RESUMO
This research assesses the brain activity and visual performance at baseline and after light therapy (LTH), of seventeen patients with strabismus and amblyopia (SA), and eleven healthy controls (HCs) from Querétaro, México. Quantitative electroencephalogram analysis (qEEG) was used to record the brain activity, and clinical metrics such as the visual acuity, angle of deviation, phoria state, stereopsis, and visual fields determined the visual performance. Results showed a constant higher alpha-wave frequency for HCs. Low voltages remained negative for HCs and positive for SA patients across stimulation. After LTH, high voltage increased in SA patients, and decreased in HCs. A second spectral peak, (theta-wave), was exclusively recorded in SA patients, at baseline and after LTH. Positive Spearman correlations for alpha-wave frequency, low and high voltages were only seen in SA patients. Synchronized brain activity was recorded in all SA patients stimulated with filters transmitting light in the blue but not in the red spectrum. Enhancement in the visual performance of SA patients was found, whereas deterioration of the phoria state and a decrease in the amount of stereopsis was seen in HCs. To conclude, only a suffering brain and a visual pathway which needs to be enabled can benefit from LTH.
RESUMO
The present study describes the electroencephalographic changes that occur during cerebral ischemia and reperfusion in animals submitted to transient focal cerebral ischemia by middle cerebral artery occlusion (MCAO) for 30 min. For this, male Wistar rats were divided into two groups (n = 6 animals/group): (1) sham (control) group, and (2) ischemic/reperfusion group. The quantitative electroencephalography (qEEG) was recorded during the ischemic and immediate reperfusion (acute) phases, and then once a day for 7 days after the MCAO (subacute phase). The acute phase was characterized by a marked increase in the relative delta wave band power (p < 0.001), with a smaller, but significant increase in the relative alpha wave bandpower in the ischemic stroke phase, in comparison with the control group (p = 0.0054). In the immediate reperfusion phase, however, there was an increase in the theta, alpha, and beta waves bandpower (p < 0.001), but no alteration in the delta waves (p = 0.9984), in comparison with the control group. We also observed high values in the delta/theta ratio (DTR), the delta/alpha ratio (DAR), and the (delta+theta)/(alpha+beta) ratio (DTABR) indices during the ischemia (p < 0.05), with a major reduction in the reperfusion phase. In the subacute phase, the activity of all the waves was lower than that of the control group (p < 0.05), although the DTR, DAR, and DTABR indices remained relatively high. In conclusion, early and accurate identification of decreased delta wave bandpower, DTR, DAR, and DTABR indices, and an increase in the activity of other waves in the immediate reperfusion phase may represent an important advance for the recognition of the effectiveness of reperfusion therapy.
RESUMO
We propose a method based on the ensemble Kalman filter (EnKF) together with quantitative electroencephalogram (QEEG) coherence and power spectrum analysis for evaluating changes in brain activity associated with cognitive processes. Such analysis framework has been widely used in the context of data assimilation (DA) in areas such as geosciences, meteorology, and aerospace. However, the use of this approach is less common in neurosciences. In our case, EnKF highlights the spectral contribution of brain signals that are more likely (according to their coherence analysis) to be related to the cognitive process of interest. The power enhancement, due to the cognitive activity, is later validated in the power spectrum analysis by comparing through statistical tests relevant frequency content in two datasets in which assessing the development of cognitive abilities is of interest: the process of getting concentrated and of learning a new skill. Our results show that our DA-based methodology can highlight important frequency characteristics of the electroencephalogram (EEG) data that have been related to different cognitive processes. Hence, our proposal has the potential to understand of neurocognitive phenomena that is tracked through QEEG.
