Visual P300 Latency Research Articles

Reliability of electroencephalogram indicator and event related potential in subacute stroke

Cognitive impairment is observed in 12% to 56% of stroke patients, and screening for cognitive impairment is often complex and time-consuming, with results dependent on patient compliance. Therefore, there is a need for an objective method to assess cognitive impairment regardless of patient compliance. Objective evaluation methods include electroencephalogram (EEG) and event-related potential (ERP). This study was conducted to assess intra-tester reliability of resting EEG-based spectral features and auditory/visual P300 latency/amplitude in patients with subacute ischemic stroke. Twenty patients with subacute ischemic stroke were included in the study. The resting EEG and P300 wave using an auditory and visual oddball paradigm were measured at baseline and once again in 24 hours. The following electrode positions (10-20 system) were constantly recorded: F3 (Frontal), Fz, F4, C3 (Central), Cz, C4, P3 (Parietal), Pz, P4. DAR (delta/alpha ratio) and BSI (brain symmetry index) were determined using EEG data. F3 and F4, C3 and C4 and P3 and P4 were switched according to the stroke side and classified as affected hemisphere (AH) and unaffected hemisphere (UH) after the evaluation. In ERP, the amplitude and latency of P300 were obtained. In reliability analysis of EEG-based spectral characteristics, significant reliability was observed for DAR (ICC = 0.447), BSldir (ICC = 0.713) and BSIdirtheta (ICC = 0.724) (Table 4). DAR was showed a poor ICC level, and BSIdir and BSIdirtheta had a moderate ICC level. Visual P300 latency showed excellent intraclass correlation coefficient (ICC) in several montages (PUH = 0.972, Pz = 0.945). In 6 montages, auditory P300 latency was reliable, while in 9 montages, visual P300 latency was reliable. In 4 montages, auditory P300 amplitude was reliable, while visual P300 amplitude was reliable in 7. The visual P300 was more reliable than the auditory P300. The ICC values for P300 latency were greater than those for amplitude. Therefore, when ERP is performed on subacute stroke patients, visual has higher reliability than auditory.

EEG-based P300 in mesial temporal lobe epilepsy and its correlation with cognitive functions: A case-control study

ObjectiveP300 is an event-related potential, being explored as an objective tool to assess cognition. This study aimed to investigate the characteristics of auditory and visual P300 in patients with TLE having unilateral HS using electroencephalography (EEG) and to study its correlation with cognition. MethodsThis is a cross-sectional case-control study, where P300 characteristics in thirty patients with unilateral hippocampal sclerosis with refractory epilepsy were compared with fifteen age-, gender-, and years of education-matched healthy controls (M: F-10:5, mean age-28 ± 4.76 years). Among patients, 15 belonged to the right HS group (M: F-9:6, age at onset-12.92 ± 10.22 years, duration of epilepsy-16.67 ± 9.38 years) and 15 to the left HS group (M: F-8:7, age at onset-10.62 ± 7.18 years, duration of epilepsy-15.53 ± 10.14 years). All subjects underwent EEG-based auditory and visual oddball tasks and cognitive assessment. The P300 latencies (in milliseconds) as well as amplitudes (in microvolts) were predicted in EEG and were correlated with cognitive scores. Source localization of P300 was performed with the CLARA algorithm. ResultsThe auditory P300 latencies in controls, right HS, and left HS were 323.93 ± 40.28, 351.06 ± 47.23, and 328.80 ± 36.03, respectively (p = 0.18) and its amplitudes were 2.3040 ± 1.46, 2.77 ± 1.19, and 2.68 ± 1.78, respectively (p = 0.48). Visual P300 latencies in controls, right HS, and left HS were 365.87 ± 47.37, 359.67 ± 64.45, and 376.00 ± 60.06, respectively (p = 0.51) and its amplitudes were 3.93 ± 2.28, 2.09 ± 1.45, and 3.56 ± 1.74, respectively (p = 0.014). Further, when compared to the control group the cognitive scores were lower in the patient group (p < 0.05). SignificanceIn comparison to the controls, patients with right HS recorded lesser amplitude on visual P300 and lower scores on cognitive tests. P300 and cognitive parameters exhibited varied relationship. P300 could be a complementary objective tool to assess cognition in patients with TLE.

