Research on enhancement of mental rotation ability based on transcranial direct current stimulation / 生物医学工程学杂志

Transcranial direct current stimulation (tDCS) is a non-invasive low-current brain stimulation technique, which is mainly based on the different polarity of electrode stimulation to make the activation threshold of neurons different, thereby regulating the excitability of the cerebral cortex. In this paper, healthy subjects were randomly divided into three groups: anodal stimulation group, cathodal stimulation group and sham stimulation group, with 5 subjects in each group. Then, the performance data of the three groups of subjects were recorded before and after stimulation to test their mental rotation ability, and resting state and task state electroencephalogram (EEG) data were collected. Finally, through comparative analysis of the behavioral data and EEG data of the three groups of subjects, the effect of electrical stimulation of different polarities on the three-dimensional mental rotation ability was explored. The results of the study found that the correct response time/accuracy rate and the accuracy rate performance of the anodal stimulation group were higher than those of the cathodal stimulation and sham stimulation groups, and there was a significant difference (

Changes of electroencephalography power spectrum during joint position perception test after anterior cruciate ligament rupture / 北京大学学报(医学版)

OBJECTIVE@#To measure the electroencephalography (EEG) of the patients with anterior cruciate ligament (ACL) rupture when performing joint position perception movement task, to compare the differences between the ACL rupture side and the unaffected side, to identify the EEG change in the power spectrum caused by the ACL rupture, and to provide evidence for the diagnosis, treatment and rehabi-litation for ACL injury as well as knee instability.@*METHODS@#Sixteen male patients, selected from the Department of Sports Medicine, Peking University Third Hospital from November 2014 to April 2015, with only ACL rupture on one side used isokinetic muscle strength testing equipment were enrolled in the study to perform unilateral active knee joint positional movement and passive knee joint positional movement tasks. EEG was recorded to compare between the affected and unaffected limb of ACL rupture patients when doing single leg movement tasks, including passive knee joint position test and active knee joint position sensation test. The target position of the active knee joint position movement task and the passive knee joint position movement task was 30 degrees of knee flexion.@*RESULTS@#During the passive knee joint position test, there was no significant difference in EEG power spectrum of Delta[F (1, 15)=0.003, P=0.957, ηP2 =0.001], Theta[F (1, 15)=0.002, P=0.962, ηP2 < 0.001], Alpha[F (1, 15)=0.002, P=0.966, ηP2 =0.001], Beta[F (1, 15)=0.008, P=0.929, ηP2 =0.001] at Fz, Cz, and Pz between the affected and unaffected limbs in the ACL patients. During the active knee joint position movement task, the EEG power spectrum of Delta, Theta, Alpha, Beta at Fz and Cz location, on the affected side was significant higher than on the unaffected side.@*CONCLUSION@#This study compared the differences between the ACL rupture side and the unaffected side during active knee position movement task and passive knee position movement task, and identifyied the EEG changes in the power spectrum caused by the ACL rupture, It was found that the central changes caused by unilateral ACL rupture still existed during contralateral (unaffected) side movement. The EEG power spectrum of the affected side during active exercise was significantly higher than that of the unaffected side This study provides new electrophysiological evidence for the study of ACL injury.

Characteristics of Electroencephalogram Power Spectrum Network on Uninjured Side of Post-stroke Aphasia / 中国康复理论与实践

Objective:To clarify the characteristics of electroencephalogram (EEG) power spectrum network of right hemisphere in patients with post-stroke aphasia (PSA) after left brain damaged. Methods:From December, 2018 to June, 2019, twelve PSA patients with left hemisphere injury were recruited and twelve healthy adults were matched as control group. China Rehabilitation Research Center aphasia examination (CRRCAE) was used to evaluated the linguistic function, and the EEG was collected. The functional connection characteristics of Alpha and Theta power spectrum were compared, and the correlation with language items was analyzed. Results:In PSA patients, the functional connection enhanced in Alpha and Theta frequency bands of central area, frontal, parietal and frontal-parietal joint areas, and decreased in Theta frequency bands of temporoparietal, parietal-occipital area, frontal, fronta-parietal and frontal central areas. The enhancement of alpha frequency functional connection from the right parietal occipital region to the central region was significantly correlated to the reduction of the expression ability (P < 0.05), while the weakening of theta frequency functional connection between the right parietal occipital region and the forehead and the center of the forehead was significantly correlated to the ability of speaking, reading, copying, dictation and calculation (r = -0.676~-0.717, P < 0.05). Conclusion:EEG power spectrum network can reflect the reorganization of right brain function network, and the change of right frontal parietal central network function connection may be closely related to PSA language injury and recovery.

