Evaluation of VEP Parameters in Patients Before and After Cardiopulmonary By-Pass Surgery

Introduction: Coronary bypass surgery is emphasized in aetiology of ischemic optic neuropathy. Our aim in this study was to investigate the pattern visual evoked potentials (PVEP) in patients before and after coronary bypass surgery.Methods: Thirty-one patients were included in the study. After a full ophthalmological evaluation, PVEP was assesed in the pre and postoperative periods. Operative times, hematological parameters, blood pressures, number of transfusions, body temperatures, anaesthetic drugs and systemic illnesses were recorded for each patient. Results: The mean age of the patients were 59±10.4 years. There was 22 men and 9 women in the study. Only 3 of them needed transfusion during the surgery. The mean duration of the surgery was 3.2±0.7 hours. None of the patients had a history of visual disturbance or postoperative ischemic optic neuropathy. The mean VEP P100 amplitude was not statistically significantly different but the mean VEP P100 latency showed statistically significant difference between the preoperative and postoperative periods. (p=0.014) This significance was more appereant in patients with systemic illnesses. (p= 0.023) There was a positive correlation between the age and VEP P100 latency. (r = 0.402, p< 0.05) Conclusions: Although surgical techniques and equipments are developing each day in the field of cardiopulmonary bypass surgery, the contributing factors such as hypothermia, anemia and diabetes still seem to affect neurophysiological functions even after a noncomplicated surgery.

Prediction of Post-operative Visual Deterioration Using Visual-Evoked Potential Latency in Extended Endoscopic Endonasal Resection of Craniopharyngiomas

Background: The current study aimed to investigate the predictive value of visual-evoked potential (VEP) latency for post-operative visual deterioration in patients undergoing craniopharyngioma resection via extended endoscopic endonasal approach (EEEA).Methods: Data from 90 patients who underwent craniopharyngioma resection via EEEA with intraoperative VEP monitoring were retrospectively reviewed. P100 latency was compared between patients with and without post-operative visual deterioration, and the threshold value of P100 latency for predicting post-operative visual deterioration was calculated by the receiver operating characteristic curve analysis. In addition, other potential prognostic factors regarding post-operative visual outcomes were also analyzed by multivariate analysis.Results: Patients with post-operative visual deterioration showed a significantly longer VEP latency than those without (p &lt; 0.001). An extension over 8.61% in VEP latency was identified as a predictor of post-operative visual deterioration (p &lt; 0.001). By contrast, longer preoperative visual impairment duration and larger tumor volume were not significant predictors for post-operative visual deterioration.Conclusions: The current study revealed that intraoperative VEP monitoring in EEEA is effective for predicting post-operative visual deterioration, and an extension over 8.61% in VEP latency can be used as a critical cut-off value to predict post-operative visual deterioration.

The effect of optic neuritis treatment trial (ONTT) combined corticosteroid regimen on pattern reversal visual evoked potentials: a prospective follow-up study

Background The combined corticosteroid regimen of the original Optic Neuritis Treatment Trial (ONTT) is used in many centers to treat optic neuritis. Though pattern reversal visual evoked potentials (PRVEPs) are a sensitive, standard measure of visual conduction in optic neuritis, no studies hitherto have investigated the effect of combined ONTT regimen on PRVEPs. We aimed to determine the effect of combined corticosteroid regimen of the ONTT on changes of PRVEPs in patients with first-episode optic neuritis over 3 months post-treatment. Methods This is a prospective, observational study in which 44 patients with optic neuritis were seen pre-treatment (baseline) and follow-up, at 1 month (FU1) and 3 months (FU2). Twenty-nine patients were treated with ONTT combined regimen (ONTT+ Group) while 15 were conservatively managed without corticosteroids (ONTT- Group). The median latency and amplitude values of the P100 PRVEP component and the visual acuity (i.e. LogMAR values) at pre-treatment, FU1 and FU2 were compared in the two groups using Friedman’s rank test and Wilcoxon Signed Ranks test. Results Median P100 latency improved significantly (to the normal range) as early as by 1 month after the commencement of treatment in the ONTT+ Group, and then remained significantly lower than the baseline over next 2 months. In the ONTT- Group, the median P100 latency improved more slowly over the two follow up assessments and reached the normal range by 3 months. Median visual acuity values also improved significantly at 1 and 3 months after the commencement of treatment in the ONTT+ Group but not in the ONTT- Group. Conclusion ONTT combined corticosteroid regimen improves conduction in the visual pathways of patients with first-episode optic neuritis earlier than does conservative management. We provide electrodiagnostic evidence that combined ONTT regimen–compared with conservative management–results in early remission of visual conduction abnormalities in first-episode optic neuritis.