Auditory and Visual P300 Responses in Early Cognitive Assessment of Children and Adolescents with Epilepsy.

ABSTRACTBackground:The event-related potential P300 has been suggested to be valuable in the assessment of cognitive dysfunctions. Not a great deal of neurophysiological assessment has been performed at early stages in patients with epilepsy involving visual and auditory P300 measures.Aims and Objectives:This study aimed to assess the cognitive status in patients with epilepsy earlier by visual and auditory P300 and to find their correlation with various risk factors.Materials and Methods:P300 was recorded in 60 children with epilepsy in the age-group of 5–18 years and 60 age- and sex-matched controls by a rare-frequent (oddball) paradigm. Mean auditory and visual P300 latencies and amplitudes were compared among patients with epilepsy and controls and among patients with generalized and focal epilepsy by unpaired t-test. Pearson’s correlation coefficient test was computed for studying the correlation between risk factors and P300 responses. A value of P < 0.05 was considered statistically significant.Results:Statistically significant delay in P300 latencies and reduction in amplitudes (both visual and auditory) was found in patients with epilepsy as compared to controls and also among patients with generalized and focal epilepsy. In generalized epilepsy, both visual and auditory P300 revealed significant delay, whereas only auditory P300 delay was found in focal form. No significant correlation was obtained with risk factors. No significant difference was found in P300 responses among patients with and without antiepileptic treatment.Conclusion:Visual and auditory P300 latencies have an important role in the evaluation of early cognitive dysfunctions in children with epilepsy. P300 potentials are not influenced by antiepileptic treatment, whereas the type of epilepsy alters them

Auditory and Visual Oddball Paradigm Evaluated Through P300 in Five Girls with Rett Syndrome

Few studies investigated information processing in genetic syndrome, such as Rett Syndrome, using ERPs. The main aim of this study was to examine visual and auditory processes in children with Rett Syndrome through the oddball paradigm. Five children with a diagnosis of Rett Syndrome, ranging from 7 to 11 age (M = 8, 8 years, SD = 4,36), matched for sex, age and mental age to typically developing children. Event-related potentials were recorded to an auditory and visual oddball task in all participants. The results showed that both auditory and visual P300 latencies were longer in the Rett group than the typically developing group. These findings suggest that children with Rett Syndrome need more time to process information.

Insights into cognitive decline in spinocerebellar Ataxia type 2: a P300 event-related brain potential study

BackgroundCognitive decline is a common non-motor feature characterizing Spinocerebellar Ataxia type 2 (SCA2) during the prodromal stage, nevertheless a reduced number of surrogate biomarkers of these alterations have been described.ObjectiveTo provide insights into cognitive dysfunction in SCA2 patients using P300 event-related potentials (ERP) and to evaluate these measures as biomarkers of the disease.MethodsA cross-sectional study was performed with 30 SCA2 patients, 20 preclinical carriers and 33 healthy controls, who underwent visual, auditory P300 ERPs, and neurological examinations and ataxia scoring.ResultsSCA2 patients showed significant increase in P300 latencies and decrease of P300 amplitudes for visual and auditory stimuli, whereas preclinical carriers exhibit a less severe, but significant prolongation of P300 latencies. Multiple regression analyses disclosed a significant effect of SARA score on visual P300 abnormalities in patients as well as of the time to ataxia onset on visual P300 latencies in preclinical carriers.ConclusionsThis paper demonstrated the role of P300 ERP for the study of attentional, discriminative and working memory abnormalities in SCA2 patients and for the search of surrogate biomarkers from prodromal to the symptomatic stages. Moreover, our findings provide psychophysiological evidences supporting the cerebellar involvement in cognitive processes and allows us to identify promising outcome measures for future trials focusing on cognitive dysfunction.

