Abnormal Excitability Research Articles

Simultaneous Motor and Visual Intraoperative Neuromonitoring in Asleep Parietal Lobe Surgery: Dual Strip Technique.

Background: The role played by the non-dominant parietal lobe in motor cognition, attention and spatial awareness networks has potentiated the use of awake surgery. When this is not feasible, asleep monitoring and mapping techniques should be used to achieve an onco-functional balance. Objective: This study aims to assess the feasibility of a dual-strip method to obtain direct cortical stimulation for continuous real-time cortical monitoring and subcortical mapping of motor and visual pathways simultaneously in parietal lobe tumour surgery. Methods: Single-centre prospective study between 19 May–20 November of patients with intrinsic non-dominant parietal-lobe tumours. Two subdural strips were used to simultaneously map and monitor motor and visual pathways. Results: Fifteen patients were included. With regards to motor function, a large proportion of patients had abnormal interhemispheric resting motor threshold ratio (iRMTr) (71.4%), abnormal Cortical Excitability Score (CES) (85.7%), close distance to the corticospinal tract—Lesion-To-Tract Distance (LTD)—4.2 mm, Cavity-To-Tract Distance (CTD)—7 mm and intraoperative subcortical distance—6.4 mm. Concerning visual function, the LTD and CTD for optic radiations (OR) were 0.5 mm and 3.4 mm, respectively; the mean intensity for positive subcortical stimulation of OR was 12 mA ± 2.3 mA and 5/6 patients with deterioration of VEPs > 50% had persistent hemianopia and transgression of ORs. Twelve patients remained stable, one patient had a de-novo transitory hemiparesis, and two showed improvements in motor symptoms. A higher iRMTr for lower limbs was related with a worse motor outcome (p = 0.013) and a longer CTD to OR was directly related with a better visual outcome (p = 0.041). At 2 weeks after hospital discharge, all patients were ambulatory at home, and all proceeded to have oncological treatment. Conclusion: We propose motor and visual function boundaries for asleep surgery of intrinsic non-dominant parietal tumours. Pre-operative abnormal cortical excitability of the motor cortex, deterioration of the VEP recordings and CTD < 2 mm from the OR were related to poorer outcomes.

Oxytocin Receptor in Cerebellar Purkinje Cells Does Not Engage in Autism-Related Behaviors.

The classical motor center cerebellum is one of the most consistent structures of abnormality in autism spectrum disorders (ASD), and neuropeptide oxytocin is increasingly explored as a potential pharmacotherapy for ASD. However, whether oxytocin targets the cerebellum for therapeutic effects remains unclear. Here, we report a localization of oxytocin receptor (OXTR) in Purkinje cells (PCs) of cerebellar lobule Crus I, which is functionally connected with ASD-implicated circuits. OXTR activation neither affects firing activities, intrinsic excitability, and synaptic transmission of normal PCs nor improves abnormal intrinsic excitability and synaptic transmission of PCs in maternal immune activation (MIA) mouse model of autism. Furthermore, blockage of OXTR in Crus I in wild-type mice does not induce autistic-like social, stereotypic, cognitive, and anxiety-like behaviors. These results suggest that oxytocin signaling in Crus I PCs seems to be uninvolved in ASD pathophysiology, and contribute to understanding of targets and mechanisms of oxytocin in ASD treatment.

Acute rapamycin rescues the hyperexcitable phenotype of accumbal medium spiny neurons in the valproic acid rat model of autism spectrum disorder

We previously demonstrated that prenatal exposure to valproic acid (VPA), an environmental model of autism spectrum disorder (ASD), leads to a hyperexcitable phenotype associated with downregulation of inward-rectifying potassium currents in nucleus accumbens (NAc) medium spiny neurons (MSNs) of adolescent rats. Aberrant mTOR pathway function has been associated with autistic-like phenotypes in multiple animal models, including gestational exposure to VPA. The purpose of this work was to probe the involvement of the mTOR pathway in VPA-induced alterations of striatal excitability. Adolescent male Wistar rats prenatally exposed to VPA were treated acutely with the mTOR inhibitor rapamycin and used for behavioral tests, ex vivo brain slice electrophysiology, single-neuron morphometric analysis, synaptic protein quantification and gene expression analysis in the NAc. We report that postnatal rapamycin ameliorates the social deficit and reverts the abnormal excitability, but not the inward-rectifying potassium current defect, of accumbal MSNs. Synaptic transmission and neuronal morphology were largely unaffected by prenatal VPA exposure or postnatal rapamycin treatment. Transcriptome analysis revealed extensive deregulation of genes implied in neurodevelopmental disorders and ionic mechanisms exerted by prenatal VPA, which was partially reverted by postnatal rapamycin. The results of this work support the existence of antagonistic interaction between mTOR and VPA-induced pathways on social behavior, neurophysiological phenotype and gene expression profile, thus prompting further investigation of the mTOR pathway in the quest for specific therapeutic targets in ASD.

