Abnormalities of electroencephalography microstates in patients with depression and their association with cognitive function

BACKGROUND A growing number of recent studies have explored underlying activity in the brain by measuring electroencephalography(EEG)in people with depression.However,the consistency of findings on EEG microstates in patients with depression is poor,and few studies have reported the relationship between EEG microstates,cognitive scales,and depression severity scales.AIM To investigate the EEG microstate characteristics of patients with depression and their association with cognitive functions.METHODS A total of 24 patients diagnosed with depression and 32 healthy controls were included in this study using the Structured Clinical Interview for Disease for The Diagnostic and Statistical Manual of Mental Disorders,Fifth Edition.We collected information relating to demographic and clinical characteristics,as well as data from the Repeatable Battery for the Assessment of Neuropsychological Status(RBANS;Chinese version)and EEG.RESULTS Compared with the controls,the duration,occurrence,and contribution of microstate C were significantly higher[depression(DEP):Duration 84.58±24.35,occurrence 3.72±0.56,contribution 30.39±8.59;CON:Duration 72.77±10.23,occurrence 3.41±0.36,contribution 24.46±4.66;Duration F=6.02,P=0.049;Occurrence F=6.19,P=0.049;Contribution F=10.82,P=0.011]while the duration,occurrence,and contribution of microstate D were significantly lower(DEP:Duration 70.00±15.92,occurrence 3.18±0.71,contribution 22.48±8.12;CON:Duration 85.46±10.23,occurrence 3.54±0.41,contribution 28.25±5.85;Duration F=19.18,P<0.001;Occurrence F=5.79,P=0.050;Contribution F=9.41,P=0.013)in patients with depression.A positive correlation was observed between the visuospatial/constructional scores of the RBANS scale and the transition probability of microstate class C to B(r=0.405,P=0.049).CONCLUSION EEG microstate,especially C and D,is a possible biomarker in depression.Patients with depression had a more frequent transition from microstate C to B,which may relate to more negative rumination and visual processing.

Enhancement of Visual Attention by Color Revealed Using Electroencephalography

Attention constitutes a fundamental psychological feature guiding our mental effort toward specific objects, concurrent with processes such as memory, reasoning, and imagination. Visual attention, crucial for selecting surrounding information, often decreases in older adults and patients with cerebrovascular disorders. Effective methods to enhance attention are scarce. Here, we investigated whether color information influences visual attention and brain activity during task performance, utilizing EEG. We examined 13 healthy young adults (seven women and six men;mean age: 21.2 ± 0.58 years) using 19-electrode electroencephalograms to assess the impact of color information on visual attention. The Clinical Assessment for Attention cancellation test was conducted under the black, red, and blue color conditions. Wilcoxon’s signed-rank test was used to assess differences in task performance (task time and error) between conditions. Spearman’s rank correlation was utilized to examine the correlation in power levels between task performance and color conditions. Significant variations in total task errors were observed among color conditions. The black condition exhibited the highest error frequency (0.7 ± 0.9 times), followed by the red condition (0.5 ± 0.8 times), with the lowest error frequency occurring in the blue (0.2 ± 0.4 times) condition (black vs. red: P = 0.03;black vs. blue: P = 0.00;red vs. blue: P = 0.032). No time difference was observed. The black condition showed negative delta and high-gamma correlations in the central electrodes. The red condition revealed positive alpha and low-gamma correlations in the frontal and occipital areas. Although no correlations were observed in the blue condition, it enhanced attentional performance. Positive alpha and low-gamma waves might be crucial for spotting attentional errors in key areas. Our findings provide insights into the effects of color information on visual attention and potential neural correlates associated with attentional processes. In conclusion, our study implies a connection between color information and attentional task performance, with blue font associated with the most accurate performance.

