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

This study was planned to evaluate cognitive functions, especially attention and immediate recall, in children with epilepsy by using P300 and neuropsychological tests, which included visual and auditory number assays. Fifty five patients with partial seizures, 45 patients with generalized seizures and 20 patients with intractable seizures were enrolled in the study. Twenty five healthy children were taken as the control group. The results were as follows: 1. P300 latencies were significantly longer in the intractable and partial groups when compared with the control subjects. 2. The duration of epilepsy, seizure frequency, cerebral imaging pathologies were not significantly correlated with delayed P300 latencies. 3. The results of the visual and auditory number assays test showed significant abnormalities when each of the three groups were compared with the normal controls. 4. Though some subgroups of the neuropsychological tests were correlated with the P300 latencies, an overall significant correlation was not present between them. So, we suggest that neuropsychological tests are more convenient for the assessment of cognitive functions in children with epilepsy than the P300 recordings.     

The auditory P300 correlates with specific cognitive deficits in Parkinson's disease

Summary An abnormally prolonged latency of the P300 event-related potential has been reported in several types of dementing illnesses, including Parkinson's disease (PD). While some PD patients have dementia, a significant number of PD patients have less severe cognitive impairments. We examined the relationship between the auditory P300 and a neuropsychological battery of 11 tasks in 43 PD patients. The quantitative relationship between the individual neuropsychological measures and the P300 was examined using partial correlation and analysis of covariance techniques which controlled for age, education, and illness duration. The strongest correlations were between P300 and both shortterm memory and visual perception. Global cognitive deficits do not appear to relate to the abnormal P300 responses in PD: instead, specific aspects of cognitive decline accounted for the electrophysiological abnormalities. An abnormally long or absent P300 correlated with deficits on select cognitive tasks: those involving memory, visual perception, and abstract reasoning. The interactions between anatomical and neurochemical abnormalities in PD are discussed in light of the pattern of deficits seen in this study.     

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

OBJECTIVES: 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.METHODS: 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.RESULTS: 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.CONCLUSIONS: 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.     

Visual evoked potentials in children with occipital epilepsies

The objectives of this study are to see if any visual evoked potential (VEP) differences are present in two forms of occipital epilepsy, childhood epilepsy with occipital paroxysms (CEOP) and symptomatic occipital epilepsy (SOE) with respect to etiology, as CEOP is a benign age- and localization-related idiopathic epilepsy while SOE is a symptomatic form. Nineteen patients with CEOP and 13 patients with SOE were included in the study and P100 potential latency and amplitude values obtained from these patients were compared with the values recorded from normal controls. The amplitude values recorded from the patients with CEOP were significantly high (P=0.033). P100 potential latency values recorded in patients with SOE were significantly long (P=0.028). High amplitude VEP responses were mostly attributed to hyperexcitability of the occipital cortical structures whereas prolonged latency P100 responses were attributed to occipital structural changes.     

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 (mean 8.5 year follow up period); (3) to study the relation between clinical, neuropsychological, and MRI data. On follow up assessment, visual and auditory oddball event related potentials (ERPs) were recorded as psychophysiological evaluation of cognitive status. Correlations between neuropsychological, MRI, and ERP data were also analysed. METHODS: Neuropsychological study assessed verbal and non-verbal IQ, deterioration index (DI) from WAIS subtests, conceptual reasoning, attention, verbal and visuospatial short-term and long term memory. MRI assessment detected presence of demyelinating lesions by using a semiquantitative method as well as cortical and subcortical atrophy over time. RESULTS: Attention, short-term and long term visuospatial memory were mildly impaired at baseline and remained unaltered longitudinally. At retesting a significant worsening of verbal long term memory (p=0.023), DI presence (p=0.041) and the increase of supratentorial and subtentorial MRI lesions load (p=0.001) emerged. Expanded disability status scale score correlated significantly with total lesion burden at both evaluations (p=0.043 and p=0.024 respectively). Temporal, occipital, and frontal horn lesions as well as cortical atrophy correlated significantly with attention and memory tests at baseline. Follow up assessment revealed significant correlation between cortical atrophy and attention as well as visuospatial short-term memory; spatial long term memory correlated significantly with lesions in body of lateral ventricle and frontal lobe. ERP study showed P300 latency abnormalities in 75% of patients, involving specifically more visual P300 (58.4 % of cases) than auditory wave (41.6 %). Visual P300 latency and amplitude correlated significantly with DI and auditory P300 latency with frontal horn and brain stem lesions. CONCLUSIONS: These findings revealed mild cognitive impairment in MS patients particularly consistent with slowing information processing over time. Increased MRI lesions do not correlate with the clinical course of the disease and cognitive deficit evolution. Thus, cognitive dysfunction could be related to disease peculiarity and not to the time course. Correlations between P300, neuropsychological, and MRI findings provide further information about ERP application to examine cognitive impairment in MS and probably to investigate their neural origin.     