RESUMO
Stress is a response in which an individual wants to have more control over a situation. A constant state of stress is called anxiety. Some patients deny symptoms. An instrument can help arrive at a diagnosis. OBJECTIVE: Using TQ-7 QEEG, this study aimed to evaluate the association of symptoms of anxiety, insecurity, fear, panic and phobia with hot temporals defined as Beta (15-23 Hz) >17% and High-Beta waves (23-38 Hz) >10% at T3 and T4. METHODS: Five hundred and forty-three patients of both genders with ages ranging from 16-59 years were evaluated, divided into two groups: Control (without hot temporals: n=274) and Case Group (with hot temporals: n=269). The Chi-square test was used (p-values ≤0.05). RESULTS: There was a significant association (p-value <0.001) between the symptoms related to amygdala activation, expressed in the temporals (Beta >17% and High-Beta >10%). (Anxiety, T3=89.6% - T4=88.8%; T3=92.6% - T4=93.3%), (Fear, T3=80.7% - T4=84.4%; T3=82.9% - T4=95.9%), (Insecurity, T3=82.2% - T4=81.4%; T3=69.5% - T4=97.8%), (Panic, T3=52.4 - T4=72.5%; T3=90.3% - T4=74.0%), (Phobia, T3=17.5% - T4=22.7%; T3=19.7% - T4=27.1%), when compared to the respective controls (Beta control, T3=8.4%, 10.2%, 21.2%, 1.1%, 0.4% and T4=11.3%, 4.4%, 23.0%, 2.6%, 1.1%) (High-Beta control, T3=4.0%, 6.9%, 6.2%, 0.4%, 0.0% and T4=17.5%, 6.2%, 3.3%, 4.0%, 0.7%). CONCLUSION: Anxiety, insecurity, fear, panic and phobia are observed by QEEG when the levels of total Beta >17% and High-Beta waves >10% at T3 and T4.
O estresse é uma resposta a uma situação na qual, um indivíduo quer ter mais controle. Um estado de estresse constante é chamado de ansiedade. Alguns pacientes negam sintomas. Um instrumento pode auxiliar um diagnóstico. OBJETIVO: Utilizando o QEEG TQ-7, este estudo objetivou avaliar a associação dos sintomas de ansiedade, insegurança, medo, pânico e/ou fobia com a categoria de temporais quentes definidos como Beta (15-23 Hz) >17% e Beta-Alta (23-38 Hz) >10% em T3 e T4. MÉTODOS: Foram avaliados 543 pacientes de ambos os gêneros na faixa etária de 16-59 anos, divididos: Controle (sem temporais quentes: n=274) Grupo estudado (com temporais quentes: n=269). Foi utilizado o teste qui-quadrado (p-valor ≤0.05). RESULTADOS: Houve associação significativa (p-valor <0.001) entre os sintomas relacionados à ativação da amigdala, expressos nos temporais (Beta >17% e Beta-Alta >10%). (Ansiedade, T3=89,6% - T4=88,8%; T3=92,6% - T4=93,3%), (Medo, T3=80,7% - T4=84,4%; T3=82,9% - T4=95,9%), (Insegurança, T3=82,2% - T4=81,4%; T3=69,5% - T4=97,8%), (Pânico, T3=52.4% - T4=72.5%; T3=90.3% - T4=74.0%), (Fobia, T3=17,5% - T4=22,7%; T3=19,7% - T4=27,1%), quando comparados aos respectivos controles (Beta controle, T3=8,4%, 10,2%, 21,2%, 1,1%, 0,4% e T4=11,3%, 4,4%, 23,0%, 2,6%, 1,1%) e (Beta-Alta Controle, T3=4,0%, 6,9%, 6,2%, 0,4%, 0,0%; T4=17,5%, 6,2%, 3,3%, 4,0%, 0,7%). CONCLUSÃO: Ansiedade, insegurança, medo, pânico e fobia são observados no QEEG, quando Beta >17% e Beta-Alta >10% em T3 e T4.
