Medizinische Universität Graz - Research portal
Selected Publication:
Linortner, P.
The impact of cerebral white matter changes on walking abilities in aging - insights from fMRI
[ Diplomarbeit/Master Thesis ] Karl-Franzens-Universität Graz; 2009. pp.93.
- Authors Med Uni Graz:
- Linortner Patricia
- Advisor:
- Enzinger Christian
- Altmetrics:
- Abstract:
- Background and Purpose: Cerebral white matter changes (WMC) are found in a large proportion of healthy, elderly individuals. They appear in different forms and at different severity levels: as punctate, early confluent and confluent lesions. The latter two have been repeatedly associated with gait disturbances, cognitive decline and depression. As ankle movement is a key component of gait, the main objective of this study was to identify the network responsible for ankle movements in people with different grades of WMC. Methods: Thirty healthy, right hand- and foot dominant people (aged 49-83 years, M = 67.8 +- 7.5 years) participated in the present study. 17 subjects displayed WMC grades 0&1 (no or punctate lesions) and 13 showed WMC grades 2&3 (early confluent and confluent lesions). They underwent a complex clinical, neuropsychological and motoric test battery. Additionally, they were scheduled for MRI scans and participation in a fMRI experiment with ankle and finger movement conditions. Results: Groups did neither differ in mobility tests nor depression questionnaires. Likewise, no significant group differences were found in tests that measure perserveration, attention and speed, visuopractical skills and cognitive functioning. Only in the Reaction test, we found that people with higher lesion load needed a shorter decision time, which can be explained with higher error rate. Frequently, test performance was influenced by age, education or sex; analyses were therefore adjusted accordingly. In the fMRI movement paradigms (left foot, right foot, left hand), people with WMC grades 2&3 specifically showed more pronounced activation in the pre-supplementary motor area (SMA), frontal and occipital regions than people with WMC grades 0&1. The reverse contrast rather showed activation in areas expected for motor paradigms, e.g. SMA, sensorimotor cortex, secondary somatosensory cortex. The functional results were modulated by age. Conclusions: Despite absent group differences in mobility tests, the activation in the simple foot movement paradigm could reflect that the task was of greater effort and cognitive demand for people with more severe WMC compared to people with minor or absent WMC. But the results were partially influenced by higher age; hence, further clarification is needed. It is of interest, whether these functional activation changes become apparent before they can be measured with mobility tests. Longitudinal studies could answer this question.