Event-related potentials and neuropsychological tests in obsessive-compulsive disorder

OBJECTIVE: Previous studies have provided evidence from event-related potentials (ERPs) and neuropsychological testing of abnormal cognitive processing in obsessive-compulsive disorder (OCD). The aim of this study was to further characterize the cognitive functions of the patients with OCD by utilizing ERPs and neuropsychological tests. METHODS: ERPs were recorded in a group of 31 drug-free OCD patients without depression and 30 normal controls following verbal auditory stimuli using an oddball paradigm. The specific neuropsychological tests administered to assess cognitive functions in all participants were the Stroop Test, Trail Making Test, Design Fluency Test, Controlled Word Association Test (Verbal Fluency test). RESULTS: The patient group showed shorter P300 duration compared to normal controls. In neuropsychological tests, no significant differences were found between the two groups. Negative correlations between Stroop duration and P300 amplitudes in occipital, parietal, and temporal anterior regions were observed. CONCLUSION: Shorter P300 duration may indicate an acceleration in the P300 process, and speeding of cognitive processing, dysfunction of cortico-subcortical circuits, or some combination of all of the above.     

Benign childhood epilepsy with occipital paroxysms: neuropsychological findings

Benign childhood epilepsy with occipital paroxysms is classified among childhood benign partial epilepsies. The absence of neurological and neuropsychological deficits has long been considered as a prerequisite for a diagnosis of benign childhood partial epilepsy. Much evidence has been reported in literature in the latest years suggesting a neuropsychological impairment in this type of epilepsy, particularly in the type with Rolandic paroxysms. The present work examines the neuropsychological profiles of a sample of subjects affected by the early-onset benign childhood occipital seizures (EBOS) described by Panayotopulos. The patient group included 22 children (14 males and 8 females; mean age 10.1+/-3.3 years) diagnosed as having EBOS. The patients were examined with a set of tests investigating neuropsychological functions: memory, attention, perceptive, motor, linguistic and academic (reading, writing, arithmetic) abilities. The same instruments have been given to a homogeneous control group as regards sex, age, level of education and socio-economic background. None of the subjects affected by EBOS showed intellectual deficit (mean IQ in Wechsler Full Scale 91.7; S.D. 8.9). Results show a widespread cognitive dysfunction in the context of a focal epileptogenic process in EBOS. In particular, children with EBOS show a significant occurrence of specific learning disabilities (SLD) and other subtle neuropsychological deficits. We found selective dysfunctions relating to perceptive-visual attentional ability (p<0.05), verbal and visual-spatial memory abilities (p<0.01), visual perception and visual-motor integration global abilities (p<0.01), manual dexterity tasks (p<0.05), some language tasks (p<0.05), reading and writing abilities (p<0.01) and arithmetic ability (p<0.01). The presence of cognitive dysfunctions in subjects with EBOS supports the hypothesis that epilepsy itself plays a role in the development of neuropsychological impairment. Supported by other studies that have documented subtle neuropsychological deficits in benign partial epilepsy, we stress the importance of reconsidering its supposed "cognitive benignity", particularly in occipital types.     