Alterations in the intrinsic discharge activity of CA1 pyramidal neurons associated with possible changes in the NADPH diaphorase activity in a rat model of autism induced by prenatal exposure to valproic acid

Autism spectrum disorder is a neurodevelopmental disorder characterized by sensory abnormalities, social skills impairment and cognitive deficits. Although recent evidence indicated that induction of autism-like behavior in animal models causes abnormal neuronal excitability, the impact of autism on neuronal properties is still an important issue. Thus, new findings at the cellular level may shed light on the pathophysiology of autism and may help to find effective treatment strategies. Here, we investigated the behavioral, electrophysiological and histochemical impacts of prenatal exposure to valproic acid (VPA) in rats. Findings revealed that VPA exposure caused a significant increase in the hot plate response latency. The novel object recognition ability was also impaired in VPA-exposed rats. Along with these behavioral alterations, neurons from VPA-exposed animals exhibited altered excitability features in response to depolarizing current injections relative to control neurons. In the VPA-exposed group, these changes consisted of a significant increase in the amplitude, evoked firing frequency and the steady-state standard deviation of spike timing of action potentials (APs). Moreover, the half-width, the AHP amplitude and the decay time constant of APs were significantly decreased in this group. These changes in the evoked electrophysiological properties were accompanied by intrinsic hyperexcitability and lower spike-frequency adaptation and also a significant increase in the number of NADPH-diaphorase stained neurons in the hippocampal CA1 area of the VPA-exposed rats. Taken together, findings demonstrate that abnormal nociception and recognition memory is associated with alterations in the neuronal responsiveness and nitrergic system in a rat model of autism-like.

The diverse role of the raphe 5-HTergic systems in epilepsy.

The raphe nuclei comprise nearly all of 5-hydroxytryptaminergic (5-HTergic) neurons in the brain and are widely acknowledged to participate in the modulation of neural excitability. "Excitability-inhibition imbalance" results in a variety of brain disorders, including epilepsy. Epilepsy is a common neurological disorder characterized by hypersynchronous epileptic seizures accompanied by many psychological, social, cognitive consequences. Current antiepileptic drugs and other therapeutics are not ideal to control epilepsy and its comorbidities. Cumulative evidence suggests that the raphe nuclei and 5-HTergic system play an important role in epilepsy and epilepsy-associated comorbidities. Seizure activities propagate to the raphe nuclei and induce various alterations in different subregions of the raphe nuclei at the cellular and molecular levels. Intervention of the activity of raphe nuclei and raphe 5-HTergic system with pharmacological or genetic approaches, deep brain stimulation or optogenetics produces indeed diverse and even contradictory effects on seizure and epilepsy-associated comorbidities in different epilepsy models. Nevertheless, there are still many open questions left, especially regarding to the relationship between 5-HTergic neural circuit and epilepsy. Understanding of 5-HTergic network in a circuit- and molecule-specific way may not only be therapeutically relevant for increasing the drug specificity and precise treatment in epilepsy, but also provide critical hints for other brain disorders with abnormal neural excitability. In this review we focus on the roles of the raphe 5-HTergic system in epilepsy and epilepsy-associated comorbidities. Besides, further perspectives about the complexity and diversity of the raphe nuclei in epilepsy are also addressed.

Neural Markers of Methylphenidate Response in Children With Attention Deficit Hyperactivity Disorder.

