Evaluating cognitive functions with visual and auditory number assays and P300 in children with epilepsy

Auditory processing in patients with temporal lobe epilepsy: A systematic review and meta-analysis

BACKGROUND

Hearing efficiency is known to influence and interact with communication and mental health. Hearing impairment may be hidden when co-occurring with neurological disorders.

PURPOSE

We performed a systematic review and meta-analysis in order to address the following questions: 1) which specific tools of auditory processing show clear deficits, separating Temporal Lobe Epilepsy (TLE) patients from normal controls,2) How well is TLE evaluated in terms of hearing and auditory processing?

METHODS

The study inclusion criteria were: 1) patients diagnosed with temporal lobe epilepsy, 2) presence of a normal control group, 3) auditory processing assessment using auditory stimuli with behavioral tests and/or P300 or Mitch Match Negativity (MMN) latency and/or amplitude, 4) publications written in English, 5) publication date after 2000. 132 articles were retrieved and based on PRISMA & PICO criteria 23 articles were analyzed.

RESULTS

Temporal resolution and processing as measured by the behavioral tests of Gaps-In-Noise (GIN) and Duration Pattern Test (DPT) document deficiencies in TLE patients and separate them from normal controls. Electrophysiology as measured by MMN & P300 shows statistically significant differences in TLE patients compared to controls with patients showing deficient auditory processing. A clear difference between studies with psychoacoustic assessment as opposed to electrophysiology ones may be due to lacking or incomplete evaluation of peripheral hearing by gold standard tools (76.9% in electrophysiology studies).

CONCLUSION

Auditory processing is deficient in patients with TLE. There is a clear need to evaluate hearing efficiency before proceeding to auditory processing evaluation with behavioral or electrophysiological tests.

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

Background:

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

The P300 Event-Related Potential Component and Cognitive Impairment in Epilepsy: A Systematic Review and Meta-analysis

Background: Epilepsy is one of the most prevalent chronic brain diseases worldwide and is often accompanied by cognitive impairment. Event-related potentials (ERPs) are an objectively non-invasive approach for studying information processing and cognitive functions in the brain. The P300 is an important and extensively explored late component of ERPs that has been widely applied to assess cognitive function in epilepsy in previous studies. However, consistent conclusions have not yet been reached for various reasons.

Objective: We conducted a comprehensive systematic review and meta-analysis of P300-related studies to assess the latency and amplitude of the P300 in epileptic patients.

Methods: PubMed, EMBASE, and Cochrane Library databases were systematically searched for eligible studies. The standard mean difference (SMD) and the 95% confidence interval (CI) were calculated as the effect size of the P300 component.

Results: The main results of the present meta-analysis indicated that epileptic patients have a longer P300 latency and a lower P300 amplitude than controls. Subgroup analysis based on age group demonstrated that these differences can be observed in both children and adult patients compared with healthy controls. In addition, the P300 latency was longer in patients with the five main types of epileptic seizures than in controls.

Conclusion: This study revealed that epileptic patients have abnormalities in the P300 component, which may reflect deficits in cognitive function. Thus, the P300 may be a potential objective approach for evaluating cognitive function in epileptic patients.

Application of the P300 Event-Related Potential in the Diagnosis of Epilepsy Disorder: A Review

Epilepsy is one of the most serious chronical neurological disorders, affecting more than 50 million people worldwide. It can be defined as a spectrum disorder, and patients with epilepsy possess abnormalities in cognitive functions. A number of factors can cause cognitive dysfunctions in epileptic syndromes, including etiology, the age of onset, type of seizure and severity, duration, and antiepileptic drugs. Event-related potentials (ERPs) are very useful clinical and research instruments to evaluate cognitive function in patients with neuropsychiatry disorders. Event-related potentials directly reflect cortical neuronal activity and provide a particular level of temporal resolution. Among various ERP components, the P300 is the most important component for assessing cognitive processes such as attention, working memory, and concentration. Numerous studies have reported the abnormalities in amplitude or latency of P300 component of ERP in epileptic patients, and these abnormalities are indicative of cognitive dysfunction. Therefore, the purpose of this review is to consolidate the existing literature in connection with the use of P300 in epileptic patients.

