P300 Latency Research Articles

Negative bias in early and late cognitive processing of coronary heart disease patients with depressive symptoms: an EPR study

BackgroundThe purpose of this research was to explore the underlying mechanisms of cognitive impairments in patients with coronary heart disease (CHD) who exhibit depressive symptoms. This was accomplished by recording Event-related potentials (ERPs) during the emotional Stroop task, with a specific focus on the temporal dynamics of attentional bias towards various emotional words.MethodsWe selected 17 CHD patients with depressive symptoms and 23 CHD patients without depression using a convenience sampling method from the Affiliated Hospital of Weifang Medical University. Each participant completed an emotional Stroop color-word task, and ERPs were recorded during the task to examine cognitive processing.ResultsCHD patients with depressive symptoms exhibited generally smaller amplitudes of N1, N2, P3 and longer latency of P3 compared to CHD patients without depression. Specifically, the N1 amplitude of negative words was smaller and the P3 amplitude of negative words was larger in the CHD with depressive group compared to the CHD group. Furthermore, within the group of CHD patients with depressive symptoms, negative words elicited a smaller N1 amplitude and larger P3 amplitude compared to positive and neutral words.ConclusionsCHD patients with depressive symptoms demonstrate decreased attentional resources, leading to cognitive impairments. Notably, significant attentional bias occurs during both early and later stages of cognitive processing. This bias is primarily characterized by an enhanced automatic processing of negative information at the early stage and difficulty disengaging from such information at the later stage. These findings contribute to the existing literature on the cognitive neural mechanisms underlying depression in CHD patients.

Effects of noise and noise reduction on audiovisual speech perception in cochlear implant users: An ERP study

ObjectiveHearing with a cochlear implant (CI) is difficult in noisy environments, but the use of noise reduction algorithms, specifically ForwardFocus, can improve speech intelligibility. The current event-related potentials (ERP) study examined the electrophysiological correlates of this perceptual improvement. MethodsTen bimodal CI users performed a syllable-identification task in auditory and audiovisual conditions, with syllables presented from the front and stationary noise presented from the sides. Brainstorm was used for spatio-temporal evaluation of ERPs. ResultsCI users revealed an audiovisual benefit as reflected by shorter response times and greater activation in temporal and occipital regions at P2 latency. However, in auditory and audiovisual conditions, background noise hampered speech processing, leading to longer response times and delayed auditory-cortex-activation at N1 latency. Nevertheless, activating ForwardFocus resulted in shorter response times, reduced listening effort and enhanced superior-frontal-cortex-activation at P2 latency, particularly in audiovisual conditions. ConclusionsForwardFocus enhances speech intelligibility in audiovisual speech conditions by potentially allowing the reallocation of attentional resources to relevant auditory speech cues. SignificanceThis study shows for CI users that background noise and ForwardFocus differentially affect spatio-temporal cortical response patterns, both in auditory and audiovisual speech conditions.

Höffding step and beyond: The impact of visual sensory impairment on cognitive performance in neuropsychological testing of survivors of acute methanol poisoning.

Sensory deficits can result in limitations regarding how well neuropsychological test findings can be interpreted. Only a few studies have investigated the influence of vision alteration on neuropsychological tests. In 2012 the Czech Republic experienced mass methanol poisoning. Methanol metabolites cause histotoxic hypoxia to the optic nerve. In the current study, the effect of the toxic damage on the parts of the visual pathway on visual and non-visual neuropsychological measures was investigated using electrophysiological methods (visual evoked potential (VEP) and optical coherence tomography (OCT) with retinal nerve fibre layer (RNFL) thickness measurement. 53 individuals who experienced methanol poisoning participated in this research (76% men; ages 24 to 74 years, mean = 43.8±14.6 years; education 11.9±1.4 years). Each participant underwent comprehensive neurological, ophthalmological, and neuropsychological examinations. The results of mixed-effect models revealed significant small to a medium association between the Stroop test weak interference and Grooved Pegboard with the left eye global, nasal and temporal RNFL thickness. Also, medium associations between the Finger Tapping test and the Stroop test weak interference and left eye temporal RNFL, right eye temporal RNFL, and the latency P1 of VEP in the left eye were significant. The results of this study found a small to medium association (r = .15- .33; p = .010- .046) between RNFL thickness and cognitive visual test performance. Careful interpretation is suggested regarding results obtained from visual tests of the executive or motor functioning with participants with RNFL decrease or other types of early visual processing damage.

