Study On The Resting-state EEG Characteristics And Event-related Potentials Of Response Inhibition In Patients With Migraine Without Aur

Part One: Literature ReviewIn recent years,cognitive dysfunction in migraineurs has attracted neurologists more and more attention.Previous studies have found that migraineurs have poor cognitive function during attack,but their cognitive function during attack is inconsistent.Population-based studies did not reveal a difference in cognitive functions between migraineurs and controls,but migraineurs show impaired cognitive function interictally in most of the clinic-based studies,involved in the field of cognitive functions including information processing speed,attention,executive function,verbal and nonverbal memory,etc.Neuro Electrophysiological techniques,functional MRI and neuropharmacological studies support clinical features of migraine cognitive dysfunction.Longitudinal studies did not show a gradual decline in cognitive function over time in migraineurs.Prophylactic treatment of migraine and comorbid disorders such as anxiety and depression disorder may affect the cognitive impairment of migraine patients,but cannot completely explain the cognitive impairment of migraine patients.In the past few decades,although conventional EEG has limited clinical diagnostic value for migraine,in recent years,with the progress of EEG analysis techniques,such as visual evoked potential,spectrum analysis,event-related potential and other clinical applications,more and more studies have found the changes of EEG characteristics in migraine patients.Part Two: EEG power spectrum analysis and source location analysis of resting state in Mwo A patients.Objective: To investigate the distribution of EEG power spectrum in resting state in patients with Mwo A and to analyze the localized brain regions in different frequency bands using standardized low-resolution electromagnetic scanning(s LORETA).Methods: The resting state EEG of 61 Mwo A patients(50 females)and 66 healthy adults(50 females)was collected by Neuro Scan EEG equipment.The original data were divided into 2s segments,and60 segments of data were selected for each subject.The time-domain information of the original data was converted into frequency domain information by using MATLAB’s " pwelch.m" script.s LORETA was used to analyze the characteristics of brain source in different frequency bands.Results: Compared with healthy controls,the Delta(0.5 ～ 3.5Hz)power spectrum was reduced in Mwo A patients.The results of source location analysis showed that the activation of Delta rhythm in Brodmann region BA30 was weak in Mwo A patients in resting state.Conclusions:The power spectrum of EEG Delta rhythm in Mwo A patients is different from that of healthy controls in the resting state,and the activity of the activated brain region is decreased,which provides an insight into the complex neurophysiology of migraine.Part Three: Abnormalities in resting-state EEG microstates are a vulnerability marker of migraineBackground: Resting-state EEG microstates are thought to reflect brief activations of several interacting components of resting-state brain networks.Surprisingly,we still know little about the role of these microstates in migraine.In the present study,we attempted to address this issue by examining EEG microstates in patients with migraine without aura(Mwo A)during the interictal period and comparing them with those of a group of healthy controls(HC).Methods: Resting-state EEG was recorded in 61 Mwo A patients(50 females)and 66 HC(50females).Microstate parameters were compared between the two groups.We computed four widely identified canonical microstate classes A-D.Results: Microstate classes B and D displayed higher time coverage and occurrence in the Mwo A patient group than in the HC group,while microstate class C exhibited significantly lower time coverage and occurrence in the Mwo A patient group.Meanwhile,the mean duration of microstate class C was significantly shorter in the Mwo A patient group than in the HC group.Moreover,among the Mwo A patient group,the duration of microstate class C correlated negatively with clinical measures of headache‐related disability as assessed by the six-item Headache Impact Test(HIT-6).Finally,microstate syntax analysis showed significant differences in transition probabilities between the two groups,primarily involving microstate classes B,C and D.Conclusions: By exploring EEG microstate characteristics at baseline we were able to explore the neurobiological mechanisms underlying altered cortical excitability and aberrant sensory,affective and cognitive processing,thus deepening our understanding of migraine pathophysiology.Part Four: Response inhibition alterations in migraine without aura: An event-related potential studyBackground: Migraine is characterized by a hypersensitivity to environmental stimulation which climaxes during headache attacks but persists during attack-free period.Despite ongoing debates about the nature of the mechanisms giving rise to this abnormality,the presence of deficient inhibitory cortical processes has been proposed to be one possible mechanism underlying its pathogenesis.Empirical evidence supporting this notion is mainly based on previous findings showing functional cortical hyperexcitability in the sensory domain.Considering that a general inhibitory control process can play an important role across early to later stage of information processing,this may in turn indicate the important role other dimensions of inhibitory control can play in migraine disability.To this end,the present study was designed to examine the pathophysiological basis of inhibitory control that takes place during suppression of prepotent responses.Methods: Twenty-two patients with migraine without aura(mean age = 30.86 ± 5.69 years;19 females)during the interictal period and 25 healthy controls(mean age = 30.24 ± 3.52 years;18 females)were recruited.We employed a stop signal task in combination with event-related potentials(ERPs)to examine participants’ neural activity supporting response inhibition.Results: Behaviorally,migraineurs exhibited prolonged reaction times to the stop signal relative to healthy controls.At the neural level,the amplitude of the stop-N2,a component of the ERPs related to conflict monitoring during early,non-motoric stages of inhibition,was significantly increased in migraineurs.Meanwhile,the amplitude of the stop-P3,a component of the ERPs reflecting late-stage inhibition of the motor system itself and cognitive evaluation of motor inhibition,was also significantly increased in migraineurs.Moreover,our time-frequency analysis has further revealed increased delta activity in the time window used to extract the mean amplitude of the stop-P3 in migraineurs relative to healthy controls.Conclusions: Consistent with the theory that cortical hyperexcitability is a key signature of migraine,these findings revealed a decrease in suppressing prepotent responses in migraineurs,which can be attributable to cortical hyperexcitability.These novel findings imply the existence of dysfunctional inhibitory control at later stage of information processing.