Visual Impairments Are Associated With Retinal Microvascular Density in Patients With Parkinson’s Disease

ObjectiveThis study aimed to evaluate retinal microvascular density in patients with Parkinson’s disease (PD) and its correlation with visual impairment.MethodsThis cross-sectional study included 24 eyes of 24 patients with PD and 23 eyes of 23 healthy controls. All participants underwent ophthalmic examination, visual evoked potential (VEP) test, 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25), and optical coherence tomography angiography (OCTA) examination. The correlation between retinal microvascular density and visual parameter was evaluated using Spearman correlation analysis, and the area under receiver operating characteristic curve (AUROC) was calculated.ResultsParkinson’s disease patients had prolonged P100 latency (P = 0.041), worse vision-related quality of life (composite score and 3 of 12 subscales in NEI VFQ-25), and decreased vessel density (VD) in all sectors of 3-mm-diameter region (all P &lt; 0.05) compared with healthy controls. There were no statistical differences in the ganglion cell-inner plexiform layer (GCIPL) thickness and retinal nerve fiber layer (RNFL) thickness between the two groups. A negative correlation was found between P100 latency and nasal and superior sectors of macular VD in a 3-mm-diameter region (r = −0.328, P = 0.030; r = −0.302, and P = 0.047, respectively). Macular VD in a 3-mm-diameter region showed diagnostic capacities to distinguish PD patients from healthy controls (AUROCs, ranging from 0.655 to 0.723).ConclusionThis study demonstrated that decreased retinal microvascular density was correlated with visual impairment in PD patients. Retinal microvasculature change may occur earlier than visual decline and retinal structure change and has the potential to be a promising diagnostic marker for early PD.

Evaluation of Visual Evoked Potential in Psoriasis Vulgaris Patients in a Tertiary Care Centre

Psoriasis is an immunologically mediated, inflammatory disease with increased risk of painful and destructive arthritis, cardiovascular morbidity and psychosocial challenges. Psoriasis vulgaris is the most common form of psoriasis, seen in approximately 90% of patients. Besides skin, other regions widely involved are bone, cardiovascular system and eye. Psoriatic eye manifestations involve many of the structures of eye; from eyelid till optic nerve. Recording of Visual evoked potential helps in studying the integrity of optic nerve and its abnormality signifies demyelination. The concept Brain skin axis proposed in literature shows involvement of nervous system with immune mediated inflammatory pathway in Psoriasis. During intense inflammatory course, highly dense sensory nerves in plaques trigger the release of neuropeptides, targeting keratinocytes and further nerve damage. With this background, the present study was aimed to assess Optic pathway integrity by Visual Evoked Potential in patients of Psoriasis vulgaris. Materials and Methods: A Case control study was done with Institutional Ethics Committee approval and written informed consent on 100 plaque type psoriatic cases and 50 apparently healthy subjects as controls. Cases were divided into 2 groups based on their disease duration as I – new cases (1 to 5 years), II – old cases (6 to 10 years). Psoriatic patients treated with UVB and Methotrexate and with relapse of both gender of 15 to 35 years were included in the study. Patients with Diabetes Mellitus, Hypertension, any other chronic illness and autoimmune disease, severe forms of psoriasis, patients on oral steroids, and with H /O ocular diseases, eye surgery and neurological illness were excluded from the study. The mean Psoriasis Area Severity Index (PASI) was 16.09 ± 11.11. According to PASI score, the cases were categorised as <10 – mild; >11-20 – moderate; and>21 – severe. Clinical and ophthalmological examination was done for study participants. After proper instructions to patients for VEP procedure, VEP was recorded using Physiopac –NEURO PERFECT EMG 2000 SYSTEM. P100 latency of controls and cases was taken for analysis and analysed using SPSS 21.0 version. Results: There was increase in P100 latency of cases when compared to controls. P100 latency progressively increases as the severity of disease increases. Conclusion: Increased latency of P100 is a sign for demyelination. As this is seen in the present study, in psoriatic patients, there is a probability of optic nerve involvement during active state of disease. Keywords: Psoriasis, VEP, P100, PASI.

Evaluation of Retinal Structure and Optic Nerve Function Changes in Multiple Sclerosis: Longitudinal Study with 1-Year Follow-Up

Background. Multiple sclerosis (MS) is an autoimmune disease characterized by inflammation and demyelination of the central nervous system which often involves the optic nerve even though only 20% of the patients experience optic neuritis (ON). Objective. This study aims to compare the retinal structure and optic nerve function between patients with MS and healthy controls (HCs), evaluate optic nerve alterations in MS over 1-year follow-up, and analyze its correlations with disease duration, number of relapses, degree of disability, and different subtypes. Methods. This is a prospective cohort study involving 58 eyes of MS patients. Optic nerve function was evaluated with best-corrected visual acuity (BCVA), contrast sensitivity, and P100 latency, while the retinal structure was evaluated from the GCIPL and RNFL thickness measured with optical coherence tomography (OCT) and fundus photography. Results. The MS group had lower BCVA ( p = 0.001 ), contrast sensitivity ( p < 0.001 ), mean GCIPL thickness ( p < 0.001 ), and mean RNFL thickness ( p < 0.001 ) than HC. At 6 and 12 months of observations, GCIPL and RNFL (nasal quadrant) of MS patients decreased significantly ( p = 0.007 and p = 0.004 , respectively). Disease duration and the number of relapses correlated with delayed P100 latency (r = −0.61, p < 0.001 and r = −0.46, p = 0.02 ). GCIPL and RNFL in the SPMS subtype were thinner than in RRMS. Conclusions. The retinal structure and optic nerve function of MS patients are worse than those of normal individuals. GCIPL and RNFL thinning occurs at 6 and 12 months but do not correlate with disease duration, the number of relapses, and degree of disability.

