A Preliminary Study of P200 in First-episode Patients, their Relatives and Healthy Controls: Search of New Endophenotypes

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
C. Silveira ◽  
F. Santos ◽  
F. Barbosa ◽  
A. Pedro ◽  
A. Palha ◽  
...  

Background/Objective:Despite the well established genetic basis of schizophrenia, the relationship between genes and the disorder itself is still elusive. Individual endophenotypes, which reduce the complexity of genetic analyses, allow statistical approaches with quantitative trait methodologies. P200 abnormalities of event-related potentials have been reported in schizophrenia with conflicting results. The present study aims to characterize the P200 in first-episode patients and to compare it with that of first-degree relatives and controls.Methods:ERPs were recorded at 19 sites with an auditory oddball for 21 first-episode patients with schizophrenia (mean age=25.14; SD=6.20), 41 of their first degree relatives (mean age=47.65; SD=15.53) and 19 healthy controls (mean age=26.32; SD=7.16). Potentials were averaged for frequent stimuli and P200 amplitude and latency measures were obtained.Results:Analysis of midline electrodes revealed significant group effects for P200 peak amplitudes (F(2, 78)=3.315, p=.042), but not for peak latencies. Post-hoc analyses revealed that patients with schizophrenia present significantly lower P200 amplitudes (M=2.466; SD=1.564) than controls (M=5.037; SD=2.500) at Pz (T(38)=3.851, p=.003). No other significant differences were found.Conclusion:The results obtained do not straight-forwardly support the P200 peak amplitude nor peak latency as an endophenotype of schizophrenia. However, the trends of our results may suggest that the P200 amplitudes of relatives may present intermediate values between healthy controls (with higher amplitudes) and patients (with lower amplitudes). Further statistical analyses will be required in order to disentangle the effects of possible confounding variables.

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
C. Silveira ◽  
F. Santos ◽  
F. Barbosa ◽  
A. Pedro ◽  
A. Palha ◽  
...  

Background/Objective:Despite the well established genetic basis of schizophrenia, the relationship between genes and the disorder itself is still elusive. Individual endophenotypes, which reduce the complexity of genetic analyses, allow statistical approaches with quantitative trait methodologies. P200 abnormalities of event-related potentials have been reported in schizophrenia with conflicting results. the present study aims to characterize the P200 in first-episode patients and to compare it with that of first-degree relatives and controls.Methods:ERPs were recorded at 19 sites with an auditory oddball for 21 first-episode patients with schizophrenia (mean age=25.14; SD=6.20), 41 of their first degree relatives (mean age=47.65; SD=15.53) and 19 healthy controls (mean age=26.32; SD=7.16). Potentials were averaged for frequent stimuli and P200 amplitude and latency measures were obtained.Results:Analysis of midline electrodes revealed significant group effects for P200 peak amplitudes (F(2, 78)=3.315, p=.042), but not for peak latencies. Post-hoc analyses revealed that patients with schizophrenia present significantly lower P200 amplitudes (M=2.466; SD=1.564) than controls (M=5.037; SD=2.500) at Pz (T(38)=3.851, p=.003). No other significant differences were found.Conclusion:The results obtained do not straight-forwardly support the P200 peak amplitude nor peak latency as an endophenotype of schizophrenia. However, the trends of our results may suggest that the P200 amplitudes of relatives may present intermediate values between healthy controls (with higher amplitudes) and patients (with lower amplitudes). Further statistical analyses will be required in order to disentangle the effects of possible confounding variables.


Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3918 ◽  
Author(s):  
Goded Shahaf ◽  
Pora Kuperman ◽  
Yuval Bloch ◽  
Shahak Yariv ◽  
Yelena Granovsky

Migraine attacks can cause significant discomfort and reduced functioning for days at a time, including the pre-ictal and post-ictal periods. During the inter-ictsal period, however, migraineurs seem to function normally. It is puzzling, therefore, that event-related potentials of migraine patients often differ in the asymptomatic and inter-ictal period. Part of the electrophysiological dynamics demonstrated in the migraine cycle are attention related. In this pilot study we evaluated an easy-to-use new marker, the Brain Engagement Index (BEI), for attention monitoring during the migraine cycle. We sampled 12 migraine patients for 20 days within one calendar month. Each session consisted of subjects’ reports of stress level and migraine-related symptoms, and a 5 min EEG recording, with a 2-electrode EEG device, during an auditory oddball task. The first minute of the EEG sample was analyzed. Repetitive samples were also obtained from 10 healthy controls. The brain engagement index increased significantly during the pre-ictal (p ≈ 0.001) and the ictal (p ≈ 0.020) periods compared with the inter-ictal period. No difference was observed between the pre-ictal and ictal periods. Control subjects demonstrated intermediate Brain Engagement Index values, that is, higher than inter-ictal, yet lower than pre-ictal. Our preliminary results demonstrate the potential advantage of the use of a simple EEG system for improved prediction of migraine attacks. Further study is required to evaluate the efficacy of the Brain Engagement Index in monitoring the migraine cycle and the possible effects of interventions.