Biomarkers of professional cybersportsmen: Event related potentials and cognitive tests study.

"Faster, higher, stronger" is the motto of any professional athlete. Does that apply to brain dynamics as well? In our paper, we performed a series of EEG experiments on Visually Evoked Potentials and a series of cognitive tests-reaction time and visual search, with professional eSport players in Counter-Strike: Global Offensive (CS:GO) and novices (control group) in order to find important differences between them. EEG data were studied in a temporal domain by Event-Related Potentials (ERPs) and in a frequency domain by Variational Mode Decomposition. The EEG analysis showed that the brain reaction of eSport players is faster (P300 latency is earlier on average by 20-70 ms, p < 0.005) and stronger (P300 peak amplitude is higher on average by 7-9 mkV, p < 0.01). Professional eSport players also exhibit stronger stimulus-locked alpha-band power. Besides, the Spearman correlation analysis showed a significant correlation between hours spend in CS:GO and mean amplitude of P200 and N200 for the professional players. The comparison of cognitive test results showed the superiority of the professional players to the novices in reaction time (faster) and choice reaction time-faster reaction, but similar correctness, while a significant difference in visual search skills was not detected. Thus, significant differences in EEG signals (in spectrograms and ERPs) and cognitive test results (reaction time) were detected between the professional players and the control group. Cognitive tests could be used to separate skilled players from novices, while EEG testing can help to understand the skilled player's level. The results can contribute to understanding the impact of eSport on a player's cognitive state and associating eSport with a real sport. Moreover, the presented results can be useful for evaluating eSport team members and making training plans.

Efficacy of donepezil plus hydrogen-oxygen mixture inhalation for treatment of patients with Alzheimer disease: A retrospective study.

To investigate the clinical effect of donepezil combined with hydrogen-oxygen mixture inhalation in the treatment of patients with Alzheimer disease (AD), a total of 273 AD patients admitted to our hospital from March 2018 to March 2022 were retrospectively analyzed and assigned into an observation group (n = 138) and a control group (n = 135) according to the different treatment that they received. The control group was treated with donepezil tablets, while the observation group was treated with donepezil tablets combined with hydrogen-oxygen mixture inhalation. The scores of mini-mental state examination (MMSE), Montreal Cognitive Assessment (MoCA), Alzheimer's Disease Assessment Scale-Cognition, activity of daily living scale (ADL) and the P300 event-related potential were compared between the 2 groups. After treatment, MMSE score, MoCA score, and ADL score in both groups increased after treatment (P < .01), while the improvement in the observation group was more significant than that in the control group (P < .001 for MMSE, P = .003 for MoCA, and P = .013 for ADL). The scores of Alzheimer's Disease Assessment Scale-Cognition in the observation group decreased after treatment (P < .05), while the improvement in the observation group was more significant than that in the control group (P = .005). After treatment, the latency of P300 in both groups was shortened (P < .01), and the improvement in the observation group was more significant than that in the control group (P < .001). The amplitude of the observation group increased after treatment (P < .01), and the improvement of the observation group was significant than that of the control group (P = .007). The clinical efficacy of donepezil combined with hydrogen-oxygen mixture inhalation in the treatment of AD is better than that of donepezil alone, which is worthy of further study.

Evidence of Vestibular and Balance Dysfunction in Patients With Mild Cognitive Impairment and Alzheimer's Disease.