Correlations between developmental test of visual perception-adolescent and adult and visual evoked potential in people with multiple sclerosis

Background: Optic neuritis (ON) is a common visual sign in multiple sclerosis (MS). Although ON is recovered in most cases, other visual functions such as visual perception are affected and are not fully recovered. The aim of this study is to investigate the relationship between visual evoked potential (VEP) P100 and N70 latencies and visual perception using the Developmental Test of Visual Perception-Adolescent and Adult (DTVP-A) in people with MS. Methods: In this cross-sectional study, 24 people with ON due to MS, aged 18-50 years old took part. In order to assess the visual perception and optic nerve conductivity, the DTVP-A and the VEP were accomplished, respectively. Pearson’s product-moment correlation coefficient was used to analyze the data. Results: There was a significant negative correlation between right VEP P100 latency and total score of DTVP-A (r = -0.450, P < 0.05) as well as a significant negative correlation between right VEP P100 latency with visual-motor integration (VMI) subtest of DTVP-A (r = -0.485, P < 0.05). Conclusion: The visual perception has an important role in safety and independent daily activities. Therefore, determining the related factors is essential. Although the findings of the current study revealed a moderate statistical correlation between visual perception and right VEP P100 latency, the small sample size might limit the generalization of our findings; therefore, further study is required to confirm our results.

Modality-specific improvements in sensory processing among baseball players

Long-term skills training is known to induce neuroplastic alterations, but it is still debated whether these changes are always modality-specific or can be supramodal components. To address this issue, we compared finger-targeted somatosensory-evoked and auditory-evoked potentials under both Go (response) and Nogo (response inhibition) conditions between 10 baseball players, who require fine hand/digit skills and response inhibition, to 12 matched track and field (T&F) athletes. Electroencephalograms were obtained at nine cortical electrode positions. Go potentials, Nogo potentials, and Go/Nogo reaction time (Go/Nogo RT) were measured during equiprobable somatosensory and auditory Go/Nogo paradigms. Nogo potentials were obtained by subtracting Go trial from Nogo trial responses. Somatosensory Go P100 latency and Go/Nogo RT were significantly shorter in the baseball group than the T&F group, while auditory Go N100 latency and Go/Nogo RT did not differ between groups. Additionally, somatosensory subtracted Nogo N2 latency was significantly shorter in the baseball group than the T&F group. Furthermore, there were significant positive correlations between somatosensory Go/Nogo RT and both Go P100 latency and subtracted Nogo N2 latency, but no significant correlations among auditory responses. We speculate that long-term skills training induce predominantly modality-specific neuroplastic changes that can improve both execution and response inhibition.

Visual Evoked Potentials in Neuromyelitis Optica Spectrum Disorders

Background Neuromyelitis optica spectrum disorders (NMOSDs) are rare antibody-mediated disorders of the central nervous system, with a predilection for the spinal cord and optic nerves. The clinical utility of evoked potential recordings (EPs) has already been established for multiple sclerosis, in particular, that of the abnormal visual evoked potentials (VEP), a key criterion in the McDonald diagnostic criteria for MS. However, there have been few reports on EPs in patients with NMOSD. AIM The aim of our study was to assess the possible involvement of the optical pathway through VEP responses in patients with NMOSD. Methods VEPs were prospectively performed in 13 patients with NMOSD. All the patients were recruited from the outpatient clinic of a demyelinating diseases center. The recording was done as recommended by the International Federation of Clinical Neurophysiology. Results We evaluated the eyes of 12 women with a mean age of 42 years and of one man who was 25 years old. In 6 of the examined eye samples, a response was not obtained, while in the remaining 20 eye samples, we found a significant increase in P100 latency without amplitude change. Conclusion VEPs showed a significant increase in P100 latency. VEP assessment is a non-invasive, painless, fast, and low-cost exam that provides neurophysiological data for diagnosis of NMOSD.

Late attentional processes potentially compensate for early perceptual multisensory integration deficits in children with autism: evidence from evoked potentials

Sensory processing deficits and altered long-range connectivity putatively underlie Multisensory Integration (MSI) deficits in Autism Spectrum Disorder (ASD). The present study set out to investigate non-social MSI stimuli and their electrophysiological correlates in young neurotypical adolescents and adolescents with ASD. We report robust MSI effects at behavioural and electrophysiological levels. Both groups demonstrated normal behavioural MSI. However, at the neurophysiological level, the ASD group showed less MSI-related reduction of the visual P100 latency, greater MSI-related slowing of the auditory P200 and an overall temporally delayed and spatially constrained onset of MSI. Given the task design and patient sample, and the age of our participants, we argue that electro-cortical indices of MSI deficits in ASD: (a) can be detected in early-adolescent ASD, (b) occur at early stages of perceptual processing, (c) can possibly be compensated by later attentional processes, (d) thus leading to normal MSI at the behavioural level.