Applications Of Visual Evoked Potentials And Fourier-domain Optical Coherence Tomography In Parkinson's Disease: A Controlled Study

Purpose: The goal of this cross-sectional observational study was to quantify the pattern-shift visual evoked potentials (VEP) and the thickness as well as the volume of retinal layers using optical coherence tomography (OCT) across a cohort of Parkinson's disease (PD) patients and age-matched controls. Methods: Forty-three PD patients and 38 controls were enrolled. All participants underwent a detailed neurological and ophthalmologic evaluation. Idiopathic PD cases were included. Cases with glaucoma or increased intra-ocular pressure were excluded. Patients were assessed by VEP and high-resolution Fourier-domain OCT, which quantified the inner and outer thicknesses of the retinal layers. VEP latencies and the thicknesses of the retinal layers were the main outcome measures. Results: The mean age, with standard deviation (SD), of the PD patients and controls were 63.1 (7.5) and 62.4 (7.2) years, respectively. The patients were predominantly in the initial Hoehn-Yahr (HY) disease stages (34.8% in stage 1 or 1.5, and 55.8 % in stage 2). The VEP latencies and the thicknesses as well as the volumes of the retinal inner and outer layers of the groups were similar. A negative correlation between the retinal thickness and the age was noted in both groups. The thickness of the retinal nerve fibre layer (RNFL) was 102.7 μm in PD patients vs. 104.2 μm in controls. Conclusions: The thicknesses of retinal layers, VEP, and RNFL of PD patients were similar to those of the controls. Despite the use of a representative cohort of PD patients and high-resolution OCT in this study, further studies are required to establish the validity of using OCT and VEP measurements as the anatomic and functional biomarkers for the evaluation of retinal and visual pathways in PD patients.774238242Lang, A.E., Lozano, A.M., Parkinson's disease: first of two parts (1998) N Engl J Med, 339 (15), pp. 1044-1053Braak, H., Del Tredici, K., Bratzke, H., Hamm-Clement, J., Sandmann-Keil, D., Rüb, U., Staging of the intracerebral inclusion body pathology associated with idiopathic Parkinson's disease (preclinical and clinical stages) III (2002) J Neurol, 249, pp. 1-5Bodis-Wollner, I., Yahr, M., Measurements of visual evoked potentials in Parkinson's disease (1978) Brain, 101 (4), pp. 661-671Regan, D., Neima, D., Low-contrast letter charts in early diabetic retinopathy, ocular hypertension, glaucoma and Parkinson's disease (1984) Br J Ophthalmol, 68 (12), pp. 885-889Onofrj, M., Ghilardi, M.F., Basciani, M., Gambi, D., Visual evoked potentials in Parkinsonism and dopamine blockade reveal a stimulus-dependent dopamine function in humans (1986) J Neurol Neurosurg Psychiatry, 49 (10), pp. 1150-1159Mariani, A.P., Amacrine cells of the rhesus monkey retina (1990) J Comp Neurol, 301 (3), pp. 382-400Kolb, H., Cuenca, N., Wang, H.H., Dekorver, L., The synaptic organization of the dopaminergic amacrine cell in the cat retina (1990) J Neurocytol, 19 (3), pp. 343-366Witkovsky, P., Nicholson, C., Rice, M.E., Bohmaker, K., Meller, E., Extracellular dopamine concentration in the retina of the clawed frog Xenopus laevis (1993) Proc Natl Acad Sci USA, 90 (12), pp. 5667-5671Bodis-Wollner, I., Antal, A., Optic nerve and central nervous dysfunctions: Parkinson's disease and multiple sclerosis (2006) Principles and practice of clinical electrophysiology of vision, pp. 867-888. , Heckenlively JR, Arden GB, editors. Cambridge, Massachusetts, London, England: The Mit PressInzelberg, R., Ramirez, J.A., Nisipeanu, P., Ophir, A., Retinal nerve fiber layer thinning in Parkinson disease (2004) Vision Res, 44 (24), pp. 2793-2797Altintas, O., Iseri, P., Ozkan, B., Caglar, Y., Correlation between retinal morphological and functional findings and clinical severity in Parkinson's disease (2008) Doc Ophthalmol, 116 (2), pp. 137-146Hajee, M.E., March, W.F., Lazzaro, D.R., Wolintz, A.H., Shrier, E.M., Glazman, S., Inner retinal layer thinning in Parkinson disease (2009) Arch Ophthalmol, 127 (6), pp. 737-741Moschos, M.M., Tagaris, G., Markopoulos, I., Margetis, I., Tsapakis, S., Morphologic changes and functional retinal impairment in patients with Parkinson disease without visual loss (2011) Eur J Ophthalmol, 21 (1), pp. 24-29Daniel, S.E., Lees, A.J., Parkinson's Disease Society Brain Bank London: overview and research (1993) J Neural Transm Suppl, 39, pp. 165-172Fenelon, G., Mahieux, F., Huon, R., Ziegler, M., Hallucinations in Parkinson's disease: prevalence, phenomenology and risk factors (2000) Brain, 123, pp. 733-745Archibald, N.K., Clarke, M.P., Mosimann, U.P., Burn, D.J., Retinal thickness in Parkinson's disease (2011) Parkinsonism Relat Disord, 17 (6), pp. 431-436Almer, Z., Klein, K.S., Marsh, L., Gerstenhaber, M., Repka, M.X., Ocular motor and sensory function in Parkinson's disease (2012) Ophthalmology, 119 (1), pp. 178-182Harnois, C., Di Paolo, T., Decreased dopamine in the retinas of patients with Parkinson's disease (1990) Invest Ophthalmol Vis Sci, 31 (11), pp. 2473-2475Bodis-Wollner, I., Antal, A., Primary visual and visuocognitive deficits (2005) Parkinson's disease and nonmotor dysfunction, pp. 233-244. , In: Pfeiffer RF, Bodis-Wolllner I, editors. Totowa, NJ: Humana Press. cap 20Marras, C., Schuele, B., Munhoz, R.P., Rogaeva, E., Langsto, J.W., Kasten, M., Phenotype in parkinsonian and nonparkinsonian LRRK2 G2019S mutation carriers (2011) Neurology, 77 (4), pp. 325-333Bodis-Wollner, I., Visual deficits related to dopamine deficiency in experimental animals and Parkinson's disease patients (1990) Trends Neurosci, 13 (7), pp. 296-302Masson, G., Mestre, D., Blin, O., Dopaminergic modulation of visual sensitivity in man (1993) Fundam Clin Pharmacol, 7 (8), pp. 449-463Sartucci, F., Orlandi, G., Lucetti, C., Bonuccelli, U., Murri, L., Visuo-cognitive dysfunctions in Parkinson's disease (2003) J Clin Neurophysiol, 20 (5), pp. 375-381Albrecht, P., Muller, A.K., Sudmeyer, M., Ferrea, S., Ringelstein, M., Optical coherence tomography in parkinsonian syndromes (2012) PLOS One, 7 (4)Schneider, M., Muller, H.P., Lauda, F., Tumani, H., Ludolph, A.C., Kassubeck, J., Retinal single-layer analysis in Parkinsonian syndromes: an optical coherence tomography study (2014) J Neural Transm, 121 (1), pp. 41-4

