Restorative Neurology and Neuroscience - Volume 34, issue 4

Authors: Bolognini, Nadia | Russo, Cristina | Edwards, Dylan J.

Article Type: Research Article

Abstract: Contemporary strategies to promote motor recovery following stroke focus on repetitive voluntary movements. Although successful movement relies on efficient sensorimotor integration, functional outcomes often bias motor therapy toward motor-related impairments such as weakness, spasticity and synergies; sensory therapy and reintegration is implied, but seldom targeted. However, the planning and execution of voluntary movement requires that the brain extracts sensory information regarding body position and predicts future positions, by integrating a variety of sensory inputs with ongoing and planned motor activity. Neurological patients who have lost one or more of their senses may show profoundly affected motor functions, even if muscle …strength remains unaffected. Following stroke, motor recovery can be dictated by the degree of sensory disruption. Consequently, a thorough account of sensory function might be both prognostic and prescriptive in neurorehabilitation. This review outlines the key sensory components of human voluntary movement, describes how sensory disruption can influence prognosis and expected outcomes in stroke patients, reports on current sensory-based approaches in post-stroke motor rehabilitation, and makes recommendations for optimizing rehabilitation programs based on sensory stimulation. Show more

Keywords: Stroke, motor recovery, sensory stimulation, motor rehabilitation, sensorimotor integration, non-invasive brain stimulation

DOI: 10.3233/RNN-150606

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 4, pp. 571-586, 2016

Authors: Tremblay, Sara | Lafleur, Louis-Philippe | Proulx, Sébastien | Beaulé, Vincent | Latulipe-Loiselle, Alex | Doyon, Julien | Marjańska, Małgorzata | Théoret, Hugo

Article Type: Research Article

Abstract: Purpose: The aim of the present study was to assess, in healthy individuals, the impact of M1-M1 tDCS on primary motor cortex excitability using transcranial magnetic stimulation and sensorimotor metabolite concentration using 1 H-MRS. Methods: For both experiments, each participant received the three following interventions (20 min tDCS, 1 mA): left-anodal/right-cathodal, left-cathodal/right-anodal, sham. The effects of tDCS were assessed via motor evoked potentials (experiment 1) and metabolite concentrations (experiment 2) immediately after and 12 minutes following the end of stimulation and compared to baseline measurement. Results: No effect of M1-M1 tDCS on corticospinal excitability was found. Similarly, …M1-M1 tDCS did not significantly modulate metabolite concentrations. High inter-subject variability was noted. Response rate analysis showed a tendency towards inhibition following left-anodal/right-cathodal tDCS in 50% of participants and increased GABA levels in 45% of participants. Conclusion: In line with recent studies showing important inter-subject variability following M1-supraorbital tDCS, the present data show that M1-M1 stimulation is also associated with large response variability. The absence of significant effects suggests that current measures may lack sensitivity to assess changes in M1 neurophysiology and metabolism associated with M1-M1 tDCS. Show more

Keywords: Magnetic resonance spectroscopy, transcranial direct current stimulation, motor cortex, GABA, glutamate

DOI: 10.3233/RNN-150569

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 4, pp. 587-602, 2016

Authors: Pazzaglia, Mariella | Haggard, Patrick | Scivoletto, Giorgio | Molinari, Marco | Lenggenhager, Bigna

Article Type: Case Report

Abstract: Purpose: Spinal cord injury (SCI), a profound impairment of sensorimotor functions, is often associated with pain related phenomena, including mechanical allodynia, a condition in which non-painful tactile sensation is perceived as pain. Pain and somatic sensation are undeniable markers of normal bodily awareness. However, the mechanism by which they are integrated into a coherent sense of the bodily self remains largely unclear. In this study, we investigated the effect of high-level multisensory manipulation on subjective experiences of pain, touch, and body-ownership. Methods: We administered visuo-tactile stimulation based on the rubber hand illusion. In a longitudinal study, we …compared the strength of the illusion in a male with SCI, who initially had lost somatosensation in all his fingers, but a few months later reported signs of tactile allodynia restricted to the left C6-dermatome. Results: After the restoration of some somatosensation, even if it were painful, synchronous but not asynchronous visuo-tactile stimulation induced body illusion. Previously painful stimuli were temporarily perceived as less painful, and the patient further regained tactile sensations in adjacent numb areas. Conclusions: The sensations of touch and pain are mutually influenced and inextricably linked to a coherent representation of one’s own body. Multisensory manipulations affecting the perception and representation of the body might thus offer a powerful opportunity to mitigate nociceptive and somatic abnormalities. Show more