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEAS) and emotional processing — A behavioral and electrophysiological approach

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEAS) may have mood enhancement effects: higher DHEAS concentrations and DHEA/cortisol ratio have been related to lower depression scores and controlled trials of DHEA administration have reported significant antidepressant effects. The balance between DHEAS and DHEA has been suggested to influence brain functioning. We explored DHEAS, DHEA, cortisol, DHEA/cortisol and DHEAS/DHEA ratios relations to the processing of negative emotional stimuli at behavioral and brain levels by recording the electroencephalogram of 21 young women while performing a visual task with implicit neutral or negative emotional content in an audio–visual oddball paradigm. For each condition, salivary DHEA, DHEAS and cortisol were measured before performing the task and at 30 and 60min intervals. DHEA increased after task performance, independent of the implicit emotional content. With implicit negative emotion, higher DHEAS/DHEA and DHEA/cortisol ratios before task performance were related to shorter visual P300 latencies suggesting faster brain processing under a negative emotional context. In addition, higher DHEAS/DHEA ratios were related to reduced visual P300 amplitudes, indicating less processing of the negative emotional stimuli. With this study, we could show that at the electrophysiological level, higher DHEAS/DHEA and DHEA/cortisol ratios were related to shorter stimulus evaluation times suggesting less interference of the implicit negative content of the stimuli with the task. Furthermore, higher DHEAS/DHEA ratios were related to reduced processing of negative emotional stimuli which may eventually constitute a protective mechanism against negative information overload.

The characteristics of visual P300 event-related potentials in children with mental retardation and the correlation with intelligent quotient

Objective To explore the characteristics of visual P300 event-related potentials (ERP) in children with mental retardation and evaluate the correlations between visual P300 in event-related potentials and intelligent quotient. Methods Thirty children with mental retardation were selected as the test group who were inpatients or saw a doctor in the Department of Rehabilitation of Hunan Children Hospital. At the same time, thirty normal children were selected as the control group who saw a doctor in the Department of Child Healthcare of Hunan Children Hospital. Two groups had no statistically significant difference in sex and age (P>0.05) and were comparable. All children were administered with the Wechsler intelligence test in the Department of Child Healthcare and the visual event-related potential test in the Department of Rehabilitation. The results of the visual P300 latency and amplitude were analyzed. Another, the relevance between intelligent quotient (IQ) and P300 latency and amplitude were also compared by statistics. Results Compared to the control group, the visual P300 latency in children with mental retardation (MR) was apparently longer and the amplitude decreased significantly in children with MR, with a statistically significant difference between two groups(P<0.05). P300 latency in MR expected negative correlation with intelligent quotient and the amplitude in MR expected no correlation with intelligent quotient. Conclusions P300 latency and amplitude of ERP could objectively reflect cognitive function in children with MR, could be regarded as one of the objective measurement in the evaluation of cognitive function in children with MR. It can be used as an objective electrophysiological index for assisting in the diagnosis of mental retardation of children in clinic. Key words: Mental retardation/PP; Event-related potentials, P300; Intelligence; Evoked potentials, visual

Effect of different doses of prophylactic cranial irradiation in childhood lymphoblastic leukemia on CNS relapse, late cognitive decline and learning disabilities

Backgroud: To evaluate the doses of prophylactic cranial irradiation (1800cGy/1200cGy) as regards central nervous system (CNS) relapse, late cognitive abilities and learning disabilities. Subjects and Methods: 42 patients treated for acute lymphoblastic leukemia (ALL) and categorized to be at high risk of relapse were assessed. None of the patients had CNS disease at diagnosis. 28 patients received 1800 cGy prophylactic cranial irradiation and 14 received 1200 cGy. All patients received intrathecal methotrexate as well as high dose methotrexate. Visual and auditory P300 studies were carried out after a mean of 4.6 years follow-up. Visual and auditory evoked potentials were done to assess visual and auditory functions at lower brain levels. Selected subscales of Wechsler Intelligence scale for children namely; similarities, vocabulary, picture completion, design, total performance, total verbal and total IQ and arithmetic abilities were applied to both subgroups. Results: There was no difference in CNS relapse between the two groups (p=0.845). The 1800cGy group showed a significant delay of the visual P300 latency and reduction of the amplitude and delay of auditory P300 latency (p<0.001). In the 1200cGy group only the visual P300 was significantly abnormal (p< 0.001). Psychometric studies showed no significant differences between the 1800cGy /1200cGy subgroups in total IQ and arithmetic abilities. The 1800cGy subgroup showed significantly abnormalities in some subscales namely in similarities, total performance and picture. Conclusions: Prophylactic whole brain irradiation if given for high risk ALL the recommended dose is 1200cGy due to the lower long term cognitive effect and no difference in the CNS relapse.