Given the expected rise in dementia prevalence, early diagnosis is vital. As a growing body of literature has identified a potential association between vestibular function and cognition, vestibular assessment may aid in early screening. The aim of the study was to better comprehend the proposed association between vestibular function and Alzheimer's disease (AD) by comparing vestibular parameters (vestibular function testing and clinical balance measures) between a group with mild cognitive impairment (MCI), AD, and healthy controls with age-normal cognition. Cross-sectional analysis of the GECkO study, an ongoing prospective single-center longitudinal cohort study. This study included 100 older adults (55 to 84 years). A total of 33 participants with MCI, 17 participants with AD, and 50 participants of age, sex, and hearing-matched healthy controls were included. Participants with AD demonstrated a delayed latency of the p13 component measured by cervical vestibular-evoked myogenic potentials (cVEMP) compared with healthy controls and participants with MCI. Other measures including n23 latency, presence of intact responses, rectified amplitude, mean rectified voltage (measured by cVEMP) and lateral vestibulo-ocular reflex gain (measured by video Head Impulse Test [vHIT]) did not differ between groups. The Timed Up and Go (TUG), Performance-Oriented Mobility Assessment-Balance subscale (POMA-B), and Functional Gait Assessment (FGA) differed significantly between the three groups. Here, more cognitively impaired groups were associated with worse clinical balance scores. Vestibular and balance deficits were more prevalent in groups with increasing cognitive decline. Regarding vestibular function testing, p13 latency as measured by cVEMP was delayed in participants with AD. Other cVEMP or vHIT measures did not differ between groups. All three clinical balance assessments (TUG, POMA-B, and FGA) resulted in worse scores along the AD continuum. Future research integrating vestibular parameters that add value (including otolith function testing, balance, and spatial navigation) is recommended to validate the association between vestibular function and cognition while avoiding redundant testing.

Electro-physiological Changes in the Central Nervous System by Visual Evoked Potential in Diabetic Patients.

Increasing sedentary lifestyle in today's world has increased the prevalence of Diabetes Mellitus. Loss of vision due to diabetic retinopathy is a major public health burden. Visual evoked potential identifies the neuronal degenerative changes in chronic metabolic disorders specially Diabetes Mellitus. The study aimed at evaluating changes in visual evoked potential waves in diabetic patients. This is a cross sectional comparative study consisting of 90 participants, out of which 60 were diabetic patients and 30 were non-diabetic control group. Among diabetic patients, 30 were without retinopathy, 10 with mild non-proliferative retinopathy, 10 with moderate non-proliferative retinopathy and 10 with severe non-proliferative retinopathy. Visually evoked potential latencies and amplitudes were compared among diabetic patients and the control group and also among individuals with different grades of retinopathy. Delay in P100 latency and decrease in its amplitude were statistically significant in diabetic patients. The changes in P100 latency, P100 amplitude and N75 latency were also significant in different grades of retinopathy. There are statistically significant changes in visually evoked potential in diabetes patients. Visual evoked potential is a useful, non-invasive investigation which can establish the central nervous system neuropathy in diabetes at an early stage of the disease. So Diabetic retinopathy can be prevented due to early detection of neuropathy by visual evoked potential test Keywords: Diabetes mellitus; diabetic retinopathy; visual evoked potential.

P300 event-related potentials in people with epilepsy: clinico-neurophysiologic study

BackgroundThere is increasing evidence that prolonged or recurrent seizures can cause or exacerbate cognitive impairment (CI) in memory, attention, orientation, and visuospatial and abstraction disabilities, all of which can jeopardize educational progress and achievement throughout life. The objectives of our study are to assess the cognitive functions in people with epilepsy (PwE) using P300 event-related potentials (ERPs), and correlate each P300 components with six explanatory variables (epilepsy type, seizure type, NHS3 score- seizure severity, disease duration, age at first seizure, and the number of anticonvulsant medications).MethodsOne hundred and two PwE [52 with focal epilepsy and 50 with generalized epilepsy, as classified by the International League Against Epilepsy in 2017]. They underwent electroencephalography (EEG) and P300. The Montreal Cognitive Assessment (MoCA) scale was used to assess baseline cognitive functions.ResultsEpileptic patients showed significant latency prolongation and amplitude reduction of P300 as compared to non-epileptic population. Longer P300 latency and lower amplitude were seen in patients with abnormal EEG records. P300 latency was longer in patients using poly-therapy. P300 components correlated well with age at presentation and disease duration but not with NHS3. According to epilepsy type, 50.98% of PwE had focal epilepsy and 49.02% had generalized epilepsy, 85.29% of them had abnormal EEG recording. Considering seizure type, 47.06% had a generalized tonic–clonic seizure, 38.24% had a focal to bilateral tonic–clonic seizure, 20.59% had a myoclonic seizure, 12.75% had a focal with impaired awareness seizure, 3.92% had a focal aware seizure, and 2.94% had an absence seizure. Seventy-seven PwE had one type of seizure, while 25 had more than one type of seizure. The NHS3 score was higher in those with a single seizure type than in those with multiple seizure types.ConclusionAll seizure types had an abnormal P300 component, indicating cognitive function deficits. P300 may be a promising objective method for assessing cognitive function in PwE. The number of antiepileptic drugs used, the presence of EEG abnormalities, the age at presentation, and the duration of the disease are the factors that best correlate with cognitive impairment (CI).

