Restorative Neurology and Neuroscience - Volume 37, issue 3

Authors: Ortiz, Tomas | Ortiz-Teran, Laura | Turrero, Agustin | Poch-Broto, Joaquin | de Erausquin, Gabriel A.

Article Type: Research Article

Abstract: Background: We previously demonstrated that using a sensory substitution device (SSD) for one week, tactile stimulation results in faster activation of lateral occipital complex in blind children than in seeing controls. Objective: We used long-term haptic tactile stimulation training with an SSD to test if it results in stable cross-modal reassignment of visual pathways after six months, to provide high level processing of tactile semantic content. Methods: We enrolled 12 blind and 12 sighted children. The SSD transforms images to a stimulation matrix in contact with the dominant hand. Subjects underwent twice-daily training sessions, 5 days/week …for six months. Children were asked to describe line orientation, name letters, and read words. ERP sessions were performed at baseline and 6 months to analyze the N400 ERP component and reaction times (RT). N400 sources were estimated with Low Resolution Electromagnetic Tomography (LORETA). SPM8 was used to make population-level inferences. Results: We found no group differences in RTs, accuracy of identifications, N400 latencies or distributions with the line task at 1 week or at 6 months. RTs on the letter recognition task were also similar. After 6 months, behavioral training increased accurate letter identification in both seeing and blind children (Chi 2 = 11906.934, p  = 0.000), but the increase was larger in blind children (Chi 2 = 8.272, p  = 0.004). Behavioral training shifted peak N400 amplitude to left occipital and bilateral parietal cortices in blind children, but to left precentral and postcentral and bilateral occipital cortices in sighted controls. Conclusions: Blind children learn to recognize SSD-delivered letters better than seeing controls and had greater N400 amplitude in the occipital region. To the best of our knowledge, our results provide the first published example of standard letter recognition (not Braille) by children with blindness using a tactile delivery system. Show more

DOI: 10.3233/RNN-180838

Citation: Restorative Neurology and Neuroscience, vol. 37, no. 3, pp. 197-206, 2019

Authors: Delorme, Marion | Vergotte, Grégoire | Perrey, Stéphane | Froger, Jérôme | Laffont, Isabelle

Article Type: Research Article

Abstract: Background: The acute phase of stroke is accompanied by functional changes and interplay of both hemispheres. However, our understanding of how the time course of upper limb functional motor recovery is related to the progression of brain reorganization in the sensorimotor areas remains limited. This study aimed to assess the time course of hemodynamic patterns of cortical sensorimotor areas using functional near infrared spectroscopy (fNIRS) and motor recovery within three months after a stroke. Method: Eight right-handed first ischemic/hemorrhagic stroke patients (60±8 years, 3 women) with mild to severe hemiparesis were examined with repetitive fNIRS measurements and motor …recovery tests (Fugl-Meyer score) during two months. Hemodynamic changes over the ipsilesional and contralesional sensorimotor areas were collected from a multi-channel fNIRS system during intermittent isometric muscle contractions at self-selected submaximal force levels for each arm. Lateralization index was computed to evaluate the changes in the interhemispheric balance between the cortical sensorimotor areas. Results: Lateralization index values during non-paretic arm movements showed no significant changes over time in patients and were comparable to those observed in eight healthy controls. Paretic-arm movements were associated early with a bilateral cortical activity before shifting to ipsilesional patterns (p  < 0.01). Progressive lateralization observed over the two months (p  < 0.05) evolved concomitantly with an increase in the Fugl-Meyer score (p  < 0.001). Conclusions: Cortical reorganization monitoring using fNIRS during the first weeks after stroke may be applied for assessing progressive brain plasticity in addition to clinical measures of performance. Show more

Keywords: Brain plasticity, fNIRS, motor recovery, sensorimotor cortex, stroke rehabilitation

DOI: 10.3233/RNN-180877

Citation: Restorative Neurology and Neuroscience, vol. 37, no. 3, pp. 207-218, 2019