Comparison of auditory event-related potentials between children with benign childhood epilepsy with centrotemporal spikes and children with temporal lobe epilepsy

The abnormal brain discharges observed in benign childhood epilepsy with centrotemporal spikes (BECTS) and temporal lobe epilepsy (TLE) are located close to areas responsible for auditory and language processing. This study aimed to analyze the results of auditory event-related potentials (P300) in children with BECTS and TLE in order to assess whether the epileptic activity in centrotemporal and temporal regions may compromise the integrity and physiology of auditory system structures. This was a prospective, comparative, and cross-sectional study. Group I (GI) consisted of 13 children diagnosed with BECTS, group II (GII), 7 children diagnosed with TLE, and control group (GIII), 16 healthy children, with no hearing or academic complaints. After neurological and basic audiological assessments, P300 was applied. The P300 latency and amplitude were compared between groups. Regarding latency, GI showed 324.1 (+31.5) ms, GII 336.3 (+23.5) ms, and GIII 318 (+27.7) ms. Amplitudes were 4.80 (+3.2) μV in GI, 4.7 (+2.5) μV in GII, and 5.8 (+2.4) μV in GIII. Although children with BECTS showed prolonged latencies and reduced amplitudes, these differences were not considered statistically significant. Children with TLE showed statistically significant prolonged P300 latency compared with the control group (P=0.037). We speculate that abnormal electrical discharges in centrotemporal and temporal regions led to the slowing of auditory processing in our sample.

Long-term neurocognitive outcome and auditory event-related potentials after complex febrile seizures in children

OBJECTIVES

Whether prolonged or complex febrile seizures (FS) produce long-term injury to the hippocampus is a critical question concerning the neurocognitive outcome of these seizures. Long-term event-related evoked potential (ERP) recording from the scalp is a noninvasive technique reflecting the sensory and cognitive processes associated with attention tasks. This study aimed to investigate the long-term outcome of neurocognitive and attention functions and evaluated auditory event-related potentials in children who have experienced complex FS in comparison with other types of FS.

METHODS

One hundred and forty-seven children aged more than 6 years who had experienced complex FS, simple single FS, simple recurrent FS, or afebrile seizures (AFS) after FS and age-matched healthy controls were enrolled. Patients were evaluated with Wechsler Intelligence Scale for Children (WISC; Chinese WISC-IV) scores, behavior test scores (Chinese version of Conners' continuous performance test, CPT II V.5), and behavior rating scales. Auditory ERPs were recorded in each patient.

RESULTS

Patients who had experienced complex FS exhibited significantly lower full-scale intelligence quotient (FSIQ), perceptual reasoning index, and working memory index scores than did the control group but did not show significant differences in CPT scores, behavior rating scales, or ERP latencies and amplitude compared with the other groups with FS. We found a significant decrease in the FSIQ and four indices of the WISC-IV, higher behavior rating scales, a trend of increased CPT II scores, and significantly delayed P300 latency and reduced P300 amplitude in the patients with AFS after FS.

CONCLUSION

We conclude that there is an effect on cognitive function in children who have experienced complex FS and patients who developed AFS after FS. The results indicated that the WISC-IV is more sensitive in detecting cognitive abnormality than ERP. Cognition impairment, including perceptual reasoning and working memory defects, was identified in patients with prolonged, multiple, or focal FS. These results may have implications for the pathogenesis of complex FS. Further comprehensive psychological evaluation and educational programs are suggested.

Temporal lobe impairment in West syndrome: event-related potential evidence

Objective

This study investigates auditory processing in infants with West syndrome (WS) using event-related potentials (ERPs).

Methods

ERPs were measured in 25 infants with mainly symptomatic WS (age range = 3–10 months) and 26 healthy term infants (age range = 3–9 months) using an auditory novelty oddball paradigm. The ERP recordings were made during wakefulness and repeated in stage II sleep.