A comparative study on long-term evoked auditory and visual potential responses between Schizophrenic patients and normal subjects

BackgroundThe electrical signals measuring method is recommended to examine the relationship between neuronal activities and measure with the event related potentials (ERPs) during an auditory and a visual oddball paradigm between schizophrenic patients and normal subjects. The aim of this study is to discriminate the activation changes of different stimulations evoked by auditory and visual ERPs between schizophrenic patients and normal subjects.MethodsForty-three schizophrenic patients were selected as experimental group patients, and 40 healthy subjects with no medical history of any kind of psychiatric diseases, neurological diseases, or drug abuse, were recruited as a control group. Auditory and visual ERPs were studied with an oddball paradigm. All the data were analyzed by SPSS statistical software version 10.0.ResultsIn the comparative study of auditory and visual ERPs between the schizophrenic and healthy patients, P300 amplitude at Fz, Cz, and Pz and N100, N200, and P200 latencies at Fz, Cz, and Pz were shown significantly different. The cognitive processing reflected by the auditory and the visual P300 latency to rare target stimuli was probably an indicator of the cognitive function in schizophrenic patients.ConclusionsThis study shows the methodology of application of auditory and visual oddball paradigm identifies task-relevant sources of activity and allows separation of regions that have different response properties. Our study indicates that there may be slowness of automatic cognitive processing and controlled cognitive processing of visual ERPs compared to auditory ERPs in schizophrenic patients. The activation changes of visual evoked potentials are more regionally specific than auditory evoked potentials.

P300 and treatment effect of modafinil on fatigue in multiple sclerosis

To evaluate the value of visual and auditory P300 for predicting the response of multiple sclerosis-related fatigue to modafinil treatment, 33 patients were treated with 100 mg modafinil once daily for 4 weeks, following a 4-week baseline phase and an optional 8-week extension phase. The main clinical outcome parameter was a decrease in the fatigue visual analogue score (VAS) before and after 4 weeks of treatment. Patients with shorter auditory P300 latency at baseline were more likely to benefit from modafinil treatment. Auditory P300 latency predicted treatment response with a specificity of 76% and a sensitivity of 75% at a cut-off latency of 350 ms. Visual P300 latency could not be used to predict treatment response. Baseline auditory P300 latency predicted treatment response, whereas visual P300 latency did not. Clinical improvement did not correlate with changes in either visual or auditory P300.

Auditory and Visual P300 Evoked Potentials Do Not Predict Response to Valproate Treatment of Aggression in Patients with Borderline and Antisocial Personality Disorders

In this study of patients with borderline personality disorder (BPD) or antisocial personality disorder (ASPD) hospitalized because of aggressive behavior, auditory and visual P300 evoked potentials were obtained prior to treatment with valproate. Eight ASPD patients (8 males, 0 females) and 11 BPD patients (2 males, 9 females) showed improvement, while in 7 patients with ASPD (7 males, 0 females) and 10 patients with BPD (2 males, 8 females), aggression was not improved. Differences in auditory and visual P300 latencies and amplitudes were not significant for either diagnosis, or for both diagnoses combined. These findings suggest that auditory or visual P300 evoked potentials may not be useful for predicting response of aggressive behavior to valproate treatment in patients with BPD or ASPD.

Longitudinal study of cognitive dysfunction in multiple sclerosis: neuropsychological, neuroradiological, and neurophysiological findings

Objective: (1) To assess cognitive function and cerebral magnetic resonance imaging (MRI) involvement in relapsing-remitting multiple sclerosis; (2) to monitor disease evolution, cognitive dysfunction, and cerebral lesion burden over time...

Visual and auditory event-related potentials in sporadic amyotrophic lateral sclerosis.