Authors: Noh, Jun Soo | Lim, Ji Hoon | Choi, Tae Woong | Jang, Seung Gul | Pyun, Sung-Bom

Article Type: Research Article

Abstract: Background: Repetitive transcranial magnetic stimulation (rTMS) modulates cortical excitability and facilitates motor learning to improve motor recovery after stroke. Action observation (AO) therapy effectively facilitates physical training for motor memory formation. Objective: To compare the effectiveness of rTMS alone with that of combined rTMS and AO for the functional recovery of upper extremity function in subacute stroke patients and to verify the safety of the interventions. Methods: The present study was a prospective, randomized controlled trial involving subacute unilateral stroke patients. In total, 22 patients were randomly assigned to 2 groups: the trial group (rTMS with …AO) and the control group (rTMS alone). Both groups received 1 Hz rTMS (intensity: 120% of resting motor threshold; rMT) over the contralesional primary motor cortex for 20 minutes on 10 consecutive days. Trial group received rTMS while watching a video of 5 different complex hand movements. The functional parameters were the Brunnstrom stage, Fugl-Meyer assessment (FMA) score of the upper extremity, Manual Function Test (MFT) score, and grip power. The following motor evoked potential (MEP) parameters were recorded from the abductor pollicis brevis muscle: rMT, latency, and amplitude. Both parameters were measured before and after the 2 week intervention. Results: After the 2 week trial, the total FMA and MFT scores were significantly improved in both groups, but the MFT subscores of hand motor function and grip power were significantly improved in the combination therapy group only. In contrast, the changes (Δ ) of FMA, MFT, grip power test, and MEP outcomes were not significantly different between the 2 groups. No adverse events or complications were reported. Conclusions: Distal upper extremity function, as measured by MFT and grip power, was improved after rTMS and AO in combination. The combination of rTMS with AO may be applied safely to improve upper extremity function after stroke. Show more

Keywords: Transcranial magnetic stimulation, stroke, hemiplegia, stroke rehabilitation, recovery of function

DOI: 10.3233/RNN-180883

Citation: Restorative Neurology and Neuroscience, vol. 37, no. 3, pp. 219-230, 2019

Authors: Cuesta-Gómez, Alicia | Carratalá-Tejada, María | Molina-Rueda, Francisco | Miangolarra-Page, Juan Carlos

Article Type: Research Article

Abstract: Background: Recovery of motor function following stroke is essential to restore adequate functionality. The use of functional electrical stimulation (FES) technology as a neuroprosthesis to enhance the motor function of the UL, and thus facilitate the performance of ADL, could lead to a stroke patient’s greater activity and participation in daily life. Objective: The aim of the present study was to establish whether the application of FES in patients who have suffered a stroke with UL motor impairment is able to modify and facilitate their reaching patterns, measured by a three-dimensional motion capture system. Methods: 20 …patients with chronic stroke participated in this study. For muscle stimulation, the electrical stimulator Compex® was used. Motion analysis was performed using the VICON Motion System®. Joint movements of the thorax, shoulder and elbow were analyzed in the sagittal plane, during the reaching movement under two different conditions of stimulation: FES condition and placebo condition. Results: Differences between FES condition and placebo condition were observed. In the FES condition it was recorded: an increased shoulder flexion and elbow extension in the reaching movement. Conclusions: Functional electrical stimulation improved reaching movement in stroke patients with upper limb impairment. Show more

Keywords: Electric Stimulation Therapy, Movement disorders, Paresis, Range of Motion, Stroke, Upper extremity.

