Hammel Neurorehabilitation and Research Center

Hammel, Denmark

Hammel Neurorehabilitation and Research Center

Hammel, Denmark
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Kothari M.,University of Aarhus | Svensson P.,University of Aarhus | Svensson P.,Aarhus University Hospital | Jensen J.,Hammel Neurorehabilitation and Research Center | And 5 more authors.
Neuroscience | Year: 2013

The primary aim of this study was to investigate the effect of different training types and secondary to test gender differences on the training-related cortical plasticity induced by three different tongue-training paradigms: (1) therapeutic tongue exercises (TTE), (2) playing computer games with the tongue using the Tongue Drive System (TDS) and (3) tongue-protrusion task (TPT). Forty-eight participants were randomized into three groups with 1. h of TTE, TDS, or TPT. Stimulus-response curves of motor evoked potentials (MEPs) and motor cortex mapping for tongue muscles and first dorsal interosseous (FDI) (control) were established using transcranial magnetic stimulation at three time-points: (1) before tongue-training, (2) immediately after training, (3) 1. h after training. Subject-based reports of motivation, fun, pain and fatigue were evaluated on 0-10 numerical rating scales after training. The resting motor thresholds of tongue MEPs were lowered by training with TDS and TPT (P<. 0.011) but not by TTE (P=. 0.167). Tongue MEP amplitudes increased after training with TDS and TPT (P<. 0.030) but not with TTE (P=. 0.302). Men had higher MEPs than women in the TDS group (P<. 0.045) at all time-points. No significant effect of tongue-training on FDI MEPs was observed (P> 0.335). The tongue cortical motor map areas were not significantly increased by training (P> 0.142). Training with TDS was most motivating and fun (P<. 0.001) and TTE was rated the most painful (P<. 0.001). Fatigue level was not different between groups (P> 0.071). These findings suggest a differential effect of tongue-training paradigms on training-induced cortical plasticity and subject-based scores of fun, motivation and pain in healthy participants. © 2013 IBRO.


Sandberg K.,Aarhus University Hospital | Sandberg K.,University College London | Sandberg K.,Hammel Neurorehabilitation and Research Center | Barnes G.R.,University College London | And 3 more authors.
Journal of Cognitive Neuroscience | Year: 2014

Studies indicate that conscious perception is related to changes in neural activity within a time window that varies between 130 and 320 msec after stimulus presentation, yet it is not known whether such neural correlates of conscious perception are stable across time. Here, we examined the generalization across time within individuals and across different individuals. We trained classification algorithms to decode conscious perception from neural activity recorded during binocular rivalry using magnetoencephalography (MEG). The classifiers were then used to predict the perception of the same participants during different recording sessions either days or years later as well as between different participants. No drop in decoding accuracy was observed when decoding across years compared with days, whereas a large drop in decoding accuracy was found for between-participant decoding. Furthermore, underlying perceptspecific MEG signals remained stable in terms of latency, amplitude, and sources within participants across years, whereas differences were found in all of these domains between individuals. Our findings demonstrate that the neural correlates of conscious perception are stable across years for adults, but differ across individuals. Moreover, the study validates decoding based on MEG data as a method for further studies of correlations between individual differences in perceptual contents and betweenparticipant decoding accuracies. © 2014 Massachusetts Institute of Technology.


Niazi I.K.,University of Aalborg | Jiang N.,University of Gottingen | Jiang N.,Otto Bock HealthCare GmbH | Tiberghien O.,École Centrale Nantes | And 3 more authors.
Journal of Neural Engineering | Year: 2011

Detection of movement intention from neural signals combined with assistive technologies may be used for effective neurofeedback in rehabilitation. In order to promote plasticity, a causal relation between intended actions (detected for example from the EEG) and the corresponding feedback should be established. This requires reliable detection of motor intentions. In this study, we propose a method to detect movements from EEG with limited latency. In a self-paced asynchronous BCI paradigm, the initial negative phase of the movement-related cortical potentials (MRCPs), extracted from multi-channel scalp EEG was used to detect motor execution/imagination in healthy subjects and stroke patients. For MRCP detection, it was demonstrated that a new optimized spatial filtering technique led to better accuracy than a large Laplacian spatial filter and common spatial pattern. With the optimized spatial filter, the true positive rate (TPR) for detection of movement execution in healthy subjects (n = 15) was 82.5 ± 7.8%, with latency of -66.6 ± 121 ms. Although TPR decreased with motor imagination in healthy subject (n = 10, 64.5 ± 5.33%) and with attempted movements in stroke patients (n = 5, 55.01 ± 12.01%), the results are promising for the application of this approach to provide patient-driven real-time neurofeedback. © 2011 IOP Publishing Ltd.


