Event-related Potentials In Patients Research Articles

Clinical study of electroacupuncture improving sleep electroencephalogram and event-related potential in patients with somatoform disorders

Clinical study of electroacupuncture improving sleep electroencephalogram and event-related potential in patients with somatoform disorders

P300 event-related potentials in patients with multiple sclerosis

BackgroundCognitive impairment (CI) is a common and disabling symptom during the disease even in the earliest “preclinical” phase of patients with MS (pwMS). This study aims to assess cognitive function by measuring P300 event-related potential (ERP) and to look into the relationship between P300 abnormalities with the severity of the physical disability, education level, and disease duration.MethodsFifty pwMS (28 females and 22 males) aged 20–54 years and fifty healthy subjects comprised of 21 females and 29 males aged 18–50 years serves as the control group was studied. All participants underwent medical history, neurological examination, cognitive functions using the Montreal Cognitive Assessment scale (MoCA) and the P300 ERP.ResultsIn this study, 48% of pwMS had CI. They had a longer P300 latency and a lower amplitude. Those with impaired cognition had a longer duration of illness and higher Expanded Disability Status Scale (EDSS), whereas those with intact cognition had a higher education level. P300 latency was correlated positively with EDSS and disease duration, but negatively with education level. P300 amplitude was found to be negatively correlated with EDSS, and disease duration but positively to the education level.ConclusionsP300, as a non-invasive test, would support the presence of CI in pwMS patients and could be used for screening in daily practice. P300 has a strong relationship with illness duration, disease subtypes, EDSS, and education level.

Features of event-related potentials during retrieval of episodic memory in patients with mild cognitive impairment due to Alzheimer's disease.

To provide a rigorous comparison between patients with mild cognitive impairment due to Alzheimer's disease (MCI-AD) and healthy elderly, as well as to assess the value of electroencephalography (EEG) in terms of early diagnosis, we conducted a neutral image recognition memory task involving individuals with positive biomarkers including β amyloid deposition, pathologic tau or neurodegeneration. The task involving study and test blocks was designed to evaluate participants' recognition memory. Electroencephalogram was recorded synchronously to elicit event-related potentials in patients with MCI-AD and healthy control subjects. We further analyzed differences between groups or conditions in terms of behavioral performance, time domain, and time-frequency domain. The MCI-AD cohort showed a slower response time to old/new images and had low accuracy regarding behavioral performance. The amplitude of the late positive complex for the old/new effects was significantly suppressed in the MCI-AD cohort when compared with that in the HC cohort. The amplitude of the late old/new effects was correlated with the Auditory Verbal Learning Test recognition score in all participants. The time-frequency domain analysis revealed that correct recognition of old items elicited a decrease in beta power, mainly limited to the HC cohort. Moreover, the combination of behavioral (processing speed and accuracy) and electrophysiological (average amplitude and relative power of delta band) measures contributes to classifying patients with MCI-AD from healthy elderly people. Changes of old/new effects, accuracy and response time are sensitive to the impairment of recognition memory in patients with MCI-AD and have moderate value in predicting the incipient stage of AD.

Effects of Healthy Aging and Gender on the Electrophysiological Correlates of Semantic Sentence Comprehension: The Development of Dutch Normative Data.

The clinical use of event-related potentials in patients with language disorders is increasingly acknowledged. For this purpose, normative data should be available. Within this context, healthy aging and gender effects on the electrophysiological correlates of semantic sentence comprehension were investigated. One hundred and ten healthy subjects (55 men and 55 women), divided among three age groups (young, middle aged, and elderly), performed a semantic sentence congruity task in the visual modality during electroencephalographic recording. The early visual complex was affected by increasing age as shown by smaller P2 amplitudes in the elderly compared to the young. Moreover, the N400 effect in the elderly was smaller than in the young and was delayed compared to latency measures in both middle-aged and young subjects. The topography of age-related amplitude changes of the N400 effect appeared to be gender specific. The late positive complex effect was increased at frontal electrode sites from middle age on, but this was not statistically significant. No gender effects were detected regarding the early P1, N1, and P2, or the late positive complex effect. Especially aging effects were found during semantic sentence comprehension, and this from the level of perceptual processing on. Normative data are now available for clinical use.