RESUMO
ABSTRACT: Stress is a response in which an individual wants to have more control over a situation. A constant state of stress is called anxiety. Some patients deny symptoms. An instrument can help arrive at a diagnosis. Objective: Using TQ-7 QEEG, this study aimed to evaluate the association of symptoms of anxiety, insecurity, fear, panic and phobia with hot temporals defined as Beta (15-23 Hz) >17% and High-Beta waves (23-38 Hz) >10% at T3 and T4. Methods: Five hundred and forty-three patients of both genders with ages ranging from 16-59 years were evaluated, divided into two groups: Control (without hot temporals: n=274) and Case Group (with hot temporals: n=269). The Chi-square test was used (p-values ≤0.05). Results: There was a significant association (p-value <0.001) between the symptoms related to amygdala activation, expressed in the temporals (Beta >17% and High-Beta >10%). (Anxiety, T3=89.6% - T4=88.8%; T3=92.6% - T4=93.3%), (Fear, T3=80.7% - T4=84.4%; T3=82.9% - T4=95.9%), (Insecurity, T3=82.2% - T4=81.4%; T3=69.5% - T4=97.8%), (Panic, T3=52.4 - T4=72.5%; T3=90.3% - T4=74.0%), (Phobia, T3=17.5% - T4=22.7%; T3=19.7% - T4=27.1%), when compared to the respective controls (Beta control, T3=8.4%, 10.2%, 21.2%, 1.1%, 0.4% and T4=11.3%, 4.4%, 23.0%, 2.6%, 1.1%) (High-Beta control, T3=4.0%, 6.9%, 6.2%, 0.4%, 0.0% and T4=17.5%, 6.2%, 3.3%, 4.0%, 0.7%). Conclusion: Anxiety, insecurity, fear, panic and phobia are observed by QEEG when the levels of total Beta >17% and High-Beta waves >10% at T3 and T4.
RESUMO: O estresse é uma resposta a uma situação na qual, um indivíduo quer ter mais controle. Um estado de estresse constante é chamado de ansiedade. Alguns pacientes negam sintomas. Um instrumento pode auxiliar um diagnóstico. Objetivo: Utilizando o QEEG TQ-7, este estudo objetivou avaliar a associação dos sintomas de ansiedade, insegurança, medo, pânico e/ou fobia com a categoria de temporais quentes definidos como Beta (15-23 Hz) >17% e Beta-Alta (23-38 Hz) >10% em T3 e T4. Métodos: Foram avaliados 543 pacientes de ambos os gêneros na faixa etária de 16-59 anos, divididos: Controle (sem temporais quentes: n=274) Grupo estudado (com temporais quentes: n=269). Foi utilizado o teste qui-quadrado (p-valor ≤0.05). Resultados: Houve associação significativa (p-valor <0.001) entre os sintomas relacionados à ativação da amigdala, expressos nos temporais (Beta >17% e Beta-Alta >10%). (Ansiedade, T3=89,6% - T4=88,8%; T3=92,6% - T4=93,3%), (Medo, T3=80,7% - T4=84,4%; T3=82,9% - T4=95,9%), (Insegurança, T3=82,2% - T4=81,4%; T3=69,5% - T4=97,8%), (Pânico, T3=52.4% - T4=72.5%; T3=90.3% - T4=74.0%), (Fobia, T3=17,5% - T4=22,7%; T3=19,7% - T4=27,1%), quando comparados aos respectivos controles (Beta controle, T3=8,4%, 10,2%, 21,2%, 1,1%, 0,4% e T4=11,3%, 4,4%, 23,0%, 2,6%, 1,1%) e (Beta-Alta Controle, T3=4,0%, 6,9%, 6,2%, 0,4%, 0,0%; T4=17,5%, 6,2%, 3,3%, 4,0%, 0,7%). Conclusão: Ansiedade, insegurança, medo, pânico e fobia são observados no QEEG, quando Beta >17% e Beta-Alta >10% em T3 e T4.