双相障碍抑郁发作患者认知功能损害及与听觉P300改变的关系

目的:探讨双相障碍抑郁发作患者认知功能损害和听觉P300变化的关系.方法:采用重复性神经心理状态测验(RBANS)及听觉诱发电位检测方法对43例首次发病未服药的双相障碍抑郁发作患者(病例组)及45名健康志愿者(对照组)进行认知功能及P300指标检测;结果 进行组间比较和分析.采用汉密尔顿抑郁量表(HAMD)评估病例组患...     

P300 under standard and surprise conditions in self-reported impulsive aggression

1. The purpose of the present study was to determine the cognitive psychophysiological correlates of impulsive aggression in a "high" functioning sample: college students. 2. Visual P300 was measured during a standard oddball task and a surprise task that included unexpected low probability stimuli. 3. Results indicated significantly reduced P300 amplitude and prolonged latency for impulsive aggressive subjects to target stimuli on the standard task. Target amplitude differences where further augmented under conditions involving unexpected stimuli although no significant latency differences were observed. The topography of P300 amplitude to unexpected stimuli differed from that of the target. 4. Topographic group differences found for unexpected stimuli are suggestive of cognitive processing deficits previously demonstrated using neuropsychological techniques in impulsive aggressive individuals.     

Frontal P300 Decrement and Executive Dysfunction in Adolescents with Conduct Problems

This study investigated the cognitive and cerebral function of adolescents with conduct problems by neuropsychological battery (STIM) and event-related potential (ERP). Eighteen adolescents with conduct disorder, and 18 age-matched normal subjects were included. Such cognitive functions as attention, memory, executive function and problem solving were evaluated using subtests of STIM. ERP was measured using an auditory oddball paradigm. The conduct group showed a significantly lower hit rate on the Wisconsin Card Sorting Test (WCST) than the control group. In addition, the conduct group showed reduced P300 amplitude at Fz and Cz, and prolonged P300 latency at Fz, and there was a significant correlation between P300 amplitude and Stroop test performance. These results indicate that adolescents with conduct problems have impairments of executive function and inhibition, and that these impairments are associated with frontal dysfunction.     

Neuropsychological testing of patients with borderline personality disorder

OBJECTIVE AND METHOD: This study examined whether a battery of neuropsychological tests could detect cognitive deficits--particularly in the areas of perception, learning, and memory--in patients with borderline personality disorder. The test battery was completed by 16 research outpatients with borderline personality disorder, typified by behavioral dyscontrol and diagnosed according to DSM-III-R criteria and the Diagnostic Interview for Borderline Patients. A comparison group of 16 normal volunteers also completed the test battery. RESULTS: The performance of the borderline patients was significantly impaired in comparison with that of the normal group on memory tests requiring uncued recall of complex, recently learned material. Cues given on an auditory memory task partially corrected that deficit. The patients' performance was also significantly impaired on several visual perceptual tests. These deficits do not appear to have been attributable to attentional problems, psychomotor impairment, current major depression, or history of alcohol abuse. CONCLUSIONS: The observed difficulties in separating essential from extraneous visual information and in recalling complex material may be relevant in understanding some of the clinical features of borderline personality disorder. The observed memory improvement resulting from cueing suggests specific strategies that may be used to aid patients' recall of complex material.     

Neurophysiological basis of cognitive deficits in long-term survivors of childhood cancer.

Thirty-three survivors of childhood cancer were tested with event-related potentials (P300), motor reaction time tests, and neuropsychological tests to assess the underlying physiological basis of treatment-related cognitive sequelae. Thirteen patients had received intrathecal chemotherapy, 11 had received intrathecal chemotherapy plus cranial radiotherapy, and nine had been treated without any form of central nervous system therapy. Neuropsychological performance of the groups treated without cranial radiotherapy was normal, but the group given cranial radiotherapy was significantly impaired. Mean reaction time and P300 latency were somewhat slower in the group given intrathecal chemotherapy relative to the group given no central nervous system treatment, but were significantly delayed in the group given cranial radiotherapy. Correlations of reaction time and P300 latency with neuropsychological test scores were also obtained. Results suggest that slowing of cortical activity secondary to white-matter damage may underlie cognitive decline in children treated with intensive central nervous system therapies, especially cranial radiotherapy.     