To investigate the relationship between amyotrophic lateral sclerosis (ALS) and cognitive function by means of oddball event-related potentials (ERPs) and to determine the usefulness of this methodology in the cognitive status assessment of physically disabled patients. Visual and auditory oddball ERPs were recorded in 16 consecutive sporadic ALS patients. A comprehensive battery of neuropsychological (NP) tests assessed intelligence, executive functions, attention, memory, word fluency, visuo-motor and visual-constructive skills. All patients performed visual and auditory ERPs and 75% of cases showed abnormal N200 and/or P300 waves. Ten patients (62.5%) carried out the entire psychometric evaluation with significant impairment on tests of executive function and attention. A significant correlation between delayed visual (P<0.04) and auditory (P<0.04) P300 latency and impaired NP tests was found. In agreement with literature data, our findings confirm the hypothesis of cognitive impairment in ALS patients especially on attention and executive functions suggesting a more extensive degeneration beyond the motor areas. ALS causes severe physical disabilities and such a condition may interfere with NP testing. Thus, the P300 seems to be a useful tool for the assessment of cognition and attention when severe physical deficits are present.

Effect of interstimulus interval on visual P300 in Parkinson’s disease

OBJECTIVEVisual event related potentials (ERPs) were studied during an oddball paradigm, to testify whether cognitive slowing in Parkinson’s disease exists and to investigate whether cognitive information processing can be influenced...

The Effects of Donepezil on the P300 Auditory and Visual Cognitive Evoked Potentials of Patients With Alzheimer's Disease

Donepezil is a cholinesterase inhibitor used for the treatment of patients with mild to moderately severe Alzheimer's disease (AD). The purpose of this study was to determine the effect of treatment with donepezil 5 mg qd on cognitive evoked potentials (EPs) of patients with AD. Although treatment with donepezil did not normalize EP latencies, treatment was associated with a significant decrease in the auditory P300 latency (mean latency pretreatment=401. 5 msec; posttreatment=392.7 msec.; P=0.04), and the visual P300 latency (mean latency pretreatment=605.7 msec; posttreatment=580.3 msec; P=0.04). Treatment with donepezil had no discernible effect on auditory or visual P300 EP amplitudes.

Effects of aerobic exercise and gender on visual and auditory P300, reaction time, and accuracy.

Visual and auditory reaction times (RTs) have been reported to decrease during moderate aerobic exercise, and this has been interpreted as reflecting an exercise-induced activation (EIA) of cognitive information processing. In the present study we examined changes in several independent measures of information processing (RT, accuracy, P300 latency and amplitude) during exercise, and their relationship to visual or auditory modalities and to gender. P300 latencies offer independent measures of cognitive speed that are unrelated to motor output, and P300 amplitudes have been used as measures of attentional allocation. Twenty-four healthy college students [mean (SD) age 20 (2) years] performed auditory and visual "oddball" tasks during resting baseline, aerobic exercise, and recovery periods. Consistent with previous studies, both visual and auditory RTs during exercise were significantly shortened compared to control and recovery periods (which did not differ from each other). We now report that, paralleling the RT changes, auditory and visual P300 latencies decreased during exercise, indicating the occurrence of faster cognitive information processing in both sensory modalities. However, both auditory and visual P300 amplitudes decreased during exercise, suggesting diminished attentional resource allocation. In addition, error rates increased during exercise. Taken together, these results suggest that the enhancement of cognitive information processing speed during moderate aerobic exercise, although operating across genders and sensory modalities, is not a global facilitation of cognition, but is accompanied by decreased attention and increased errors.

Auditory and visual P300 cognitive evoked responses in patients with COPD: relationship to degree of pulmonary impairment.

Twenty-two subjects with documented COPD and no other significant illnesses were studied to assess the effect of varying degrees of COPD on cognitive P300 auditory and visual evoked potentials. The severity of COPD was determined by spirometry with assessment of FEV1, FVC, and FEV1/FVC. Auditory P300 latency was significantly correlated with the FEV1/FVC ratio (Pearson Product Moment correlations r = -.56, N = 20, probability level = 0.1), indicating that increasingly severe airflow impairment is associated with longer auditory P300 latencies. There was no significant association of FEV1/FVC with visual P300 latency or with auditory or visual evoked potential amplitude measures. Progressive impairment of the auditory P300 evoked potential latency occurs with increasing severity of COPD. This impairment is present even in patients with mild COPD, suggesting some degree of accompanying cognitive decline early in the course of COPD with worsening as the disease progresses.