P300 event-related potentials in patients with different subtypes of depressive disorders.

To explore the differences in event-related potentials (ERPs) of the subclinical types of major depressive disorders (MDD): melancholic (MEL), atypical (ATY), and anxious (ANX). Patients with MDD treated in the Clinical Department of Shanghai Mental Health Center between September 2017 and December 2020 were prospectively included. This study was approved by the Ethics Committee of the Shanghai Mental Health Center. They were evaluated using the Mini-International Neuropsychiatric Interview (MINI), 17-item Hamilton Depression Scale (HAMD-17), 30-item Self-rated Inventory of Depressive Symptomatology (IDS-30SR), 16-item Quick Inventory of Negative Symptom Scale (QIDS-16SR), and auditory and visual P300 ERPs. Finally, 27, 14, and 20 patients with MEL, ATY, and ANX MDD were included in this study, respectively. There were no significant differences in demographic characteristics and HAMD-17, IDS-30SR, and QIDS-16SR total scores among the three groups (all P > 0.05). On the C3 lead, the latency for patients with MEL MDD was the longest, and the latency for patients with ATY MDD was the shortest (MEL vs. ATY vs. ANX: 373.89 ± 6.60 vs. 344.79 ± 9.78 vs. 359.33 ± 7.62, P = 0.039). On the Pz lead, the latency for patients with MEL MDD was the longest, and the latency for patients with ATY MDD was the shortest (MEL vs. ATY vs. ANX: 376.14 ± 6.51 vs. 347.21 ± 9.42 vs. 362.22 ± 8.63, P = 0.047). There were no differences in visual P300 ERPs among the three groups. There are significant differences in auditory C3 and Pz latency among MEL, ATY, and ANX MDD. These differences could help diagnose the subtype of MDD.

Cortical Brain Perfusion and Cognitive Event Related Potentials in Patients with Psychomotor Retardation in Late Onset Depression.

Late onset depression is characterised by pronounced cognitive impairment, more somatic complaints and psychomotor retardation. Psychomotor slowing may be due to impairment in either motor or cognitive domain. Electrophysiology may be particularly convenient as a tool in studies of psychomotor retardation, as it can separate central cognitive processing from the motor processing. In this study we compared event related potentials (ERP) in the two groups of patients with late onset depression and psychomotor slowing as measured by reaction time (RT): a group of patients with lower RT was compared to a group with a higher RT. Twenty patients with late onset depression were included in the study after they had reached remission. Four weeks after reaching remission patients were reevaluated clinically using Hamilton Depression Rating Scale, Mini Mental State Examination, and with a computer version of the Stroop task. ERP, accuracy and RTs were simultaneously recorded. Both groups of patients aditionaly underwent a perfusion SPECT imaging. There were no differences between the short and long RT groups of patients in amplitudes of the late positive Stroop related potentials. The group of patients with longer RTs showed significant hyperperfusion in precentral gyrus, parietal regions, cuneus and hypoperfusion within insular, frontal, temporal and limbic (parahyppocampal gyrus and anterior cingulate) cortices, as well as cerebellum. We found no ERP differences between the two groups suggesting that although patients may differ on psychomotor retardation measured as RT, their cognitive abilities may be quite similar. Perfusion SPECT imaging however revealed a significant difference between them. This may be due to a process of compensation and applying different strategies to cope with cognitive impairment in the two groups.

