Restorative Neurology and Neuroscience - Volume 34, issue 5

Authors: Fusco, Gabriele | Tidoni, Emmanuele | Barone, Nicola | Pilati, Claudio | Aglioti, Salvatore Maria

Article Type: Research Article

Abstract: Background: Studies in healthy people show that stimulation of muscle spindles through frequency-specific tendon vibration (TV) induces the illusory perception of movement. Following spinal cord injury (SCI), motor and sensory connections between the brain and parts of the body below-the-lesion level are partially or totally impaired. Objective: The present investigation is a descriptive study aimed to investigate whether people living with SCI may experience movement illusions comparable to a control group. Methods: Healthy and people with SCI were asked to report on three illusion-related features (Vividness, Duration, Illusory Extension) after receiving 70 Hz TV on the …biceps brachii tendon of both arms. Two different forces of stimulation were applied: 2.4 N and 4.2 N. Results: Both patients and controls were susceptible to the kinesthetic illusion. However patients presented lower sensitivity to TV than healthy subjects. Participants rated stronger illusions of movement after 4.2 N than 2.4 N stimulation in all the three illusion-related features. Further, patients reported atypical illusory experiences of movement (e.g. as if the arm wanted to extend, or a sensation of pushing against something) that may reflect different reorganization processes following spinal cord injury. Conclusion: The study provides a preliminary evidence of the possible use of the proprioceptive stimulation in the upper limbs of people living with SCI. Results are discussed in the light of recent advancements of brain-computer applications based on motor imagery for the control of neuroprosthetic and robotic devices in patients with severe sensorimotor deficits. Show more

Keywords: Spinal cord injury, tendon vibration, illusion of movement, spinal cord rehabilitation, proprioception

DOI: 10.3233/RNN-160660

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 5, pp. 815-826, 2016

Authors: Moore, Tara L. | Pessina, Monica A. | Finklestein, Seth P. | Killiany, Ronald J. | Bowley, Bethany | Benowitz, Larry | Rosene, Douglas L.

Article Type: Research Article

Abstract: Background: Inosine, a naturally occurring purine nucleoside, has been shown to stimulate axonal growth in cell culture and promote corticospinal tract axons to sprout collateral branches after stroke, spinal cord injury and TBI in rodent models. Objective: To explore the effects of inosine on the recovery of motor function following cortical injury in the rhesus monkey. Methods: After being trained on a test of fine motor function of the hand, monkeys received a lesion limited to the area of the hand representation in primary motor cortex. Beginning 24 hours after this injury and continuing daily …thereafter, monkeys received orally administered inosine (500 mg) or placebo. Retesting of motor function began on the 14th day after injury and continued for 12 weeks. Results: During the first 14 days after surgery, there was evidence of significant recovery within the inosine-treated group on measures of fine motor function of the hand, measures of hand strength and digit flexion. While there was no effect of treatment on the time to retrieve a reward, the treated monkeys returned to asymptotic levels of grasp performance significantly faster than the untreated monkeys. Additionally, the treated monkeys evidenced a greater degree of recovery in terms of maturity of grasp pattern. Conclusion: These findings demonstrate that inosine can enhance recovery of function following cortical injury in monkeys. Show more

Keywords: Inosine, cortical injury, rhesus monkey, recovery, motor function

DOI: 10.3233/RNN-160661

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 5, pp. 827-848, 2016

Authors: Yau, Suk-Yu | Li, Ang | Tong, Jian-Bin | Bostrom, Crystal | Christie, Brian R. | Lee, Tatia M.C. | So, Kwok-Fai

Article Type: Research Article

Abstract: Background: Our previous work has shown that exposure to the stress hormone corticosterone (40 mg/kg CORT) for two weeks induces dendritic atrophy of pyramidal neurons in the hippocampal CA3 region and behavioral deficits. However, it is unclear whether this treatment also affects the dentate gyrus (DG), a subregion of the hippocampus comprising a heterogeneous population of young and mature neurons. Objective: We examined the effect of CORT treatment on the dendritic complexity of mature and young granule cells in the DG. Methods: We utilized a Golgi staining method to investigate the dendritic morphology and spine density …of young neurons in the inner granular cell layer (GCL) and mature neurons in the outer GCL in response to CORT application. The expressions of glucocorticoid receptors during neuronal maturation were examined using Western blot analysis in a primary hippocampal neuronal culture. Results: Sholl analysis revealed that CORT treatment decreased the number of intersections and shortened the dendritic length in mature, but not young, granule cells. However, the spine density of mature and young neurons was not affected. Western blot analysis showed a progressive increase in the protein levels of glucocorticoid receptors (GRs) in the cultured primary hippocampal neurons during neuronal maturation. Conclusion: These data suggest that mature neurons are likely more vulnerable to chronic exposure to CORT; this may be due to their higher expression of GRs when compared to younger DG neurons. Show more

