Fatigue in brain tumor patients, towards a neuronal biomarker.

BACKGROUND: Many brain tumor patients suffer from fatigue which severely affects their quality of life. There is a lack of objective measurements for fatigue in brain tumor patients. We aimed to find a neurophysiological correlate for fatigue in brain tumor patients. For this purpose, we correlated brain activity associated with phasic alertness with self-reported ratings of fatigue. METHODS: Patients with a meningioma, a low-grade glioma or a high-grade glioma (N = 63) participated in this fMRI study. Brain activity in the central executive network (CEN) and default mode network (DMN) associated with phasic alertness was correlated with self-reported fatigue measured with the multidimensional fatigue inventory (MFI-20). Follow-up analyses were performed for MFI-20 domain scores, individual regions within CEN and DMN, and the tumor sub-groups separately. RESULTS: MFI-20 scores correlated significantly with DMN activity associated with phasic alertness, but not with CEN activity. These results were consistent for each tumor sub-group. Within the DMN, the correlations were strongest in left and right lingual cortex, left and right cuneus, and right precuneus. DISCUSSION: Self-reported fatigue in brain tumor patients was associated with objective measurements of brain activity, specifically the DMN activity related to phasic alertness. This association represents an important step in the development of a biomarker for fatigue in brain tumor patients, and possibly for other patients that suffer from fatigue.

Processing of Targets and Non-targets in Verbal Working Memory.

In this study we used functional MRI (fMRI) to examine whether defining a stimulus as a target affects brain activation associated with a verbal working memory (WM) task. Seventeen healthy right-handed volunteers performed a Sternberg task with three consonants as memory set. We performed a region of interest based fMRI analysis to examine differences in brain activity patterns between targets and non-targets. Non-target brain activity was subtracted from target activity and hemispheric and fronto-parietal differences were tested by conducting a MANOVA. Participants responded correctly to 97.5% of the stimuli. The fMRI results showed a hemisphere by fronto-parietal location interaction, where targets evoked increased activity in the right frontal regions compared to non-targets, whereas the left frontal task activation did not differ between targets and non-targets. In the parietal regions, targets evoked increased activity compared to non-targets in the lateral anterior, but not the medial posterior part. Our study revealed that defining a stimulus as a target within a verbal WM task evokes an increase in brain activity in right frontal brain regions, compared to non-targets. Our results suggest an important hemispheric differentiation in target processing, in which the right frontal cortex is predominantly involved in processes associated with target stimuli. The left frontal cortex does not differentiate between processing target and non-target stimuli, suggesting involvement in WM processes that are independent of stimulus type. Parietal, the lateral anterior part is predominantly involved in target processing, while the medial posterior part does not differentiate between target and non-target processing.

Rehabilitation, exercise therapy and music in patients with Parkinson's disease: a meta-analysis of the effects of music-based movement therapy on walking ability, balance and quality of life.

Recent evidence suggests that music-based movement (MbM) therapy may be a promising intervention to improve gait and gait-related activities in Parkinson's disease (PD) patients, because it naturally combines cognitive movement strategies, cueing techniques, balance exercises and physical activity while focussing on the enjoyment of moving on music instead of the current mobility limitations of the patient. A meta-analysis of RCTs on the efficacy of MbM-therapy, including individual rhythmic music training and partnered dance classes, was performed. Identified studies (K = 6) were evaluated on methodological quality, and summary effect sizes (SES) were calculated. Studies were generally small (total N= 168). Significant homogeneous SESs were found for the Berg Balance Scale, Timed Up and Go test and stride length (SESs: 4.1,2.2,0.11; P-values <0.01; I(2) 0,0,7%, respectively). A sensitivity analysis on type of MbM-therapy (dance- or gait-related interventions) revealed a significant improvement in walking velocity for gait-related MbM-therapy, but not for dance-related MbM-therapy. No significant effects were found for UPDRS-motor score, Freezing of Gait and Quality of Life. Overall, MbM-therapy appears promising for the improvement of gait and gait-related activities in PD. Future studies should incorporate larger groups and focus on long-term compliance and follow-up.