EEG Signal Analysis Methods and Their Applications / 中国医疗器械杂志

EEG is a weak physiological electrical signal, which has important value in clinical and laboratory research. This paper mainly introduces several common methods of EEG signal processing, including power spectrum analysis, time-frequency analysis, bispectral analysis, etc, it mainly introduces their principles and applications in EEG signal processing, and provides methods and approaches for studying EEG.

Prediction of recurrence of paroxysmal atrial fibrillation based on RR interval / 生物医学工程学杂志

Atrial fibrillation (AF) is one of the most common arrhythmias, which does great harm to patients. Effective methods were urgently required to prevent the recurrence of AF. Four methods were used to analyze RR sequence in this paper, and differences between Pre-AF (preceding an episode of AF) and Normal period (far away from episodes of AF) were analyzed to find discriminative criterion. These methods are: power spectral analysis, approximate entropy (ApEn) and sample entropy (SpEn) analysis, recurrence analysis and time series symbolization. The RR sequence data used in this research were downloaded from the Paroxysmal Atrial Fibrillation Prediction Database. Supporting vector machine (SVM) classification was used to evaluate the methods by calculating sensitivity, specificity and accuracy rate. The results showed that the comprehensive utilization of recurrence analysis parameters reached the highest accuracy rate (95%); power spectrum analysis took second place (90%); while the results of entropy analyses and time sequence symbolization were not satisfactory, whose accuracy were both only 70%. In conclusion, the recurrence analysis and power spectrum could be adopted to evaluate the atrial chaotic state effectively, thus having certain reference value for prediction of AF recurrence.

Correlation between heart rate variability and exercise ability in patients with cardiac syndrome X / 中国实用内科杂志

OBJECTIVE: To investigate whether heart rate variability(HRV) can assess exercise ability in patients with cardiac syndrome X(CSX). METHODS: A total of 246 subjects(55.2 ± 12.2 years, 68.3% male), who were diagnosed with CSX by the positive exercise stress test and normal coronary angiogram in Cardiovascular Department of the Second Affiliated Hospital of Harbin Medical University from March 2016 to August 2017 were enrolled. The 24-hour dynamic ECG monitoring was used to analyze HRV for long-time frequency domain analysis. The HRV power spectrum index included total power(TP),very low frequency(VLF), low frequency(LF) and high frequency(HF). RESULTS: VLF, LF and TP, but not LF/HF, were higher in the patients with good exercise capacity(≥90% of the age predicted maximal heart rate). After accounting for age, sex, systolic blood pressure and heart rate, VLF, LF and TP remained significantly associated with good exercise capacity. In addition, increased VLF, LF and TP were also associated with increased exercise duration, rate-pressure product, and heart rate recovery. In subgroup analysis, VLF, LF and TP demonstrated similar predictive values related to exercise capacity across various subpopulations, especially in the young. CONCLUSION: In patients with CSX, HRV is independently associated with exercise capacity, and is an independent predictor of ischemic tolerance in CSX patients, which can be used as an important index for evaluating the exercise ability of CSX patients.

Prediction of seizures in sleep based on power spectrum / 生物医学工程学杂志

Seizures during sleep increase the probability of complication and sudden death. Effective prediction of seizures in sleep allows doctors and patients to take timely treatments to reduce the aforementioned probability. Most of the existing methods make use of electroencephalogram (EEG) to predict seizures, which are not specific developed for the sleep. However, EEG during sleep has its characteristics compared with EEG during other states. Therefore, in order to improve the sensitivity and reduce the false alarm rate, this paper utilized the characteristics of EEG to predict seizures during sleep. We firstly constructed the feature vector including the absolute power spectrum, the relative power spectrum and the power spectrum ratio in different frequencies. Secondly, the separation criterion and branch-and-bound method were applied to select features. Finally, support vector machine classifier were trained, which is then employed for online prediction. Compared with the existing method that do not consider the characteristics of sleeping EEG (sensitivity 91.67%, false alarm rate 9.19%), the proposed method was superior in terms of sensitivity (100%) and false alarm rate (2.11%). This method can improve the existing epilepsy prediction methods and has important clinical value.