Face-induced gamma oscillations and event-related potentials in patients with epilepsy: an intracranial EEG study

BackgroundTo examine the pathological effect of a mesial temporal seizure onset zone (SOZ) on local and inter-regional response to faces in the amygdala and other structures of the temporal lobe.MethodsIntracranial EEG data was obtained from the amygdala, hippocampus, fusiform gyrus and parahippocampal gyrus of nine patients with drug-refractory epilepsy during visual stimulation with faces and mosaics. We analyzed event-related potentials (ERP), gamma frequency power, phase-amplitude coupling and phase-slope-index and compared the results between patients with versus without a mesial temporal SOZ.ResultsIn the amygdala and fusiform gyrus, faces triggered higher ERP amplitudes compared to mosaics in both patient groups and higher gamma power in patients without a mesial temporal SOZ. In the hippocampus, famous faces triggered higher gamma power for both groups combined but did not affect ERPs in either group. The differentiated ERP response to famous faces in the parahippocampal gyrus was more pronounced in patients without a mesial temporal SOZ. Phase-amplitude coupling and phase-slope-index results yielded bidirectional modulation between amygdala and fusiform gyrus, and predominately unidirectional modulation between parahippocampal gyrus and hippocampus.ConclusionsA mesial temporal SOZ was associated with an impaired response to faces in the amygdala, fusiform gyrus and parahippocampal gyrus in our patients. Compared to this, the response to faces in the hippocampus was impaired in patients with, as well as without, a mesial temporal SOZ. Our results support existing evidence for face processing deficits in patients with a mesial temporal SOZ and suggest the pathological effect of a mesial temporal SOZ on the amygdala to play a pivotal role in this matter in particular.

Cognitive deficits correlated with increased latency of event-related potentials in drug-free patients with generalized anxiety disorder

Objective: Few studies have identified a relationship between cognitive deficits and altered event-related potentials (ERPs), which measure the synchronous activity of neurons in response to a stimulus in patients with generalized anxiety disorder (GAD). In this study, we intended to explore the relation between cognitive function and ERP in patients with GAD. Methods: Fourteen drug-free participants with GAD and 14 healthy controls were recruited. ERPs were measured, and neuropsychological tests were administered. We compared the differences of the data between two groups of the study participants. Results: Poor performances of full IQ and the numbers of the categories completed on the Wisconsin Card Sorting Test were found significantly correlated with increased frontal lobe latency in the patients with GAD (Spearman's ρ = −0.70, p

EFFECT OF ANTIEPILEPTIC DRUGS ON P300 EVENT-RELATED POTENTIALS IN PATIENTS WITH EPILEPSY.

Epilepsy is one of the most prevalent chronic neurological diseases, affecting about 70 million people worldwide. Patients with epilepsy often encounter cognitive dysfunction, which is influenced by different factors including age at the onset of epilepsy, etiology of epilepsy, type of seizures, seizure frequency and duration, psychiatric comorbidity, and antiepileptic drug (AED) therapy. Event-related potentials are useful, noninvasive, objective clinical and research instrument for evaluation of cognitive functions in patients. The aim of this study was to investigate and determine the effect of AED monotherapy and polytherapy on cognitive changes in patients with epilepsy, detected with P300 event-related potentials and compared with age- and gender-matched healthy individuals. The study was conducted in 82 patients with generalized and focal epilepsy and 82 healthy individuals aged 18-65 years. Cognitive evoked P300 potentials were recorded in all study subjects using auditory 'oddball' paradigm. The results showed the patients taking AED polytherapy to have a significantly longer P300 latency and significantly lower N200-P300 amplitude. These results indicate that AED polytherapy might worsen cognitive impairment in patients with epilepsy.

The Neurophysiology of Implicit Alcohol Associations in Recently Abstinent Patients With Alcohol Use Disorder: An Event-Related Potential Study Considering Gender Effects.

