Neglect and Rehabilitation

Question 1

Left-sided hemianopia

Answer 1

Left homonymous hemianopia is a visual condition that causes a loss of vision in the left half of the visual field in the left eye and the right half of the visual field in the right eye

Question 2

left sided hemianopia causes

Answer 2

Neglect typically involves damage to
parietal, not occipital, lobe but may
include optic radiations

Question 3

unilateral neglect

Answer 3

a neurological condition where individuals fail to attend to or recognize one side of their visual field or environment, typically the side opposite to a brain injury, most commonly after damage to the right hemisphere, causing neglect of the left side.

Question 4

Anosognosia

Answer 4

– unawareness, or denial of illness or
deficit (e.g. hemiplegia, hemianopia)

Question 5

Anosodiaphoria

Answer 5

indifference to illness or disability

Question 6

effects of anosognosia and anosodiaphoria

Answer 6

Both associated with damage to right frontal lobe.
– Both contribute to problems for rehabilitation

Question 7

Definition of neglect

Answer 7

“Following right hemisphere brain damage a patient without impairment of intellectual functioning appears to ignore, forget or turn away from the left side of space- as if that half of the world has ceased to exist…” Mesulam, (1985)

Question 8

Central anchor

Answer 8

spatial coordinates can vary with size, content of stimulus array and the behavioural response required

Question 9

left vs right hemipshere neglect

Answer 9

Chronic neglect associated with Right hemisphere damage
Left hemisphere damage can produce right neglect but this is usually less severe and resolves quickly

Question 10

Nature of brain damage (1)

Answer 10

Cerebrovascular ischemia (restriction) or haemorrhage (bleeding) produces tissue damage

Question 11

Nature of brain damage (2)

Answer 11

– Right middle cerebral artery (MCA) damage usually
involving right inferior parietal lobe (IPL)
Husain & Nachev, (2006)

Question 12

Nature of brain damage (3)

Answer 12

Frontal neglect (Husain and Kennard, 1996)
Right hemisphere Brodmann’s Area 44 premotor cortex (equivalent of Broca’s area in L.H.)

Question 13

nature of brain damage (4) MCA

Answer 13

Middle Cerebral Artery (MCA)
Contour map of lesion location (CT) of 8 neglect patients - right hemisphere
Overlap - Inferior parietal lobe (IPL) – associated with sever neglect
(Superior parietal lobe – may cause extinction and mis-reaching)
Vallar & Perani, 1986

Question 14

early cases (1)

Answer 14

Brain (1941)
Three patients with parieto-occipital damage “When asked to describe the route from the tube station to her flat she described this in detail correctly and apparently visualising landmarks, but she
consistently said right instead of left for the turnings…”

Question 15

early cases (2)

Answer 15

Paterson and Zangwill’s (1944) classic
case
39 year old male, penetrating wound right
parieto-occiptal region (explosion)
X-ray possible (unlike earlier cases) confirmed involvement of right inferior parietal lobe (supramarginal gyrus/angular gyrus)

Question 16

early case (2,2)

Answer 16

Unimpaired: Speech and language, reading words, writing and
calculation, object recognition, depth perception

Deficits
- Left hemianopia (upper quadrant improved), neglect,
extinction, visual-construction, agnosia for left side of space
(collided with objects)

• Left eye movements – problem reading text
  Allochiria - objects transposed from left to right side

-Setting time on a clock e.g. twenty to two, set as twenty past two

-Pointing (eyes closed) to objects on left – pointed towards right showing an ipsilesional spatial bias

Question 17

Clinical tests of neglect (1)

Answer 17

Confrontational testing for visual fields and extinction
fingers at opposing sides of peripheral and see if they recognise finger before it gets to middle

Question 18

Clinical tests of neglect (3)

Answer 18

Touch – hemianaesthesia loss of
touch
Visual and tactile extinction

Question 19

Clinical tests of neglect (2)

Answer 19

Anosognosia
e.g. Bisiach’s 4-point scale of awareness:
- 0 = disorder spontaneously acknowledged
- 1 = reported only following specific questioning
- 2 = acknowledged only after its demonstration
- 3 = no acknowledgement of the disorder

Question 20

drawing test of neglect

Answer 20

right side will be far more detailed than left in those with left sided hemianopia

Question 21

behavioural innatention tests

Answer 21

…

Question 22

nelgect dyslexia

Answer 22

ommissions and substitutes where they give a similar response but not accurate
Fred “Red.”

Question 23

Object-based neglect

Answer 23

…

Question 24

Chimaeric faces and objects

Answer 24

…

Question 25

Heterogeneous

Answer 25

• Not a unitary disorder
  – Representations of space not unitary
  – Personal space, peripersonal (reaching) and extrapersonal space

Question 26

Representations of space
Retinotopic

Answer 26

spatial layout on retina

Question 27

Representations of space
egocentric

Answer 27

– location in relation to own body (to my left) IPL

Question 28

Representations of space
allocentric

Answer 28

independent of own position (episodic memory e.g. north of here, road map)
hippocampus

Question 29

quote about rehabilitation

Answer 29

“Rehabilitation should have a central place in both theoretical and clinical thinking..’”
(Robertson et al. 1993)

Question 30

real world findings

Answer 30

Neglect is a predictor of poor Activities Daily
Living (ADL) functioning Even after florid symptoms have resolved
Rehabilitation strategies should be tied to
theoretical models and inform these models insights into mechanisms involved in neglect.

Question 31

Heilman’s Attentional-intentional model

Answer 31

Neglect reflects a failure to attend (detect) and intent (to make action)
Representation of left and right space mapped across both hemispheres
*Right-hemisphere dominant role (both directions), left-hemisphere attends to right only
* Failure to attend and intend linked to hypoarousal (decrease) following right-hemisphere damage

Question 32

Kinsbourne’s vectorial model

Answer 32

• Each hemisphere involved in directing contraversive attention (e.g. L.H. – rightward)
• L.H. stronger orienting tendency (even in non brain damage) but natural inhibition
• Damage to RH – leaves LH overactive with rightward bias of attention
• Activation of hemisphere (e.g. LH by language) induces shift attention

Question 33

Rizzolatti’s pre-motor model

Answer 33

Spatial attention mediated by neural circuits
each involved in different region of space
* Personal – own body
* peripersonal – around body
* extrapersonal – beyond reach
* Combined activity of neurons in this circuit
form representation used to control goaldirected responses
* Neglect is a deficit of spatial awareness
resulting from damage to the underlying
neural representation of space

Question 34

Behavioural interventions

Answer 34

Based on the use of strategies to
help patient orient to neglected
side of space
E.G. Visual scanning training
Involves instructions and cueing to
get patient to make leftward eye
and head movements ‘Scanning machine’

Question 35

more on scanning training