Inhibitory effect of ethosuximide on sevoflurane-induced emergence delirium in neonatal rats / 临床麻醉学杂志

Objective To investigate the inhibitory effect of ethosuximide,an antiepileptic drug,on sevoflurane-induced emergence delirium in neonatal rats.Methods Twelve SD rats (17-23 g) at postnatal day 9-11 were randomly divided into ethosuximide group (4 mg/100 μl,intraperitoneal injection,n=6) and saline group (100 μ1,intraperitoneal injection,n =6).Then the pups were treated with 1％ sevoflurane for 10 minutes and agitated behaviors was observed using PAHBs scoring method for every 2 minutes.Ten more pups were randomly divided into two groups as previously described.Then the pups were treated with 1％ sevoflurane for 10 minutes and EEG power spectrum of frontal lobe was monitored for every 2 minutes.Results Both PAHBs scores and EEG power spectrum at 2 min,4 min,6 min,8 min and 10 min were significantly decreased in ethosuximide group when comparing with saline group under 1％ sevoflurane inhalation (P ＜ 0.05).Conclusion Ethosuximide can decrease frontal lobe EEG power spectrum in sevoflurane-induced agitated rats and inhibit sevoflurane-induced emergence delirium in neonatal rats.

The noise analysis of CT imaging based on noise power spectrum of different reconstruction type / 中国医学装备

Objective: To evaluate the noise characteristic of different reconstruction type CT image by using the noise power spectrum (NPS), and analyze the correlation between this results and subjective vision noise evaluation. Methods: QA water phantom of CT equipment was scanned and 8 common reconstruction algorithms were applied to dispose image. NPS peak value, the peak frequency and standard deviation (SD) were compared with the subjective evaluation measurements, such as granularity, contrast, sharpness and optical noise level, by using the correlation analysis. Results: Each reconstruction algorithm owned different peak value and peak frequency. Granularity negatively correlated with the peak frequency. A positive correlation was found between contrast and peak value. Sharpness was positively correlated with both peak value and peak frequency. All of the subjective evaluation measurements were correlated with SD. Conclusion: Comparing with SD, NPS can reflect both intensity and morphological feature of the noise and possess applicative potential as a more comprehensive evaluation index.

Evolución de la potencia absoluta, relativa e índices de ritmos electroencefalográficos en estudiantes de primaria, licenciatura y maestría / Evolution of absolute and relative power and indices of electroencephalographic rhythms in elementary, college, and graduate students

Resumen: ANTECEDENTES: La función cerebral resulta de la actividad eléctrica en redes glío-neuronales, integradas de forma activa por interacciones sensoriales, motoras y reguladores. Redes que oscilan desde la infancia y se modulan por diversos factores de maduración, incluyendo procesos educativos. OBJETIVO: Identificar el espectro de potencia separado en delta (δ), theta (θ), alfa 1 (α1), alfa 2 (α2), beta 1 (β1) y beta 2 (β2) y su topografía en los hemisferios cerebrales de niños, jóvenes y adultos para establecer indicadores EEGc. MÉTODO: Se estudiaron tres grupos de 16 participantes: niños en primaria (GN), estudiantes de licenciatura (GL) y de maestría (GM). Los padres y los participantes otorgaron su consentimiento. En el aparato Nicolet se registró el EEG utilizando el sistema 10/20. Se analizaron muestras bipolares, con T Fourier se obtuvo la potencia absoluta (PA), se calculó su promedio (PPA), la potencia relativa (PR) y los índices de frecuencias lentas/rápidas. Las diferencias se evaluaron con Kruskal Wallis y la comparación de Dunnet para sub-grupos. RESULTADOS: El PPA de seis frecuencias fue mayor en GN que en GL y GM. En éstos fue similar con excepciones, relacionadas con la distribución topográfica. El índice δ/α fue mayor en GN con particular distribución topográfica y θ/α fue más variable. La PR de α fue mayor en GL y GM comparados con GN, la de θ y de δ en algunas derivaciones, fueron mayores en el GN. DISCUSIÓN Y CONCLUSIÓN: En la maduración cerebral disminuye la PA debido a la integración de más ensambles glío-neuronales, que presentan mayor asimetría en determinada frecuencia. Estos perfiles establecen indicadores para compararlos con futuros registros EEG.

