SUMMARYPurpose: In patients with idiopathic generalized epilepsy (IGE), blood oxygen level dependent (BOLD) EEG during functional MRI (EEG-fMRI) has been successfully used to link changes in regional neuronal activity to the occurrence of generalized spike-and-wave (GSW) discharges. Most EEG-fMRI studies have been performed on adult patients with long-standing epilepsy who were on antiepileptic medication. Here, we applied EEG-fMRI to investigate BOLD signal changes during absence seizures in children with newly diagnosed childhood absence epilepsy (CAE). Methods: Ten drug-naive children with newly diagnosed CAE underwent simultaneous EEG-fMRI. BOLD signal changes associated with ictal EEG activity (i.e., periods of three per second GSW) were analyzed in predefined regions-of-interests (ROIs), including the thalamus, the precuneus, and caudate nucleus. Results: In 6 out of 10 children, EEG recordings showed periods of three per second GSW during fMRI. Three per second GSW were associated with regional BOLD signal decreases in parietal areas, precuneus, and caudate nucleus along with a bilateral increase in the BOLD signal in the medial thalamus. Taking into account the normal delay in the hemodynamic response, temporal analysis showed that the onset of BOLD signal changes coincided with the onset of GSW. Discussion: In drug-naive individuals with CAE, ictal three per second GSW are associated with BOLD signal changes in the same striato-thalamocortical network that changes its regional activity during primary and secondary generalized paroxysms in treated adults. No BOLD signal changes in the striato-thalamo-cortical network preceded the onset of three per second GSW in unmediated children with CAE.

Deep brain stimulation of the subthalamic nucleus improves motor functions in patients suffering from advanced Parkinson's disease but in some patients, it is also associated with a mild decline in cognitive functioning about one standard deviation from the preoperative state. We assessed the impact of the cortical lead entry point, the subcortical electrode path and the position of the active electrode contacts on neuropsychological changes after subthalamic nucleus-deep brain stimulation compared to a control group of patients receiving best medical treatment. Sixty-eight patients with advanced Parkinson's disease were randomly assigned to have subthalamic nucleus-deep brain stimulation or best medical treatment for Parkinson's disease. All patients had a blinded standardized neuropsychological exam (Mattis Dementia Rating scale, backward digit span, verbal fluency and Stroop task performance) at baseline and after 6 months of treatment. Patients with subthalamic nucleus-deep brain stimulation were defined as impaired according to a mild decline of one or more standard deviations compared to patients in the best medical treatment group. The cortical entry point of the electrodes, the electrode trajectories and the position of the active electrode contact were transferred into a normalized brain volume by an automated, non-linear registration algorithm to allow accurate statistical group analysis using pre- and postoperative magnetic resonance imaging data. Data of 31 patients of the subthalamic nucleus-deep brain stimulation group and 31 patients of the best medical treatment group were analysed. The subthalamic nucleus-deep brain stimulation group showed impaired semantic fluency compared with the best medical treatment group 6 months after surgery (P = 0.02). Electrode trajectories intersecting with caudate nuclei increased the risk of a decline in global cognition and working memory performance. Statistically, for every 0.1 ml overlap with a caudate nucleus, the odds for a decline >1 standard deviation increased by a factor of 37.4 (odds ratio, confidence interval 2.1-371.8) for the Mattis Dementia Rating Scale and by a factor of 8.8 (odds ratio, confidence interval 1.0-70.9) for the backward digit span task. Patients with subthalamic nucleus-deep brain stimulation who declined in semantic verbal fluency, Stroop task and the backward digit span task performance showed a position of the active electrode outside the volume built by the active electrodes of stable performers. Passage of the chronic stimulation lead through the head of the caudate increases the risk of global cognitive decline and working memory performance after subthalamic nucleus-deep brain stimulation in Parkinson's disease. Therefore the electrode path should be planned outside the caudate nuclei, whenever possible. This study also stresses the importance of precise positioning of the active stimulating contact within the subthalamic volume to avoid adverse effects on semantic verbal fluency and response inhibition.