Effect of acoustic stimuli in patients with disorders of consciousness: a quantitative electroencephalography study

Auditory stimuli are proposed as beneficial neurorehabilitation methods in patients with disorders of consciousness. However, precise and accurate quantitative indices to estimate their potential effect remain scarce. Fourteen patients were recruited from the Neuro-Rehabilitation Unit of Hangzhou Hospital of Zhejiang Armed Police Corps of China. Altogether, there were seven cases of unresponsive wakefulness syndrome（five males and two females, aged 45.7 ± 16.8 years） and seven cases of minimally conscious state（six males and one female, aged 42.3 ± 20.8 years）. Simultaneously, fourteen healthy controls（10 males and 4 females, aged 51.7 ± 9.7 years） also participated in this case-control experiment. Brain response to music, subjects＇ own name, and noise was monitored by quantitative electroencephalography（QEEG） in the resting state and with acoustic stimulation. Predictive QEEG values in various brain regions were investigated. Our results show that cerebral activation was high in subjects stimulated by their own name, especially in the temporal lobe in patients with disorders of consciousness, and the frontal lobe in the control group. Further, during resting and stimulation, QEEG index（δ ＋ θ/α ＋ β ratio） negatively correlated with the Coma Recovery Scale-Revised score in traumatic disorders of consciousness patients. Hence, we speculate that a subject＇s own name might be an effective awakening therapy for patients with disorders of consciousness. Moreover, QEEG index in specific stimulation states may be used as a prognostic indicator for disorders of consciousness patients（sensitivity, 75%; specificity, 50%）.

Benefits of combination of electroencephalography, short latency somatosensory evoked potentials, and transcranial Doppler techniques for confirming brain death

Objective: Optimization of combining electroencephalography (EEG), short latency somatosensory evoked potentials (SLSEP) and transcranial Doppler (TCD) techniques to diagnose brain death. Methods: One hundred and eleven patients (69 males, 42 females) from the major hospitals of Zhejiang Province were examined with portable EEG, SLSEP and TCD devices. Re-examinations occurred ≤12 h later. Results: The first examination revealed that the combination of SLSEP and EEG led to more sensitive diagnoses than the combination of SLSEP and TCD. Re-examination confirmed this and also revealed that the combination of TCD and EEG was the most sensitive. Conclusion: The results show that using multiple techniques to diagnose brain death is superior to using single method, and that the combination of SLSEP and EEG is better than other combinations.

Electroencephalography Analysis Using Neural Network and Support Vector Machine during Sleep

The purpose of this paper is to analyze sleep stages accurately using fast and simple classifiers based on the frequency domain of electroencephalography(EEG) signal. To compare and evaluate system performance, the rules of Rechtschaffen and Kales(R&K rule) were used. Parameters were extracted from preprocessing process of EEG signal as feature vectors of each sleep stage analysis system through representatives of back propagation algorithm and support vector machine (SVM). As a result, SVM showed better performance as pattern recognition system for classification of sleep stages. It was found that easier analysis of sleep stage was possible using such simple system. Since accurate estimation of sleep state is possible through combination of algorithms, we could see the potential for the classifier to be used for sleep analysis system.

Repetitive transcranial magnetic stimulation improves consciousness disturbance in stroke patients A quantitative electroencephalography spectral power analysis

Repetitive transcranial magnetic stimulation is a noninvasive treatment technique that can directly alter cortical excitability and improve cerebral functional activity in unconscious patients. To investigate the effects and the electrophysiological changes of repetitive transcranial magnetic stimulation cortical treatment, 10 stroke patients with non-severe brainstem lesions and with disturbance of consciousness were treated with repetitive transcranial magnetic stimulation. A quantitative electroencephalography spectral power analysis was also performed. The absolute power in the alpha band was increased immediately after the first repetitive transcranial magnetic stimulation treatment, and the energy was reduced in the delta band. The alpha band relative power values slightly decreased at 1 day post-treatment, then increased and reached a stable level at 2 weeks post-treatment. Glasgow Coma Score and JFK Coma Recovery Scale-Revised score were improved. Relative power value in the alpha band was positively related to Glasgow Coma Score and JFK Coma Recovery Scale-Revised score. These data suggest that repetitive transcranial magnetic stimulation is a noninvasive, safe, and effective treatment technology for improving brain functional activity and promoting awakening in unconscious stroke patients.