Abstract: ANTECEDENTS: Cerebral function results from the electrical activity in glial-neuronal networks, integrated proactively through sensory, motor, and regulating interactions. These networks oscillate since early life and are modulated by diverse maturation factors, including educational processes. OBJECTIVE: To identify the power spectrum separated in delta (δ), theta (θ), alfa 1 (α1), alfa 2 (α2), beta 1 (β1) y beta 2 (β2), and their topography in cerebral hemispheres of children, youngsters, and adults to establish qEEG indicators. METHOD: We studied three groups of 16 participants each: elementary school children (CG), undergraduate students (UG), and graduate students (GG). Parents and participants granted their consent. The EEG was recorded (Nicolet) following the 10/20 system. Bipolar samples were analyzed. Absolute power (AP) was obtained with Fourier transform; its average (AAP) relative power (RP), and slow/fast frequencies and indices were calculated. Differences were assessed with Kruskal Wallis and Dunnet's comparison for subgroups. RESULTS: The AAP of six frequencies was higher in CG than in UG and GG. Frequencies were similar with exceptions correlating with topographic distribution. The δ/α index was higher in CG with a particular topographic distribution, θ/α varied more. RP of α was higher in UG and GG than in CG; that of θ and δ were higher in some leads of CG. DISCUSSION AND CONCLUSION: During cerebral maturation, AP diminishes due to integration of more glial-neuronal ensembles, presenting greater asymmetry in a giving frequency. These profiles establish indicators for comparison with future EEG recordings.

Long-term correlation of the electrocorticogram as a bioindicator of brain exposure to ionizing radiation

Understanding the effects of radiation and its possible influence on the nervous system are of great clinical interest. However, there have been few electrophysiological studies on brain activity after exposure to ionizing radiation (IR). A new methodological approach regarding the assessment of the possible effects of IR on brain activity is the use of linear and nonlinear mathematical methods in the analysis of complex time series, such as brain oscillations measured using the electrocorticogram (ECoG). The objective of this study was to use linear and nonlinear mathematical methods as biomarkers of gamma radiation regarding cortical electrical activity. Adult Wistar rats were divided into 3 groups: 1 control and 2 irradiated groups, evaluated at 24 h (IR24) and 90 days (IR90) after exposure to 18 Gy of gamma radiation from a cobalt-60 radiotherapy source. The ECoG was analyzed using power spectrum methods for the calculation of the power of delta, theta, alpha and beta rhythms and by means of the α-exponent of the detrended fluctuation analysis (DFA). Using both mathematical methods it was possible to identify changes in the ECoG, and to identify significant changes in the pattern of the recording at 24 h after irradiation. Some of these changes were persistent at 90 days after exposure to IR. In particular, the theta wave using the two methods showed higher sensitivity than other waves, suggesting that it is a possible biomarker of exposure to IR.

Effects of naloxone on the hippocampal electroencephalographic power spectrum in morphine-addicted rats / 中华行为医学与脑科学杂志

Objective To investigate the effect of opiate receptor antagonist naloxone on the electroencephalographic (EEG) power spectrum in morphine-addicted rats.Methods 20 male adult Wistar rats were alternately injected with morphine (Mf, 10 mg/kg,sc.;Mf withdrawal (Mf-Wd) group, n=10) or saline (Sal, 1 ml/kg, sc.;Sal-Wd group, n=10) for 8 days to establish Mf physical dependent model.Withdrawal scores were evaluated by naloxone-precipitated withdrawl signs (5 mg/kg,ip.).Another 20 rats were divided into Sal-CPP group and Mf-CPP group with 10 rats in each group.Rats in the sal-CPP group were injected with saline once a day for 8 days while rats in the Mf-CPP group were injected with saline and morphine alternatively once a day for 8 days.The EEG signals were recorded from their dorsal hippocampi before and after naloxone injection under anesthesia;and the EEG power data (1 ～ 100 Hz) were analyzed.Results (1) Compared with Sal-Wd group (22.69± 3.59), the Mf-Wd group showed a higher withdrawal scores after naloxone injection(84.90± 13.40, P＜0.01).(2) The CPP scores of Mf-CPP rats (80.69± 14.96) were significantly higher than the baseline (45.29± 15.79) and the Sal-CPP rats (41.84± 12.47;all P＜0.01).(3)After naloxone injection,the EEG powers of δ band and γ band of Mf-CPP rats decreased temporarily c ompared with their baseline (δ band: (81.80±30.91) mV2 · Hz vs (112.49±39.43) mV2 · Hz;γ band:(25.35±11.20)mV2 · Hzvs (28.71±13.06)mV2 · Hz;allP＜0.05).Conclusion Opiate receptor antagonist naloxone can decrease the hippocampal EEG powers of δ band and γband in Mf-addicted rats.

