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Background: Given the widely distributed network of midbrain, pontine, cerebellar, and cortical areas involved in the neural control of vergence, one might expect various vergence deficits in stroke patients. In this article, we investigated the localizing value of bedside vergence testing with respect to different supratentorial and infratentorial infarction locations. Methods: Three hundred five stroke patients and 50 age-matched controls were examined prospectively by means of bedside tests to assess slow and fast binocular (i.e., symmetrical) as well as slow and fast monocular (i.e., asymmetrical) convergence. Infarction locations, as identified on MRI, were correlated with vergence performance using multinomial logistic regression. Results: Vergence deteriorated with age in both stroke patients and healthy controls. Most infarction locations did not show significant associations with vergence parameters, apart from cases with parietal lobe lesions, which exhibited insufficient asymmetrical, slow and fast vergence for both the left and the right eye. Finally, patients with severe ischemic small vessel disease showed a slight but significant decrease in their fast binocular vergence performance. Conclusions: There is only a limited localizing value of vergence deficits in stroke. Parietal lobe infarctions are more frequently associated with insufficient binocular and monocular vergence. Midbrain strokes were too few to draw final conclusions. However the most robust factor to emerge from our data is age. Older subjects show poor slow binocular as well as slow and fast monocular vergence. Extended white matter lesions are also correlated with deficient vergence ability suggesting a role for subcortical wide range connections in maintaining an intact vergence circuitry. [ABSTRACT FROM AUTHOR]

Remyelination is a physiological response to demyelinating events aiming to restore saltatory conduction and preserve axonal integrity. Resident oligodendrocyte precursor cells (OPC) of the CNS tissue under appropriate conditions are mobilized to proliferate, migrate, and differentiate, in order to produce new myelin sheaths in the demyelinated lesion. In multiple sclerosis (MS), the most common immune-mediated demyelinating disease, remyelination efficiency declines with increasing age and disease duration. As myelin regeneration attempts in clinical trials so far are scarce, and have been met with limited success, the need to explore new remyelinating strategies is more compelling. Recently, ageing and cellular senescence have been implicated in the pathophysiology of a number of neurodegenerative diseases, including multiple sclerosis. Evidence on OPC senescence brings forward the possibility of exploiting cellular senescence as a possible target for promoting the endogenous remyelinating capacity of the CNS. Here we discuss the data indicating how cellular senescence affects remyelination, and the putative benefits to be drawn through the use of senolytic or senomorphic therapies targeting senescent cell populations in MS., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose: The aim of our study was the comparison of active denervation (fibrillation and/or positive sharp wave potentials) in thoracic paraspinal muscles with rectus abdominis in patients with definite amyotrophic lateral sclerosis., Methods: Ninety-five consecutive patients with clinically definite amyotrophic lateral sclerosis according to the revised El Escorial criteria were studied prospectively over a 5-year period. Concentric needle electromyogram was performed in thoracic paraspinal muscles, in the rectus abdominis at the T9 level, and in limb muscles., Results: Active denervation was present in thoracic paraspinal muscles in 75 patients (79%) and in rectus abdominis in 62 patients (65.3%) (P = 0.02). No significant difference was found between the two muscles regarding the type of onset (bulbar, upper, and lower limbs), amyotrophic lateral sclerosis functional rating scale values, and creatine phosphokinase levels., Conclusions: Thoracic paraspinal muscles are the first to be tested in patients with amyotrophic lateral sclerosis. Absence of active denervation in T-PSM is rarely associated with active denervation in rectus abdominis.

Polysialic acid (PSA) is a carbohydrate polymer added post-translationally on the neural cell adhesion molecule (NCAM) affecting its adhesion properties. It has been suggested that the presence of PSA in demyelinated lesions in multiple sclerosis could prevent axon-glia interactions inhibiting spontaneous remyelination. The enzyme St8siaIV is one of the two polysialyltransferases responsible for PSA synthesis, and it is predominantly active during adult life. Here we treated 8-10-weeks old St8siaIV deficient and wild-type mice for 5 weeks with cuprizone, which is a reliable model for de- and remyelination in the corpus callosum and cortex. Developmental myelination of the St8siaIV knock-out mice was not disturbed and adult mice showed normal myelin protein expression. Demyelination did not differ between transgenic and wild-type mice but early myelin protein re-expression and thus remyelination were accelerated in St8siaIV knock-out mice during the first week after withdrawal of the toxin. This was mainly due to enhanced oligodendrocyte precursor cells (OPC) differentiation and to a lesser extent to OPC recruitment. These data are proof of principle that PSA expression interferes at least to some extent with remyelination in vivo., (Copyright © 2010 IBRO. Published by Elsevier Ltd. All rights reserved.)