Results

The obligatory components (P150, N250, P350) and novelty response components (P300, Nc) were recordable during both sleep and wakefulness in patients and controls. All ERP latencies decreased with age in controls but not in the WS group (age × group interaction, F = 22.3, p < 0.0001). These ERP latency alterations were not affected by pharmacological treatment for WS.

Interpretation

This study demonstrated a persistently altered ERP signature in patients with a recent history of infantile spasms. The prolongation of auditory obligatory and novelty ERPs in WS patients indicates a severe failure of temporal lobe maturation during infancy. It remains to be investigated whether this predicts long-term cognitive impairments characteristic for this epileptic encephalopathy.

Electrophysiological and auditory behavioral evaluation of individuals with left temporal lobe epilepsy

The purpose of this study was to determine the repercussions of left temporal lobe epilepsy (TLE) for subjects with left mesial temporal sclerosis (LMTS) in relation to the behavioral test-Dichotic Digits Test (DDT), event-related potential (P300), and to compare the two temporal lobes in terms of P300 latency and amplitude. We studied 12 subjects with LMTS and 12 control subjects without LMTS. Relationships between P300 latency and P300 amplitude at sites C3A1,C3A2,C4A1, and C4A2, together with DDT results, were studied in inter-and intra-group analyses. On the DDT, subjects with LMTS performed poorly in comparison to controls. This difference was statistically significant for both ears. The P300 was absent in 6 individuals with LMTS. Regarding P300 latency and amplitude, as a group, LMTS subjects presented trend toward greater P300 latency and lower P300 amplitude at all positions in relation to controls, difference being statistically significant for C3A1 and C4A2. However, it was not possible to determine laterality effect of P300 between affected and unaffected hemispheres.

Working memory in children with epilepsy: an event-related potentials study

PURPOSE

The aim of this study was to find out whether children with idiopathic epilepsy did show different cortical activation patterns compared to non-epileptic children during performance of a working memory task. To this end event-related potentials (ERPs) were measured during a visual 1-backmatching task. A quantitative analysis technique to analyze the ERP data, without any 'a priori' decisions on 'peak' presence, amplitudes or latencies, is used.

METHODS

46 children were tested (6-16 years old): 21 children with well-controlled "benign" epilepsy (benign rolandic epilepsy, n=9, idiopathic generalized epilepsy, n=12) and a control group of 25 non-epileptic children. Behavioral task performance and ERPs following both target and nontarget stimuli were compared across both study groups.

RESULTS

No differences were found in the number of omission errors or commission errors or in the reaction times between groups. However, ERPs following target stimuli showed significantly higher amplitude in the epilepsy group compared to the control group over frontal and central regions within the time window between 250 and 425 ms poststimulus, what coincides with the time window of target-nontarget stimulus discrimination.

DISCUSSION

Our study shows that children with benign, well-controlled epilepsy show a different cortical activation pattern during a visual working memory task. We hypothesize that they need more brain processing effort to achieve the same performance level as their age matched controls.

Cognitive functions evaluated by P300 and visual and auditory number assays in children with childhood epilepsy with occipital paroxysms (CEOP)

PURPOSE

This study was planned to evaluate cognitive functions, especially attention and immediate recall, in children with childhood epilepsy with occipital paroxysms (CEOP), by using P300 and neuropsychological tests, which included visual and auditory number assays. Thirty patients with CEOP, ages ranging from 5 to 17 years were enrolled in the study. Twenty-five healthy children were taken as the control group.

METHODS

Oddball paradigm was used in P300 recordings. The latency and the amplitude of the P300 wave recorded from Cz were taken into consideration. The neuropsychological test battery included visual and auditory number assays.

RESULTS

P300 latency was significantly longer in the CEOP group (p=0.014). The results of the visual and auditory number assay test showed significant decline in the patient group when compared with the normal controls.

CONCLUSIONS

Attention and immediate recall deficits as well as prolonged P300 latencies in children with CEOP can be due to an ongoing epileptic activity either influencing the whole brain or only the occipital lobe which can also be involved in the neuropsychological organization of the human cortex. Therefore, children with CEOP should be evaluated with more detailed neuropsychological tests for possible cognitive deficits.