Quantitative EEG analysis disease during resting and memory task in carriers and non-carriers of PS-1 E280A mutation of familial Alzheimer's / Análisis del EEG cuantitativo durante tareas de memoria y reposo en portadores y no portadores de la mutación PS-1 E280A de la enfermedad de Alzheimer

ABSTRACT Background: Alzheimer's disease is the most leading cause of dementia in the world; the mutation PS-1 E280A alters the gene of the Presenilin-1 and causes an early onset familial Alzheimer's disease. This mutation has been found in large kindred of Antioquia, Colombia. The objective of this study was to find differences revealed by electroencephalogram between healthy subjects and asymptomatic carriers that can be used as clinical markers of the disease in this population. Methods: EEG was recorded in 15 asymptomatic E280A carriers and 15 healthy non carriers during resting and a memory task using 64 channels amplifier. Two conditions in the memory task were analyzed: encoding and retrieval, the process of recording and evocating information, respectively. Power spectrum was calculated in delta (0. 5-4. 0 Hz), theta (4. 0-8. 0 Hz), alpha-1 (8. 0-10. 0 Hz), alpha-2 (10. 0-13. 0 Hz), beta (13. 0-25. 0 Hz) and gamma (25. 0-50 Hz) frequency bands for four regions of interest. Changes were evaluated in different conditions by ANOVA analysis.. Results: In resting condition a significant decrease was found in theta (p=0. 0001) and an increase in alpha-2 frequencies (p=0.037) in carriers compare with controls. During encoding of the memory task theta was significantly lower in carriers compared with controls (p=0. 008) and comparing resting versus retrieval process for each group, there was more theta synchronization in carriers. Conclusions: Early changes in theta frequencies were observed in the EEG recordings, it could be use as clinical markers in this population. Also it seems carriers activate additional cortical regions in order to conserve successful cognitive functions before clinical impairment.

RESUMEN Introducción: la enfermedad de Alzheimer es la principal causa de demencia en el mundo; la mutación PS-1 E280A altera el gen presenilin-1 y causa una variante familiar de la enfermedad que se caracteriza por una aparición temprana. La mutación se ha descubierto en un grupo de familias de Antioquia, Colombia. El objetivo de este estudio fue encontrar diferencias, a partir de registros electroencefalográficos de personas portadores de la mutación en una etapa asintomática y sujetos sanos para evaluar si pueden ser utilizadas como un marcador temprano de la enfermedad en la población portadora de la mutación. Metodología: se realizaron registros EEG en 15 portadores asintomáticos de la mutación E280A y 15 personas sanas no portadoras durante una tarea de memoria y en reposo utilizando un amplificador de 64 canales. En la tarea de memoria se evaluaron dos condiciones: codificación y evocación; el proceso de memorizar y recuperar la información, respectivamente. La potencia espectral fue calculada en las bandas de frecuencia delta (0,5-4,0 Hz), teta (4,0-8,0 Hz), alfa-1 (8,0-10,0 Hz), alfa-2 (10,0-13,0 Hz), beta (13,0-25,0 Hz) y gamma (25,0-50 Hz) para cuatro regiones de interés. Los cambios del espectro fueron evaluados por análisis de varianza ANOVA. Resultados: bajo la condición de reposo se encontró una disminución importante en la potencia de la banda teta (p=0,0001) y un incremento en la banda alfa-2 (p=0,037) en portadores comparados con controles. Durante la tarea de codificación, los portadores mostraron una disminución significativa en la banda teta (p=0,008). Al comparar reposo contra memoria de evocación se encontró una mayor sincronización en teta en los portadores de la mutación. Conclusión: se encontraron cambios tempranos de la potencia en la banda teta que pueden ser utilizados como un marcador clínico de la enfermedad en esta población. Una hipótesis adicional basada en los resultados es que los portadores necesitan ...