Artifact suppression and analysis of brain activities with electroencephalography signals

Brain-computer interface is a communication system that connects the brain with computer （or other devices） but is not dependent on the normal output of the brain （i.e., peripheral nerve and muscle）. Electro-oculogram is a dominant artifact which has a significant negative influence on further analysis of real electroencephalography data. This paper presented a data adaptive technique for artifact suppression and brain wave extraction from electroencephalography signals to detect regional brain activities. Empirical mode decomposition based adaptive thresholding approach was employed here to suppress the electro-oculogram artifact. Fractional Gaussian noise was used to determine the threshold level derived from the analysis data without any training. The purified electroencephalography signal was composed of the brain waves also called rhythmic components which represent the brain activities. The rhythmic components were extracted from each electroencephalography channel using adaptive wiener filter with the original scale. The regional brain activities were mapped on the basis of the spatial distribution of rhythmic components, and the results showed that different regions of the brain are activated in response to different stimuli. This research analyzed the activities of a single rhythmic component, alpha with respect to different motor imaginations. The experimental results showed that the proposed method is very efficient in artifact suppression and identifying individual motor imagery based on the activities of alpha component.

Significance of ambulatory electroencephalography for differential diagnosis of epilepsy and syncope

BACKGROUND： Twenty-four hour ambulatory electroencephatography （AEEG） provides advantages for continuous electroencephalogram, monitoring brief loss of consciousness complicated by suspect or mild limb spasm. OBJECTIVE： To explore the significance of AEEG for differentially diagnosing epilepsy and syncope, compared to EEG. DESIGN, TIME AND SETTING： Sixty patients with brief loss of consciousness, complicated by suspect or mild limb spasm, were selected from Suqian People＇s Hospital between January 2006 and June 2007. PARTICIPANTS： Sixty participants comprised 34 males and 26 females, aged 13-64 years. According to clinical symptoms prior to the study, 36 patients were initially diagnosed with epilepsy and 24 with syncope. METHODS AND MAIN OUTCOME MEASURES： Abnormalities and epileptiform discharge were detected using EEG and AEEG, and the diagnostic value of the two methods for epilepsy and syncope was compared. RESULTS： A total of sixty patients were included in the final analysis. Abnormal AEEGs were observed in 37 cases （62%） and epileptiform discharge AEEGs in 23 cases （38%）, both of which were significantly greater than EEGs [37% （22/60）, 18% （11/60）, respectively, P 〈 0.01, 0.05]. The detection rate of abnormal AEEG and epileptiform discharge in the epilepsy group [75% （27/36）, 47% （17/36）, respectively was significantly greater than in the syncope group [42% （10/24）, 25% （6/24）, respectively, P 〈 0.01, 0.05]. CONCLUSION： AEEG can improve detection probability of epileptiform discharge and exhibits significant differences in the differential diagnosis of epilepsy and syncope.

Percentage of beta 2 band power of quantitative pharmaco-electroencephalography decreases in propofol anesthetized rabbits A dose-dependent analysis