Harbo T.,Arhus University Hospital | Brincks J.,Hammel Neurorehabilitation and Research Center | Andersen H.,Arhus University Hospital
European Journal of Applied Physiology | Year: 2012

The main objective of this study was to establish normative values for maximal concentric isokinetic strength and maximal isometric strength of all major muscle groups in healthy subjects applying sex, age, height, and body mass-adjusted statistical models. One hundred and seventy-eight (178) (93 male and 85 female) healthy non-athletic Danish volunteers aged 15-83 years were recruited. Eighteen test protocols for each sex were applied to determine isokinetic and isometric muscle strength at knee, ankle, hip, shoulder, elbow, and wrist using a dynamometer (Biodex System 3 PRO). Multiple linear regressions were performed with maximal muscle strength (peak torque) as dependent variable and age, height, and body mass as independent variables. Muscle strength significantly related to age in 24, to height in 13 and to body mass in 27 out of the 36 models. In gender-specific analyses, the variables age, height and body mass accounted for 25% (20-29) (95% confidence interval) of the variation (r 2) in strength for men and 31% (25-38) for women. The r 2 was similar for the isokinetic models and the isometric models [31% (22-40) vs. 28% (23-34)]. Age, height, and body mass related to strength in most muscle groups and gender-specific models with estimated prediction intervals were established for maximal strength of major muscle groups. © 2011 Springer-Verlag.


Evald L.,University of Aarhus | Evald L.,Aarhus University Hospital | Evald L.,Hammel Neurorehabilitation and Research Center
Neuropsychological Rehabilitation | Year: 2015

Use of assistive devices has been shown to be beneficial as a compensatory memory strategy among brain injury survivors, but little is known about possible advantages and disadvantages of the technology. As part of an intervention study participants were interviewed about their experiences with the use of low-cost, off-the-shelf, unmodified smartphones combined with Internet calendars as a compensatory memory strategy. Thirteen community-dwelling patients with traumatic brain injury (TBI) received a 6-week group-based instruction in the systematic use of a smartphone as a memory compensatory aid followed by a brief structured open-ended interview regarding satisfaction with and advantages and disadvantages of the compensatory strategy. Ten of 13 participants continued to use a smartphone as their primary compensatory strategy. Audible and visual reminders were the most frequently mentioned advantages of the smartphone, and, second, the capability as an all-in-one memory device. In contrast, battery life was the most often mentioned disadvantage, followed by concerns about loss or failure of the device. Use of a smartphone seems to be a satisfactory compensatory memory strategy to many patients with TBI and smartphones come with features that are advantageous to other compensatory strategies. However, some benefits come hand-in-hand with drawbacks, such as the feeling of dependency. These aspects should be taken into account when choosing assistive technology as a memory compensatory strategy. © 2014 Taylor and Francis.


Lapitskaya N.,Hammel Neurorehabilitation and Research Center | Nielsen J.F.,Hammel Neurorehabilitation and Research Center | Fuglsang-Frederiksen A.,Aarhus University Hospital
Brain Injury | Year: 2011

Primary objective: This prospective controlled non-randomized study investigated the effects of robotic gait training on electroencephalographic (EEG) brain activity in patients with impaired consciousness due to severe traumatic brain injury (TBI). Methods: Twelve TBI patients and 14 healthy controls underwent a single training session on a computer-driven gait orthosis (Lokomat®). The sensory pathways were assessed using sensory evoked potentials (SEPs). The global delta-alpha EEG power ratio (DAR) and latency of the P300 component of the event-related potentials was assessed prior to and following a training session. Results: Baseline measurements showed impaired SEPs in the majority of patients and significantly larger DAR in patients compared to healthy controls. Robotic gait training resulted in a reduction of the DAR in healthy subjects but not in patients. No changes were observed in P300 latencies after training in either patients or healthy controls. Conclusion: The study showed that robotic gait training induced measurable changes in the EEG power spectrum in healthy individuals, while no changes were observed in patients with severe TBI. The absence of the EEG changes following training might be an indicator of the severity of brain dysfunction. © 2011 Informa UK Ltd All rights reserved.


Lapitskaya N.,Hammel Neurorehabilitation and Research Center | Moerk S.K.,Hammel Neurorehabilitation and Research Center | Gosseries O.,University of Liège | Nielsen J.F.,Hammel Neurorehabilitation and Research Center | De Noordhout A.M.,University of Liège
Brain Stimulation | Year: 2013

Background: Transcranial magnetic stimulation (TMS) have been frequently used to explore changes in motor cortex excitability in stroke and traumatic brain injury, while the extent of motor cortex reorganization in patients with diffuse non-traumatic brain injury remains largely unknown. Objective/ Hypothesis: It was hypothesized that the motor cortex excitability would be decreased and would correlate to the severity of brain injury and level of functioning in patients with anoxic, traumatic, and non-traumatic diffuse brain injury. Methods: TMS was applied to primary motor cortices of 19 patients with brain injury (5 traumatic and 14 non-traumatic causes; on average four months after insult), and 9 healthy controls. The test parameters included resting motor threshold (RMT), short intracortical inhibition (SICI), intracortical facilitation (ICF), and short latency afferent inhibition (SAI). Excitability parameters were correlated to the severity of brain injury measured with Glasgow Coma Scale and the level of functioning assessed using the Ranchos Los Amigos Levels of Cognitive Functioning Assessment Scale and Functional Independence Measure. Results: The patient group revealed a significantly decreased SICI and SAI compared to healthy controls with the amount of SICI correlated significantly to the severity of brain injury. Other electrophysiological parameters did not differ between the groups and did not exhibit any significant relationship with clinical functional scores. Conclusions: The present study demonstrated the impairment of the cortical inhibitory circuits in patients with brain injury of traumatic and non-traumatic aetiology. Moreover, the significant correlation was found between the amount of SICI and the severity of brain injury. © 2013 Elsevier Inc. All rights reserved.


