxia
- Inability to dress oneself properly due to disorder in body schema or spatial relationships
- Damage to non-dominant occipital or parietal lobe
Clinical Tests of Apraxia
- See if patient can use common objects for ADLs
- See if patient can imitate gesture like peace, sign, okay sign
- Is response clumsy?
- Does pt perseverate?
- Can pt do things spontaneously that they cannot do on command?
- Do they know what to do with object?
Treatment principles for patients with apraxia
- Explicit information or not
- Give short, simple commands
- Pt should repeat aloud or in their heads
- Verbal or visual mediation of the task
- As therapist, adjust or facilitate movement
- Start and master first component before moving on
- Task should be done same way each time
- Repetition
Agnosia
- Inability to recognize
- Tends to be in non-dominant hemisphere
- Types: Tactile, visual, auditory, autotopagnosia, anosognosia, prosopagnosia
Tactile Agnosia
- Areas 5, 7 - non-dominant parietal lobe
- Cannot recognize objects by touch
Visual Agnosia
- Areas 18, 19 - visual association areas for nonsymbolic objects (paperclip, teacup) AND non-dominant inferior parietal lobule for symbols
- Cannot recognize by sight, “what” visual pathway
Auditory agnosia
- Cannot recognize by sound
- Superior part of temporal lobe, bilateral damage
Autotopagnosia (a.k.a somatoagnosia)
- Inability to identify body or its parts or to orient them correctly
- Non-dominant inferior parietal lobule (areas 39, 40)
Anosognosia
- Unawareness or denial of illness
- Nondominant inferior parietal lobule (areas 39,40)
Prosopagnosia
- Inability to recognize faces
- Damage to non-dominant occipto-temporal area (“what” pathway)
Neglect
- Failure to report, orient toward, or respond to stimuli on the contralateral side of space that cannot be attributed to sensory or motor dysfunction
Neglect - area of lesion
- Usually non-dominant inferior parietal lobe (areas 39, 40) –> usually involved with a left hemiparesis
Features of unilateral neglect
- Fails to respond to stimuli on contralateral side
- Overattends to stimuli on ipsilateral side
- Can see patient turn head away from side that they are neglecting
- Degree of neglect varies much from patient to patient
- Often occurs with anosognosia
Proposed mechanisms of neglect
- Disorder of attention - attention biased to ipsilateral side
- Disorder of coding visual information - cannot put parts together to make the whole
Testing for neglect
- Copy a simple drawing
- Line bisection
- Cancellation
- Reading aloud
- Extinction
Homonymous Hemianopia v. Neglect
- Homonymous hemianopia is sensory deficit
- Neglect is perceptual deficit
- Can teach someone with HH to compensate by scanning but not able to do so with neglect
Intervention for unilateral neglect
- Simple and direct commands, avoid subtleties and sarcasm
- Use perceptual anchor to direct attention to left
- Direct information to patient’s left side
- use hemiparetic side limb movement
- Encourage visual tracking to the left
- Eliminate distractions
- Educate patient on compensatory strategies
Right Parietal Syndrome
- Damage to the non-dominant (right) hemisphere, specifically parietal lobe, often resulting in severe perceptual deficits that often occur in combination
Right Parietal Syndrome Symptoms/Impairments
- Anosognosia
- Autotopagnosia
- Constructional apraxia
- Contralateral neglect
- Easily disoriented/distracted
- Be labile/inappropriate with verbal expression
- Apraxic in dressing
- Concrete communication style
MCA v. ACA Stroke
MCA - areas affected - face = hand > arm > UE
ACA LE > UE
Brainstem signs
- Cortical stroke - cortico-bulbar tracts affected
- Brainstem signs with UMN components (+ reflexes)
- Usually recover well because bilateral innervation
Internal Capsule
- Pure motor hemiplegia and/or sensory hemianesthesia
- other impairments depend on size of infarct
Hypoperfusion (Borderzone or Watershed)
- Distal most territory of each artery affected
- Weakness shoulder > arm > face
- Anomic aphasia & ideational apraxia
Left MCA Superior Division Stroke
- Right face & arm weakness
- Non-fluent/Broca’s aphasia
- Left gaze preference
- Can have right face and arm sensory issues
Left MCA Inferior Division
- Right visual field deficit
- Apraxia possible
- Fluent/Wernicke’s aphasia
- Maybe right face and arm sensory issues & weakness
Left MCA Deep territory
- Right pure motor hemiparesis
- Can have aphasia
Left MCA Stem
- Right hemiplegia & hemianesthesia
- Right homonymous hemianopia
- Global aphasia
- Left gaze preference
- Apraxia possible
Right MCA Superior Division
- Left arm and face weakness
- Left hemineglect
- Right gaze preference possible
- Sometimes left sensory loss
Right MCA Inferior Division
- Profound left hemi-neglect
- Left visual field and somatosensory deficits
- Motor neglect with decreased voluntary and spontaneous initiation of movements on L side
- Right gaze preference
Right MCA Deep territory
- Left pure motor hemiparesis
- Left hemi-neglect
Right MCA Stroke
- Left hemiparesis, hemianestheisa
- Left homonymous hemianopia
- Left hemi-neglect
- Right gaze preference
Left ACA
- Right leg weakness and sensory loss
- Grasp reflex, frontal lobe behavioral abnormalities, transcortical aphasia
- Right hemiplegia
Right ACA
- Left leg weakness and sensory loss
- Grasp reflex, frontal lobe behavioral abnormalities, transcortical aphasia
- Left hemiplegia
Left PCA
- Right homonymous hemianopia
- With thalamus and internal capsule - aphasia, right hemisensory loss, right hemiparesis
Right PCA
- Left homonymous hemianopia
- With thalamus and internal capsule - aphasia, left hemisensory loss, left hemiparesis