BACKGROUND： Quantitative pharmaco-electroencephalography can be used for studying the dose-effect and time-effect relationships of drugs affecting central nervous system. Therefore, it may become an effective means for monitoring the anesthetic degree of anesthetic drug in the operation. OBJECTIVE： To observe the dose-effect relationship of propofol influencing β2-band power of quantitative pharmaco-electroencephalography in rabbits. DESIGN： A randomized block design. SETTING： Department of Anesthesiology, Xuzhou Medical College. MATERIALS： Thirty-six healthy adult rabbits of either gender, weighing （2.4 ± 0.5 ） kg, of clean grade, were provided by the Laboratory Animal Center of Xuzhou Medical College. The involved rabbits were randomly divided into 3 groups with 12 in each by table of random digit： high-dose propofol group, moderate-dose propofol group, and low-dose propofol group. The protocol was carried out in accordance with animal ethics guidelines for the use and care of animals. METHODS： This study was carried out in the Department of Anesthesiology, Xuzhou Medical College between August 1999 and April 2000. Rabbits in the high-dose propofol group, moderate-dose propofol group, and low-dose propofol group were injected with 10, 5 and 2.5 mg/kg propofol （ZENECA Company, British, Batch No. 032000）, respectively. Before and after intravenous administration of propofol, percentage of β2-band power of quantitative pharmaco-electroencephalography was measured, and the latent and persistent periods when rabbit righting reflex disappeared were observed by quantitative pharmaco-electroencephalography and power spectrum analysis. MAIN OUTCOME MEASURES： （1） Percentage of β2-band power of quantitative pharmaco-electroencephalography. （2）Latent period and persistent period of abolition of righting reflex of rabbits. RESULTS： Thirty-six rabbits were involved in the final analysis. （1）Effect of propofol on righting reflex of rabbits： Righting reflex disappeared within 1 minute after the rabbits being intravenously injected with propofol. The higher dose, the shorter latent period （r = - 0.94, P 〈 0.01）, and the longer persistent period （r =0.79, P 〈 0.01）. Both latent period and persistent period had good correlation with propofol dose. （2） Effect of propofol on the percentage of β2-band power of quantitative pharmaco-electroencephalography： In the low-dose propofol group, no significant changes in the percentage of β2-band power of quantitative pharmaco-electroencephalography existed between before and after administration within 30 minutes （P 〉 0.05）. In the moderate-dose propofol group, the percentage of β2-band power of quantitative pharmaco-electroencephalography in each brain region except for left and right frontal areas was significantly decreased within 30 s to 5 minutes （P 〈 0.05）, and recovered to the level before administration 10 minutes later. In the high-dose propofol group, the percentage of β2-band power of quantitative pharmaco-electroencephalography in each brain region was significantly decreased from 20 s to 5 minutes after administration （P 〈 0.05 - 0.01）, and that was gradually recovered to the level before administration 5 to 10 minutes after administration. This tendency was basically the same as the changes of latent period and persistent period. CONCLUSION： Propofol decreases the percentage of β2-band power of quantitative pharmacoelectroencephalography in dose-dependent manner, It indicates that β2-band power might become one of indexes for reflecting the anesthetic degree of propofol,

Effects of Immediate Dental Loading Implant Therapy on Electroencephalography (EEG) and Stress

Purpose: Implant therapy restores masticatory function by restoring lost tooth morphology. It has been shown that mastication contributes not only to food intake and digestion, but also to the improvement of overall health. However, there have been no studies on the effects of implant treatment on electroencephalography (EEG). In this study, we investigated the effects of restoration of masticatory function by implant treatment on EEG and stress. Methods: 13 subjects (6 males, 7 females, age 64.1 ± 5.8 years) who had lost masticatory function due to tooth loss and 11 healthy subjects (6 males, 5 females, age 47.6 ± 2.4 years) as a control group. EEG (θ, α, β waves, α/β ratio) and salivary cortisol were measured before immediate dental implant treatment and every month of treatment for 6 months. EEG (θ, α, β waves, α/β ratio) was measured with a simple electroencephalograph miniature DAQ terminal (Intercross-410, Intercross Co., Ltd., Japan) in a resting closed-eye condition, and salivary cortisol was measured using an ELISA kit. Results: Compared to the control group, the appearance of θ and α waves were significantly decreased and β waves were increased, and α/β ratio was significantly decreased. The cortisol level of the subject group was significantly higher compared with the control group. With the course of implant treatment, the appearance of θ and α waves of the subject group increased, while β waves decreased. However, no significant difference was observed. The α/β ratio of the subject group increased from the first month after implant treatment and increased significantly after 5 and 6 months (0 vs. 5 months: p < 0.05, 0 vs. 6 months: p < 0.01). The cortisol levels in the subject group decreased from the first month after implant treatment and significantly decreased after 3 or 4 months (0 vs. 3 months: p < 0.05, 0 vs. 4 months: p < 0.01). These results suggest that tooth loss causes mental stress, which decreases brain stimulation and affects function. Restoration of masticatory function by implants was suggested to alleviate the effects on brain function and stress.