DOI: 10.3233/RNN-180884

Citation: Restorative Neurology and Neuroscience, vol. 37, no. 3, pp. 231-238, 2019

Authors: Digiacomo, Fabio | Tamburin, Stefano | Tebaldi, Stefano | Pezzani, Marco | Tagliafierro, Mario | Casale, Roberto | Bartolo, Michelangelo

Article Type: Research Article

Abstract: Background: Robot-assisted gait training (RAGT) is widely used in children with cerebral palsy (CP), but information about optimal intervention frequency and duration is still lacking and the current evidence about effect of RAGT on motor endurance and fitness is very preliminary. Objective: To investigate the effect of RAGT on motor performance and endurance in children affected by CP. Methods: Data from 14 consecutive children (6 females, age range: 4.6–15.8 years) affected by CP, who underwent a multidisciplinary rehabilitation program during a 18–24 month period, were retrospectively collected. Rehabilitation program included conventional physical therapy and RAGT (60/60 …minutes, 20 daily sessions, 5 days/week). CP severity was stratified according to the Gross Motor Function Classification System. Clinical evaluation was performed by means of the six-minute walking test, the modified Ashworth scale, and RAGT measures (total distance, mean distance for session and speed). Results: Clinical outcomes and speed did not improve after treatment, while total distance (p  = 0.006) and mean distance for session (p  = 0.007) significantly improved. Conclusions: Our preliminary study suggests that RAGT combined with conventional treatment may improve motor performance and endurance in children with CP. Future randomized controlled trials comparing RAGT to conventional treatment are needed. Show more

Keywords: Robotic gait training, cerebral palsy, endurance, neurorehabilitation, outcome

DOI: 10.3233/RNN-180897

Citation: Restorative Neurology and Neuroscience, vol. 37, no. 3, pp. 239-244, 2019

Authors: Abrahamson, Eric E. | Poloyac, Samuel M. | Dixon, C. Edward | Dekosky, Steven T. | Ikonomovic, Milos D.

Article Type: Research Article

Abstract: Background: Altered glutamatergic neurotransmission after traumatic brain injury (TBI) contributes to excitotoxic cell damage and death. Prevention or suppression of such changes is a desirable goal for treatment of TBI. Memantine (3,5-dimethyl-1-adamantanamine), an uncompetitive NMDA receptor antagonist with voltage-dependent open channel blocking kinetics, was reported to be neuroprotective in preclinical models of excitotoxicity, brain ischemia, and in TBI when administered prophylactically, immediately, or within minutes after injury. Methods: The current study examined effects of memantine administered by single intraperitoneal injection to adult male rats at a more clinically relevant delay of one hour after moderate-severe controlled cortical impact …(CCI) injury or sham surgery. Histopathology was assessed on days 1, 7, 21, and 90, vestibulomotor function (beam balance and beam walk) was assessed on days 1–5 and 71–75, and spatial memory (Morris water maze test, MWM) was assessed on days 14–21 and 83–90 after CCI injury or sham surgery. Results: When administered at 10 mg/kg, but not 2.5 or 5 mg/kg, memantine preserved cortical tissue and reduced neuronal degeneration 1 day after injury, and attenuated loss of synaptophysin immunoreactivity in the hippocampus 7 days after injury. No effects of 10 mg/kg memantine were observed on histopathology at 21 and 90 days after CCI injury or sham surgery, or on vestibulomotor function and spatial memory acquisition assessed during any of the testing periods. However, 10 mg/kg memantine resulted in trends for improved search strategy in the MWM memory retention probe trial. Conclusions: Administration of memantine at a clinically-relevant delay after moderate-severe CCI injury has beneficial effects on acute outcomes, while more significant improvement on subacute and chronic outcomes may require repeated drug administration or its combination with another therapy. Show more

Keywords: Excitotoxicity, glutamate, hippocampus, NMDA, traumatic brain injury

DOI: 10.3233/RNN-190909

Citation: Restorative Neurology and Neuroscience, vol. 37, no. 3, pp. 245-263, 2019

Authors: Jaminet, Patrick | Schäufele, Martin | Mager, Alice | Fornaro, Michele | Ronchi, Giulia | Geuna, Stefano | Schaller, Hans-Eberhard | Rosenberger, Peter | Köhler, David

