P 70 MR imaging correlates of impaired eye movement control in parkinsonian syndromes

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freedom representing reaching (Fig. 1), standing up, and walking motion in sagittal plane, Fig. 2. In Fig. 1, the convergence to the target in a reaching motion task is achieved after a very small number of trials. The efficiency of our CL algorithm is confirmed also in a real body experiment – healthy subject performing fast reaching (ballistic-like) movements. Special attention in our current research is devoted to the challenging problem of CL in the real, three-dimensional human locomotion. We can perform proper decomposition of this complex motion task into several goal-directed movements and apply the proposed CL scheme for each of them. Discussion: We believe that the proposed approach can be used to rebuild the so-called internal models (cortical reorganization) by proper training procedures. The work outlined here can provide a fundamental understanding of motor learning and may lead to the development of optimal strategies for efficient neuro-muscular rehabilitation. In addition we have found that our approach is very promising and could be efficiently applied to the more complex, human/robot systems. Various assistive devices may be used for restoration of human movement functionality, such as passive and active orthoses, robotic exoskeletons, EMG, FES, brain-computer interfaces (BCI). Keywords Zolpidem; Paradoxical arousal; Disorders Vegetative state; Minimally conscious state

of

consciousness;

References Despotova D, Kiriazov P. Motor learning and optimisation in gait control. In: TAR 2015 – Technically Assisted Rehabilitation. Proceeding Berin; 12–15 March 2015. ISSN 2192-161x. Despotova D, Kiriazov P, Nikolova G. The importance of controllability in dynamic movement training. Ser Biomech [submitted for publication].

diffusion tensor imaging (DTI) measures, and (2) to investigate differences in these measures between chronic stroke patients and healthy older adults matched for age and gender. Methods: We included 12 chronic stroke patients with residual upper limb motor impairment (mean age 61.5 years – range 49– 75 years; 3 females) and 17 healthy older adults (mean age 60.4 years – range 48–77 years; 9 females). All participants completed a 3T MRI session and a 96-electrode EEG session. The MRI session included a high-resolution anatomical scan, DTI, and fMRI during rest, motor execution and kinesthetic MI of repeated hand opening and closing. The EEG session consisted of three blocks: motor execution, kinesthetic MI and kinesthetic MI with real-time EEG-based visual feedback, all with the same hand movement as during fMRI. Each patient also completed a motor assessment consisting of the upper limb section of the Fugl-Mayer Assessment and the Modified Ashworth Scale. Results: We will present preliminary results regarding the correlations of ERD and fMRI activation related to motor execution and imagination. Moreover, we will present the results of a replication of the analysis of Halder et al. (2013) that for young healthy adults indicated a significant association between MI-induced ERD and white matter integrity (fractional anisotropy) in subcortical structures. References Halder S, Varkuti B, Bogdan M, Kübler A, Rosenstiel W, Sitaram R, et al. Prediction of brain-computer interface aptitude from individual brain structure. Front Hum Neurosci 2013;7(April):1–9. Zich C, Debener S, Kranczioch C, Bleichner MG, Gutberlet I, De Vos M. Real-time EEG feedback during simultaneous EEG-fMRI identifies the cortical signature of motor imagery. Neuroimage 2015;114:438–47. doi:10.1016/j.clinph.2017.06.145

doi:10.1016/j.clinph.2017.06.144

Poster Poster P 69 Assessing the relation between brain structure and function during motor imagery in stroke patients and controls using EEG and MRI—J. Meekes *, S. Debener, C. Zich, C. Kranczioch (University of Oldenburg, Neuropsychology Lab, Oldenburg, Germany) ⇑

Corresponding author.