Investigating Neural Representation of Finger-Movement Directions Using Electroencephalography Independent Components

There are few EEG studies on finger movement directions because ocular artifacts also convey directional information, which makes it hard to separate the contribution of EEG from that of the ocular artifacts. To overcome this issue, we designed an experiment in which EEG’s temporal dynamics and spatial information are evaluated together to improve the performance of brain-computer interface (BCI) for classifying finger movement directions. Six volunteers participated in the study. We examined their EEG using decoding analyses. Independent components (ICs) that represented brain-source signals successfully classified the directions of the finger movements with higher rates than chance level. The weight analyses of the classifiers revealed that maximal performance of the classification was recorded at the latencies prior to the onset of finger movements. The weight analyses also revealed the relevant cortical areas including the right lingual, left posterior cingulate, left inferior temporal gyrus, and right precuneus, which indicated the involvement of the visuospatial processing. We concluded that combining spatial distribution and temporal dynamics of the scalp EEG may improve BCI performance.

Physician Perception and Practice of Electroencephalography in Enugu, South East Nigeria

Background: Electroencephalography (EEG) is established for evaluating several acute and chronic medical conditions of neurological basis. In much of Nigeria and Africa, it is largely unavailable and underutilized due to scarcity of neurologists and high costs of the equipment. It offers a relatively simple and efficient way to help manage many encephalopathies if well utilized in trained hands. Aim: This study aimed to determine how physicians practicing in Enugu perceive and utilize electroencephalography routinely. Method: Physicians attending a statewide meeting in Enugu in August 2018 were consecutively recruited and a pretested questionnaire was administered after obtaining prior consent. Sociodemographic data as well as their knowledge, attitude and practice of electroencephalography were documented and analyzed. Results: There were 486 respondents (males 335: females 151) and 345 (71%) were specialists in various disciplines while 141 (29%) were general practitioners. Only 7 doctors (1.4%) claimed ignorance of electroencephalography and 6 (1.2%) stated it was not useful. Majority, 333 doctors (69.1%) believed it had no impact on routine patient management. This perception was highest for Dental Surgery (100%) and lowest for Internal Medicine (23%) specialists. Most doctors (425, 87.4%) agreed that neurologists should analyze recordings. Most physicians had no access to electroencephalography (61.7%) and had no interest in acquiring the machine (50.8%). Conclusion: Electroencephalography is an underappreciated investigative modality amongst physicians in Enugu, despite a high burden of neurological diseases in the population. More education, training and awareness of its utility are needed for medical students and doctors to reverse the trend.

Quantitative electroencephalography in predicting on outcome of awakening in long-term unconscious patients after severe traumatic brain injury

Objective To explore quantitative electroencephalography in unconscious patients after severe traumatic brain injury (TBI) to predict awakening. Methods All cases were divided into two groups(the awake group 19 cases and the unfavourable prognosis group 22 cases).Two weeks after admission the original EEGs were preformed in 41 patients suffering from severe TBI with duration of disturbance of