Application of Percentage Layouts of Power Spectrum in Balance Assessment of Stroke Patients / 中国康复理论与实践

Objective To study the general rule in the power spectrum percentage of balance when normal people standing and the dif-ferences of the power spectrum percentage between normal people and the stroke patients. Methods 30 normal people and 30 stroke patients was tested with Active Balancer EAB-100 (Sakai Iryo) open-and close-eye. The whole path length, circumference area and the percentages of power spectrum on the X, Y and Z axes were recorded. The correlation and the differences were analyzed. Results The percentages of power spectrum were not statistically correlated (P>0.05) with age, height, weight or gender. There was significant difference between two groups in the percentage of power spectrum (P<0.05). On the frequency spectrum, the ratio rised on the low and middle frequency part, espe-cially within 0.2~2 Hz, but the ratio decreased on the high frequency part (2~10 Hz) (P<0.05). Conclusion The percentage of power spec-trum can be an important reference in assessing the stroke patients' balancing functions.

Effective Detective Quantum Efficiency (eDQE) Evaluation for the Influence of Focal Spot Size and Magnification on the Digital Radiography System / 의학물리

The magnification technique has recently become popular in bone radiography, mammography and other diagnostic examination. However, because of the finite size of X-ray focal spot, the magnification influences various imaging properties with resolution, noise and contrast. The purpose of study is to investigate the influence of magnification and focal spot size on digital imaging system using eDQE (effective detective quantum efficiency). Effective DQE is a metric reflecting overall system response including focal spot blur, magnification, scatter and grid response. The adult chest phantom employed in the Food and Drug Administration (FDA) was used to derive eDQE from eMTF (effective modulation transfer function), eNPS (effective noise power spectrum), scatter fraction and transmission fraction. According to results, spatial frequencies that eMTF is 10% with the magnification factor of 1.2, 1.4, 1.6, 1.8 and 2.0 are 2.76, 2.21, 1.78, 1.49 and 1.26 lp/mm respectively using small focal spot. The spatial frequencies that eMTF is 10% with the magnification factor of 1.2, 1.4, 1.6, 1.8 and 2.0 are 2.21, 1.66, 1.25, 0.93 and 0.73 lp/mm respectively using large focal spot. The eMTFs and eDQEs decreases with increasing magnification factor. Although there are no significant differences with focal spot size on eDQE (0), the eDQEs drops more sharply with large focal spot than small focal spot. The magnification imaging can enlarge the small size lesion and improve the contrast due to decrease of effective noise and scatter with air-gap effect. The enlargement of the image size can be helpful for visual detection of small image. However, focal spot blurring caused by finite size of focal spot shows more significant impact on spatial resolution than the improvement of other metrics resulted by magnification effect. Based on these results, appropriate magnification factor and focal spot size should be established to perform magnification imaging with digital radiography system.

Comparing Quantitative EEG and Low Resolution Electromagnetic Tomography Imaging between Deficit Syndrome and Non-Deficit Syndrome of Schizophrenia / 수면정신생리

OBJECTIVES: Deficit schizophrenia (DS) constitutes a disease separate from non-deficit schizophrenia (NDS). The aim of the current study was to compare the quantitative EEG and low resolution electromagnetic tomography (LORETA) imaging between DS and NDS. METHODS: This study was performed by 32 channels EEG for 42 schizophrenia patients who we categorized into DS and NDS using proxy instrument deficit syndrome (PDS). We performed the absolute power spectral analyses for delta, theta, alpha, low beta and high beta activities. We compared power spectrum between two groups using Independent t-test. Partial correlation test was performed with clinical parameters. Standardized LORETA (sLORETA) was used for comparison of cortical activity, and statistical nonparametric mapping (SnPM) was applied for the statistical analysis. RESULTS: DS showed significantly increased delta and theta absolute power in fontal and parietal region compared with NDS (p<0.05). Power spectrum showed significant correlation with 'anergia' and 'hostility/suspiciousness' subscale of brief psychiatric rating scale (BPRS)(p<0.05). sLORETA found out the source region (anterior cingulate cortex/limbic part) that delta activity was significantly increased in DS (p=0.042). CONCLUSIONS: DS showed different cortical activity compared with NDS. Our results may suggest QEEG and LORETA could be the marker in differentiating between DS and NDS.