Background: Motor imagery (MI) training, in particular in combination with EEG-based neurofeedback (MI-NF), has been suggested as a potential add-on therapy for rehabilitation of upper limb motor impairments after stroke. Most MI-NF implementations are based on the event-related desynchronization (ERD) in the 8–30 Hz frequency range that is typically observed over sensorimotor areas during motor execution and imagination. The amplitude and consistency of the ERD depends, among other things, on brain structure and function during motor imagery (e.g., Halder et al., 2013; Zich et al., 2015). Because the vast majority of the research on MI-NF has been conducted with young healthy individuals, it is unclear to what degree changes regarding the relationship between MI-induced ERD, MI-induced functional magnetic resonance imaging (fMRI) activation and brain structure in stroke patients are due to normal aging and the stroke, respectively. Objectives: (1) to investigate in healthy older adults (>45 years) associations of MI-induced ERD, MI-induced fMRI activation and

P 70 MR imaging correlates of impaired eye movement control in parkinsonian syndromes—M. Gorges *, H.P. Müller, J. Rosskopf, O. Vintonyak, A.C. Ludolph, E.H. Pinkhardt, J. Kassubek (Uniklinik Ulm, Neurologie, Ulm, Germany) ⇑

Corresponding author.

Background: The neurophysiology of eye movement control provides a window into brain pathology in neurodegenerative diseases such as Parkinson’s disease (PD), Multisystem Atrophy (MSA) and Progressive Supranuclear Palsy (PSP) (Gorges et al., 2016). Structural and functional brain architecture can be investigated using Diffusion tensor imaging (DTI), Atlas-based morphometry (ABV) and ‘‘resting-state” fMRI. Objective: To investigate the association between impaired oculomotor control and both volumetric as well as structural and functional brain connectivity changes in PD, MSA, and PSP patients. Methods: A total of 152 patients including 71 PD, 56 PSP, and 25 MSA patients together with 56 matched healthy controls underwent video-oculographic examination (EyeSeeCamÒ) and whole-brain based DTI, high-resolution3DT1-weighted, and ‘resting-state’ MRI. Results: Impaired executive oculomotor control was a prominent feature in PD as measured for the rate of saccadic intrusions (p < 0.001) which was significantly correlated with cerebral brain atrophy (p < 0.001, corrected), white matter impairment (p < 0.01, corrected), and functional connectivity loss along the default mode network’s midline cores (p < 0.001, corrected), respectively. Vertical

Abstracts / Clinical Neurophysiology 128 (2017) e305–e412

gaze palsy is the eponymous feature in PSP and was significantly correlated with midbrain atrophy (p < 0.01, corrected), midbrain microstructural damage (p < 0.001, corrected), and regional functional connectivity loss in the midbrain (p < 0.001, corrected). Pronounced saccadized pursuit (p < 0.001) was a cardinal feature in MSA which was correlated with pontine atrophy and white matter damage in the middle cerebral peduncle (p < 0.001). Conclusions: Worse oculomotor performance in the diseasespecific domain was associated with more severely impaired regional macro- and microstructure and reduced regional functional connectivity in disease-specific brain structures. These findings increase our pathophysiological knowledge of the underlying parkinsonismassociated pathology and pave the way towards a videooculographic surrogate marker. References Gorges M, Müller H-P, Lulé, et al. Brain Imag Behav 2016;10:79–91. doi:10.1016/j.clinph.2017.06.146

Poster P 71 Levodopa modulates beta and gamma oscillations in the cortico-basal ganglia loop with a higher efficacy than the dopamine receptor agonist apomorphine in experimental Parkinsonism—J. Kühn, J. Haumesser, M. Beck, J. Altschüler, A. Kühn, V. Nikulin, C. van Riesen * (Charite Berlin, Neurologie, Berlin, Germany) ⇑

Corresponding author.