Retinal structure and visual pathway function at school age in children born extremely preterm: a population-based study

BackgroundChildren born extremely preterm (gestational age < 28 weeks) show reduced visual function even without any cerebral or ophthalmological neonatal diagnosis. In this study, we aimed to assess the retinal structure with optical coherence tomography (OCT) and visual function with pattern-reversal visual evoked potentials (PR-VEPs) in a geographically defined population-based cohort of school-aged children born extremely preterm. Moreover, we aimed to explore the association between measures of retinal structure and visual pathway function in this cohort.MethodsAll children born extremely preterm from 2006–2011 (n = 65) in Central Norway were invited to participate. Thirty-six children (55%) with a median age of 13 years (range = 10–16) were examined with OCT, OCT-angiography (OCT-A), and PR-VEPs. The foveal avascular zone (FAZ) and circularity, central macular vascular density, and flow were measured on OCT-A images. Central retinal thickness, circumpapillary retinal nerve fibre layer (RNFL) and inner plexiform ganglion cell layer (IPGCL) thickness were measured on OCT images. The N70-P100 peak-to-peak amplitude and N70 and P100 latencies were assessed from PR-VEPs.ResultsParticipants displayed abnormal retinal structure and P100 latencies (≥ 2 SD) compared to reference populations. Moreover, there was a negative correlation between P100 latency in large checks and RNFL (r = -.54, p = .003) and IPGCL (r = -.41, p = .003) thickness. The FAZ was smaller (p = .003), macular vascular density (p = .006) and flow were higher (p = .004), and RNFL (p = .006) and IPGCL (p = .014) were thinner in participants with ROP (n = 7).ConclusionChildren born extremely preterm without preterm brain injury sequelae have signs of persistent immaturity of retinal vasculature and neuroretinal layers. Thinner neuroretinal layers are associated with delayed P100 latency, prompting further exploration of the visual pathway development in preterms.

A prospective study of the effect of functional endoscopic sinus surgery on the recovery of olfactory function in patients with chronic rhinosinusitis with nasal polyposis

Objective:To investigate the efficacy of functional endoscopic sinus surgery（FESS） in the treatment of olfactory dysfunction in patients with chronic rhinosinusitis with nasal polyps （CRSwNP） , at the same time, it provides an evidence for the prognosis evaluation of olfaction and the clinical application of oERPs to evaluate the plasticity of olfaction cortex. Methods:From October 2021 to October 2022, 45 patients with CRSwNP who underwent FESS nine-step standardized treatment in our department were recruited as the research subjects, divided into 22 patients with eosinophilic CRSwNP（ECRS）and 23 patients with non-eosinophilic CRSwNP（nECRS）. VAS-olfactory dysfunction （VAS-OD） score, SNOT-22 olfactory score, Sniffin' Sticks test and oERPs collection and processing were performed before the operation. All items were evaluated again 3 months after the operation. Results:VAS-OD and SNOT-22 olfactory score were significantly lower in all CRSwNP patients after the operation than those before the operation[F（1, 43） =357.429, P<0.001; F（1, 43） =185.657, P<0.001], the scores of T, D, I and TDI scores in Sniffin' Sticks test were significantly higher than those before the operation[F（1, 43） =126.302, P<0.001; F（1, 43） =311.301, P<0.001; F（1, 43） =131.401, P<0.001; F（1, 43） =295.885, P<0.001]; The decrease of VAS-OD and SNOT-22 olfactory score in the ECRS group was smaller than that in the nECRS group[F（1, 43） =4.825, P=0.033; F（1, 43） =9.916, P=0.003], T, D and TDI scores were significantly lower in nECRS group than those in nECRS group[F（1, 43） =6.719, P=0.013; F（1, 43） =4.890, P=0.032; F（1, 43） =4.469, P=0.040]; There was a positive correlation between preoperative eosinophil-to-lymphocyte ratio（ELR） and SNOT-22 olfactory score and how much it changes（r=0.455, P=0.002; r=-0.414, P=0.005）, a negative correlation between T, TDI score and how much they change respectively（r=-0.431, P=0.003; r=-0.385, P=0.009; r=-0.383, P=0.010; r=-0.316, P=0.035）. The latency of P3 was significantly shorter after operation than that before operation in all CRSwNP patients[F（1, 14） =24.840, P<0.001], however, the amplitude has no significant surgical effect. Conclusion:FESS could significantly improve the olfactory function of CRSwNP patients, while changes in plasticity may occur in the olfactory cortex. In addition, the preoperative peripheral blood eosinophil granulocyte level can predict the postoperative olfactory improvement.