The Clinical use of quantitative EEG in cognitive disorders / A utilização clínica do EEG quantitativo nos transtornos cognitivos

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.

Resumo: O uso clínico do EEG Quantitativo nas doenças cognitivas. O diagnóstico das doenças cognitivas geralmente é clínico mas o EEG é importante como exame auxiliar na avaliação, diagnóstico e classificação de algumas delas. O debate atual refere-se ao uso clínico do EEGq. Embora muitos achados no EEGq ainda aguardem validação, o EEGq pode ser usado cautelosamente em situações específicas e por um neurofisiologista experiente. Nas doenças cognitivas ele pode contribuir na análise da atividade de base, em atividades focais lentas ou rápidas, assimetrias sutís, pontas e ondas e no acompanhamento longitudinal dos pacientes.

Linear/Non-Linear Tools and Their Applications to Sleep EEG: Spectral, Detrended Fluctuation, and Synchrony Analyses / 수면정신생리

Sleep is an essential process maintaining the life cycle of the human. In parallel with physiological, cognitive, subjective, and behavioral changes that take place during the sleep, there are remarkable changes in the electroencephalogram (EEG) that reflect the underlying electro-physiological activity of the brain. However, analyzing EEG and relating the results to clinical observations is often very hard due to the complexity and a huge data amount. In this article, I introduce several linear and non-linear tools, developed to analyze a huge time series data in many scientific researches, and apply them to EEG to characterize various sleep states. In particular, the spectral analysis, detrended fluctuation analysis (DFA), and synchrony analysis are administered to EEG recorded during nocturnal polysomnography (NPSG) processes and daytime multiple sleep latency tests (MSLT). I report that 1) sleep stages could be differentiated by the spectral analysis and the DFA; 2) the gradual transition from Wake to Sleep during the sleep onset could be illustrated by the spectral analysis and the DFA; 3) electrophysiological properties of narcolepsy could be characterized by the DFA; 4) hypnic jerks (sleep starts) could be quantified by the synchrony analysis.

Estimation of Percentage of Electrogastrogram Slow Wave Rhythm / 航天医学与医学工程

Objective To improve the estimation and the percentage of electrogastrogram(EGG)slow wave rhythm with power spectrum estimation and calculation rule set.Methods Chirp Z-transformation was introduced for estimation power spectrum of EGG,which can obtain both high frequency resolution and accurate estimation of power;while the power proportion of main frequency components in each segment was used to substitute for conventional method in time domain.Results The variance of proposed method was about one-eighth of that of conventional method.Incorporating the power proportion of main frequency components,the proposed method gave better results especially for those EGG signals in which abnormal frequencies appeared frequently.Conclusion As compared with the conventional method,the proposed method is less affected by segmentation process in estimating the percentage of EGG slow wave rhythm,which may promote future clinical applications.

The effect of oxysophoridine on electric activities and its power spectrums of cerebral frontal cortex in rats / 中国药理学通报

Aim To observe the effect of oxysophori-dine( OSR) on the EEG changes and its power spectrums of cerebral frontal cortex in anaesthetized rats. Methods With the equipment of brain stereotactic apparatus,electrode was implanted into frontal lobe of cerebral cortex in rats. Unipolar lead and computerized FFT technique were employed to record the index of EEG,power spectrum and frequency distributions to analyze the effect of OSR on the bioelectricity altera-tions of frontal lobe in cerebral cortexi in rats. Results Administrated( icv) with OSR at the dose of 2. 5,5, 10 mg/rat in rats,the EEG of frontal lobe of cerebral cortex was mainly featured by low amplitude and slow waves accompanied by spindle-formed sleeping waves with a significant decrease of total power of EEG( P