Visual P300 latency predicts treatment response to modafinil in patients with narcolepsy

Objective: To evaluate the hypothesis that visual P300 latency (VL) predicts treatment response to modafinil (a new wake-promoting agent) in patients with narcolepsy.Methods: Design: Comparison of responders and non-responders in a double-blind randomized placebo-controlled trial. Setting: Private practice referral sleep disorders center. Patients: Twenty one patients with narcolepsy (ages 17–65 years). Interventions: Auditory and visual P300 testing using 31 evenly spaced scalp electrodes, and baseline polysomnograms and objective and subjective tests of daytime sleepiness, followed by modafinil treatment for 9 weeks. Polysomnograms and tests of sleepiness were then repeated. Main outcome measure: The Maintenance of Wakefulness Test (MWT). Response defined as a final MWT>7.3min (normative sample mean−3 SD), plus an increase >1SD based on normative sample (3.6 min) over baseline MWT.Results: Non-responders had longer age-adjusted 31-electrode mean VL (448.4 ms vs. 410.8 ms, P=0.024), and larger auditory P300 amplitude, with no topographical P300 differences. Non-responders and responders did not differ on any other baseline clinical variable. Using a cut-off of 0.5 SE from normal regression constant, shorter age-adjusted VL predicted modafinil response, with specificity of 0.71 and sensitivity of 0.86.Conclusions: VL predicts treatment response to modafinil in patients with narcolepsy.

Longer Auditory and Visual P300 Latencies in Patients with Narcolepsy

To compare auditory and visual P300 amplitude and latency magnitudes and topographies in patients with narcolepsy and normal subjects, 20 patients with polysomnographically-confirmed narcolepsy and 40 normal subjects were administered auditory and visual P300 testing using 31 evenly spaced scalp electrodes. Patients with narcolepsy were then administered baseline polysomnograms and objective (MSLT, Maintenance of Wakefulness Test or MWT) and subjective tests (Epworth Sleepiness Scale, Clinical Global Impression) of daytime sleepiness. Patients had longer 31-electrode mean age-adjusted auditory P300 latencies (406.0 +/- 27.8 vs. 385.7 +/- 28.9 ms, p = 0.012) and visual P300 latencies (427.3 +/- 29.0 vs. 411.4 +/- 27.7 ms., p = 0.044) than 40 normal subjects in the same age range. Age-adjusted auditory P300 latency was correlated with MWT (r = -0.49, p = 0.028), but not with any other clinical variable or measure of sleepiness. Age-adjusted visual P300 latency was not correlated with any clinical variable or measure of sleepiness. Patients with narcolepsy had longer auditory and visual P300 latencies than normal subjects.

Measurement of P300 and sleep characteristics in patients with hypersomnia: do P300 latencies, P300 amplitudes, and multiple sleep latency and maintenance of wakefulness tests measure different factors?

To explore further the relationship between ease of falling asleep, ability to maintain wakefulness, attention and information processing in sleep apnea and other sleep disorders, we conducted a thorough analysis of the similarities, differences and correlations between auditory and visual P300 amplitudes and latencies, and tests of sleepiness. The 283 consecutive patients presenting with hypersomnia were administered nocturnal polysomnography. Next day they underwent auditory and visual P300 recordings, Multiple Sleep Latency Test (MSLT) and Maintenance of Wakefulness Test (MWT). Correlation coefficients were calculated between auditory and visual P300 amplitudes and latencies, respiratory disturbance index (RDI), sleep efficiency, % stage 1, and the tests for sleepiness. Factor analysis was performed with data from P300 testing, MSLT and MWT. Auditory P300 amplitude was correlated with sleep efficiency. Auditory P300 latency was correlated with % stage 1, RDI, MSLT and MWT. Visual P300 latency was correlated with % stage 1, sleep efficiency and MWT. MSLT but not MWT was negatively correlated with sleep efficiency. Factor analysis suggests three factors: attention, information processing, and sleepiness. We conclude that P300 latencies and tests of sleepiness (MSLT and MWT) measure different abilities in patients with diagnosable disorders of daytime sleepiness.