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This Consensus Group concluded that two of the methods qualified as reliable measures of the trunk angles in standing patients based on their clinimetric properties. They propose that the 'total camptocomia angle' be the angle between the line from the lateral malleolus to the L5 spinous process and the line between the L5 spinous process and the spinous process of C7. They also propose that the 'upper camptocormia angle' be the angle of the lines between the vertebral fulcrum to the spinous processes of L5 and C7, respectively. An app is provided on the web for these measurements (http://www.neurologie.uni-kiel.de/de/axial-posturale-stoerungen/camptoapp).

Recent research indicates that physiotherapy can improve motor performance of patients with cerebellar degeneration. Given the known contributions of the cerebellum to motor learning, it remains unclear whether such observable changes in performance are mediated by the cerebellum or cerebral brain areas involved in motor control and learning. The current study addressed this question by assessing the increase in gray matter volume due to sensorimotor training in cerebellar patients using voxel-based morphometry. Nineteen human subjects with pure cerebellar degeneration and matched healthy controls were trained for 2 weeks on a balance task. Postural and clinical assessments along with structural magnetic resonance imaging were performed pretraining and post-training. The main findings were as follows. First, training enhanced balance performance in cerebellar patients. Second, in contrast to controls patients revealed significantly more post-training gray matter volume in the dorsal premotor cortex. Third, training-related increase in gray matter volume was observed within the cerebellum and was more pronounced in controls than in patients. However, statistically cerebellar changes were at the trend level and thus require additional, independent confirmation. We conclude that sensorimotor training of patients with cerebellar neurodegeneration induces gray matter changes primarily within nonaffected neocortical regions of the cerebellar-cortical loop. Residual function of the cerebellum appears to be exploited suggesting either a recovery from degeneration or intact processes of cerebellar plasticity in the remaining healthy tissue.

In highly trained pianists with and without MD, the volume of the associative motor territory in the middle putamen reflects both the skill level of piano playing and the presence of dystonia. While a smaller volume is associated with better timing skills, a relative expansion is correlated with the presence of focal task-specific hand dystonia.

Recently, interest has been growing to understand the underlying dynamic directional relationship between simultaneously activated regions of the brain during motor task performance. Such directionality analysis (or effective connectivity analysis), based on non-invasive electrophysiological (electroencephalography-EEG) and hemodynamic (functional near infrared spectroscopy-fNIRS; and functional magnetic resonance imaging-fMRI) neuroimaging modalities can provide an estimate of the motor task-related information flow from one brain region to another. Since EEG, fNIRS and fMRI modalities achieve different spatial and temporal resolutions of motor-task related activation in the brain, the aim of this study was to determine the effective connectivity of cortico-cortical sensorimotor networks during finger movement tasks measured by each neuroimaging modality. Nine healthy subjects performed right hand finger movement tasks of different complexity (simple finger tapping-FT, simple finger sequence-SFS, and complex finger sequence-CFS). We focused our observations on three cortical regions of interest (ROIs), namely the contralateral sensorimotor cortex (SMC), the contralateral premotor cortex (PMC) and the contralateral dorsolateral prefrontal cortex (DLPFC). We estimated the effective connectivity between these ROIs using conditional Granger causality (GC) analysis determined from the time series signals measured by fMRI (blood oxygenation level-dependent-BOLD), fNIRS (oxygenated-O2Hb and deoxygenated-HHb hemoglobin), and EEG (scalp and source level analysis) neuroimaging modalities. The effective connectivity analysis showed significant bi-directional information flow between the SMC, PMC, and DLPFC as determined by the EEG (scalp and source), fMRI (BOLD) and fNIRS (O2Hb and HHb) modalities for all three motor tasks. However the source level EEG GC values were significantly greater than the other modalities. In addition, only the source level EEG showed a significantly greater forward than backward information flow between the ROIs. This simultaneous fMRI, fNIRS and EEG study has shown through independent GC analysis of the respective time series that a bi-directional effective connectivity occurs within a cortico-cortical sensorimotor network (SMC, PMC and DLPFC) during finger movement tasks.

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