BackgroundNeuroscientific models of alcohol use disorders (AUDs) postulate an imbalance between automatic, implicit, and controlled (conscious) processes. Implicit associations towards alcohol indicate the automatically attributed appeal of alcohol‐related stimuli. First, behavioral studies indicate that negative alcohol associations are less pronounced in patients compared to controls, but potential neurophysiological differences remain unexplored. This study investigates neurophysiological correlates of implicit alcohol associations in recently abstinent patients with AUD for the first time, including possible gender effects.MethodsA total of 62 patients (40 males and 22 females) and 21 controls performed an alcohol valence Implicit Association Test, combining alcohol‐related pictures with positive (incongruent condition) or negative (congruent condition) words, while brain activity was recorded using 64‐channel electroencephalography. Event‐related potentials (ERPs) for alcohol‐negative and alcohol‐positive trials were computed. Microstate analyses investigated the effects of group (patients, controls) and condition (incongruent, congruent); furthermore, possible gender effects in patients were analyzed. Significant effects were localized with standardized low‐resolution brain electromagnetic topography analysis.ResultsAlthough no behavioral group differences were found, ERPs of patients and controls were characterized by distinct microstates from 320 ms onwards. ERPs between conditions differed only in patients with higher signal strength during incongruent trials. Around 600 ms, controls displayed higher signal strength than patients. A gender effect mirrored this pattern with enhanced signal strength in females as opposed to male patients. Around 690 ms, a group‐by‐valence interaction indicated enhanced signal strength in congruent compared to incongruent trials, which was more pronounced in controls.ConclusionsFor patients with AUD, the pattern, timing, and source localization of effects suggest greater effort regarding semantic and self‐relevant integration around 400 ms during incongruent trials and attenuated emotional processing during the late positive potential timeframe. Interestingly, this emotional attenuation seemed reduced in female patients, thus corroborating the importance of gender‐sensitive research and potential treatment of AUD.

Prediction of Antidepressant Treatment Outcome Using Event-Related Potential in Patients with Major Depressive Disorder

(1) Background: Prediction of treatment outcome has been one of the core objectives in clinical research of patients with major depressive disorder (MDD). This study explored the possibility of event-related potential (ERP) markers to predict antidepressant treatment outcomes among MDD patients; (2) Methods: Fifty-two patients with MDD were recruited and evaluated through Hamilton depression (HAM-D), Hamilton anxiety rating scale (HAM-A), and CORE. Patients underwent a battery of ERP measures including frontal alpha symmetry (FAA) in the low alpha band (8–10 Hz), mismatch negativity (MMN), and loudness-dependent auditory evoked potentials (LDAEP); (3) Results: During the eight weeks of study, 61% of patients achieved remission, and 77% showed successful treatment responsiveness. Patients with low FAA in F5/F6 demonstrated a significantly higher remission/response ratio and better treatment responsiveness (F (2.560, 117.755) = 3.84, p = 0.016) compared to patients with high FAA. In addition, greater FAA in F7/F8 EEG channels was significantly associated with greater melancholia scores (r = 0.34, p = 0.018). Other ERP markers lacked any significant effect; (4) Conclusions: Our results suggested low FAA (i.e., greater left frontal activity) could reflect a good treatment response in MDD patients. These findings support that FAA could be a promising index in understanding both MDD and melancholic subtype.

Effect of music listening on P300 event-related potential in patients with schizophrenia: A pilot study

Reduced amplitude and increased latency of P300 auditory event-related potential (ERP) in patients with schizophrenia (SZ) indicate impairment in attention. Overall arousal level can determine the amount of processing capacity required for attention allocation. Music evokes strong emotions and regulates arousability. Music has been used to modulate P300, especially in normals. This exploratory study examined the effect of music listening on the amplitude and latency of P300 in SZ patients.EEG/ERP was recorded (32-channels) while SZ patients (n = 20; 18–45 years) performed an auditory oddball P300 task after the eyes-closed rest condition (Condition-A) and ten-minute music listening condition (Condition-B) as per the complete counterbalancing design (AB-BA). Patients listened to the researcher chosen, instrumental presentation of raag-Bhoopali in the North-Indian-Classical-Music, for ten-minutes. All patients rated the music excerpt as a relaxing and positively valenced.A significant increase in accuracy score and reaction time during the oddball task after music listening was noted. There was an increase in amplitude at TP7. A trend of increased amplitude was noted across all electrodes in the music condition compared to the rest condition. Mean amplitude in an apriori defined time window of interest (250 to 750 ms) showed significant changes in the frontal and central electrode sites. Power spectral analysis indicated a slight increase in frontal and central alpha and theta activity during music listening. However, this was not statistically significant.Findings add further impetus to examine the effect of music in chronic psychiatric conditions. Need for systematic studies on a larger cohort is underscored.