Efficacy of ozone therapy on visual evoked potentials in diabetic patients

BackgroundThe involvement of the central nervous system is a frequent yet underestimated complication of diabetes mellitus. Visual evoked potentials (VEP) are a simple, sensitive, and noninvasive method for detecting early alterations in central optic pathways. The objective of this paralleled randomized controlled trial was to evaluate the impact of ozone therapy on visual pathways in diabetic patients.MethodsSixty patients with type 2 diabetes visiting clinics of Baqiyatallah university in Tehran (Iran) hospital were randomly assigned to two experimental groups: Group 1 (N = 30) undergoing a cycle of 20 sessions of systemic oxygen-ozone therapy in addition to standard therapy for metabolic control; Group 2 (N = 30)—serving as control—receiving only standard therapy against diabetes. The primary study endpoints were two VEP parameters; P100 wave latency and P100 amplitude at 3 months. Moreover, HbA1c levels were measured before the start of treatment and three months later as secondary study endpoint.ResultsAll 60 patients completed the clinical trial. P100 latency significantly reduced at 3 months since baseline. No correlation was found between repeated measures of P100 wave latency and HbA1c (Pearson’s r = 0.169, p = 0.291). There was no significant difference between baseline values and repeated measures of P100 wave amplitude over time in either group. No adverse effects were recorded.ConclusionsOzone therapy improved the conduction of impulses in optic pathways of diabetic patients. The improved glycemic control following ozone therpay may not fully explain the reduction of P100 wave latency though; other mechanistic effects of ozone may be involved.

Altered Auditory and Visual Evoked Potentials following Single and Repeated Low-Velocity Head Rotations in 4-Week-Old Swine.

Auditory and visually evoked potentials (EP) have the ability to monitor cognitive changes after concussion. In the literature, decreases in EP are commonly reported; however, a subset of studies shows increased cortical activity after injury. We studied auditory and visual EP in 4-week-old female Yorkshire piglets (N = 35) divided into anesthetized sham, and animals subject to single (sRNR) and repeated (rRNR) rapid non-impact head rotations (RNR) in the sagittal direction. Two-tone auditory oddball tasks and a simple white-light visual stimulus were evaluated in piglets pre-injury, and at days 1, 4- and 7 post injury using a 32-electrode net. Traditional EP indices (N1, P2 amplitudes and latencies) were extracted, and a piglet model was used to source-localize the data to estimate brain regions related to auditory and visual processing. In comparison to each group's pre-injury baselines, auditory Eps and brain activity (but not visual activity) were decreased in sham. In contrast, sRNR had increases in N1 and P2 amplitudes from both stimuli. The rRNR group had decreased visual N1 amplitudes but faster visual P2 latencies. Auditory and visual EPs have different change trajectories after sRNR and rRNR, suggesting that injury biomechanics are an important factor to delineate neurofunctional deficits after concussion.

Impact of Long-Term Shaolin Zen Meditation on Emotional Processing in Aging: A Visual ERP Study.