Keywords: Corticosterone, glucocorticoid receptors, dendritic complexity, dentate gyrus, Golgi staining

DOI: 10.3233/RNN-160662

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 5, pp. 849-857, 2016

Authors: Koo, Ho | Kim, Min Sun | Han, Sang Who | Paulus, Walter | Nitche, Michael A. | Kim, Yun-Hee | Kim, Hyoung-Ihl | Ko, Sung-Hwa | Shin, Yong-Il

Article Type: Research Article

Abstract: Purpose: Transcranial direct current stimulation (tDCS) is increasingly seen as a useful tool for noninvasive cortical neuromodulation. A number of studies in humans have shown that when tDCS is applied to the motor cortex it can modulate cortical excitability. It is especially interesting to note that when applied with sufficient duration and intensity, tDCS can enable long-lasting neuroplastic effects. However, the mechanism by which tDCS exerts its effects on the cortex is not fully understood. We investigated the effects of anodal tDCS under urethane anesthesia on field potentials in in vivo rats. Methods: These were measured …on the skull over the right motor cortex of rats immediately after stimulating the left corpus callosum. Results: Evoked field potentials in the motor cortex were gradually increased for more than one hour after anodal tDCS. To induce these long-lasting effects, a sufficient duration of stimulation (20 minutes or more) was found to may be required rather than high stimulation intensity. Conclusion: We propose that anodal tDCS with a sufficient duration of stimulation may modulate transcallosal plasticity. Show more

Keywords: Transcranial direct stimulation, cerebral cortex, cortical excitability, neurophysiology, rat

DOI: 10.3233/RNN-160664

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 5, pp. 859-868, 2016

Authors: Spina, Emanuele | Carotenuto, Antonio | Aceto, Maria Gabriella | Cerillo, Ilaria | Silvestre, Francesco | Arace, Francesco | Paone, Paolo | Orefice, Giuseppe | Iodice, Rosa

Article Type: Research Article

Abstract: Background: Multiple Sclerosis is a heterogeneous disorders involving in early stage gait and balance. Together with immunomodulating therapies, rehabilitation had a crucial role in improving motor tasks and quality of life. Between the emerging techniques, Focal Vibrations (FV) could play a role, but they have been used in MS only to reduce muscle tone and fatigue alone or together with botulinum toxin. Objective: To assess whether FV is effective on walking impairment in a cohort of MS patients. Methods: We performed a single-centre randomized, double-blind, sham-controlled study to investigate efficacy of FV vs sham vibration …in 20 RR MS patients. Ten patients received treatment with the active device and ten patients sham treatment. Demographical, clinical and gait instrumental data analysis have been collected for each patient at baseline (T0), after treatment (T1) and after three weeks of wash out (T2). Results: Both groups were clinically and demographically comparable. Treated patients showed significant improvements during the first right step (FRS) (p  = 0.007), average stride lenght (ASL) (p  = 0.012), double support right (DSRT) (p  = 0.016) and left (DSLT) (p  = 0.003) time. Non-treated patients didn’t show any significance for any dynamic variables. Moreover, on posturographic measurements we registered only a trend towards significance in swing area with eyes open (SAEO) (p  = 0.087). We also found in treated group significant improvements in FRT (p  = 0.018); BBS (p  = 0.037) and FSS scales (p  = 0.038) between T1 and T0. Lastly, we found a significant inverse correlation in the treated group between disease duration and percentage of improvement for DSLT (r = – 0.775; p  = 0.014) in T1 vs T0 and percentage of improvement of FSS, with an inverse correlation with both disease duration (r = – 0.775; p  = 0.014) and AGE (r = – 0.733, p  = 0.025) in T1 vs T0 Conclusion: Our results suggest a beneficial effect of FV on walking impairment in MS patients suffering from spasticity and/or postural instability, which partially lasted until follow up. Show more

Keywords: Multiple sclerosis, neurorehabilitation, focal vibrations, gait analysis

DOI: 10.3233/RNN-160665

Citation: Restorative Neurology and Neuroscience, vol. 34, no. 5, pp. 869-876, 2016