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Short involuntary paroxysmal movements or behavioral patterns are an important differential diagnosis to epileptic seizures, especially when occurring for the first time. Typically, these attacks are not witnessed by medically trained personnel and the patient anamnesis or observations by a third party are often not specific enough to differentiate between epileptic seizures and the differential diagnoses. This review presents the epidemiology, the clinical presentation, the necessary diagnostic steps and the differential diagnostic approach to parasomnias and dyskinesias. The focus is on the clinical aspects, and therapeutic principles are also briefly described. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the Pull Test--Retropusion Test and the Push and Release Test (P&R) as regards their ability to predict Parkinson (PD) fallers and nonfallers in relation to their medication state. Eighty-two PD patients participated in the study. Fallers (N = 36) and nonfallers (N = 46) were grouped on the basis of their fall history. Fallers were those who had fallen at least once within the last 6 months. The two groups were compared on the basis of the patients' performance in the Pull and the P&R tests, both in their 'OFF' and 'ON' medication state. The overall accuracy of the classification of PD patients as fallers and nonfallers was determined by means of binomial logistic regression (BLR) and the analysis of the 'area under the receiver operating characteristics curve' (AUC). In the OFF medication state, the statistical analysis revealed that the Pull Test was accurate (methods BLR (AUC)) in 85.4% (0.87) of cases and the P&R Test in 86.6% (0.90). In the ON medication state, the Pull Test was only 76.8% (0.78) accurate, while the P&R Test was 87.8% (0.87) accurate. Both clinical tests are valid and relatively equivalent when assessing patients in their OFF medication state; however, the P&R Test is more accurate than the Pull Test in the ON state. This indicates that it is more widely applicable in clinical practice. [ABSTRACT FROM AUTHOR]

PD patients with implanted DBS electrodes allow for the investigation of basal ganglia activity during gait. Whereas the overall spectral content of local field potentials (LFP) in the BG is known to change with movement, it is still unclear how exactly the BG-LFP change during gait. We investigated the electric local field potentials of the STN of 10 patients with PD during gait. Gait parameters were recorded with inertial sensor units and the gait was subsequently analyzed in parallel to the electrophysiological activity in Matlab. Additionally, we recorded LFPs during rest and control experiments to probe for movement related artifacts. Stimulation was off in all experiments reported here. On a group level, a frequency analysis shows that the high beta frequency band gets significantly downregulated during gait as compared to sitting rest. On an individual level, a linear classifier trained with frequency profiles of small epochs of LFP activity recorded during gait and rest can distinguish between walking and resting episodes with a mean classification accuracy across all patients of 90%. A time–frequency analysis on the group level reveals a distinct modulation pattern. Whereas low frequencies in the theta and alpha range and high frequencies in the gamma range are modulated up and down time-locked to the gait cycle, the beta band gets modulated down during the complete gait cycle. [ABSTRACT FROM AUTHOR]

PD patients with implanted DBS electrodes allow for the investigation of basal ganglia activity during gait. Whereas the overall spectral content of local field potentials (LFP) in the BG is known to change with movement, it is still unclear how exactly the BG-LFP change during gait. We investigated the electric local field potentials of the STN of 10 patients with PD during gait. Gait parameters were recorded with inertial sensor units and the gait was subsequently analyzed in parallel to the electrophysiological activity in Matlab. Additionally, we recorded LFPs during rest and control experiments to probe for movement related artifacts. Stimulation was off in all experiments reported here. On a group level, a frequency analysis shows that the high beta frequency band gets significantly downregulated during gait as compared to sitting rest. On an individual level, a linear classifier trained with frequency profiles of small epochs of LFP activity recorded during gait and rest can distinguish between walking and resting episodes with a mean classification accuracy across all patients of 90%. A time–frequency analysis on the group level reveals a distinct modulation pattern. Whereas low frequencies in the theta and alpha range and high frequencies in the gamma range are modulated up and down time-locked to the gait cycle, the beta band gets modulated down during the complete gait cycle. [ABSTRACT FROM AUTHOR]

Purpose Deep Brain Stimulation (DBS) is an established surgical treatment for neurodegenerative diseases such as Parkinson’s Disease (PD) or Dystonia. In terms of imaging, pre-operative MRI scans are used for surgical planning and post-operative CT scans for control of electrode placement. Intra-operatively, however, imaging guidance is often avoided, due to contra-indications of DBS electrode contacts with MRI and difficulty of acquiring CT scans. Ultrasound imaging could be an attractive alternative, but has not been investigated yet due to difficult positioning of the transducer in the narrow burr-holes. Recently, there has been interest in the community towards the usage of non-invasive transcranial ultrasound (TCUS) through the pre-aureal bone window. In a seminal work ( Walter, 2012 ), Walter described the intra-operative usage of TCUS for lead electrode imaging and post-operative placement assessment of DBS electrode, showing its potential and limitations. In this work, we investigate, for the first time, the feasibility of using 3D-TCUS for imaging of already implanted Deep Brain Stimulation (DBS) electrodes. As a first step towards this goal, we report electrode localization errors outside of the operating room on six previously operated DBS patients. Methods Post-operative CT scans are registered to already acquired pre-operative T1 and T2 MRI sequences to localize the actual electrode tip locations in MRI. We then acquire 3D-TCUS sweeps and co-register them to the pre-operative MRI as well, using a head-surface point-cloud registration first (using Iterative Closest Points, ICP) and a manual refinement using several pairs of corresponding points on anatomical structures (midbrain, ventricles) in TCUS and MRI. The comparison between electrode tips identified in 3D-TCUS and actual tip positions in CT are a first step towards assessing whether 3D-TCUS could provide a benefit intra-operatively in future. Results Quantitative evaluation is performed by reporting the accuracy of electrode tip localization after ICP-based registration (mean 5.62 mm, stdev 2.26 mm) and after manual registration refinement (mean 4.09 mm, stdev 1.75 mm). Additionally, we provide multiple image examples showing the dependence of 3D-TCUS quality depending on the bone window, and multiple examples of image artifacts in TCUS images and 3D reconstructions. Conclusions Intra-operative 3D ultrasound imaging has potential for electrode tip localization during DBS procedures. 3D transcranial US could be an attractive alternative to intra-cranial imaging through the narrow burr-hole. We report the first results of volumetric 3D-TCUS imaging on already operated patients in a post-operative scenario. Initial results still show a relatively high inaccuracy of electrode tip localization, e.g. due to TCUS artifacts and imperfect registration to the pre-operative MRI. Nevertheless, the potential of TCUS for DBS electrode imaging as described by Walter (2012) can be extended to 3D, allowing for electrode tip and shaft localization. This motivates further work, e.g. on improved MRI-US registration and computer-aided tip detection ( Figs. 1 and 2 ). [ABSTRACT FROM AUTHOR]