Sustainable development of electroencephalography materials and technology

Electroencephalogram(EEG)is one of the most important bioelectrical signals related to brain activity and plays a crucial role in clinical medicine.Driven by continuously expanding applications,the development of EEG materials and technology has attracted considerable attention.However,systematic analysis of the sustainable development of EEG materials and technology is still lacking.This review discusses the sustainable development of EEG materials and technology.First,the developing course of EEG is introduced to reveal its significance,particularly in clinical medicine.Then,the sustainability of the EEG materials and technology is discussed from two main aspects:integrated systems and EEG electrodes.For integrated systems,sustainability has been focused on the developing trend toward mobile EEG systems and big-data monitoring/analyzing of EEG signals.Sustainability is related to miniaturized,wireless,portable,and wearable systems that are integrated with big-data modeling techniques.For EEG electrodes and materials,sustainability has been comprehensively analyzed from three perspectives:performance of different material/structural categories,sustainablematerials for EEGelectrodes,and sustainable manufacturing technologies.In addition,sustainable applications of EEG have been presented.Finally,the sustainable development of EEG materials and technology in recent decades is summarized,revealing future possible research directions as well as urgent challenges.

Pathogenesis, diagnosis, and treatment of epilepsy: electromagnetic stimulation-mediated neuromodulation therapy and new technologies

Epilepsy is a severe,relapsing,and multifactorial neurological disorder.Studies regarding the accurate diagnosis,prognosis,and in-depth pathogenesis are crucial for the precise and effective treatment of epilepsy.The pathogenesis of epilepsy is complex and involves alterations in variables such as gene expression,protein expression,ion channel activity,energy metabolites,and gut microbiota composition.Satisfactory results are lacking for conventional treatments for epilepsy.Surgical resection of lesions,drug therapy,and non-drug interventions are mainly used in clinical practice to treat pain associated with epilepsy.Non-pharmacological treatments,such as a ketogenic diet,gene therapy for nerve regeneration,and neural regulation,are currently areas of research focus.This review provides a comprehensive overview of the pathogenesis,diagnostic methods,and treatments of epilepsy.It also elaborates on the theoretical basis,treatment modes,and effects of invasive nerve stimulation in neurotherapy,including percutaneous vagus nerve stimulation,deep brain electrical stimulation,repetitive nerve electrical stimulation,in addition to non-invasive transcranial magnetic stimulation and transcranial direct current stimulation.Numerous studies have shown that electromagnetic stimulation-mediated neuromodulation therapy can markedly improve neurological function and reduce the frequency of epileptic seizures.Additionally,many new technologies for the diagnosis and treatment of epilepsy are being explored.However,current research is mainly focused on analyzing patients’clinical manifestations and exploring relevant diagnostic and treatment methods to study the pathogenesis at a molecular level,which has led to a lack of consensus regarding the mechanisms related to the disease.

Amplitude-Integrated Electroencephalography Predicts Outcome in Patients with Coma After Acute Brain Injury

Prognostication of coma patients after brain injury is important, yet challenging. In this study, we evaluated the predictive value of amplitude-integrated electroencephalography （aEEG） for neurological outcomes in coma patients. From January 2013 to January 2016, 128 coma patients after acute brain injury were prospectively enrolled and monitored with aEEG. The 6-month neurological outcome was evaluated using the Cerebral Performance Category Scale. aEEG monitoring commenced at a median of 7.5 days after coma onset. Continuous normal voltage predicted a good 6-month neurological outcome with a sensitivity of 93.6% and specificity of 85.2%. In contrast, continuous extremely low voltage, burst-suppression, or a flat tracing was correlated with poor 6-month neurological outcome with a sensitivity of 76.5% and specificity of 100%. In conclusion, aEEG is a promising predictor of 6-month neurological outcome for coma patients after acute brain injury.