Assuntos
Humanos , Estresse Psicológico/diagnóstico por imagem , Ansiedade , Pânico , Eletroencefalografia/métodosRESUMO
BACKGROUND: Presenilin-1 (PSEN1) mutations are the most common cause of familial early onset Alzheimer's disease (AD). The PSEN1 E280A (E280A) mutation has an autosomal dominant inheritance and is involved in the production of amyloid-ß. The largest family group of carriers with E280A mutation is found in Antioquia, Colombia. The study of mutation carriers provides a unique opportunity to identify brain changes in stages previous to AD. Electroencephalography (EEG) is a low cost and minimally invasiveness technique that enables the following of brain changes in AD. OBJECTIVE: To examine how previous reported differences in EEG for Theta and Alpha-2 rhythms in E280A subjects are related to specific regions in cortex and could be tracked across different ages. METHODS: EEG signals were acquired during resting state from non-carriers and carriers, asymptomatic and symptomatic subjects from E280A kindred from Antioquia, Colombia. Independent component analysis (ICA) and inverse solution methods were used to locate brain regions related to differences in Theta and Alpha-2 bands. RESULTS: ICA identified two components, mainly related to the Precuneus, where the differences in Theta and Alpha-2 exist simultaneously at asymptomatic and symptomatic stages. When the ratio between Theta and Alpha-2 is used, significant correlations exist with age and a composite cognitive scale. CONCLUSION: Theta and Alpha-2 rhythms are altered in E280A subjects. The alterations are possible to track at Precuneus regions using EEG, ICA, and inverse solution methods.
Assuntos
Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Ondas Encefálicas/genética , Lobo Parietal/fisiopatologia , Polimorfismo de Nucleotídeo Único/genética , Presenilina-1/genética , Adulto , Alanina/genética , Doença de Alzheimer/complicações , Doença de Alzheimer/fisiopatologia , Mapeamento Encefálico , Ondas Encefálicas/fisiologia , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/genética , Eletroencefalografia , Feminino , Ácido Glutâmico/genética , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Análise de Componente Principal , Escalas de Graduação Psiquiátrica , Adulto JovemRESUMO
PURPOSE: Understanding the neural mechanisms of stroke recovery is of paramount importance for neurorehabilitation. METHODS: For this purpose, we analyzed several TMS and EEG variables and their association with motor recovery. Thirty-five subjects with chronic stroke were recruited. The neurophysiological examination included assessments by transcranial magnetic stimulation (TMS), intra- and inter-hemispheric EEG coherence in different frequency bands (e.g. alpha (8-13âHz)) as determined by quantitative electroencephalography (qEEG). Motor function was measured by Fugl-Meyer (FM). Multiple univariate and multivariate linear regression analyses were performed to identify the predictors for FM. RESULTS: Multivariate analyses, showed a significant interaction effect of motor threshold (MT) in the lesioned hemisphere and beta coherence in the unlesioned hemisphere. This interaction suggests that higher beta activity in the unlesioned hemisphere strengthens the negative association between MT and FM scores. CONCLUSIONS: Our results suggest that MT in the lesioned hemisphere is the strongest predictors of motor recovery after stroke. Moreover, cortical activity in the unlesioned hemisphere measured by qEEG provides additional information, specifying the association between MT and FM scores. Therefore, complementary application of EEG and TMS can help constitute a better model of the lesioned and the unlesioned hemispheres that supports the importance of bihemispheric activity in recovery.
Assuntos
Encéfalo/fisiopatologia , Eletroencefalografia , Atividade Motora/fisiologia , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Estimulação Magnética Transcraniana , Doença Crônica , Eletroencefalografia/métodos , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Recuperação de Função Fisiológica/fisiologia , Estimulação Magnética Transcraniana/métodosRESUMO
The present study analyzed absolute theta power (ATP) in brain areas involved with attention in the three phase of BD while the patients performing a saccadic attention task. We hypothesized that patients in depression and mania states show a higher ATP compared to euthymic patients, since a higher ATP is indicative of attention deficit. We analyzed the frontal (F7, F3, Fz, F4 and F8) and central (C3, Cz and C4) areas. Thirty bipolar patients were enrolled in this study. The subjects performed a saccadic attention task while their brain activity pattern was recorded using quantitative electroencephalography (20 channels). Our results showed a main effect for group over C3, C4, Cz, F7, F4, F8 electrodes, and a main effect for moment over Cz, F7, F8 electrodes. These results indicate that both task and groups produce changes in theta activity in distinct cortical areas that participate in the organization of attention. Our results therefore demonstrate that, although it is well established in the literature that theta has a relevant role in the attention process, it is necessary to deepen the investigations to better understand the specifics of theta during visual processing tasks that have a demand for attention.