2018 ◽  
Vol 49 (4) ◽  
pp. 238-247 ◽  
Author(s):  
Derek J. Fisher ◽  
Debra J. Campbell ◽  
Shelagh C. Abriel ◽  
Emma M. L. Ells ◽  
Erica D. Rudolph ◽  
...  

The mismatch negativity (MMN) is an EEG-derived event-related potential (ERP) elicited by any violation of a predicted auditory “rule,” regardless of whether one is attending to the stimuli and is thought to reflect updating of the stimulus context. Redirection of attention toward a rare, distracting stimulus event, however, can be measured by the subsequent P3a component of the P300. Chronic schizophrenia patients exhibit robust MMN deficits, as well as reductions in P3a amplitude. While, the substantial literature on the MMN in first-episode and early phase schizophrenia in this population reports reduced amplitudes, there also exist several contradictory studies. Conversely, P3a reduction in this population is relatively consistent, although the literature investigating this is small. The primary goal of this study was to contribute to our understanding of whether auditory change detection mechanisms are altered in early phase schizophrenia and, if so, under what conditions. Event-related potentials elicited by duration, frequency, gap, intensity, and location deviants (as elicited by the “optimal” multi-feature paradigm) were recorded in 14 early phase schizophrenia (EP) patients and 17 healthy controls (HCs). Electrical activity was recorded from 15 scalp electrodes. MMN/P3a amplitudes and latencies for each deviant were compared between groups and were correlated with clinical measures in EPs. There were no significant group differences for MMN amplitudes or latencies, though EPs did exhibit reduced P3a amplitudes to gap and duration deviants. Furthermore, PANSS (Positive and Negative Syndrome Scale) positive symptom scores were correlated with intensity MMN latencies and duration P3a amplitudes in EPs. These findings suggest that MMNs may not be as robustly reduced in early phase schizophrenia (relative to chronic illness), but that alterations may be more likely in patients with increased positive symptomatology. Furthermore, these findings offer further support to previous work suggesting that the understudied P3a may have good complementary utility as a marker of early cortical dysfunction in psychosis.


2018 ◽  
Vol 49 (5) ◽  
pp. 868-875 ◽  
Author(s):  
Caitlyn Kruiper ◽  
Birgitte Fagerlund ◽  
Mette Ø. Nielsen ◽  
Signe Düring ◽  
Maria H. Jensen ◽  
...  

AbstractBackgroundCognitive deficits are already present in early stages of schizophrenia. P3a and P3b event-related potentials (ERPs) are believed to underlie the processes of attention and working memory (WM), yet limited research has been performed on the associations between these parameters. Therefore, we explored possible associations between P3a/b amplitudes and cognition in a large cohort of antipsychotic-naïve, first-episode schizophrenia (AN-FES) patients and healthy controls (HC).MethodsSeventy-three AN-FES patients and 93 age- and gender-matched HC were assessed for their P3a/b amplitude with an auditory oddball paradigm. In addition, subjects performed several subtests from the Cambridge Neuropsychological Test Automated Battery (CANTAB).ResultsAN-FES patients had significantly reduced P3a/b amplitudes, as well as significantly lower scores on all cognitive tests compared with HC. Total group correlations revealed positive associations between P3b amplitude and WM and sustained attention and negative associations with all reaction time measures. These associations appeared mainly driven by AN-FES patients, where we found a similar pattern. No significant associations were found between P3b amplitude and cognitive measures in our HC. P3a amplitude did not correlate significantly with any cognitive measures in either group, nor when combined.ConclusionsOur results provide further evidence for P3a/b amplitude deficits and cognitive deficits in AN-FES patients, which are neither due to antipsychotics nor to disease progress. Furthermore, our data showed significant, yet weak associations between P3b and cognition. Therefore, our data do not supply evidence for deficient P3a/b amplitudes as direct underlying factors for cognitive deficits in schizophrenia.


2016 ◽  
Vol 47 (2) ◽  
pp. 377-388 ◽  
Author(s):  
J. Rydkjær ◽  
J. R. Møllegaard Jepsen ◽  
A. K. Pagsberg ◽  
B. Fagerlund ◽  
B. Y. Glenthøj ◽  
...  

BackgroundDeficient mismatch negativity (MMN) has been proposed as a candidate biomarker in schizophrenia and may therefore be potentially useful in early identification and intervention in early onset psychosis. In this study we explored whether deficits in the automatic orienting and reorienting responses, measured as MMN and P3a amplitude, are present in young adolescents with first-episode psychosis (FEP) and whether findings are specific to psychosis compared to young adolescents with attention deficit hyperactivity disorder (ADHD).MethodMMN and P3a amplitude were assessed in young adolescents (age 12–17 years) with either FEP (N = 27) or ADHD (N = 28) and age- and gender-matched healthy controls (N = 43). The MMN paradigm consisted of a four-tone auditory oddball task with deviant stimuli based on frequency, duration and their combination.ResultsSignificantly less MMN was found in patients with psychosis compared to healthy controls in response to frequency and duration deviants. MMN amplitudes in the group of patients with ADHD were not significantly different from patients with psychosis or healthy controls. No significant group differences were found on P3a amplitude.ConclusionYoung adolescents with FEP showed impaired MMN compared to healthy controls while intermediate and overlapping levels of MMN were observed in adolescents with ADHD. The findings suggest that young FEP patients already exhibit pre-attentive deficits that are characteristic of schizophrenia albeit expressed on a continuum shared with other neuropsychiatric disorders.