Article Type: Research Article

Abstract: Background: In this study, we evaluate the role of RGMa (Repulsive Guidance Molecule a) during peripheral nerve regeneration using the mouse median nerve model. Methods: By real-time PCR and Western Blot analysis, we examined expression changes of RGMa mRNA and RGMa protein in neural tissue after transection and microsurgical repair of the mouse median nerve distal to the transection site. We evaluated histomorphometrical changes in neural tissue distal to the injury site and functional recovery of the grasping force after median nerve transection and repair in wild-type mice and RGMa +/– heterozygous mice. Results: RT-PCR …revealed a 1,8 fold increase of RGMa mRNA two weeks and a 4,4 fold increase of RGMa mRNA 3 weeks after nerve transection and repair in the nerve segment distal to the injury site. In Western blot analysis, we could show a high increase of RGMa in the nerve segment distal to the injury site at day 14. Histomorphometrical analysis showed significant differences between wild-type animals and heterozygous animals. The absolute number of myelinated fibres was significantly higher in operated heterozygous RGMa+/– animals compared to operated wildtye animals. Using the functional grasping test, we could demonstrate that peripheral nerve regeneration is significantly diminished in heterozygous RGMa+/ – mice. Conclusions: Employing the mouse median nerve model in transgenic animals, we demonstrate that RGMa plays an important role during peripheral nerve regeneration. Show more

Keywords: Median nerve model, transgenic, peripheral nervous system, RGMa, grasping test, DGUV (Deutsche Gesetzliche Unfallversicherung), FR 175

DOI: 10.3233/RNN-190913

Citation: Restorative Neurology and Neuroscience, vol. 37, no. 3, pp. 265-272, 2019

Authors: Neva, J.L. | Brown, K.E. | Wadden, K.P. | Mang, C.S. | Borich, M.R. | Meehan, S.K. | Boyd, L.A.

Article Type: Research Article

Abstract: Background: In individuals with chronic stroke, impairment of the paretic arm may be exacerbated by increased contralesional transcallosal inhibition (TCI). Continuous theta burst stimulation (cTBS) can decrease primary motor cortex (M1) excitability and TCI. However, contralesional cTBS shows inconsistent effects after stroke. Variable effects of cTBS could stem from failure to pair stimulation with skilled motor practice or a focus of applying cTBS over M1. Objective: Here, we investigated the effects of pairing cTBS with skilled practice on motor learning and arm function. We considered the differential effects of stimulation over two different brain regions: contralesional M1 (M1c) …or contralesional primary somatosensory cortex (S1c). Methods: 37 individuals with chronic stroke participated in five sessions of cTBS and paretic arm skilled practice of a serial targeting task (STT); participants received either cTBS over M1c or S1c or sham before STT practice. Changes in STT performance and Wolf Motor Function Test (WMFT) were assessed as primary outcomes. Assessment of bilateral corticospinal, intracortical excitability and TCI were secondary outcomes. Results: cTBS over sensorimotor cortex did not improve STT performance and paretic WMFT-rate beyond sham cTBS. TCI was reduced bi-directionally following the intervention, regardless of stimulation group. In addition, we observed an association between STT performance change and paretic WMFT-rate change in the M1c stimulation group only. Conclusions: Multiple sessions of STT practice can improve paretic arm function and decrease TCI bilaterally, with no additional benefit of prior cTBS. Our results suggest that improvement in STT practice following M1c cTBS scaled with change in paretic arm function in some individuals. Our results highlight the need for a better understanding of the mechanisms of cTBS to effectively identify who may benefit from this form of brain stimulation. Show more

Keywords: Stroke, transcranial magnetic stimulation, skilled motor practice, motor function, transcallosal inhibition, continuous theta burst stimulation

DOI: 10.3233/RNN-190916

Citation: Restorative Neurology and Neuroscience, vol. 37, no. 3, pp. 273-290, 2019