The aging process is always accompanied by a decline in cognitive and emotional functions. Although previous studies have identified the positive effects of different meditative practices on emotional and cognitive functions, few studies have investigated the most primitive Chinese meditation-Shaolin Zen meditation. In particular, data are extremely limited regarding the brain mechanism of the effects of Shaolin Zen meditation on cognitive and emotional functions during aging. The current study aimed to explore the effects of long-term Shaolin Zen meditation practice on event-related potentials (ERPs) during facial emotion recognition in aging. ERPs were recorded from 16 monks with long-term meditation experience and 20 controls without meditation experience. The significant age-related degenerative changes in the early ERP components did not present in the meditators but only in the controls without meditation experience. Additionally, we found no group differences in the late P3 component. These findings suggest that long-term Shaolin Zen meditation practice can counteract the age-related cognitive decline in the "down-top" automatic processing of emotional stimuli.

A-46 MMA Athletes Demonstrate Different Brain Vital Sign Profiles Compared to Matched Controls at “Baseline”

Abstract Purpose We compared objective brain vital sign metrics derived from event-related potentials (ERPs) of mixed martial arts (MMA) athletes and matched control participants. Methods We recorded 101 successful EEG scans from 12 MMA athletes (24.8 ± 2.6 yr) and 18 matched control participants (26.5±3.5 yr). For this analysis, only “baseline” scans were considered (n=30). “Baseline” was at least 90 days from a previous fight and 90 days (MMA) or 1 year (control) following medical clearance from a previously diagnosed concussion. We derived objective, clinical metrics (brain vital signs) from ERPs for auditory sensation (N100), basic attention (P300), and cognitive processing (N400) evoked while participants listen to a 6-minute auditory stimulus sequence. EEG data were processed using standard methods. N100, P300, and N400 amplitudes and latencies were manually identified on evoked potential waveforms by a blinded reviewer. Differences between groups at the waveform level were evaluated with a mass-univariate analysis using non-parametric resampling. Brain vital signs were compared across groups with a Kruskal-Wallis H-test for independent samples, with FDR correction for multiple comparisons. Results Mass-univariate waveform analyses showed significant differences (P &amp;lt; 0.05) between MMA athletes and controls in both P300 and N400 ERPs. The Kruskal-Wallis test identified a significant difference in N400 amplitude (H=7.04, P=.008, Padj=.047) between MMA athletes and controls. Conclusions MMA athletes demonstrate significant differences in “baseline” brain vital signs compared to controls, indicating that exposure to repetitive head impacts in MMA may be associated with subconcussive changes in brain function.

Defect of the Endogenous Inhibitory Pain System in Idiopathic Restless Legs Syndrome: A Laser Evoked Potentials Study.

Restless legs syndrome (RLS) is a complex sensorimotor disorder. Symptoms worsen toward evening and at rest and are temporarily relieved by movement. Symptoms are perceived as painful in up to 45% of cases, and nociception system may be involved. To assess the descending diffuse noxious inhibitory control in RLS patients. Twenty-one RLS patients and twenty age and sex-matched healthy controls (HC) underwent a conditioned pain modulation protocol. Cutaneous heat stimuli were delivered via laser evoked potentials (LEPs) on the dorsum of the right hand (UL) and foot (LL). N2 and P2 latencies, N2/P2 amplitude and pain ratings (NRS) were recorded before (baseline), during, and after a heterotopic noxious conditioning stimulation (HNCS) application. The baseline/HNCS ratio was calculated for both UL and LL. N2 and P2 latencies did not vary between groups at each condition and limbs. Both groups showed a physiological N2/P2 amplitude and NRS reduction during the HNCS condition in UL and LL in comparison to baseline and post conditions (all, P < 0.003). Between-groups comparisons revealed a significant lower amplitude reduction in RLS at the N2/P2 amplitude during the HNCS condition only for LL (RLS, 13.6 μV; HC, 10.1 μV; P = 0.004). Such result was confirmed by the significant difference at the ratio (RLS, 69%, HC, 52.5%; P = 0.038). The lower physiological reduction during the HNCS condition at LL in RLS patients suggests a defect in the endogenous inhibitory pain system. Further studies should clarify the causal link of this finding, also investigating the circadian modulation of this paradigm. © 2023 International Parkinson and Movement Disorder Society.

