Beeinflussung des Essentiellen Tremors und des Tremors beim Morbus Parkinson durch transkranielle Gleichstromstimulation

Ziel dieser Arbeit war es die Rolle des primärmotorischen Kortex bei der Entstehung und Weiterleitung des Essentiellen Tremors und des Tremors beim Morbus Parkinson zu untersuchen. Hierzu wurde eine transkranielle Gleichstromstimulation über dem primärmotorischen Kortex bei Patienten mit oben genannten Tremorsyndromen durchgeführt und die klinischen sowie elektrophysiologisch messbaren Änderungen des Tremors beurteilt

Multi-modal causality analysis of eyes-open and eyes-closed data from simultaneously recorded EEG and MEG

Owing to the recent advances in multi-modal data analysis, the aim of the present study was to analyze the functional network of the brain which remained the same during the eyes-open (EO) and eyes-closed (EC) resting task. The simultaneously recorded electroencephalogram (EEG) and magnetoencephalogram (MEG) were used for this study, recorded from five distinct cortical regions of the brain. We focused on the `alpha' functional network, corresponding to the individual peak frequency in the alpha band. The total data set of 120 seconds was divided into three segments of 18 seconds each, taken from start, middle, and end of the recording. This segmentation allowed us to analyze the evolution of the underlying functional network. The method of time-resolved partial directed coherence (tPDC) was used to assess the causality. This method allowed us to focus on the individual peak frequency in the `alpha' band (7-13 Hz). Because of the significantly higher power in the recorded EEG in comparison to MEG, at the individual peak frequency of the alpha band, results rely only on EEG. The MEG was used only for comparison. Our results show that different regions of the brain start to `disconnect' from one another over the course of time. The driving signals, along with the feedback signals between different cortical regions start to recede over time. This shows that, with the course of rest, brain regions reduce communication with each another

Source analysis of beta-synchronisation and cortico-muscular coherence after movement termination based on high resolution electroencephalography

We hypothesized that post-movement beta synchronization (PMBS) and cortico-muscular coherence (CMC) during movement termination relate to each other and have similar role in sensorimotor integration. We calculated the parameters and estimated the sources of these phenomena.We measured 64-channel EEG simultaneously with surface EMG of the right first dorsal interosseus muscle in 11 healthy volunteers. In Task1, subjects kept a medium-strength contraction continuously; in Task2, superimposed on this movement, they performed repetitive self-paced short contractions. In Task3 short contractions were executed alone. Time-frequency analysis of the EEG and CMC was performed with respect to the offset of brisk movements and averaged in each subject. Sources of PMBS and CMC were also calculated.High beta power in Task1, PMBS in Task2-3, and CMC in Task1-2 could be observed in the same individual frequency bands. While beta synchronization in Task1 and PMBS in Task2-3 appeared bilateral with contralateral predominance, CMC in Task1-2 was strictly a unilateral phenomenon; their main sources did not differ contralateral to the movement in the primary sensorimotor cortex in 7 of 11 subjects in Task1, and in 6 of 9 subjects in Task2. In Task2, CMC and PMBS had the same latency but their amplitudes did not correlate with each other. In Task2, weaker PMBS source was found bilaterally within the secondary sensory cortex, while the second source of CMC was detected in the premotor cortex, contralateral to the movement. In Task3, weaker sources of PMBS could be estimated in bilateral supplementary motor cortex and in the thalamus. PMBS and CMC appear simultaneously at the end of a phasic movement possibly suggesting similar antikinetic effects, but they may be separate processes with different active functions. Whereas PMBS seems to reset the supraspinal sensorimotor network, cortico-muscular coherence may represent the recalibration of cortico-motoneuronal and spinal systems

Topography, frequency and latency of PMBS and cortico-muscular coherence (CMC) contralateral to the movement in Task1-3.

<p>f: female, m: male.</p

Source analysis of Post-Movement Beta Synchronization and Cortico-muscular Coherence (grand average data).

<p>In Task1 high beta power and strong CMC could be detected in the primary sensorimotor cortex. In Task2 the strongest sources could be presented in the same area, but second source of PMBS was estimated in the secondary sensory cortex, second source of CMC in the premotor cortex. Sources of PMBS were bilateral; sources of CMC were unilateral in Task1-2. In Task3 source of PMBS in the primary sensorimotor and supplementary motor area were bilateral and we could detect additional source in the thalamus.</p

Time-frequency analysis of EEG power and cortico-muscular coherence of one representative subject.

<p>The plots A, B and C represent the raw EMG data from the three tasks. The corresponding EEG power spectrums of each task are shown in plots D, E and F. The dashed white line indicates the movement termination in Task2 and Task3. The G shows the coherence between the C1 electrode and EMG in Task1; F plot represent the coherence between the C3 electrode and EMG in Task2. Note the same frequency range for beta power increase and cortico-muscular coherence in the tasks.</p

MNI co-ordinates of the voxels with the maximum PMBS and maximum coherence in Task2.

<p>Note that data of Subjects No 5 and 9 are not in this table because these subjects did not show any change in corticomuscular coherence after the brisk squeeze movements.</p

MNI co-ordinates of the first source voxel with the maximum PMBS and maximum coherence in Task 1.

<p>MNI co-ordinates of the first source voxel with the maximum PMBS and maximum coherence in Task 1.</p

Orthostatic myoclonus associated with Caspr2 antibodies

Orthostatic myoclonus (OM) is a clinical phenomenon in which myoclonus of the lower limbs appears or becomes worse upon standing.(1) OM usually affects patients older than 65 years and may be a frequent cause of unsteadiness upon standing in the elderly.(2) Although the underlying etiology remains unclear, OM has predominantly been described in association with neurodegenerative diseases.(1) We describe a patient with OM in association with antibodies against contactin-associated protein-2 (Caspr2) whose symptoms markedly improved with immunotherapy