Knapp F.,Kliniken Schmieder |
Viechtbauer W.,Maastricht University |
Leonhart R.,Albert Ludwigs University of Freiburg |
Nitschke K.,Albert Ludwigs University of Freiburg |
Kaller C.P.,Albert Ludwigs University of Freiburg
Psychological Medicine | Year: 2017
Background: Despite a large body of research on planning performance in adult schizophrenia patients, results of individual studies are equivocal, suggesting either no, moderate or severe planning deficits. This meta-analysis therefore aimed to quantify planning deficits in schizophrenia and to examine potential sources of the heterogeneity seen in the literature. Method: The meta-analysis comprised outcomes of planning accuracy of 1377 schizophrenia patients and 1477 healthy controls from 31 different studies which assessed planning performance using tower tasks such as the Tower of London, the Tower of Hanoi and the Stockings of Cambridge. A meta-regression analysis was applied to assess the influence of potential moderator variables (i.e. sociodemographic and clinical variables as well as task difficulty). Results: The findings indeed demonstrated a planning deficit in schizophrenia patients (mean effect size: (Formula presented.); 95% confidence interval 0.56–0.78) that was moderated by task difficulty in terms of the minimum number of moves required for a solution. The results did not reveal any significant relationship between the extent of planning deficits and sociodemographic or clinical variables. Conclusions: The current results provide first meta-analytic evidence for the commonly assumed impairments of planning performance in schizophrenia. Deficits are more likely to become manifest in problem items with higher demands on planning ahead, which may at least partly explain the heterogeneity of previous findings. As only a small fraction of studies reported coherent information on sample characteristics, future meta-analyses would benefit from more systematic reports on those variables. Copyright © Cambridge University Press 2017
Schoenfeld M.A.,Otto Von Guericke University of Magdeburg |
Schoenfeld M.A.,Leibniz Institute for Neurobiology |
Hassa T.,Kliniken Schmieder |
Hopf J.-M.,Otto Von Guericke University of Magdeburg |
And 3 more authors.
Cerebral Cortex | Year: 2011
The neural mechanisms underlying conversion disorders such as hysterical blindness are at present unknown. Typically, patients are diagnosed through exclusion of neurological disease and the absence of pathologic neurophysiological diagnostic findings. Here, we investigate the neural basis of this disorder by combining electrophysiological (event-related potentials) and hemodynamic measures (functional magnet resonance tomography) in a patient with hysterical blindness before and after successful treatment. Importantly, the blindness was limited to the left upper and right lower visual quadrant offering the possibility to use the other 2 sighted quadrants as controls. While the functional magnetic resonance imaging activations were normal for visual stimulation electrophysiological indices of visual processing were modulated in a specific manner. Before treatment, the amplitude of the N1 event-related potentials component had smaller amplitudes for stimuli presented in the blind quadrants of the visual field. Following successful treatment the N1 component elicited by stimuli presented in formerly blind quadrants had a normal distribution without any amplitude differences between the 4 quadrants. The current findings point out that dissociative disorders such as hysterical blindness may have neurophysiological correlates. Furthermore, the observed neurophysiological pattern suggests an involvement of attentional mechanisms in the neural basis hysterical blindness. © The Author 2011. Published by Oxford University Press. All rights reserved.
Liepert J.,Kliniken Schmieder |
Greiner J.,Kliniken Schmieder
Journal of Rehabilitation Medicine | Year: 2014
Objective: To explore whether stroke patients exhibit increases in motor excitability during action observation, whether differences exist between the affected and non-affected sides, and between pure motor strokes and predominantly sensory strokes. Methods: In 18 patients (10 pure motor strokes, 8 predominantly sensory strokes, < 6 months after the stroke) transcranial magnetic stimulation was used to test motor excitability while the patients viewed a video showing a hand performing pinch grips. Transcranial magnetic stimulation pulses were applied at 120% of the individual motor threshold at rest, as obtained from the affected hemisphere. Recordings were taken simultaneously from the first dorsal interosseous muscle of both hands. Motor performance was evaluated with the Box and Block Test. Results: Transcranial magnetic stimulation-evoked muscle responses obtained from the affected and the unaffected sides were significantly higher during action observation than during rest (p = 0.024 and p = 0.004, respectively). This effect was significantly stronger when measuring the same hand as the one viewed in the video (p = 0.019). No difference was found between motor and sensory strokes. In 11 patients there was an action observation-associated increase in the amplitudes of motor evoked potentials in the affected side. In 15 patients there was an action observation-associated increase in motor evoked potentials amplitudes in the unaffected side. Conclusion: The results are potentially relevant for the use of action observation as a treatment strategy. © 2014 The Authors.
Haubrich C.,RWTH Aachen |
Pies K.,RWTH Aachen |
Dafotakis M.,RWTH Aachen |
Block F.,Helios Kliniken Schwerin |
And 2 more authors.