Evaluation of retinal structure and function in prediabetes

PurposeAlterations in retinal structure and function have been well documented in type 2 diabetes (T2DM). However, few studies have evaluated the eye in prediabetes (preDM), a precursor to T2DM. It is unknown which retinal deficits, if any, occur before T2DM diagnosis. This study evaluates retinal structure via optical coherence tomography (OCT) and retinal function via multifocal electroretinogram (mfERG) N1 and P1 in those with PreDM. The goal is to evaluate associations between structure and function across glucose dysfunction. Methods85 subjects (aged 28–69yrs) were tested with VERIS mfERG and Heidelberg Spectralis OCT. Demographic and health information was collected. Subjects were grouped by HbA1c: 33 controls (HbA1c <5.7%), 31 with preDM (HbA1c 5.7–6.4%), and 21 with T2DM (HbA1c >6.4% at the time of testing or diagnosed by physician) and mild or no retinopathy. mfERG N1 and P1 latency and amplitude were measured for the right eye in the foveal hexagon (central 2.4°). Average macular thickness was also measured over the central 3.3°. Groups were compared with ANOVA and corrected t-tests. Models of these associations with diabetes diagnosis (in groups above) were created with backward multivariate regression. ResultsThe T2DM group was exceptionally well-controlled with an HbA1c of 7.0% ± 0.68 but also had elevated systolic blood pressure compared to other groups (P<0.01). The age of the control group was younger (P<0.01), so other testing was age controlled. There was a borderline but statistically significant difference in P1 between the control group and both the preDM and T2DM groups after Bonferroni corrections (P<0.03). There was also a difference in N1 latency between the control and other groups (P<0.001). A multivariate model demonstrated a significant relationship between T2DM/PreDM diagnosis and delayed N1 latency, reduced foveal thickness, and age. ConclusionsStructure and function together can provide an associative model of preDM or T2DM changes for patients. Based on this multivariate model, N1 is strongly associated with preDM and T2DM. N1 findings and decreasing foveal thickness are additive and can together inform ocular health related to preDM. Future longitudinal studies are needed to understand changes in function and structure in preDM and T2DM.

The P300 Auditory Evoked Potential: A Physiological Measure of the Engagement of Cognitive Systems Contributing to Listening Effort?

This study aimed to explore the potential of the P300 (P3b) as a physiological measure of the engagement of cognitive systems contributing to listening effort. Nineteen right-handed young adults (mean age: 24.79 years) and 20 right-handed older adults (mean age: 58.90 years) with age-appropriate hearing were included. The P300 was recorded at Fz, Cz, and Pz using a two-stimulus oddball paradigm with the Flemish monosyllabic numbers "one" and "three" as standard and deviant stimuli, respectively. This oddball paradigm was conducted in three listening conditions, varying in listening demand: one quiet and two noisy listening conditions (+4 and -2 dB signal to noise ratio [SNR]). At each listening condition, physiological, behavioral, and subjective tests of listening effort were administered. P300 amplitude and latency served as a potential physiological measure of the engagement of cognitive systems contributing to listening effort. In addition, the mean reaction time to respond to the deviant stimuli was used as a behavioral listening effort measurement. Last, subjective listening effort was administered through a visual analog scale. To assess the effects of listening condition and age group on each of these measures, linear mixed models were conducted. Correlation coefficients were calculated to determine the relationship between the physiological, behavioral, and subjective measures. P300 amplitude and latency, mean reaction time, and subjective scores significantly increased as the listening condition became more taxing. Moreover, a significant group effect was found for all physiological, behavioral, and subjective measures, favoring young adults. Last, no clear relationships between the physiological, behavioral, and subjective measures were found. The P300 was considered a physiological measure of the engagement of cognitive systems contributing to listening effort. Because advancing age is associated with hearing loss and cognitive decline, more research is needed on the effects of all these variables on the P300 to further explore its usefulness as a listening effort measurement for research and clinical purposes.

