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Zhe Qu, Yulong Ding
During recent years, perceptual/attentional load paradigms have been frequently used to investigate whether the initial visual cortical processing can be modified by spatial attention. For example, Rauss and colleagues reported significant modulations of the earliest component (i.e. the C1) of the visual evoked potential (VEP) as a function of attentional load. It may be questioned, however, whether these load effects represent modulations of the C1 or overlaps from other components. Here we summarize some methods to identify and remove the overlaps, which is important to clarify the question of whether the initial visual cortical processing could be modulated by attention...
October 12, 2017: Cognitive Neuroscience
Junkyu Chung, Kyung Hyun Jin, Jaheon Kang, Tae Gi Kim
RATIONALE: Functional visual loss (FVL) can manifest as various symptoms. Decreased distant visual acuity is the most common symptom and visual field defect is the second most common symptom. Hemianopsia is rarely reported. In an atypical situation of FVL, it is important to prove that no organic pathology exists, through detailed history taking and appropriate examinations. PATIENT CONCERNS: This review presents the case of a 48-year-old male patient presented with decreased bilateral visual acuity and visual field defect after a traffic accident 3 weeks ago...
October 2017: Medicine (Baltimore)
Javier Sanchez-Lopez, Caterina A Pedersini, Francesco Di Russo, Nicolò Cardobi, Cristina Fonte, Valentina Varalta, Massimo Prior, Nicola Smania, Silvia Savazzi, Carlo A Marzi
Hemianopia is a visual field defect characterized by decreased vision or blindness in the contralesional visual field of both eyes. The presence of well documented above-chance unconscious behavioural responses to visual stimuli presented to the blind hemifield (blindsight) has stimulated a great deal of research on the neural basis of this important phenomenon. The present study is concerned with electrophysiological responses from the blind field. Since previous studies found that transient Visual Evoked Potentials (VEPs) are not entirely suitable for this purpose here we propose to use Steady-State VEPs (SSVEPs)...
October 5, 2017: Neuropsychologia
Iwona Obuchowska, Grzegorz Turek, Jan Kochanowicz, Andrzej Lewszuk, Zofia Mariak, Zenon Mariak
Late ocular manifestations of aneurysmal subarachnoid hemorrhage (SAH) have not been previously investigated except for one study which demonstrated that one half of patients subjected to aneurysm clipping suffer from symptoms of visual pathway impairment. We assessed ophthalmological status of patients after 1-4.5 years from SAH and aneurysm embolization to identify predictors of damage to the visual pathways. Complete ophthalmological examination, static perimetry, and visual evoked potentials (VEPs) were performed in 74 patients (26 men, 48 women, aged 19-76 years), who constituted a consecutive sample of 129 patients treated with aneurysm embolization in the years 2008-2010...
September 22, 2017: Neurologia i Neurochirurgia Polska
Gert R J Christoffersen, Jakob L Laugesen, Per Møller, Wender L P Bredie, Todd R Schachtman, Christina Liljendahl, Ida Viemose
Human recognition of foods and beverages are often based on visual cues associated with flavors. The dynamics of neurophysiological plasticity related to acquisition of such long-term associations has only recently become the target of investigation. In the present work, the effects of appetitive and aversive visuo-gustatory conditioning were studied with high density EEG-recordings focusing on late components in the visual evoked potentials (VEPs), specifically the N2-P3 waves. Unfamiliar images were paired with either a pleasant or an unpleasant juice and VEPs evoked by the images were compared before and 1 day after the pairings...
2017: Frontiers in Human Neuroscience
Michael B Hoffmann, Jan Brands, Wolfgang Behrens-Baumann, Michael Bach
PURPOSE: Objective assessment of visual acuity (VA) is possible with VEP methodology, but established with sufficient precision only for vision better than about 1.0 logMAR. We here explore whether this can be extended down to 2.0 logMAR, highly desirable for low-vision evaluations. METHODS: Based on the stepwise sweep algorithm (Bach et al. in Br J Ophthalmol 92:396-403, 2008) VEPs to monocular steady-state brief onset pattern stimulation (7.5-Hz checkerboards, 40% contrast, 40 ms on, 93 ms off) were recorded for eight different check sizes, from 0...
October 4, 2017: Documenta Ophthalmologica. Advances in Ophthalmology
Jayantee Kalita, Ravi Uniyal, Usha K Misra, Sanjeev K Bhoi
We report neuronal sensitization and impaired habituation in migraine using pattern reversal visual evoked potential (PRVEP) and correlate these with clinical characteristics of migraine. Sixty-five migraineurs and 30 healthy controls were included. A detailed clinical examination was done and migraine characteristics, including migraine trigger, photophobia, phonophobia, and allodynia were noted. Consecutive 5 blocks of PRVEP were recorded averaging 100 epochs at 3 Hz stimuli. The amplitude of N75 and P100 were measured...