Ocular findings in patients with systemic sclerosis

OBJECTIVE: To evaluate the frequency and characteristics of ocular manifestations in outpatients with systemic sclerosis. METHODS: In this cross-sectional study, 45 patients with systemic sclerosis were enrolled. Data regarding demographics, disease duration and subtype, age at diagnosis, nailfold capillaroscopic pattern and autoantibody profile were collected, and a full ophthalmic examination was conducted. Parametric (Student's t-test) and nonparametric (Mann-Whitney U test) tests were used to compare continuous variables. Fisher's exact test was used to compare categorical data. P values < 0.05 were considered significant. RESULTS: Twenty-three subjects (51.1%) had eyelid skin changes; 22 (48.9%) had keratoconjunctivitis sicca, 19 (42.2%) had cataracts, 13 (28.9%) had retinal microvascular abnormalities and 6 (13.3%) had glaucoma. Eyelid skin changes were more frequent in patients with the diffuse subtype of systemic sclerosis and were associated with a younger age and an earlier age at diagnosis. Cataracts were presumed to be age-related and secondary to corticosteroid treatment. There was no association between demographic, clinical or serological data and keratoconjunctivitis sicca. The retinal microvascular abnormalities were indistinguishable from those related to systemic hypertension and were associated with an older age and a severe capillaroscopic pattern. CONCLUSIONS: Eyelid skin abnormalities and keratoconjunctivitis sicca were the most common ocular findings related to systemic sclerosis. Some demographic and clinical data were associated with some ophthalmic features and not with others, showing that the ocular manifestations of systemic sclerosis are characterized by heterogeneity and reflect the differences in the implicated pathophysiological mechanisms

An overview of burst, buckling, durability and corrosion analysis of lightweight FRP composite pipes and their applicability

© 2019 Elsevier Ltd. All rights reserved.The main aim of this review article was to address the performance of filament wound fibre reinforced polymer (FRP) composite pipes and their critical properties, such as burst, buckling, durability and corrosion. The importance of process parameters concerning merits and demerits of the manufacturing methods was discussed for the better-quality performance. Burst analysis revealed that the winding angle of ±55° was observed to be optimum with minimum failure mechanisms, such as matrix cracking, whitening, leakage and fracture. The reduction of buckling effect was reported in case of lower hoop stress value in the hoop to axial stress ratio against axial, compression and torsion. A significant improvement in energy absorption was observed in the hybrid composite pipes with the effect of thermal treatment. However, the varying winding angle in FRP pipe fabrication was reported as an influencing factor affecting all the aforementioned properties. Almost 90% of the reviewed studies was done using E-glass/epoxy materials for the composite pipe production. By overcoming associated limitations, such as replacing synthetic materials, designing new material combinations and cost-benefit analysis, the production cost of the lightweight FRP composite pipes can be decreased for the real-time applications.Peer reviewe