The pharmacotherapy of Parkinson’s disease (PD) is based on levodopa, and dopamine receptor agonists, such as apomorphine. Although both types of agents provide beneficial clinical effects on motor and non-motor symptoms in PD clinical efficiency and side effects differ substantially between levodopa and dopamine receptor agonists. Levodopa is known to provide a greater symptomatic relief than dopamine receptor agonists. Since long-term levodopa treatment often results in debilitating motor fluctuations, dopamine receptor agonists are recommended in younger patients. The pharmacodynamic basis of these profound differences is not understood so far. Levodopa and dopamine receptor agonists may have a different impact on beta and gamma oscillations in the cortico-basal ganglia loop that have been shown to be of importance for the pathophysiology of PD. We performed in vivo electrophysiological recordings in anesthetized dopamine-intact and dopaminedepleted rats compare the impact of levodopa or apomorphine on neuronal population oscillations. Our results demonstrated that levodopa had a higher potency than apomorphine to suppress the abnormal beta oscillations that are often associated with bradykinesia while simultaneously increasing the gamma oscillations often associated with increased movement. Our data suggests that the higher clinical efficacy of levodopa as well as some of its side effects, as e.g. dyskinesias may be based on its characteristic ability to modulate beta-/gamma-oscillation dynamics in the cortico-basal ganglia loop circuit. doi:10.1016/j.clinph.2017.06.147

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Poster P 72 Influence of anesthesia on the outcome in patients with Parkinson’s disease undergoing deep brain stimulation of the subthalamic nucleus—F. Blasberg 1,*, L. Wojtecki 1, J. Vesper 2, A. Schnitzler 1, S.J. Groiss 1 (1 Heinrich-Heine-Universität, Institut für klinische Neurowissenschaften und medizinische Psychologie, Düsseldorf, Germany, 2 Heinrich-Heine-Universität, Funktionelle Neurochirurgie und Stereotaxie, Düsseldorf, Germany) ⇑

Corresponding author.

Background: Currently, implantation of electrodes for Deep Brain Stimulation (DBS) as a treatment for patients with Parkinson’s Disease (PD) is usually performed under local anaesthesia (LA) to allow intraoperative testing of effects and side effects. Recently, several studies have indicated that surgery under general anaesthesia (GA) may lead to comparable outcomes. However, most of these studies did not compare the types of anesthesia directly. Objective: This study aims to investigate whether the type of anesthesia (LA vs. GA) affects the outcome of motor and cognitive symptoms and reduction of levodopa-equivalent daily dose (LEDD) after subthalamic nucleus (STN)-DBS over a period of one year in a large single center population. Methods: 48 patients underwent DBS in GA between 2008 and 2015 at the center of movement disorders in Düsseldorf. From the other 140 patients operated by the standard procedure in LA in the same period of time, 48 patients were matched to the GA group. These groups were compared regarding improvement in motor function measured by the Unified Parkinson’s Disease Rating Scale (UPDRS) III, decrease of LEDD, setting of stimulation parameters, cognitive function measured with neuropsychological tests and occurrence of stimulation induced side effect. Results: Motor function measured by the UPDRS III score in the medication off, stimulation on state was significantly better in the LA group compared to the GA group. Subscore analysis revealed that axial symptoms ‘‘freezing” and ‘‘speech” were significantly worse in the GA group at three months and one year, respectively. Postoperative LEDD-reduction was significant in both groups and did not differ between the groups over the whole period of one year. There were no significant differences of stimulation amplitude and cognition between the groups. Stimulation induced side effects tended to be less frequent in the LA group but did not reach statistical significance. Conclusions: In our study, motor function of patients undergoing DBS surgery in LA improved significantly more over the period of one year postoperatively compared to those operated in GA. Furthermore postoperative stimulation induced side effects tended to be less frequent in the LA group. We therefore conclude that surgery in LA with intraoperative testing is still significantly advantageous for PD patients undergoing STN-DBS and should be first choice if there are no other specific limitations that make GA unavoidable. doi:10.1016/j.clinph.2017.06.148

Poster P 73 Shorter pulse width reduces gait ataxia associated with VIMDBS—D. Kroneberg 1,*, A.C. Meyer 1, G.H. Schneider 2, A. Kühn 1