Modality dependent changes in event-related potentials correlate with specific cognitive functions in nondemented patients with Parkinson's disease

Summary The relationship between event-related potentials (ERPs) and cognitive functioning was studied in patients with Parkinson's Disease (PD) but without dementia. Auditory and visual stimuli were used; 30 subjects participated in the auditory study and 20 in the visual study. Patient groups did not differ with respect to gender, age, education, illness duration, and level of cognitive functioning. Visual stimuli were 2.3 cpd sinusoidal grating patterns randomly presented in an oddball paradigm (oblique vs. vertical spatial orientation). Auditory stimuli were tones presented at 70dB SPL at a rate of 1.1/second, also using the oddball paradigm (1.5K vs. 1K tones). All patients were given neuropsychological tests to measure verbal fluency, memory, visual spatial perception, and abstract reasoning. P300 and N200 abnormalities correlated with a number of these measures, such that longer ERP latencies were related to lower scores on tests of cognitive functioning. Patterns of results suggest that auditory and visual ERPs correlate with different subsets of neuropsychological functions in nondemented PD patients and that N200 may provide a new metric for clinical use.     

Relationships between event-related potentials and neuropsychological tests in neurologically healthy adults.

The aim of this study was to investigate the relationship between conventional neuropsychological tests and an event-related potential (P300). Subjects were 118 neurologically normal healthy adults 18-74 years old with no history of neurological, neurosurgical, or psychiatric disorders. We administered a neuropsychological test battery and recorded auditory P300 in all subjects. A significant correlation was seen between P300 latency and age, but not between amplitude and age. While significant negative correlations were apparent between some neuropsychological tests and age and P300 latency, stepwise regression analysis to assess the significance of each factor determined that age alone correlated with P300 latency. We therefore concluded that P300 measurements cannot be replaced by neuropsychological tests; rather, brain function should be evaluated by both methods.     

P300 auditory event-related potentials and neuropsychological study during donepezil treatment in vascular dementia

Abstract After Alzheimer’s disease (AD), vascular dementia (VaD) is the most common cause of dementia among the elderly. Abnormalities in neurotransmitter pathways are common pathogenic mechanisms shared by AD and VaD. For one month we studied the effects of donepezil, an acetylcholinesterase inhibitor (5 mg daily), on the cognitive system using P300 auditory event-related potentials (P300) and neuropsychological tests in 10 patients affected by probable VaD according to the NINDS-AIREN criteria. Our data showed a significant improvement of neuropsychological items and P300 latency after one month of donepezil treatment. In conclusion both P300 and neuropsychological tests are indicated in patients with VaD to confirm the efficacy of donepezil treatment during follow-up.     

P300 and neuropsychological evaluation in Behçet’s disease with and without neurological manifestations

Abstract. We evaluated cognitive dysfunction in Behçets disease (BD) with and without neurological manifestations by P300 and neuropsychological tests. Thirtyfour BD patients without neurological manifestations, eighteen BD patients with neurological manifestations and 15 controls were studied. P300 potentials and neuropsychological tests were performed. P300 latency values and neuropsychological tests were not significantly different from the normal controls in BD patients without neurological manifestations. In neurologically symptomatic patients attention and memory deficits and delayed P300 potentials were found.     

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.     

