Sexual differences of visual attention in cryptogenic partial epilepsy

The performance in visual verbal and non-verbal attentional tests was studied in 14 male and 18 female control subjects and 33 patients with cryptogenic partial epilepsy. The epileptic group was formed of 17 men and 16 women with no evidence of brain damage in CT scan examinations. Interictal epileptiform activity was observed only unilaterally, either in the right (8 male, 8 female) or left (9 male, 8 female) temporal lobes. The performance of epileptic men in visual tests was similar to that of normal men. On the other hand, the performance of epileptic women was worse than that of normal women. These results seem in accordance with the literature that suggests mat visual attention in women depends on the functional integrity of both cerebral hemispheres. In men, verbal visual attention is suggested to occur in the left cerebral hemisphere while non-verbal processes, predominantly in the right cerebral hemisphere. Further studies are necessary for the understanding of these sexual differences in cerebral hemispheric asymmetry.Estudamos o rendimento em testes de atenção visual verbal e não-verbal de 14 homens e 18 mulheres controles normais e 33 pacientes com epilepsia parcial criptogênica. O grupo epiléptico foi constituído de 17 homens e 16 mulheres sem evidência de lesões à tomografia computadorizada de crânio. As descargas epilépticas interictais localizavam-se unilateralmente, no lobo temporal direito (8 homens, 8 mulheres) ou no esquerdo (9 homens, 8 mulheres). O desempenho dos homens epilépticos foi semelhante ao dos homens controles. Por outro lado, o rendimento das mulheres epilépticas foi pior que o das mulheres controles. Estes resultados parecem de acordo com a literatura que sugere que a atenção visual nas mulheres dependa da integridade funcional dos dois hemisférios cerebrais. Os homens processariam basicamente os estímulos visuais verbais no hemisfério cerebral esquerdo e os não-verbais no hemisfério cerebral direito. São necessários estudos posteriores para o melhor entendimento dessas diferenças sexuais da assimetria funcional hemisférica.Escola Paulista de Medicina Setor de Investigação e Tratamento das EpilepsiasUNIFESP, EPM, Setor de Investigação e Tratamento das EpilepsiasSciEL

Epilepsies with midline foci: a study with quantitative and topographic EEG

We report a topographic and quantitative EEG (EEGQT) study of four patients with analogic EEG diagnostics of midline foci. the new study with EEGQT offered an increased definition of the electrical source with advantages in foci localization. These findings should be confirmed with studies including a greater number of patients.Hosp Servidor Publ Estado São Paulo, IAMSPE, Serv Neurol, São Paulo, BrazilUNIFESP, Escola Paulista Med, São Paulo, BrazilUNIFESP, Escola Paulista Med, São Paulo, BrazilWeb of Scienc

Wavelets analysis with support vector machine in Alzheimer\'s disease EEG

INTRODUÇÃO. O objetivo deste estudo foi responder se a transformada wavelet Morlet e as técnicas de aprendizagem de Máquina (ML), chamada Máquinas de Vetores de Suporte (SVM) são adequadas para procurar padrões no EEG que diferenciem controles normais de pacientes com DA. Não há um teste de diagnóstico específico para a doença de Alzheimer (DA). O diagnóstico da DA baseia-se na história clínica, neuropsicológica, exames laboratoriais, neuroimagem e eletroencefalografia. Portanto, novas abordagens são necessárias para permitir um diagnóstico mais precoce e preciso e para medir a resposta ao tratamento. EEG quantitativo (EEGq) pode ser utilizado como uma ferramenta de diagnóstico em casos selecionados. MÉTODOS: Os pacientes eram provenientes do Ambulatório do Grupo de Neurologia Cognitiva e do Comportamento (GNCC) da Divisão de Clínica Neurológica do HCFMUSP ou foram avaliados pelo grupo do Laboratório de Eletrencefalografia Cognitiva do CEREDIC HC-FMUSP. Estudamos EEGs de 74 indivíduos normais (33 mulheres/41 homens, com idade média de 67 anos) e 84 pacientes com provável DA leve a moderada (52 mulheres/32 homens, idade média de 74,7 anos. A transformada wavelet e a seleção de atributos foram processadas pelo software Letswave. A análise SVM dos atributos (bandas delta, teta, alfa e beta) foi calculada usando-se a ferramenta WEKA (Waikato Ambiente para Análise do Conhecimento). RESULTADOS: Na classificação dos grupos controles e DA obteve-se Acurácia de 90,74% e área ROC de 0,90. Na identificação de um único probando dentre todos os demais se conseguiu acurácia de 81,01% e área ROC de 0,80. Desenvolveu-se um método de processamento de EEG quantitativo (EEGq) para uso na diferenciação automática de pacientes com DA versus indivíduos normais. O processo destina-se a contribuir como complemento ao diagnóstico de demência provável principalmente em serviços de saúde onde os recursos sejam limitadosINTRODUCTION. The aim of this study was to answer if Morlet wavelet transform and machine learning techniques (ML), called Support Vector Machines (SVM) are suitable to look for patterns in EEG to differentiate normal controls from patients with AD. There is not a specific diagnostic test for Alzheimer\'s disease (AD). The diagnosis of AD is based on clinical history, neuropsychological testing, laboratory, neuroimaging and electroencephalography. Therefore, new approaches are needed to allow an early diagnosis and accurate to measure response to treatment. Quantitative EEG (qEEG) can be used as a diagnostic tool in selected cases. METHODS: The patients came from the Clinic Group Cognitive Neurology and Behavior (GNCC), Division of Clinical Neurology HCFMUSP or evaluated by the group of the Laboratory of Cognitive electroencephalography CEREDIC HCFMUSP. We studied EEGs of 74 normal subjects (33 females/41 men, mean age 67 years) and 84 patients with mild to moderate probable AD (52 females/32 men, mean age 74.7 years. Wavelet transform and the selection of attributes were processed by software Letswave. SVM analysis of attributes (bands delta, theta, alpha and beta) was calculated using the tool WEKA (Waikato Environment for Knowledge analysis). RESULTS: The group classification of controls and DA obtained an accuracy of 90.74% and ROC area 0.90. The identification of a unique proband among all others was achieved with accuracy of 81.01% and ROC area 0.80. It was developed a method of processing EEG quantitative (qEEG) for use in automatic differentiation of AD patients versus normal subjects. This process is intended to complement the diagnosis of probable dementia primarily in health services where resources are limite