2021 ◽  
Vol 11 (7) ◽  
pp. 835
Author(s):  
Alexander Rokos ◽  
Richard Mah ◽  
Rober Boshra ◽  
Amabilis Harrison ◽  
Tsee Leng Choy ◽  
...  

A consistent limitation when designing event-related potential paradigms and interpreting results is a lack of consideration of the multivariate factors that affect their elicitation and detection in behaviorally unresponsive individuals. This paper provides a retrospective commentary on three factors that influence the presence and morphology of long-latency event-related potentials—the P3b and N400. We analyze event-related potentials derived from electroencephalographic (EEG) data collected from small groups of healthy youth and healthy elderly to illustrate the effect of paradigm strength and subject age; we analyze ERPs collected from an individual with severe traumatic brain injury to illustrate the effect of stimulus presentation speed. Based on these critical factors, we support that: (1) the strongest paradigms should be used to elicit event-related potentials in unresponsive populations; (2) interpretation of event-related potential results should account for participant age; and (3) speed of stimulus presentation should be slower in unresponsive individuals. The application of these practices when eliciting and recording event-related potentials in unresponsive individuals will help to minimize result interpretation ambiguity, increase confidence in conclusions, and advance the understanding of the relationship between long-latency event-related potentials and states of consciousness.


2013 ◽  
Vol 88 (2) ◽  
pp. 149-156 ◽  
Author(s):  
Mirjam J. van Tricht ◽  
Emma C. Harmsen ◽  
Johannes H.T.M. Koelman ◽  
Lo J. Bour ◽  
Thérèse A. van Amelsvoort ◽  
...  

2008 ◽  
Vol 20 (10) ◽  
pp. 1753-1761 ◽  
Author(s):  
Vera Ferrari ◽  
Maurizio Codispoti ◽  
Rossella Cardinale ◽  
Margaret M. Bradley

Visual attention can be voluntarily oriented to detect target stimuli in order to facilitate goal-directed behaviors. Other visual stimuli capture attention because of motivational significance. The aim of the present study was to investigate the relationship between directed and motivated attention using event-related potentials. Affectively engaging pictures were presented either as target stimuli or as nontargets in a categorization task. Results indicated that both task relevance and emotional significance modulated the late positive potential (LPP) over centro-parietal sensors. Effects of directed and motivated attention on the LPP were additive, with the largest centro-parietal positivity found for emotional pictures that were targets of directed attention, and the least for neutral pictures that were nontargets. Taken together, the data provide new information regarding the relationship between motivated and directed attention, and suggest that the LPP reflects the operation of attentional neural circuits that are utilized by both top-down and bottom-up processes.


2021 ◽  
Vol 36 (6) ◽  
pp. 1030-1030
Author(s):  
Milena Y Gotra ◽  
Elmma Khalid ◽  
Madison M Dykins ◽  
Scot K Hill

Abstract Objective The present study applied a developmentally based subgrouping procedure previously examined in chronic psychosis patients to a sample of first-episode psychosis (FEP) and examined change in cognition following treatment with antipsychotic medication. Method Medication naïve FEP patients (n = 119; age = 27.96; 63.9% male; 62.2% White, 32.8% Black, 5.0% Other) recruited during initial hospitalization were categorized into groups based on 1) estimated premorbid intellectual ability and 2) the discrepancy between predicted (modeled on 151 healthy controls) and current cognitive ability. Consistent with findings from chronic psychosis samples, groups were characterized as Preserved (n = 46; average premorbid, no discrepancy), Deteriorated (n = 44; average premorbid, significant discrepancy), and Compromised (n = 29, low premorbid and current cognitive ability). A mixed analysis of variance was used to examine change in a composite cognitive score derived from a comprehensive neuropsychological battery at baseline, 6 weeks, and 12 months. Results There was a significant group by time interaction [Figure 1; F(5.4142.4) = 2.81, p = 0.02] in which the Preserved group performed similar to healthy controls across all time points, the Compromised group demonstrated stable deficits after treatment, and the Deteriorated group diverged from the Compromised group at 6 weeks and 12 months. Discussion There is considerable cognitive heterogeneity in FEP at baseline and after initiation of antipsychotic medication. Findings of cognitive improvement in the Deteriorated group after treatment initiation suggests a differential response to antipsychotic medications that was not found in the Compromised or Preserved groups. Future work may benefit from examining medication and symptom severity as potential factors contributing to the unique change observed in the Deteriorated group.


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