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66 Cards in this Set
- Front
- Back
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Neglect: definition
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failure to respond to, report, or orient to novel or meaningful stimuli presented to the side opposite the lesion
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Neglect: rule outs
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sensory, motor, or memory deficits
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Neglect: other terms for
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unilateral spatial agnosia, amorphosynthesis, left-sided fixed hemianopia, hemi-inattention, hemi-neglect, hemispatial agnosia
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Neglect: first description by
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jackson (1978)
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Sensory neglect: definition
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deficit in awareness of stimuli contralateral to a lesion not involving sensory projection systems or primary cortical sensory areas
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Neglect: 2 types OR 2 other types
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spatial, personal
OR attentional/sensory and intentional/motor |
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Spatial neglect: 3 frames of reference
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body centered, environmentally centered, object centered
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Sensory neglect: associated disturbances
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inattentive to stimuli ipsilateral to lesion- but this is less severe, problems with disengaging or shifting attention in contralateral direction
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Distinguishing sensory neglect from sensory deficit
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increasing instructional cues, using novel stimuli, or using strongly motivational cues
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Probes for sensory neglect
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tests of extinction, line bisection, covert attentional shifts
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Sensory-representational neglect: probes for
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have pt close eyes and point to body midline, pt usually points to right of midline
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Motor-exploratory neglect: definition
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reluctance to scan and explore L hemispace
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Motor-exploratory neglect: probes
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target detection tasks: more difficult tasks are more sensitive in detection (lines easier than letters, letters easier than complex shapes)
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Neglect dyslexia: definition
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failure to read words on left side of page
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intentional neglect or limb akinesia: definition
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reluctance to move limbs on L in absence to damage to corticospinal system
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hemispatial akinesia: definition
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pt fails to spontaneously use contralateral extremity, but may have good strength when focusing on that part
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hypokinesia: definition
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milder form of hemispatial akinesia, in which there is a delay in initiating movement
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limbic-motivational neglect: definition
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pts devalue the L side of space and act as if nothing important could happen on that side; there is no emotional salience for that side of space
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Inattention: probes for milder versions
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sensory extinction to double simultaneous stimulation: may still occur after hemi-attention improves, pt fails to report stimulation on contralateral side when both sides are stimulated simultaneously
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Inattention: behaviors suggestive of
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failure to respond to stimuli presented contralateral to lesion, but possible response if the pts attention is directed to that side
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Inattention: behaviors suggestive of
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failure to recognize that contralateral extremities are their own
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Inattention: behaviors suggestive of
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pts will recognize that the limbs are their own, but refer to them as though they were objects
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Allesthesia: behaviors suggestive of
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disturbance of body schema perception in tactile modailty, in which stimulation of one side of body is perceived as located on other side
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4 types of motor neglect
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akinesia, hypokinesia, motor extinction, motor impersistence
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motor extinction: definition
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pts who do not display akinesia when they are moving only one limb may do so when they must move both limbs simultaneously
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motor impersistence: definition
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inability to sustain a motor activity
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spatial neglect
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can occur in three dimensions of space: horizontal, vertical, and radial (near, far)
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spatial neglect: behavioral manifestations and probes for
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line bisection, cancelleation tasks, and drawing
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spatial neglect: adaptive behavior manifestations
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failure to groom or dress contralateral side
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hemispatial neglect: frames of reference (2)
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body-centered or environmental
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Neglect classifications: sectors of space
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personal neglect, peripersonal neglect (within reaching space), and far extrapersonal neglect (only when stimuli are out of reach)
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anosagnosia: definition
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unawareness or denial of deficits or of affected extremities
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anosagnosia: behavioral manifestations
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if pts are asked to complete a task wtih affected limb, will say they are left handed or claim to have done the task when they haven't
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anosodiaphoria: definition
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pt will admit to sensory or motor impairment, but be unconcerned about it, may follow a period of anosagnosia
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Neglect: which hemisphere?
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Much more frequent and severe after R hemi lesions because R hemi specializes in spatial distribution of attention.
