Hemispatial Neglect Flashcards
1
Q
LESION
A
- area of brain damage
- site of lesion depends on which blood vessel is occluded
2
Q
CONTRALESIONAL STIMULI
A
- things occurring on opposite side as lesion
3
Q
IPSILESIONAL STIMULI
A
- things occurring on same side as lesion
4
Q
EXTINCTION
A
- milder form of neglect only apparent when stimuli occur on both sides of space
5
Q
STROKE
A
- when a blood clot breaks off & travels up the artery until it gets caught & blocks blood flow to 1 side of the brain
- blood flow restricted to 1 half of brain -> neuronal death & eventual fluid-filled cavity (shown in white on MRI scans)
6
Q
BLOOD VESSELS
A
MIDDLE CEREBRAL ARTERY (MCA)
ANTERIOR CEREBRAL ARTERY (ACA)
POSTERIOR CEREBRAL ARTERY (PCA)
7
Q
MIDDLE CEREBRAL ARTERY (MCA)
A
- largest branch of internal carotid
- supplies:
1) lateral/inferior frontal lobe
2) lateral surface of temporal/parietal lobes (incl. primary motor & sensory face/throat/hand/arm areas) & dominant hemisphere (Broca’s area)
STEIN ET AL. (2007) - 51% stroke victims suffer this region
8
Q
ANTERIOR CEREBRAL ARTERY (ACA)
A
- supplies:
1) medial frontal lobes
2) basal ganglia
3) primary motor cortex
9
Q
POSTERIOR CEREBRAL ARTERY (PCA)
A
- supplies:
1) temporal lobes
2) occipital lobes
10
Q
MCA: CLINICAL STROKE
A
- contra-lesional hemiparesis (weakness/inability to move opposite side of body/face)
- contra-lesional hemisensory loss (inability to feel touch on opposite side of face/body)
- hemianopia (loss of vision on opposite side of space)
- aphasia (if stroke affects dominant hemisphere for language (left))
- hemi-spatial neglect
11
Q
CANCELLATION TESTS
A
- right hemisphere lesion affects left side of space (vice versa) due to crossed nature of human sensory system
- aka. patients w/right hemisphere lesions have weakness on left body half & issues noticing things on left side of space
- cancellation tests = standard for hemispatial neglect; require patient w/right hemisphere lesion to cross out all lines on a page
- patient will only cross out right-hand side lines
12
Q
COPYING TESTS
A
- simply requires patients to copy what they see
- patients w/hemispatial neglect will ignore all features on left-hand side of picture
13
Q
RECOGNISING BLINDNESS
A
- hemispatial neglect isn’t specific to any sense; a patient w/it will have difficulty identifying contra-lesional visual/auditory/tactile stimuli
EXTINCTION - patients can oft detect contra-lesional stimuli BUT not when they occur simultaneously w/ipsilesional stimuli
14
Q
ACQUIRED BRAIN INJURY: EXTINCTION
A
- neglect oft resolves into extinction during patient recovery
- extinction = patient perceives individual touches on left/right side
- BUT can only perceive right side when presented w/simultaneous touch on both sides
- same w/visual stimuli; patients can see on either side individually BUT will miss things on contra-lesional side (opposite lesion) when presented together w/things on ipsilesional side (same side)
15
Q
“BROKEN” NEGLECT
A
- neglect x extinction = disorder of attention & spatial representation
- inability to consciously detect/respond to stimuli in contra-lesional side of space
- manifests as gradient of awareness from ipsilesional -> contralesional > clear divide