Ultrasound in Medicine and Biology | Year: 2010
Despite of precipitous blood pressure falls in Parkinson's Disease (PD) patients, they may not experience syncope or postural complaints. Can cerebral blood flow regulation explain why orthostatic hypotension (OH) has often no accompanying symptoms? In patients with PD and OH (18 asymptomatic; 8 symptomatic), arterial blood pressure (ABP) as well as Doppler-detected cerebral blood flow velocity (CBFV) in middle and posterior cerebral arteries (MCA and PCA) were monitored during head-up tilt and compared with 25 controls and eight non-PD-OH patients. Analysis included the transfer function between slow spontaneous pressure and flow-oscillations. ABP and CBFV were maintained at significantly higher levels in asymptomatic than symptomatic PD-OH (ABP: 85.7 ± 10.5 vs. 66.9 ± 12.5%; MCA-FV: 83.3 ± 9.3 vs. 66.1 ± 6.8%; PCA-FV: 84.4 ± 12.2 vs. 65.9 ± 9.3% of supine). When orthostatic complaints occurred, CBFV depended directly on ABP changes (MCA r2 = 0.64; PCA r2 = 0.62; both p < 0.05). Despite of a tilt-induced blood pressure instability in PD-OH, the transfer function parameters did not differ from normal [phase: MCA: 46.6 ± 20.5°; PCA 39.2 ± 28.8°, gain: MCA 2.0 ± 0.7; PCA 2.9 ± 1.6)]. Results showed a normal autoregulatory response to downward blood pressure shifts in PD. Moreover, orthostatic blood pressure instability is compensated equally sufficient in anterior and posterior parts of cerebral circulation. Whether in PD patients, OH becomes symptomatic rather seems to depend on blood pressure falling below the autoregulated range. (E-mail: Christina.Haubrich@t-online.de). © 2010 World Federation for Ultrasound in Medicine & Biology.
Liepert J.,Kliniken Schmieder |
Liepert J.,Albert Ludwigs University of Freiburg |
Hassa T.,Kliniken Schmieder |
Tuscher O.,Albert Ludwigs University of Freiburg |
Schmidt R.,Kliniken Schmieder
Journal of Psychosomatic Research | Year: 2011
Background: Patients with a psychogenic paresis have difficulties performing voluntary movements. Typically, diagnostic interventions are normal. We tested whether patients with a psychogenic lower limb paresis exhibit abnormal motor excitability during motor imagery or movement observation. Methods: Transcranial magnetic stimulation (TMS) with single and paired pulses was used to explore motor excitability at rest, during imagination of ankle dorsiflexions and during watching another person perform ankle dorsiflexions. Results obtained in ten patients with a flaccid psychogenic leg paresis were compared with a healthy age-matched control group. In addition, results of two patients with a psychogenic fixed dystonia of the leg are presented. Results: During rest, motor excitability evaluated by motor thresholds, size of motor-evoked potentials (MEP) by single pulse TMS, intracortical inhibition and intracortical facilitation tested by paired-pulse TMS were similar in patients and healthy subjects. MEPs recorded in five patients during movement observation were also comparable across the two groups. During motor imagery, patient MEPs were significantly smaller than in the control group and smaller than during rest, indicating an inhibition. Conclusion: In patients with motor conversion disorder, the imagination of own body movements induces a reduction of corticospinal motor excitability whereas it induces an excitability increase in healthy subjects. This discrepancy might be the electrophysiological substrate of the inability to move voluntarily. Watching another person perform movements induces a normal excitability increase, indicating a crucial role of the perspective and suggesting that focusing the patient's attention on a different person might become a therapeutic approach. © 2011 .
Liepert J.,Kliniken Schmieder
Journal fur Neurologie, Neurochirurgie und Psychiatrie | Year: 2010
An increasing number of publications dealing with motor rehabilitation now allows to denominate evidence-based therapies. In this review, old and new treatments for motor rehabilitation of upper and lower limbs after stroke will be presented. In particular, randomised, controlled trials, meta-analyses and systematic reviews have been taken into consideration. In summary, evidence is best for constraint-induced movement therapy and for application of botulinum toxin type A in patients with focal spasticity. Some efficacy has been demonstrated for other therapies such as impairment-oriented training, mirror therapy, mental practice, the use of electromechanical devices and specific gait training. Without doubt, further scientific research is required for already well-known as well as new treatment strategies.
Liepert J.,Kliniken Schmieder |
Binder C.,Kliniken Schmieder
Restorative Neurology and Neuroscience | Year: 2010
Background: Spasticity manifesting as a dysbalance between extensor and flexor muscles may contribute to an impaired hand function. We studied clinical (n=10 patients) and electrophysiological (n=9 patients) changes produced by vibration of forearm extensor muscles (FEM) in chronic stroke patients with spastic hemiparesis. Methods: In Exp. 1, the Box and Block Test (BBT) was applied to test dexterity before and after 5 minutes of FEM vibration. In Exp. 2, transcranial magnetic stimulation was used to study the cortical silent period (CSP) before and during FEM vibration. Recordings were taken from the antagonistic flexor carpi radialis muscle. Results: After vibration, performance of the BBT was improved by 20%. The effect persisted for at least 10-15 minutes. Vibration induced a prolongation of the CSP. This effect occurred in the affected and non-affected side to a similar degree. The magnitude of performance changes and CSP changes was not correlated. Conclusions: FEM vibration enhances inhibitory neuronal circuits targeting the antagonistic forearm flexor muscles and is associated with an improved dexterity in the spastic arm. It might become a supporting tool in the motor recovery of spastic hemiparesis. © 2010 - IOS Press and the authors. All rights reserved.