A pilot study on salivary cortisol secretion and auditory P300 event-related potential in patients with physical disability-related stress

Objective: To evaluate the stress level and attention in workers with physical disabilities-related stress.Methods: Morning salivary cortisol was used as a stress marker while the event-related potential during the performance of the auditory oddball paradigm was conducted to investigate the attentive ability to sound stimuli. Eighteen injured workers (IP) and eighteen unaffected healthy adults (CP) were recruited for this study with half being men and the other half women (aged 21–55). Behavioral performance measures including reaction time (RT), accuracy rate, and commission error as well as the latency and amplitude of P300 wave over the central (Cz), centroparietal (CPz), and parietal (Pz) electroencephalogram electrode sites were used to compare the two groups.Results: This study demonstrated significantly higher salivary cortisol levels, longer RT, less accuracy to respond to the target during the auditory oddball paradigm in the IP group as compared to CP group. In addition, a significant prolongation of the peak latency of auditory P300 wave over CPz electrodes was also detected in IP group.Conclusion: The increased cortisol levels found in the IP group reflect the alteration of the basal hypothalamic-pituitary-adrenal axis as a result of the stresses of living with a physical disability. Delayed RT and the decreased in accuracy together with changing in peak latencies of auditory P300 wave indicate the impairment of attention networks in IP. Our study revealed that the patients with permanent physical disability.

Correlation analysis about cranial magnetic resonance imaging and electroencephalogram abnormalities and event-related potentials in patients with temporal lobe epilepsy

Objective: To investigate and evaluate the correlation between event-related potentials, cranial magnetic resonance imaging and electroencephalogram on cognitive function in patients with temporal lobe epilepsy. Methods: According to the exclusion criteria, 60 adult temporal lobe epilepsy patients (24 males and 36 females, 34±13 years old of average age) were enrolled in the First Affiliated Hospital of Kunming Medical University from March 2017 to September 2018. The magnetic resonance imaging (MRI), 24 h video electroencephalogram (EEG) and event-related potentials (ERPs) were detected in all patients, comparing the latency of N1, P2, N2, P3 waves and the amplitude of P3 waves. Results: The mean latency of the waves of N1, P2, N2 and P3 and the mean amplitude of P3 wave were (108±25), (182±30), (256±33), (367±40) ms and (6.4±5.8) μV. There were significant differences in ERPs (latency of N1 wave, N2 wave and P3 wave) between the MRI abnormal group and the normal group (all P<0.05). There was a statistically significant difference in the ERPs (P3 wave latency) between EEG examination found epileptiform or paroxysmal slow waves release group and the patients with EEG normality in the past 1 year (P<0.05) and the EEG test results were positively correlated with the latency of P2, N2 and P3 waves in ERPs, and negatively correlated with the amplitude of P3 waves (P<0.05). Conclusion: Patients with cognitive dysfunction in temporal lobe epilepsy are more likely to have abnormal MRI and EEG in the head. Both of them show different effects on the cognitive process of patients in ERPs.

Childhood trauma affects processing of social interactions in borderline personality disorder: An event-related potential study investigating empathy for pain

Objectives: Patients with borderline personality disorder (BPD) have difficulties in empathising with others and show disturbances in social interactions. Using a ‘Social Interaction Empathy Task’, we found that BPD patients judged neutral and psychologically painful conditions as more painful than healthy subjects. Here, we present the neural correlates underlying these differences in empathy for pain.Methods: Female BPD patients and healthy controls completed the ‘Social Interaction Empathy Task’ during EEG recording. Event-related potentials (ERP) were analysed for an early anterior component and a late latency positivity. Empathic abilities were assessed using the Interpersonal Reactivity Index and early aversive experiences were measured by the Childhood Trauma Questionnaire (CTQ).Results: ERPs in the patient group matched the behaviour results and correlated with the level of personal distress and CTQ. In addition, ERPs of patients were predicted by childhood maltreatment and stress.Conclusions: Taken together, our findings indicate that the observed behavioural differences between patients with BPD and controls might be due to modulatory effects of empathic abilities on the evaluation of pain-related social stimuli, which are supposed to be based on childhood maltreatment.