qEEG spectral peak in Alzheimer's disease: A possible tool for treatment follow-up

Abstract qEEG spectral analysis has been considered highly sensitive to cortical functional changes and agrees strongly with the clinical diagnosis of AD. The sensitivity of spectral analysis has ranged from 71% to 81% in several studies.1-3. Objective: The aim of this study was to retrospectively evaluate whether alpha qEEG spectral peak can supplement clinical examination by constituting an independent tool to monitor treatment and follow-up of dementia progression in Alzheimer's disease (AD). In addition, we examined the demographic data and alpha power spectra distribution of patients and elderly normal controls. Methods: qEEGs were selected from 2 groups of patients: normal controls (n=30), and patients who fulfilled criteria for mild probable AD diagnosis (n=41). The alpha qEEG spectral analysis and MMSE were performed once or twice a year. Results: In our groups, MMSE scores and qEEG alpha spectral peak were unchanged (no statistical differences) after anticholinesterase use where qEEG spectral peak was never lower than 8 Hz in the control group. Conclusion: This study supports two important concepts. First, 8 Hz alpha appears to be the lowest awake spectral peak compatible with normality. And finally, in a clinical context, qEEG is a valuable diagnostic tool that could prove useful for Dementia follow-up

Quantitative and topographic EEG: a study of normal adult population

We studied the electric brain activity during wakefulness in 20 Brazilian people through digital EEG and spectral analysis in order to propose a standardization for Brazilian adult population. All this group is healthy with laboratory examinations and mini-mental state (scores higher than 27) evaluation normal. After Fourier fast transformation (FFT) calculation, we found a histogram display with monomodal distribution, with higher values in alpha band. Analyzing the average of these results, different standards from the analogical traditional EEG were found, as the distribution of alpha band and delta activity behavior. The beta 2 and beta 3 behavior showed a diffuse distribution, that is not the usual. By the other hand, other findings are congruent to the analogical EEG as the alpha posterior predominance and the bigger presence of theta activity at the central regions.IAMSPE, HSPE, Hosp Serv Publ Estado Sao Paulo, Sao Paulo, BrazilUNIFESP, Escola Paulista Med, Sao Paulo, BrazilIAMSPE, HSPE, Neurol Serv, Sao Paulo, BrazilUNIFESP, Escola Paulista Med, Sao Paulo, BrazilWeb of Scienc

The clinical use of quantitative EEG in cognitive disorders

Abstract The primary diagnosis of most cognitive disorders is clinically based, but the EEG plays a role in evaluating, classifying and following some of these disorders. There is an ongoing debate over routine use of qEEG. Although many findings regarding the clinical use of quantitative EEG are awaiting validation by independent investigators while confirmatory clinical follow-up studies are also needed, qEEG can be cautiously used by a skilled neurophysiologist in cognitive dysfunctions to improve the analysis of background activity, slow/fast focal activity, subtle asymmetries, spikes and waves, as well as in longitudinal follow-ups