September 1, 2017: Clinical EEG and Neuroscience: Official Journal of the EEG and Clinical Neuroscience Society (ENCS)
Antonio Chiaretti, Giorgio Conti, Benedetto Falsini, Danilo Buonsenso, Matteo Crasti, Luigi Manni, Marzia Soligo, Claudia Fantacci, Orazio Genovese, Maria Lucia Calcagni, Daniela Di Giuda, Maria Vittoria Mattoli, Fabrizio Cocciolillo, Pietro Ferrara, Antonio Ruggiero, Susanna Staccioli, Giovanna Stefania Colafati, Riccardo Riccardi
BACKGROUND: Nerve growth factor (NGF) promotes neural recovery after experimental traumatic brain injury (TBI) supporting neuronal growth, differentiation and survival of brain cells and up-regulating the neurogenesis-associated protein Doublecortin (DCX). Only a few studies reported NGF administration in paediatric patients with severe TBI. METHODS: A four-year-old boy in a persistent unresponsive wakefulness syndrome (UWS) was treated with intranasal murine NGF administration 6 months after severe TBI...
October 3, 2017: Brain Injury: [BI]
Valentine L Marcar, Lutz Jäncke
BACKGROUND: Clarifying the enigmatic relationship between stimulus property, neural response and the evoked potential is essential if non-invasive functional imaging is to make a meaningful contribution to the understanding of how maturational or degenerative processes influence brain activity. Visual cortex has proven a favourite target to elucidate this relationship. However, to date most studies involving the visual system have yielded inconsistent results or have been strongly criticised...
September 27, 2017: Journal of Neuroscience Methods
Said Dahbour, Fatima Jamali, Dana Alhattab, Ali Al-Radaideh, Osama Ababneh, Nosaiba Al-Ryalat, Muawyeh Al-Bdour, Bayan Hourani, Mohammed Msallam, Murad Rasheed, Ammar Huneiti, Yacoub Bahou, Emad Tarawneh, Abdalla Awidi
AIMS: This open-label prospective phase I/IIa clinical study used autologous bone marrow-derived mesenchymal stromal cells (BM-MSCs) followed by mesenchymal stromal cells conditioned media (MSC-CM) for the first time to treat multiple sclerosis (MS) patients. The primary goal was to assess the safety and feasibility and the secondary was efficacy. The correlation between the MSC-CM content and treatment outcome was investigated. METHODS: Ten MS patients who failed conventional therapy were enrolled...
November 2017: CNS Neuroscience & Therapeutics
Philipp Schwenkenbecher, Anastasia Sarikidi, Lena Bönig, Ulrich Wurster, Paul Bronzlik, Kurt-Wolfram Sühs, Refik Pul, Martin Stangel, Thomas Skripuletz
While the revised McDonald criteria of 2010 allow for the diagnosis of multiple sclerosis (MS) in an earlier stage, there is still a need to identify the risk factors for conversion to MS in patients with clinically isolated syndrome (CIS). Since the latest McDonald criteria were established, the prognostic role of cerebrospinal fluid (CSF) and visual evoked potentials (VEP) in CIS patients is still poorly defined. We conducted a monocentric investigation including patients with CIS in the time from 2010 to 2015...
September 27, 2017: International Journal of Molecular Sciences
Jiahui Zheng, Jingyue Wang, Huanglei Pan, Hongli Wu, Difeng Ren, Jun Lu
The aim of the present study was to investigate the antihypertensive effects of the bioactive Spirulina platensis peptides Ile‑Gln‑Pro (IQP), Val‑Glu‑Pro (VEP), as well as Spirulina platensis hydrolysates (SH), and assessed whether the synthesis of components of the myocardial and renal local renin angiotensin system (RAS) are regulated differentially in spontaneously hypertensive rats (SHR). The SHR were administrated with IQP, VEP and SH respectively (10 mg/kg/day) for 6 weeks and received continuous monitoring of blood pressure (BP) for two more weeks...
September 25, 2017: Molecular Medicine Reports
Paolo Bonanni, Susanna Negrin, Lisa Antoniazzi, Martina Da Rold, Franco Fabbro, Anna Serafini
In epileptic encephalopathies (EE), interictal epileptiform discharges (IEDs) contribute to cognitive impairment. The EE process has been studied in a patient affected by epilepsy with occipital calcification and celiac disease (CEC syndrome) by combining the administration of brain area stimulus specific (visual and auditory) reaction times (RT) during continuous EEG monitoring with the off-line reconstruction of auditory and visual evoked potentials (EP). Visual RT and VEP were abnormal only if recorded concomitantly to the IEDs...