Changes in event-related potentials in patients with first-episode schizophrenia and their siblings

BackgroundThis study aimed to explore the characteristics of event-related potentials induced by facial emotion recognition in patients with first-episode schizophrenia and in their siblings.MethodsIn this case-control study, 30 first-episode schizophrenia patients, 26 siblings, and 30 healthy controls were enrolled. They completed facial emotion recognition tasks from the Ekman Standard Faces Database as an induction for evoked potentials. Evoked potential data were obtained using a 64-channel electroencephalography system. Average evoked potential waveforms were computed from epochs for each stimulus type. The amplitudes and latency of the event-related potentials for P100 (positive potential 100 ms after stimulus onset), N170 (negative potential 170 ms after stimulus onset), and N250 (fronto-central peak) were investigated at O1, O2, P7, and P8 electrode locations.ResultsThere were significant differences between the groups for P100 amplitude (F = 11.526, P < 0.001), electrode position (F = 450.592, P < 0.001), emotion (disgust vs. happiness vs. fear) (F = 1722.467, P < 0.001), and emotion intensity (low vs. moderate vs. high) (F = 1737.169, P < 0.001). Post hoc analysis showed significantly larger amplitudes in the schizophrenia group at the O1, O2, P7, and P8 electrode positions. There were no significant differences between the siblings of schizophrenia patients and the healthy controls.ConclusionsPatients with schizophrenia showed abnormalities in P100 amplitude, but similar results were not observed in their siblings. These results provide evidence of dysfunctional event-related potential patterns underlying facial emotion processing in patients with schizophrenia. P100 may be a characteristic index of schizophrenia.

Circadian course of the P300 ERP in patients with amyotrophic lateral sclerosis - implications for brain-computer interfaces (BCI)

BackgroundAccidents or neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) can lead to progressing, extensive, and complete paralysis leaving patients aware but unable to communicate (locked-in state). Brain-computer interfaces (BCI) based on electroencephalography represent an important approach to establish communication with these patients. The most common BCI for communication rely on the P300, a positive deflection arising in response to rare events. To foster broader application of BCIs for restoring lost function, also for end-users with impaired vision, we explored whether there were specific time windows during the day in which a P300 driven BCI should be preferably applied.MethodsThe present study investigated the influence of time of the day and modality (visual vs. auditory) on P300 amplitude and latency. A sample of 14 patients (end-users) with ALS and 14 healthy age matched volunteers participated in the study and P300 event-related potentials (ERP) were recorded at four different times (10, 12 am, 2, & 4 pm) during the day.ResultsResults indicated no differences in P300 amplitudes or latencies between groups (ALS patients v. healthy participants) or time of measurement. In the auditory condition, latencies were shorter and amplitudes smaller as compared to the visual condition.ConclusionOur findings suggest applicability of EEG/BCI sessions in patients with ALS throughout normal waking hours. Future studies using actual BCI systems are needed to generalize these findings with regard to BCI effectiveness/efficiency and other times of day.

Cognitive Event-Related Potentials in Patients With Adenoid Hypertrophy: A Case-Control Pilot Study.