Liepert J.,Kliniken Schmieder
Current Opinion in Neurology | Year: 2010
Purpose of review: The diversity of interventions aimed at improving upper extremity dysfunction is increasing. This article reviews the effectiveness of different therapeutic approaches that have been published in 2009 and 2010. Evidence is based on randomized controlled trials, systematic reviews, and meta-analyses. Recent findings: Application of constraint-induced movement therapy in acute stroke patients was not more effective than a control intervention, and a more intense therapy may even be harmful. Botulinum toxin injections do not only reduce spasticity but, in children, also improve motor functions if combined with occupational therapy. Strength training improves arm function but not necessarily activities of daily living. Bilateral arm training is as effective as other interventions. Extrinsic feedback and sensory training may further improve motor functions. Mirror therapy was particularly effective for patients with initial hand plegia. Summary: For some interventions (e.g. constraint-induced movement therapy, botulinum toxin), efficacy is evident, for others (e.g. mental practice, virtual reality), well designed studies with sufficient numbers of patients are needed. The ultimate goal still is to develop evidence-based therapies for all different degrees of motor impairment. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.
Pohl M.,Helios Klinik Schloss Pulsnitz |
Bertram M.,Kliniken Schmieder
Nervenarzt | Year: 2016
Background: Early neurological and neurosurgical rehabilitation (ENNR) as a complex post-acute form of treatment for patients with severe neurological diseases and continued need for intensive care is well established in Germany. Objective: To assess the efficacy of ENNR from the perspective of evidence-based medicine as well as to present data on the outcome of ENNR patients including the analysis of prognostic factors. Material and methods: A search was carried out in PubMed databases to identify early rehabilitation treatment forms evaluated by randomized controlled trials and with respect to large multicenter surveys of outcome and prognostic factors. Results: For ENNR as a complex treatment concept, effectiveness not has been shown with regard to evidence-based medicine but it includes individually effective treatment forms. In two large multicenter evaluations the average duration of treatment was between 51 and 57 days and mortality was between 6 % and 10 %, increasing with the proportion of mechanically ventilated patients. Lower need for nursing support on admission indicated better outcome, whereas mechanical ventilation was more likely to be associated with poor outcome. Long-term outcome was negatively influenced by mechanical ventilation as well as severe neurogenic dysphagia with and without the need for a tracheal cannula and/or percutaneous endoscopic gastrostomy (PEG) and also by severely impaired communication at the end of ENNR. Discussion: These prognostic factors indicate the primary aims of ENNR, which are to reduce the need for nursing support and to establish the capability for rehabilitation. If these aims are achieved, favorable functional and long-term outcome can be expected for ENNR patients. The presented studies verify the sustained efficacy of ENNR as an essential part of the overall treatment concept for severely neurologically impaired patients. © 2016 Springer-Verlag Berlin Heidelberg
Liepert J.,Kliniken Schmieder |
Heller A.,Kliniken Schmieder |
Behnisch G.,Leibniz Institute for Neurobiology |
Schoenfeld A.,Leibniz Institute for Neurobiology |
Schoenfeld A.,Otto Von Guericke University of Magdeburg
Neurorehabilitation and Neural Repair | Year: 2013
Background. To explore whether a polymorphism in dopamine metabolism influences the effectiveness of neurological rehabilitation and the outcome after ischemic stroke. Methods. The Barthel Index (BI) and the Rivermead Motor Assessment (RMA) were assessed in 78 moderately affected stroke patients (1) after they had entered a neurological inpatient rehabilitation, (2) after 4 weeks of rehabilitation therapy, and (3) 6 months later. Polymorphisms of the gene encoding catechol-O-methyltransferase (COMT) were determined. BI and RMA results were analyzed with respect to the genetic profiles of COMT. Results. Carriers of COMT Val/Val alleles showed better results in BI and RMA than COMT Met/Met carriers at all 3 time points. Val/Met carriers exhibited results in between the homozygotes, suggesting a gene-dose relationship. Altogether, BI and RMA results were highly correlated. Conclusion. Stroke patients with COMT Val/Val alleles had higher motor functions and abilities of activities of daily living even at the beginning of the rehabilitation period. All patient groups improved during the rehabilitation period to a similar degree, suggesting that physical therapy is comparably effective in all polymorphism subtypes. © The Author(s) 2013.