CERVICAL VESTIBULAR EVOKED MYOGENIC POTENTIALS IN PATIENTS WITHTYPE IIDIABETES MELLITUS

Introduction:Vestibular impairment has been demonstrated in patients with diabetes mellitus. Vestibular evoked myogenic potential (VEMP) is a short latency electromyographic response to sound or vibration stimuli that may reflect otolith organ or related reflex functions. cVEMPs are summation responses recorded from the contracted sternocleidomastoid inresponse to synchronized acoustic stimulation of the ipsilateral ear/saccule.In diabetic patients. Objective: Here, we asses prevalence of vestibular dysfunction by measuring cVEMP findings in patients with diabetes mellitus typeII. Methods: This study was carried out on two groups of subjects including 20 adult subjects with diabetes mellitustypeIIand 20 adult subjectsnon-diabetics, both group their aged ranged from 20-60 years. Results:showed statistically significant difference in cVEMP between diabetes mellitus type 2 control group with increase in latencies of P1 and N1 and decrease in amplitude. Conclusion: In diabetic individuals who are asymptomatic and never complained of vestibular dysfunction, cVEMPsis able to identify these patients.

Visual evoked potentials waveform analysis to measure intracortical damage in a preclinical model of multiple sclerosis.

Visual evoked potentials (VEPs) are a non-invasive technique routinely used in clinical and preclinical practice. Discussion about inclusion of VEPs in McDonald criteria, used for Multiple Sclerosis (MS) diagnosis, increased the importance of VEP in MS preclinical models. While the interpretation of the N1 peak is recognized, less is known about the first and second positive VEP peaks, P1 and P2, and the implicit time of the different segments. Our hypothesis is that P2 latency delay describes intracortical neurophysiological dysfunction from the visual cortex to the other cortical areas. In this work, we analyzed VEP traces that were included in our two recently published papers on Experimental Autoimmune Encephalomyelitis (EAE) mouse model. Compared with these previous publications other VEP peaks, P1 and P2, and the implicit time of components P1-N1, N1-P2 and P1-P2, were analyzed in blind. Latencies of P2, P1-P2, P1-N1 and N1-P2 were increased in all EAE mice, including group without N1 latency change delay at early time points. In particular, at 7 dpi the P2 latency delay change was significantly higher compared with N1 latency change delay. Moreover, new analysis of these VEP components under the influence of neurostimulation revealed a decrease in P2 delay in stimulated animals. P2 latency delay, P1-P2, P1-N1, and N1-P2 latency changes which reflect intracortical dysfunction, were consistently detected across all EAE groups before N1 change. Results underline the importance of analyzing all VEP components for a complete overview of the neurophysiological visual pathway dysfunction and treatment efficacy.

Does Inferior Oblique Muscle Overaction Affect Ocular Vestibular Evoked Myogenic Potentials?

Objectives: Inferior oblique muscle overaction (IOOA) is a common ocular motility disorder. Ocular Vestibular Evoked Myogenic Potentials (oVEMP) are tests that evaluate the reflex pathway between the utricular macula and the inferior oblique muscle to detect vestibular diseases. Our study is of great importance as it is the first study in the literature to evaluate the effect of inferior oblique muscle overaction on oVEMP parameters. Methods: Thirty-five patients with unilateral inferior oblique muscle overaction (IOOA group) and 18 healthy volunteers without any neurological or vestibulocochlear disease were included in this study. All patients and healthy volunteers were evaluated with oVEMP. Results: No statistically significant difference was found between the n1 latency, p1 latency, n1-p1 latency measurement values of the participants included in the study (p&gt;0,05). A statistically significant difference was found between the n1-p1 amplitude measurement values of the participants in patient groups (non-squint eyes, squint eyes) and control groups (p-value was 0.038). Conclusion: In IOOA patients, vestibulo-ocular reflex pathway may be affected, vestibular symptoms may develop thus o-VEMP responses may be affected. A careful anamnesis should be taken in IOOA patients, and it should be kept in mind that n1-p1 amplitudes and asymmetries may be significantly higher when o-VEMP is performed Keywords: o-VEMP, Strabismus, Inferior oblique muscle overaction, Balance, Vertigo