Kjaersgaard A.,University of Southern Denmark | Kjaersgaard A.,Hammel Neurorehabilitation and Research Center | Nielsen L.H.,Hammel Neurorehabilitation and Research Center | Sjolund B.H.,University of Southern Denmark
Clinical Rehabilitation | Year: 2014

Objective: To examine whether patients assessed for initiation of oral intake only by Facial-Oral Tract Therapy had a greater risk of developing aspiration pneumonia during neurorehabilitation than patients assessed by Fibreoptic Endoscopic Evaluation of Swallowing. Design: Randomized controlled trial. Setting: Specialized, national neurorehabilitation centre. Subjects: Adult patients with acquired brain injury. Six hundred and seventy-nine patients were assessed for eligibility and 138 were randomly allocated between June 2009 and April 2011. Interventions: Assessment by Facial-Oral Tract Therapy (control group) or Fibreoptic Endoscopic Evaluation of Swallowing (intervention group). Main measure: Primary outcome was the number of aspiration pneumonias that developed after initiation of oral intake. Results: One hundred and nineteen patients were included in the analysis of the primary outcome (62 controls/57 interventions). Sixteen patients were clinically diagnosed with pneumonia (4 controls/12 interventions). Nine patients had to be excluded: 6 patients got pneumonia before initiating oral intake; 3 patients with the clinical diagnosis of pneumonia did not show radiological signs. Seven patients were left for analysis, 4 of whom developed aspiration pneumonia within 10 days after initiating oral intake (1 control/3 interventions). Conclusion: In the presence of a structured clinical assessment with the Facial-Oral Tract Therapy approach, it is unnecessary to undertake an instrumental investigation of swallowing before initiation of oral intake. © The Author(s) 2013.


Pallesen H.,Hammel Neurorehabilitation and Research Center | Pallesen H.,University of Southern Denmark
Disability and Rehabilitation | Year: 2014

Objective: The purpose of this article is to identify, from a long-term perspective, stroke survivors' self-identity, their views of any associated disabilities and how they manage their lives after stroke. Methods: The interviews and analyses were conducted using a phenomenological qualitative method. A total of 10 men and 5 women, aged 42-84, participated. All had suffered first-time stroke 5 years earlier. Results: After 5 years, participants had greater acceptance of their situation compared with immediately after participating in the rehabilitation programme. However, they described how they still had to deal with the consequences of stroke. They had suffered further illnesses and additions to side effects of the stroke. In dealing with their disabilities and changes to self-identity and life patterns, they seemed to be in a continuous process of change that never truly stabilised. They coped with this continuous process in at least two different ways, including resignation or personal growth. Conclusion: Stroke survivors suffered considerable ongoing and changing difficulties in relation to disability, self-perception and to coping with a new life. This continuous process of change could be seen to drain their energy. The study shows that many survivors live a more home-centred life with fewer social relations and less active participation in their community. This can entail the risk of depression and loneliness. The study also shows, however, that adopting an optimistic approach to life can lead to continued learning about abilities and limitations, to the development of new skills and to the fashioning of a new self-identity. © 2014 Informa UK Ltd All rights reserved.


Brincks J.,Hammel Neurorehabilitation and Research Center | Nielsen J.F.,Hammel Neurorehabilitation and Research Center
Clinical Biomechanics | Year: 2012

Background: Establishing changes in net joint power in the lower extremity of patients during recovery of walking might direct gait training in early stroke rehabilitation. It is hypothesized that (1) net joint power in the lower extremity joints would increase in sub-acute stroke patients following gait rehabilitation, and (2) the improvements in net joint power would be significantly correlated with changes in walking speed. Methods: Thirteen sub-acute patients (<3 months from stroke onset) participated in the study. All patients completed 6 weeks of gait training (3 weeks of robotic gait training and 3 weeks of physiotherapy). The gait patterns were analyzed using 3D motion analysis before and after training. The assessed variables were; gait speed and the net peak joint power of the ankle plantar flexors, hip extensors, hip flexors, hip abductors, and knee extensors. Findings: Ankle plantar flexor power in the impaired limb and hip extensor power in the unimpaired limb increased significantly following training (133% and 77%, respectively; P < 0.002). Improvements (from 20% to 133%) in net joint power of the ankle plantar flexors, hip extensors, hip flexors, and hip abductors of the impaired limb and ankle plantar flexors and hip abductors of the unimpaired limb significantly correlated with the recovery of walking speed following training (0.24 m/s to 0.51 m/s) (r = 0.71-0.86). Interpretation: The findings suggested investigations for strengthening the plantar flexors, hip flexors, hip extensors, and hip abductors concentrically, and knee extensors eccentrically in the impaired limb to determine the effectiveness in improving gait performance. © 2011 Elsevier Ltd. All rights reserved.

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