A Special Electroencephalography Pattern Might Help in the Diagnosis of Antibody-positive Encephalitis

Background： Patterns observed with electroencephalography （EEG） for patients who have encephalitis are usually known as generalized nonspecific cerebral abnormalities. The aim of this study was to investigate the presence of a special EEG pattern for patients with encephalitis and to explore features related to this special and uncommon pattern. Methods： EEG monitoring was performed for every patient aged 〉15 years with encephalitis who was hospitalized between December 2011 and March 2014. Clinical characteristics and EEG recordings were collected and evaluated. Results： Filly-two patients with encephalitis were enrolled in our study with a 2-h median EEG recording time, and extreme beta brushes （EBBs） occurred in 17 patients （32.7%）. Its presence was not significant regarding gender, age, psychiatric medication use, EEG rhythmic disorganization （P 〉 0.05）. Nevertheless, among the patients with EBBs, nine patients （52.9%） had epileptic seizures that had a significant detection rate （P 〈 0.05）： moreover, the cerebrospinal fluid （CSF） or serum of 15 patients （88.2%） with EBBs was positive for antibodies （P 〈 0.05）. Four patients （23.5%） who had EBB had corresponding regional distributions on neurnimaging scans. The EBBs completely correlated with the regional distributions of spike discharges for four patients. Conclusion： EBB is a special EEG pattern for patients with encephalitis, especially those with epileptic seizures or who have antibody-positive CSF/serum, and should be considered in clinical practice.

Advances of Intracranial Electroencephalography in Localizing the Epileptogenic Zone

Intracranial electroencephalography（i EEG）provides the best precision in estimating the location and boundary of an epileptogenic zone. Analysis of i EEG in the routine EEG frequency range（0.5-70 Hz） remains the basis in clinical practice. Low-voltage fast activity is the most commonly reported ictal onset pattern in neocortical epilepsy, and low-frequency high-amplitude repetitive spiking is the most commonly reported ictal onset pattern in mesial temporal lobe epilepsy. Recent studies using wideband EEG recording have demonstrated that examining higher（80-1000 Hz） and lower（0.016-0.5 Hz） EEG frequencies can provide additional diagnostic information and help to improve the surgical outcome. In addition,novel computational techniques of i EEG signal analysis have provided new insights into the epileptic network.Here, we review some of these recent advances. Although these sophisticated and advanced techniques of i EEG analysis show promise in localizing the epileptogenic zone,their utility needs to be further validated in larger studies.

Recommendations for Electroencephalography Monitoring in Neurocritical Care Units

INTRODUCTION Since the 1950s, electroencephalography （EEG） has been used extensively in Neurocritical Care Units （NCUs）. At the beginning of this century, China＇s NCUs underwent rapid development. According to an incomplete statistical report, 76 NCUs had achieved the construction standard in 2010.

Newborns' sleep-wake cycle development on amplitude integrated electroencephalography

Background:To observe the development of neonatal sleep among healthy infants of different conceptional age(CA)by analyzing the amplitude-integrated electroencephalography(aEEG)of their sleep-wake cycles(SWC).Methods:Bedside aEEG monitoring was carried out for healthy newborns from 32 to 46 weeks CA between September 1,2011 and August 30,2012.For each aEEG tracing,mean duration of every complete SWC,number of SWC repetition within 12 hours,mean duration of each narrow and broadband of SWC,mean voltage of the upper edge and lower edge of SWC,mean bandwidth of SWC were counted and calculated.Analysis of the correlations between voltages or bandwidth of SWC and CA was performed to assess the developmental changes of central nervous system of newborns with different CA.Results:The SWC of different CA on aEEG showed clearly identifiable trend after 32 weeks of CA.The occurrence of SWC gradually increases from preterm to post-term infants;term infants had longer SWC duration.The voltage of upper edge of the broadband decreased at 39 weeks,while the lower edge voltage increases and the bandwidth of broadband declined along with the growing CA.The upper edge of the narrowband dropped while the lower edge rised gradually,especially in preterm stage.The width of the narrowband narrowed down while CA increased.Conclusions:The SWC on aEEG of 32-46 weeks infants showed a continuous,dynamic and developmental progress.The appearance of SWC and the narrowing bandwidth of narrowband is the main indicator to identify the CA-dependent SWC from the preterm to the late preterm period.The lower edge of the broadband identifi es the term to post-term period.