Eye-hand coordination in patients with unilateral spatial neglect.

Damage to cortical areas involved in sensori-motor systems due to stroke,
impair the integration of sensory information and execution of motor tasks,
which may have a great impact on the quality of life. A special group in these
stroke patients are patients with USN. USN is defined as *the inability to
attend to objects, or even one*s own body, in a portion of space, despite the
fact that visual acuity, somatic sensation and motor ability remain intact*.
USN is a heterogeneous disorder that is a common consequence of stroke, it
mostly presents itself in affecting the egocentric or allocentric frame of
reference. Although it is generally accepted that visuo-spatial attention may
be the underlying cause for neglect, the heterogeneous presentation complicates
the construction of cognitive models of spatial attention that might account
for all types of USN. This in term leads to problems in developing tests to
diagnose USN.
In clinical settings neglect is often under-diagnosed. Most clinical care
focuses on severe presentations, which are most often cases with right
hemisphere damage (RHD). This group of patients typically show neglect for the
left side of their visual field or left side of their body.
USN mostly occurs after posterior inferior parietal cortex damage, but
up-to-date, information is lacking about the role of eye-hand coordination and
in the degree it is affected in USN patients, either with left hemisphere
damage (LHD) or RHD. However, the role of parietal and frontal regions in
coordinating eye-hand tasks has been shown in human as well as in studies
involving non-human primates. We aim at developing specific eye-hand
coordination tasks together with word spelling tasks based on the reference
frames and apply these tests in patients with parietal or frontal damage. We
expect that the sensitivity to diagnose neglect, as well in the LHD as in the
RHD patients, will be higher by combining tasks examining eye-hand coordination
and tasks examining word spelling abilities in these patients.

Primary researchquestion:
1. What are the differences in eye-hand coordination in patients with left or
right hemisphere damage compared to healthy age-matched controls?

Secondary research questions:
2. What is the difference in eye-hand coordination and word spelling abilities
in patients with left hemesphere damage compared to patients with right
hemisphere damage?
3. Is this method applicable and reproducable?
4. To what extent is the spatial processing ability affected?
5. Which frames of reference are affected?

Experimental / test development

Low.
The risks of this research are negligible. There will be little intervention
and the investigation is not invasive.
The only possibility is that the subject gets frustrated because he is unable
to complete a task. But the
expectation is that this will be minimal, moreover, the test may be interrupted
if desired.