Our objective is to get insight into whether and how the visual system reorganises after acquiring HH. Visual processing will be investigated and cortical reorganisation at a structural level will be examined. For this purpose, we will assess…
ID
Source
Brief title
Condition
- Structural brain disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Our main primary outcome parameters are:
* Ophthalmic functioning/condition (assessed by ophthalmic examination)
* Contrast values of grey and white matter volumes
* Water diffusion in brain tissue expressed in fractional anisotropy (FA),
* Retinal nerve fibre layer thickness
Secondary outcome
Our secondary study parameters, derived from our primary study parameters, are:
* Visual Field maps
* Cortical thickness maps
* Course of white matter tracts
* Retinal nerve fibre degeneration
* Myelin content
Background summary
Our present knowledge of the adaptive capacity of the brain following
homonymous hemianopia (HH), a visual field defect due to pathology along the
visual system, is incomplete and largely qualitative in nature. Most studies on
HH have focussed on the behavioural and psychophysical aspects of the
condition, whilst quantitative research on cortical plasticity following the
condition is lacking. In particular, we have very limited understanding of how
changes in visual processing are reflected in sustained structural cortical
changes. Therefore, we aim to study a group of (post-chiasmatic brain injured)
participants with HH to quantitatively assess the cortical reorganisation in
this population. We hypothesise that changes in visual in HH are reflected in
structural changes in the visual system (i.e. cortical thickness and white
matter tracts), and changes in structural connectivity maps.
Study objective
Our objective is to get insight into whether and how the visual system
reorganises after acquiring HH. Visual processing will be investigated and
cortical reorganisation at a structural level will be examined. For this
purpose, we will assess cortical plasticity by MRI. In this way, we will
investigate the impact of homonymous visual field defects on perceptual
processing and correlate it to structural cortical plasticity.
Study design
The study will be an observational study; a cross-sectional case-control design
with participants with HH and controls matched for age and gender. The study
consists of three parts: 1) a functional questionnaire (only patients), 2)
physiological measurements, and 3) an MRI experiment.
Study burden and risks
There are no risks associated with this study. Participants will be exposed to
standard clinical tests and a magnetic resonance imaging (MRI) experiment with
a magnetic field of 3 Tesla and fast fluctuating magnetic gradients and
radio-frequency fields. These field strengths are common in MRI research. Up
till now no side effects have been reported and hemianopia has been studied
with MRI before without any side effects. In rare cases an abdominal peripheral
nerve could possibly be stimulated because of the fluctuating magnetic fields.
This results in a tickling, but harmless, feeling.
Hanzeplein 1
Groningen 9700 RB
NL
Hanzeplein 1
Groningen 9700 RB
NL
Listed location countries
Age
Inclusion criteria
Participants with hemianopia:
- have signed written consent
- age older than 18
- homonymous hemianopia due to post chiasmic brain injury
- stable ophthalmologic conditions;Controls:
- have signed written consent
- age older than 18
- subjectively healthy
Exclusion criteria
Participants with hemianopia:
- clinical eye conditions
- auditory impairments;Controls:
- visual impairments
- auditory impairments
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
In other registers
| Register | ID |
|---|---|
| Other | 5752 |
| CCMO | NL55973.042.15 |
| OMON | NL-OMON21100 |