Children with adenoid hypertrophy commonly have sleep-disordered breathing. Sleep-disordered breathing is associated with various neurocognitive problems. The aim of this study was to assess the cognitive function in those patients using cognitive event-related potentials. Twenty-three patients with moderate to severe adenoid hypertrophy were compared with 20 healthy controls. The intelligence quotient was performed for all study participants. The latencies of the N200, P300 peaks and the amplitudes of the N200/P300 components of event-related potentials were recorded. The above variables were measured at baseline for both patients and control groups and 2 months after adenoidectomy for the patient group. There was no significant difference between patients and controls regarding full intelligence quotient scales. P300 latency was significantly prolonged in patient group compared with the healthy controls. Moreover, postoperative P300 latency was significantly reduced compared with the preoperative P300 latency. Postoperative P300 latency was not statistically different from healthy controls' data. P300 latency delay may reflect some sort of cognitive impairment in patients with adenoid hypertrophy. This delay was reversible after adenoidectomy. Event-related potentials may help for assessment of cognitive functions in patients with adenoid hypertrophy.

Cognitive performance, fatigue and event-related potentials in patients with clinically isolated syndrome

ObjectivesCognitive impairment and fatigue are regarded as important aspects of multiple sclerosis. The aim of this study was to evaluate cognitive performance, the level of fatigue and parameters of event-related potentials (ERP) in patients diagnosed with clinically isolated syndrome (CIS). Patients and methodsThe study comprised 44 patients with CIS and 45 healthy controls. Cognitive performance was assessed using the Brief Repeatable Battery of Neuropsychological Tests (BRBNT), fatigue - using the Fatigue Severity Scale (FSS) and Modified Fatigue Impact Scale (MFIS). Auditory ERP were performed and the parameters of N200 and P300 components were analyzed. Neuropsychological and electrophysiological measures were referred to clinical and radiological features of the disease activity. ResultsForty five% of patients failed in at least one test from BRBNT, mainly within the domains of memory and attention. In 18% of patients FSS corresponded with moderate or severe fatigue. The mean latency of N200 and P300 was significantly longer and amplitude of P300 was lower in those patients with CIS than in the controls. Significant correlations were found between the results of MFIS and tests evaluating verbal memory and attention, as well as between N200 latency and results of tests for verbal memory. ConclusionsCognitive performance and fatigue deserve attention from the earliest clinical stage of MS. Abnormalities of event-related potentials in CIS suggest early impact of the disease on functional neural networks.

The Impact of a Cognitive-Behavioral Therapy on Event-Related Potentials in Patients with Tic Disorders or Body-Focused Repetitive Behaviors.

Tic disorders (TD) are characterized by the presence of non-voluntary contractions of functionally related groups of skeletal muscles in one or multiple body parts. Patients with body-focused repetitive behaviors (BFRB) present frequent and repetitive behaviors, such as nail biting or hair pulling. TD and BFRB can be treated with a cognitive-behavioral therapy (CBT) that regulates the excessive amount of sensorimotor activation and muscular tension. Our CBT, which is called the cognitive-psychophysiological (CoPs) model, targets motor execution and inhibition, and it was reported to modify brain activity in TD. However, psychophysiological effects of therapy are still poorly understood in TD and BFRB patients. Our goals were to compare the event-related potentials (ERP) of TD and BFRB patients to control participants and to investigate the effects of the CoPs therapy on the P200, N200, and P300 components during a motor and a non-motor oddball task. Event-related potential components were compared in 26 TD patients, 27 BFRB patients, and 27 control participants. ERP were obtained from 63 EEG electrodes during two oddball tasks. In the non-motor task, participants had to count rare stimuli. In the motor task, participants had to respond with a left and right button press for rare and frequent stimuli, respectively. ERP measures were recorded before and after therapy in both patient groups. CoPs therapy improved symptoms similarly in both clinical groups. Before therapy, TD and BFRB patients had reduced P300 oddball effect during the non-motor task, in comparison with controls participants. An increase in the P300 oddball effect was observed posttherapy. This increase was distributed over the whole cortex in BFRB patients, but localized in the parietal area in TD patients. These results suggest a modification of neural processes following CoPs therapy in TD and BFRB patients. CoPs therapy seems to impact patients' attentional processes and context updating capacities in working memory (i.e., P300 component). Our results are consistent with a possible role of the prefrontal cortex and corpus callosum in mediating interhemispheric interference in TD.