Search for supersymmetry in proton-proton collisions at 13 TeV using identified top quarks

A search for supersymmetry is presented based on proton-proton collision events containing identified hadronically decaying top quarks, no leptons, and an imbalance p(T)(miss) in transverse momentum. The data were collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). Search regions are defined in terms of the multiplicity of bottom quark jet and top quark candidates, the p(T)(miss) , the scalar sum of jet transverse momenta, and themT2 mass variable. No statistically significant excess of events is observed relative to the expectation from the standard model. Lower limits on the masses of supersymmetric particles are determined at 95% confidence level in the context of simplified models with top quark production. For a model with direct top squark pair production followed by the decay of each top squark to a top quark and a neutralino, top squark masses up to 1020 GeVand neutralino masses up to 430 GeVare excluded. For amodel with pair production of gluinos followed by the decay of each gluino to a top quark-antiquark pair and a neutralino, gluino masses up to 2040 GeVand neutralino masses up to 1150 GeVare excluded. These limits extend previous results.Peer reviewe

Search for resonances in the mass spectrum of muon pairs produced in association with b quark jets in proton-proton collisions at root 8 and 13 TeV

A search for resonances in the mass range 12-70 GeV produced in association with a b quark jet and a second jet, and decaying to a muon pair, is reported. The analysis is based on data from proton-proton collisions at center-of-mass energies of 8 and 13 TeV, collected with the CMS detector at the LHC and corresponding to integrated luminosities of 19.7 and 35.9 fb(-1), respectively. The search is carried out in two mutually exclusive event categories. Events in the first category are required to have a b quark jet in the central region (|| 2.4) and at least one jet in the forward region (|| > 2.4). Events in the second category are required to have two jets in the central region, at least one of which is identified as a b quark jet, no jets in the forward region, and low missing transverse momentum. An excess of events above the background near a dimuon mass of 28 GeV is observed in the 8 TeV data, corresponding to local significances of 4.2 and 2.9 standard deviations for the first and second event categories, respectively. A similar analysis conducted with the 13 TeV data results in a mild excess over the background in the first event category corresponding to a local significance of 2.0 standard deviations, while the second category results in a 1.4 standard deviation deficit. The fiducial cross section measurements and 95% confidence level upper limits on those for a resonance consistent with the 8 TeV excess are provided at both collision energies

Search for Evidence of the Type-III Seesaw Mechanism in Multilepton Final States in Proton-Proton Collisions at root s=13 TeV

Peer reviewe

Pseudorapidity distributions of charged hadrons in proton-lead collisions at root s(NN)=5:02 and 8.16 TeV

The pseudorapidity distributions of charged hadrons in proton-lead collisions at nucleon-nucleon center-of-mass energies root s(NN) = 5.02 and 8.16 TeV are presented. The measurements are based on data samples collected by the CMS experiment at the LHC. The number of primary charged hadrons produced in non-single-diffractive proton-lead collisions is determined in the pseudorapidity range vertical bar eta(lab)vertical bar vertical bar(vertical bar eta cm vertical bar) <0.5 are 17.1 +/- 0.01 (stat) +/- 0.59 (syst) and 20.10 +/- 0.01 (stat) +/- 0.5(syst) at root s(NN) = 5.02 and 8.16 TeV, respectively. The particle densities per participant nucleon are compared to similar measurements in proton-proton, proton-nucleus, and nucleus-nucleus collisions.Peer reviewe

Measurement of vector boson scattering and constraints on anomalous quartic couplings from events with four leptons and two jets in proton-proton collisions at root s=13 TeV

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Search for Higgsino pair production in pp collisions at root s=13 TeV in final states with large missing transverse momentum and two Higgs bosons decaying via H -> b(b)over bar

Results are reported from a search for new physics in 13 TeV proton-proton collisions in the final state with large missing transverse momentum and two Higgs bosons decaying via H -> b(b)over bar. The search uses a data sample accumulated by the CMS experiment at the LHC in 2016, corresponding to an integrated luminosity of 35.9 fb(-1). The search is motivated by models based on gauge-mediated supersymmetry breaking, which predict the electroweak production of a pair of Higgsinos, each of which can decay via a cascade process to a Higgs boson and an undetected lightest supersymmetric particle. The observed event yields in the signal regions are consistent with the standard model background expectation obtained from control regions in data. Higgsinos in the mass range 230-770 GeV are excluded at 95% confidence level in the context of a simplified model for the production and decay of approximately degenerate Higgsinos.Peer reviewe