Assuntos
Atenção/fisiologia , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/fisiopatologia , Eletroencefalografia , Movimentos Sacádicos/fisiologia , Ritmo Teta/fisiologia , Adulto , Transtorno Bipolar/psicologia , Mapeamento Encefálico , Córtex Cerebral/fisiopatologia , Feminino , Lobo Frontal/fisiopatologia , Humanos , Masculino , Processamento de Sinais Assistido por Computador , Estatística como AssuntoRESUMO
Bromazepam is a benzodiazepine, which has been widely employed in the treatment of anxiety. We investigated the electrophysiological changes in absolute theta power within the frontal cortex when individuals performed a visuomotor task under bromazepam. The sample of 17 healthy individuals was randomized into 2 experimental conditions, under which bromazepam 6 mg and placebo were administered on different days. All subjects were right -handed, with no mental or physical illness and were not using any psychoactive or psychotropic substance during the entire period of the study. We found an increase in reaction time under bromazepam compared with placebo . With regard to the electrophysiological variable, we found a lower theta power value in the prefrontal cortex prior to task execution, compared with after. We therefore suggested that this could be an increase of neural activity in this region, because of the subjects' readiness to perform the task, that is, because of their higher alertness. The right lateral frontal region showed lower theta power under bromazepam for pre- and post-finger movement. This could have occurred because of more effort to execute the task. In the left frontal region: premovement did not demonstrate any difference between conditions, possibly because the proposed task was simple to execute. In conclusion, theta power plays an important role in the analysis of visuomotor performance, assuming that bromazepam causes impairment on sustained attention and sensory perception.
Assuntos
Ansiolíticos/farmacologia , Atenção/efeitos dos fármacos , Bromazepam/farmacologia , Eletroencefalografia , Lobo Frontal/efeitos dos fármacos , Desempenho Psicomotor/efeitos dos fármacos , Ritmo Teta/efeitos dos fármacos , Acelerometria , Adolescente , Adulto , Método Duplo-Cego , Feminino , Voluntários Saudáveis , Humanos , Masculino , Testes Neuropsicológicos , Estimulação LuminosaRESUMO
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.
A análise espectral do EEG tem sido considerada muito sensível para mudanças da função cortical e compatível com o diagnóstico clínico da Doença de Alzheimer (DA). A sensibilidade da análise espectral varia de 71% a 81% em alguns estudos.1-3. OBJETIVO: A proposta deste estudo foi uma avaliação retrospectiva sobre a possibilidade do pico espectral do alfa no EEG quantitativo (EEGq) complementar o exame clínico fornecendo uma ferramenta independente para monitorizar o tratamento e para seguimento da progressão da demência na DA. Além disso, foram examinados dados demográficos e a distribuição do espectro da potência alfa de pacientes e controles da mesma idade. MÉTODOS: EEGq foram selecionados de dois grupos de pacientes: os controles sem alterações e queixas de memória (n=30) e os pacientes com critérios preenchidos para DA provável (n=41). A análise do pico espectral do alfa no EEGq e o Mini-Exame do Estado Mental foram realizados uma ou duas vezes no ano. RESULTADOS: Neste grupo estudado, o Mini-Exame do Estado Mental e o pico espectral do alfa no EEGq não foram estatisticamente diferentes depois do uso de anticolinesterásicos e o pico espectral do EEGq não foi menor do que 8 Hz em todos indivíduos do grupo controle. CONCLUSÃO: Este estudo sustenta dois conceitos importantes. Primeiro, 8 Hz de pico espectral de alfa, em vigília, aparenta ser o menor valor compatível com normalidade. E finalmente, em contexto clínico, EEGq é uma ferramenta que pode ser útil no seguimento da de Demência.