September 20, 2017: Neurocase
Jonas L Isaksen, Ali Mohebbi, Sadasivan Puthusserypady
BACKGROUND: In a c-VEP BCI setting, test subjects can have highly varying performances when different pseudorandom sequences are applied as stimulus, and ideally, multiple codes should be supported. On the other hand, repeating the experiment with many different pseudorandom sequences is a laborious process. AIMS: This study aimed to suggest an efficient method for choosing the optimal stimulus sequence based on a fast test and simple measures to increase the performance and minimize the time consumption for research trials...
2017: PloS One
Yulong Ding
Almost ten years ago, Kelly and collegues reported that the earliest component (i.e., the C1) of the visual evoked potential (VEP) could be modulated by spatial attention. Using a similar experimental design and data analysis methods, however, Baumgartner et al. (this issue) recently failed to provide confirmative evidence. In this commentary, I suggest that some minor differences in experimental design may account for the inconsistent results between the two studies. I also propose a hypothesis that the C1 effect reported in Kelly et al...
September 18, 2017: Cognitive Neuroscience
Gorana Sulejmanpasic, Senad Drnda
AIM: To examine the morphologic variations of occipital sulci patterns in patients with schizophrenia and migraine haeadache regarding gender and laterality as well as damage of visual pathway in patients with schizophrenia using magnetic resonance imagining (MRI) and visual evoked potentials (VEPs). METHODS: This study included 80 patients and brain scans and visual evoked potential responses recorded over the occipital cortex were performed to analyze the occipital region of both hemispheres...
June 2017: Acta Informatica Medica: AIM
Daniela Pelclova, Pavel Urban, Zdenka Fenclova, Stepanka Vlckova, Petr Ridzon, Karel Kupka, Zuzana Meckova, Ondrej Bezdicek, Tomas Navratil, Jan Rosmus, Sergey Zakharov
The last eight survivors of 80 workers accidentally exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during production of herbicides based on trichlorophenoxyacetic acid in 1965-1967 in a chemical factory were followed. All were men, mean age 72.4 ± 1.3 years. Their current median TCDD blood level was 112 (46-390) pg/g lipids. Neurological examination revealed central nervous system impairment in all subjects, and signs of polyneuropathy in 87.5%, which was confirmed by a nerve conduction study (NCS) in 75%...
September 1, 2017: Basic & Clinical Pharmacology & Toxicology
Simon P Kelly, Kieran S Mohr
In Kelly, Gomez-Ramirez and Foxe (2008), we demonstrated strong spatial attentional modulation of initial afferent activity in human area V1 reflected in the C1 visual evoked potential (VEP) component. Using the same task and analysis strategy, Baumgartner and colleagues provide compelling evidence that there is no such modulation in their data. Here, we examine differences in task conditions between this new study and our original study, speculate on how they may account for the discrepant findings, and discuss the broader theoretical implications...
August 27, 2017: Cognitive Neuroscience
Tal Shahar, Akiva Korn, Gal Barkay, Tali Biron, Amir Hadanny, Tomer Gazit, Erez Nossek, Margaret Ekstein, Anat Kesler, Zvi Ram
OBJECTIVE Resection of intraaxial tumors adjacent to the optic radiation (OR) may be associated with postoperative visual field (VF) deficits. Intraoperative navigation using MRI-based tractography and electrophysiological monitoring of the visual pathways may allow maximal resection while preserving visual function. In this study, the authors evaluated the value of visual pathway mapping in a series of patients undergoing awake craniotomy for tumor resection. METHODS A retrospective analysis of prospectively collected data was conducted in 18 patients who underwent an awake craniotomy for resection of intraaxial tumors involving or adjacent to the OR...
August 25, 2017: Journal of Neurosurgery
Christopher Nishioka, Hsiao-Fang Liang, Chen-Fang Chung, Shu-Wei Sun
PURPOSE: Diffusion tensor imaging (DTI) is commonly used to evaluate white matter integrity in multiple sclerosis (MS), but the relationship between DTI measures and functional changes during disease remains ambiguous. Using a mouse model of MS, we tested the hypothesis that DTI measures would correlate to the visual evoked potential (VEPs) dynamically at different disease stages. METHODS: In vivo DTI, gadolinium-enhanced T1WI (Gd-T1WI) and VEPs were performed in 5 control and 25 mice after 2-12 weeks of experimental autoimmune encephalomyelitis (EAE)...
August 24, 2017: Neuroradiology
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