Keywords: Bodily illusions, somatosensory perception, pain, allodynia, spinal cord injury, rehabilitation, analgesia

DOI: 10.3233/RNN-150611

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 4, pp. 603-613, 2016

Authors: Huchon, Laure | Badet, Lionel | Roy, Alice Catherine | Finos, Livio | Gazarian, Aram | Revol, Patrice | Bernardon, Laurence | Rossetti, Yves | Morelon, Emmanuel | Rode, Gilles | Farnè, Alessandro

Article Type: Research Article

Abstract: Purpose: Hand allograft has recently emerged as a therapeutic option for upper limb amputees. Functional neuroimaging studies have progressively revealed sensorimotor cortices plasticity following both amputation and transplantation. The purpose of our study was to assess and characterize the functional recovery of the visuo-motor control of prehension in bilateral hand transplanted patients. Methods: Using kinematics recordings, we characterized the performance of prehension with or without visual feed-back for object of different position and size, in five bilateral hand allograft recipients and age-matched control subjects. Both hands were assessed, separately. Results: Despite an overall slower execution, …allografted patients succeeded in grasping for more than 90% of the trials. They exhibited a preserved hand grip scaling according to object size, and preserved prehension performances when tested without visual feedback. These findings highlight the allograft recipients’ abilities to produce an effective motor program, and a good proprioceptive-dependent online control. Nevertheless, the maximum grip aperture was reduced and delayed, the coupling between Transport and Grasp components was altered, and the final phase of the movement was lengthened. Conclusion: Hand allotransplantation can offer recipients a good recovery of the visuo-motor control of prehension, with slight impairments likely attributable to peripheral neuro-orthopedic limitations. Show more

Keywords: Hand transplantation, kinematics, prehension, visuo-motor control, neural plasticity

DOI: 10.3233/RNN-150502

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 4, pp. 615-633, 2016

Authors: Lee, Minji | Park, Chang-hyun | Im, Chang-Hwan | Kim, Jung-Hoon | Kwon, Gyu-Hyun | Kim, Laehyun | Chang, Won Hyuk | Kim, Yun-Hee

Article Type: Research Article

Abstract: Purpose: In brain–computer interfaces (BCIs), electrical brain signals during motor imagery are utilized as commands connecting the brain to a computer. To use BCI in patients with stroke, unique brain signal changes should be characterized during motor imagery process. This study aimed to examine the trial-dependent motor-imagery-related activities in stroke patients. Methods: During the recording of electroencephalography (EEG) signals, 12 chronic stroke patients and 11 age-matched healthy controls performed motor imagery finger tapping at 1.3 sec intervals. Trial-dependent brain signal changes were assessed by analysis of the mu and beta bands. Results: Neuronal activity in healthy …controls was observed over bilateral hemispheres at the mu and beta bands regardless of changes in the trials, whereas neuronal activity in stroke patients was mainly seen over the ipsilesional hemisphere at the beta band. With progression to repeated trials, healthy controls displayed a decrease in cortical activity in the contralateral hemisphere at the mu band and in bilateral hemispheres at the beta band. In contrast, stroke patients showed a decreasing trend in cortical activity only over the ipsilesional hemisphere at the beta band. Conclusions: Trial-dependent changes during motor imagery learning presented in a different manner in stroke patients. Understanding motor imagery learning in stroke patients is crucial for enhancing the effectiveness of motor-imagery-based BCIs. Show more

Keywords: Motor imagery, stroke, electroencephalography, brain-computer interfaces, SPM

DOI: 10.3233/RNN-150534

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 4, pp. 635-645, 2016

Authors: Yang, Liuzhu | Yan, Xinping | Xu, Zunying | Tan, Wei | Chen, Zhong | Wu, Bo

Article Type: Research Article

Abstract: Purpose: A previous study showed that a 1-h delay in treatment of thoracic spinal cord injury (SCI) with recombinant human erythropoietin (rhEPO) lacked neuroprotective efficacy. The aim of the present study was to reassess delayed administration of different doses of rhEPO on acute spinal cord compressive injury in rats. Methods: The experiment was divided into first and second stages, which SCI rats were observed for 4 and 28 days, respectively. All rats were randomly divided into four groups at both stages: control group, and rhEPO-3,000U (Unit), rhEPO-4,000U and rhEPO-5,000U groups. SCI rats received rhEPO treatment at different …time points. The primary indicators were locomotor recovery, histopathology, apoptotic index, inflammatory index, ultrastructural scoring system and volume of areas of demyelination. Results: The most significant locomotor functional and histopathological improvements and the best myelin protection were observed after administration of 5,000 U/kg rhEPO. rhEPO at 3,000, 4,000 and 5,000 U/kg showed similar ultrastructural neuroprotection, as well as similar inhibition of apoptosis and regulation of inflammation. Conclusion: Delayed administration of rhEPO can reduce apoptosis and inflammation, and promote myelin repair and functional recovery following spinal cord compressive injury in rats. Show more

