Contributions
Abstract: 127
Type: Oral
Abstract Category: Pathology and pathogenesis of MS - Imaging
Introduction: The brain demonstrates plasticity, the ability to change and to adapt to damage. Plasticity supports functional recovery after damage and is driven adaptively by rehabilitation, a major non-pharmacological intervention in multiple sclerosis (MS). Early prediction of response to rehabilitation is desirable and relies on the identification of the individual"s potential for recovery as distinct from the disease prognosis.
Objective: To test whether short-term brain plasticity, measured as BOLD changes during a motor sequence task, can predict successful longer-term training of the same task in patients with MS.
Methods: 69 right-handed MS patients underwent a structural and a BOLD-weighted fMRI scan, the latter while performing a serial reaction time task (SRT). A sequence of 8 stimuli was repeatedly presented and patients had to react as quickly and accurately as possible to each stimulus by pressing the correct out of four buttons with their right hand. Sequence blocks were interleaved with random blocks in order to control for general task improvements. After the scanning, participants practised the same task with a longer sequence for four weeks at home. For each training session, a contrast score between sequence and random blocks was calculated for reaction time. From these values, the slope of performance changes over the training sessions was established by fitting a linear model. The slope was used as an indicator for sequence-specific changes in task performance and as a regressor of interest in the fMRI analysis.
Results: The slopes showed sequence-specific reaction time decreases during the longer-term training (t[68]=-11.5, p< .0001). Brain activity changed over the duration of the short-term task and these changes were related to the performance changes in the longer-term training: patients with better longer-term training outcome displayed significantly weaker sequence-related activation increase and stronger sequence-related activation decreases over time in the posterior cingulate and lateral occipital cortices. This association was not confounded by short-term performance changes, nor by age, gender or right hand dexterity.
Discussion: Functional plasticity in MS can be detected with fMRI over the course of a few minutes. This short-term plasticity can predict the outcome of longer-term training independently of short-term performance changes and so might represent a functional predictor of motor rehabilitation success.
Disclosure: The study was funded by the MS society (grant number: 505593)
Abstract: 127
Type: Oral
Abstract Category: Pathology and pathogenesis of MS - Imaging
Introduction: The brain demonstrates plasticity, the ability to change and to adapt to damage. Plasticity supports functional recovery after damage and is driven adaptively by rehabilitation, a major non-pharmacological intervention in multiple sclerosis (MS). Early prediction of response to rehabilitation is desirable and relies on the identification of the individual"s potential for recovery as distinct from the disease prognosis.
Objective: To test whether short-term brain plasticity, measured as BOLD changes during a motor sequence task, can predict successful longer-term training of the same task in patients with MS.
Methods: 69 right-handed MS patients underwent a structural and a BOLD-weighted fMRI scan, the latter while performing a serial reaction time task (SRT). A sequence of 8 stimuli was repeatedly presented and patients had to react as quickly and accurately as possible to each stimulus by pressing the correct out of four buttons with their right hand. Sequence blocks were interleaved with random blocks in order to control for general task improvements. After the scanning, participants practised the same task with a longer sequence for four weeks at home. For each training session, a contrast score between sequence and random blocks was calculated for reaction time. From these values, the slope of performance changes over the training sessions was established by fitting a linear model. The slope was used as an indicator for sequence-specific changes in task performance and as a regressor of interest in the fMRI analysis.
Results: The slopes showed sequence-specific reaction time decreases during the longer-term training (t[68]=-11.5, p< .0001). Brain activity changed over the duration of the short-term task and these changes were related to the performance changes in the longer-term training: patients with better longer-term training outcome displayed significantly weaker sequence-related activation increase and stronger sequence-related activation decreases over time in the posterior cingulate and lateral occipital cortices. This association was not confounded by short-term performance changes, nor by age, gender or right hand dexterity.
Discussion: Functional plasticity in MS can be detected with fMRI over the course of a few minutes. This short-term plasticity can predict the outcome of longer-term training independently of short-term performance changes and so might represent a functional predictor of motor rehabilitation success.
Disclosure: The study was funded by the MS society (grant number: 505593)