Restorative Neurology and Neuroscience - Volume 33, issue 3

Authors: Ren, Changhong | Wang, Pengcheng | Wang, Brian | Li, Ning | Li, Weiguang | Zhang, Chenggang | Jin, Kunlin | Ji, Xunming

Article Type: Research Article

Abstract: Purpose: Limb remote ischemic per-conditioning or post-conditioning has been shown to be neuroprotective after cerebral ischemic stroke. However, the effect of combining remote per-conditioning with post-conditioning on ischemic/reperfusion injury as well as the underlying mechanisms are largely unexplored. Methods: Here, adult male Sprague Dawley rats were subjected to middle cerebral artery occlusion (MCAO). The limb ischemic stimulus was immediately applied after onset of focal ischemia (per-conditioning), followed by repeated short episodes of remote ischemia 24 hr after reperfusion (post-conditioning). The infarct volume, motor function, and the expression of neuroglobin (Ngb) were measured at different durations …after reperfusion. Results: We found that a single episode of limb remote per-conditioning afforded short-term protection, but combining repeated remote post-conditioning during the 14 days after reperfusion significantly ameliorated cerebral ischemia/reperfusion injury. Interestingly, we also found that ischemic per- and post-conditioning significantly increased expression of Ngb, an oxygen-binding globin protein that has been demonstrated to be neuroprotective against stroke, at peri-infarct regions from day 1 to day 14 following ischemia/reperfusion. Conclusion: Our results suggest that the conventional per-conditioning combined with post-conditioning may be used as a novel neuroprotective strategy against ischemia-reperfusion injury, and Ngb seems to be one of the important players in limb remote ischemia-mediated neuroprotection. Show more

Keywords: Ischemia, stroke, remote conditioning, neuroglobin

DOI: 10.3233/RNN-140413

Citation: Restorative Neurology and Neuroscience, vol. 33, no. 3, pp. 369-379, 2015

Authors: Zhou, Jiawei | Baker, Daniel H. | Simard, Mathieu | Saint-Amour, Dave | Hess, Robert F.

Article Type: Research Article

Abstract: Purpose: Several recent studies have demonstrated that following short-term monocular deprivation in normal adults, the patched eye, rather than the unpatched eye, becomes stronger in subsequent binocular viewing. However, little is known about the site and nature of the underlying processes. In this study, we examine the underlying mechanisms by measuring steady-state visual evoked potentials (SSVEPs) as an index of the neural contrast response in early visual areas. Methods: The experiment consisted of three consecutive stages: a pre-patching EEG recording (14 minutes), a monocular patching stage (2.5 hours) and a post-patching EEG recording (14 minutes; …started immediately after the removal of the patch). During the patching stage, a diffuser (transmits light but not pattern) was placed in front of one randomly selected eye. During the EEG recording stage, contrast response functions for each eye were measured. Results: The neural responses from the patched eye increased after the removal of the patch, whilst the responses from the unpatched eye remained the same. Such phenomena occurred under both monocular and dichoptic viewing conditions. Conclusions: We interpret this eye dominance plasticity in adult human visual cortex as homeostatic intrinsic plasticity regulated by an increase of contrast-gain in the patched eye. Show more

Keywords: Monocular patching, eye dominance plasticity, intrinsic plasticity, contrast-gain, steady-state visual evoked potentials, visual cortex

DOI: 10.3233/RNN-140472

Citation: Restorative Neurology and Neuroscience, vol. 33, no. 3, pp. 381-387, 2015

Authors: Mullick, Aditi A. | Subramanian, Sandeep K. | Levin, Mindy F.

Article Type: Research Article

Abstract: Purpose: Motor and cognitive impairments are common and often coexist in patients with stroke. Although evidence is emerging about specific relationships between cognitive deficits and upper-limb motor recovery, the practical implication of these relationships for rehabilitation is unclear. Using a structured review and meta-analyses, we examined the nature and strength of the associations between cognitive deficits and upper-limb motor recovery in studies of patients with stroke. Methods: Motor recovery was defined using measures of upper limb motor impairment and/or activity limitations. Studies were included if they reported on at least one measure of cognitive function and one …measure of upper limb motor impairment or function. Results: Six studies met the selection criteria. There was a moderate association (r  = 0.43; confidence interval; CI:0.09– 0.68, p  = 0.014) between cognition and overall arm motor recovery. Separate meta-analyses showed a moderately strong association between executive function and motor recovery (r  = 0.48; CI:0.26– 0.65; p  <  0.001), a weak positive correlation between attention and motor recovery (r  = 0.25; CI:0.04– 0.45; p  = 0.023), and no correlation between memory and motor recovery (r  = 0.42; CI:0.16– 0.79; p  = 0.14). Conclusion: These results imply that information on the presence of cognitive deficits should be considered while planning interventions for clients in order to design more personalized interventions tailored to the individual for maximizing upper-limb recovery. Show more

Keywords: Motor learning, upper limb, cognition, rehabilitation

DOI: 10.3233/RNN-150510

Citation: Restorative Neurology and Neuroscience, vol. 33, no. 3, pp. 389-403, 2015