Keywords: Erythropoietin, delayed treatment, spinal cord injury, myelin, functional recovery, rats

DOI: 10.3233/RNN-150498

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 4, pp. 647-663, 2016

Authors: Mammele, Stefan | Frauenknecht, Katrin | Sevimli, Sevgi | Diederich, Kai | Bauer, Henrike | Grimm, Christina | Minnerup, Jens | Schäbitz, Wolf-Rüdiger | Sommer, Clemens J.

Article Type: Research Article

Abstract: Purpose: Using G-CSF deficient mice we recently demonstrated neuroprotective properties of endogenous G-CSF after ischemic stroke. The present follow-up study was designed to check, whether specific alterations in ligand binding densities of excitatory glutamate or inhibitory GABAA receptors may participate in this effect. Methods: Three groups of female mice were subjected to 45 minutes of MCAO: wildtype, G-CSF deficient and G-CSF deficient mice substituted with G-CSF. Infarct volumes were determined after 24 hours and quantitative in vitro receptor autoradiography was performed using [3 H]MK-801, [3 H]AMPA and [3 H]muscimol for labeling of NMDA, AMPA and …GABAA receptors, respectively. Ligand binding densities were analyzed in regions in the ischemic core, peri-infarct areas and corresponding contralateral regions. Results: Infarct volumes did not significantly differ between the experimental groups. Ligand binding densities of NMDA and GABAA receptors were widely in the same range. However, AMPA receptor binding densities in G-CSF deficient mice were substantially enhanced compared to wildtype mice. G-CSF substitution in mice lacking G-CSF largely reversed this effect. Conclusions: Although infarct volumes did not differ 24 hours after ischemia the increase of AMPA receptor binding densities in G-CSF deficient mice may explain the bigger infarcts previously observed at later time-points with the same stroke model. Show more

Keywords: G-CSF, focal ischemia, MCAO, autoradiography, infarct volume, excitotoxicity, AMPA, mouse

DOI: 10.3233/RNN-150543

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 4, pp. 665-675, 2016

Authors: Bashir, Shahid | Vernet, Marine | Najib, Umer | Perez, Jennifer | Alonso-Alonso, Miguel | Knobel, Mark | Yoo, Woo-Kyoung | Edwards, Dylan | Pascual-Leone, Alvaro

Article Type: Research Article

Abstract: Background: The net effect of altered interhemispheric interactions between homologous motor cortical areas after unilateral stroke has been previously reported to contribute to residual hemiparesis. Using this framework, we hypothesized that navigated 1 Hz repetitive transcranial magnetic stimulation (rTMS) over the contralesional hemisphere would induce a stronger physiological and behavioural response in patients with residual motor deficit than in healthy subjects, because an imbalance in interhemispheric excitability may underlie motor dysfunction. Methods: Navigated rTMS was conducted in 8 chronic stroke patients (67.50±13.77 years) and in 8 comparable normal subjects (57.38±9.61 years). We evaluated motor function (Finger tapping, Nine …Hole Peg test, Strength Index and Reaction Time) as well as the excitatory and inhibitory function (resting motor threshold, motor evoked potential amplitude, intra-cortical inhibition and facilitation, and silent period) of the stimulated and non-stimulated motor cortex before and after navigated rTMS. Results: rTMS induced an increase in excitability in the ipsilesional (non-stimulated) motor cortex and led to improved performance in the finger tapping task and pinch force task. These physiological and behavioral effects were more prominent (or robust) in the group of stroke patients than in the control group. Conclusion: Navigated low-frequency rTMS involving precise and consistent targeting of the contralesional hemisphere in stroke patients enhanced the cortical excitability of the ipsilesional hemisphere and the motor response of the hemiparetic hand. Show more

Keywords: Navigated rTMS, rehabilitation, plasticity, cortex excitability, intra-cortical inhibition, motor behavior

DOI: 10.3233/RNN-140460

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 4, pp. 677-689, 2016