Neuropsychological correlates of P300 abnormalities in patients with schizophrenia and obsessive-compulsive disorder

The cognitive significance of P300 abnormalities in schizophrenia and obsessive-compulsive disorder (OCD) was investigated. P300 was measured by an auditory oddball paradigm, in which a series of standard tones (1000 Hz) and target tones (1500 Hz) were presented. The subject's task was to count the number of the presented target tones. Cognitive functions were evaluated by neuropsychological tests, which were chosen to be sensitive to frontal and temporal dysfunction. Twenty-two schizophrenic patients, 19 OCD patients and 21 healthy controls participated. Event-related potentials measured at 15 electrode sites, which consisted of five levels on the left-right dimension and three levels on the anterior-posterior dimension, were included in the statistical analysis. P300 amplitudes on all 15 electrode sites were significantly smaller in schizophrenic and OCD patients than in the controls. Schizophrenic patients performed poorly on almost all neuropsychological tests, while OCD patients showed impaired performance on the Rey-Osterrieth Complex Figure Test and on a controlled oral word association test. In schizophrenic patients, P300 amplitude was associated with performance on verbal memory and learning by the Luria-Nebraska Neuropsychological Battery, while for OCD patients, P300 amplitude was related to the Trail Making Test, Part B response time. These results indicate that schizophrenic patients have generalized cognitive impairments, which are substrated by a wide range of cortical dysfunctions. The major cognitive deficits observed in OCD patients were impairments of controlled attention and self-guided, flexible behavior, which are mediated by the fronto-striatal system. The neurophysiological mechanisms underlying P300 abnormalities observed in schizophrenic and OCD patients are discussed.     

Neuropsychological prediction of conversion to Alzheimer disease in patients with mild cognitive impairment

CONTEXT: The likelihood of conversion to Alzheimer disease (AD) in mild cognitive impairment (MCI) and the "optimal" early markers of conversion need to be established. OBJECTIVES: To evaluate conversion rates to AD in subtypes of MCI and to identify neuropsychological measures most predictive of the time to conversion. DESIGN: Patients were followed up semiannually and controls annually. Subtypes of MCI were determined by using demographically adjusted regression norms on neuropsychological tests. Survival analysis was used to identify the most predictive neuropsychological measures. SETTING: Memory disorders clinic. PARTICIPANTS: One hundred forty-eight patients reporting memory problems and 63 group-matched controls. MAIN OUTCOME MEASURE: A consensus diagnosis of probable AD. RESULTS: At baseline, 108 patients met criteria for amnestic MCI: 87 had memory plus other cognitive domain deficits and 21 had pure memory deficits. The mean duration of follow-up for the 148 patients was 46.6 +/- 24.6 months. In 3 years, 32 (50.0%) of 64 amnestic-"plus" and 2 (10.0%) of 20 "pure" amnestic patients converted to AD (P = .001). In 148 patients, of 5 a priori predictors, the percent savings from immediate to delayed recall on the Selective Reminding Test and the Wechsler Adult Intelligence Scale-Revised Digit Symbol Test were the strongest predictors of time to conversion. From the entire neuropsychological test battery, a stepwise selection procedure retained 2 measures in the final model: total immediate recall on the Selective Reminding Test (odds ratio per 1-point decrease, 1.10; 95% confidence interval, 1.05-1.14; P < .0001) and Digit Symbol Test coding (odds ratio, 1.06; 95% confidence interval, 1.01-1.11; P = .01). The combined predictive accuracy of these 2 measures for conversion by 3 years was 86%. CONCLUSIONS: Mild cognitively impaired patients with memory plus other cognitive domain deficits, rather than those with pure amnestic MCI, constituted the high-risk group. Deficits in verbal memory and psychomotor speed/executive function abilities strongly predicted conversion to AD.     

Cognition in Parkinson disease: An event-related potential perspective

Auditory event-related potentials (ERP) elicited in a target detection stimulus paradigm and pattern-shift visual ERPs were studied in 20 male patients with idiopathic Parkinson disease (PD) and 20 age-matched normal controls. Patients showed significantly increased latencies for both the P200 and P300 components of the auditory ERP. Patients and controls showed no significant differences in latency of the visual ERP but patients showed significantly decreased amplitude. Only one of five neuropsychological measures, the Symbol Digit Modalities test (SDMT), showed a significant negative correlation with P300 latency. The significant association between the two measures that showed impairments in the PD patients (P300 latency and SDMT scores) suggested that these measures reflect a common, disrupted aspect of cognitive function in PD.