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Neglect: three cortical regions involved
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Parietal (inferior), frontal, limbic
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Neglect: subcortical regions involved
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thalamus, striatum, superior collliculus
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thalamic neglect: deficit attributed to
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problem with engaging, not disengaging as seen in parietal lesions
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Neglect: parietal component
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inferior parietal lobe, key role is in spatial attention as integrating spatial map with motor output channels
small lesions here rarely lead to neglect, need subcortical damage and large parietal lesion |
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Neglect: frontal component
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? plays critical role in attention network by converting plan and intentions into sequences of motor acts that shift focus of attention
lesions confined to frontal lobe can cause neglect specific regions possibly frontal eye fields or inferior frontal gyrus |
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Neglect: limbic component
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cingulate is least well understood, but may play role in identifying motivational relevance of events and sustaining effort
can have neglect with only cingulate gyrus lesion, rarely |
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Neglect: cingulate gyrus two proposed components
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anterior- reflecting global attentional engagement
posterior- lateralized shifts of relevance and focal attention |
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Two hypotheses of mechanisms underlying neglect syndromes
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reprsentational hypothesis (one proponent Bisiach)
attentional hypothesis (seems to be more accepted, proponents include Heilman, Posner, Mesulam) |
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Neglect: representational hypotheses defined
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posterior parietal cortex is thought to contain an elaborate spatial representation of the external world, unilateral loss of this representation causes neglect
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Representational hypotheses of neglect: classic experiment
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Pts were asked to describe a cathedral in Milan; they failed to describe landmarks imagined on left side of scene
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Which cathedral was it?
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Piazza del Duomo in Milan
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Piazza del Duomo experiment could be interpreted...
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impaired representation (mental), impaired scanning of representation, inability to attend to contralesional hemispace
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Cueing of Piazza del Duomo experiment patients
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improved performance, suggesting attentional component, which isn't well explained by representational view
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Unilateral Akinesia Hypothesis of Neglect
(an Attentional hypothesis proposed by Heilman) |
defect in orienting to stimuli due to disruption in arousal system in affected hemisphere.
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Unilateral Akinesia Hypothesis of Neglect
(an Attentional hypothesis proposed by Heilman): Problem |
why don't most severe cases of neglect follow damage to RAS?
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Covert Orienting Hypothesis of neglect (an attentional hypothesis proposed by Posner)
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disengage, shift, engage model
neglect results from inability to shift away from intact hemispace |
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ATtentional network hypothesis of neglect (an attentional hypothesis proposed by Mesulam)
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neglect is a network syndrome, represents damage to one or more components of a distributed network, represents a domain-specific impairment of spatial attention
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Neglect: assessment issues, what to rule out
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primary sensory deficits (by varying attentional cues),
motor deficits |
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unilateral hearing loss
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does not occur after unilateral lesions, if pt has unilateral hearing loss, it is neglect
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visual field cuts
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are not affected by position of eyes in space, neglect is
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sensory evoked potentials
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are normal in neglect pts
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assessment of neglect should include these modalities
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auditory, visual, somesthetic
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standardized testing for neglect
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cancellation: look at omissions and search strategy
line bisection: deviations to ipsilateral side drawing: copy or draw clock reading and writing |
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Neglect: treatment by managing environment
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arrange to reduce risk of injury, position important stimuli on R side, reduce competing/distracting stimuli, present some stimuli in neglected field for therapy
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Neglect: training
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operant techniques can improve exploration of contralesional space, but this might remain task specific and not generalize
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Neglect: cueing
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attentional cueing may help, bottom up cues include providing novel stimuli, top down cues include providing directions to attend
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Neglect: behavioral goals
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conscious knowledge of the importance of searching to left hemispace before engaging
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kinesia paradoxica: definition
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principally, an endo-evoked akinesia, with poor response to internal cues, but normal response to external cues (often seen in parkinson's disease)
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endogenously evoked akinesia: definition
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poor motor response to internal stimuli
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exogenously evoked akinesia: definition
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poor motor response to external stimuli
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defective vigilance: definition
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pt will be able to detect contralesional stimuli initially, but, with repeated stimulation, will eventually fail
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