BackgroundDespite widespread use of stimulants to treat ADHD, individual responses vary considerably and few predictors of response have been identified. The identification of reliable and clinically feasible biomarkers would facilitate a precision medicine approach to pharmacological treatment of ADHD. We test the hypothesis that two electroencephalography (EEG) based neural signatures of ADHD, resting aperiodic slope exponent and novelty P3 amplitude, are markers of methylphenidate response in children. We hypothesize that positive response to methylphenidate treatment will be associated with greater abnormality of both neural markers.MethodsTwenty-nine 7-11 year-old children with ADHD and a history of methylphenidate treatment, and 30 controls completed resting EEG and visual oddball event related potential (ERP) paradigms. ADHD participants were characterized as methylphenidate responders (n = 16) or non-responders (n = 13) using the clinical global improvement (CGI-I) scale during blinded retrospective interview. All participants abstained from prescribed medications for at least 48 hours prior to the EEG.ResultsAs expected, methylphenidate responders (CGI-I rating < 3) demonstrated attenuated P3 amplitude relative to controls. Unexpectedly, methylphenidate non-responders showed atypically flat aperiodic spectral slope relative to controls, while responders did not differ on this measure.ConclusionADHD symptoms associated with atypical patterns of intrinsic neural activity may be less responsive to methylphenidate. In contrast, ADHD symptoms associated with abnormal frontal-striatal neural network excitation may be correctable with methylphenidate. Altogether, EEG is a feasible and promising candidate methodology for identifying biomarkers of stimulant response.

Bifurcations and Proarrhythmic Behaviors in Cardiac Electrical Excitations.

The heart is a hierarchical dynamic system consisting of molecules, cells, and tissues, and acts as a pump for blood circulation. The pumping function depends critically on the preceding electrical activity, and disturbances in the pattern of excitation propagation lead to cardiac arrhythmia and pump failure. Excitation phenomena in cardiomyocytes have been modeled as a nonlinear dynamical system. Because of the nonlinearity of excitation phenomena, the system dynamics could be complex, and various analyses have been performed to understand the complex dynamics. Understanding the mechanisms underlying proarrhythmic responses in the heart is crucial for developing new ways to prevent and control cardiac arrhythmias and resulting contractile dysfunction. When the heart changes to a pathological state over time, the action potential (AP) in cardiomyocytes may also change to a different state in shape and duration, often undergoing a qualitative change in behavior. Such a dynamic change is called bifurcation. In this review, we first summarize the contribution of ion channels and transporters to AP formation and our knowledge of ion-transport molecules, then briefly describe bifurcation theory for nonlinear dynamical systems, and finally detail its recent progress, focusing on the research that attempts to understand the developing mechanisms of abnormal excitations in cardiomyocytes from the perspective of bifurcation phenomena.

Epilepsy and Autonomic Nervous System

Epileptic activity that involves the central autonomic system, including the insular lobe, medial prefrontal cortex, amygdala, hypothalamus, periaqueductal gray, parabrachial complex, nucleus tractus solitarius, and ventrolateral medulla results in seizures with various autonomic manifestations. Some autonomic manifestations suggest localization and lateralization of epileptic foci. The autonomic nervous system modulates cerebral activity under physiological and pathological conditions. Vagus nerve stimulation (VNS) has attracted much attention for treatment of various neurological and psychiatric disorders and is an established palliative care strategy for patients with medically intractable epilepsy. Clinical and experimental studies suggest that VNS stabilizes cerebral cortical activity and inhibits abnormal excitability via pathways including upward vagus nerve conduction, nucleus tractus solitarius, and the thalamus, which consequently produces an anti-epileptic effect.

Bimodal sensory integration in migraine: A study of the effect of visual stimulation on somatosensory evoked cortical responses.

Merging of sensory information is a crucial process for adapting the behaviour to the environment in all species. It is not known if this multisensory integration might be dysfunctioning interictally in migraine without aura, where sensory stimuli of various modalities are processed abnormally when delivered separately. To investigate this question, we compared the effects of a concomitant visual stimulation on conventional low-frequency somatosensory evoked potentials and embedded high-frequency oscillations between migraine patients and healthy volunteers. We recorded somatosensory evoked potentials in 19 healthy volunteers and in 19 interictal migraine without aura patients before, during, and 5 min after (T2) simultaneous synchronous pattern-reversal visual stimulation. At each time point, we measured amplitude and habituation of the N20-P25 low-frequency-somatosensory evoked potentials component and maximal peak-to-peak amplitude of early and late bursts of high-frequency oscillations. In healthy volunteers, the bimodal stimulation significantly reduced low-frequency-somatosensory evoked potentials habituation and tended to reduce early high-frequency oscillations that reflect thalamocortical activity. By contrast, in migraine without aura patients, bimodal stimulation significantly increased low-frequency-somatosensory evoked potentials habituation and early high-frequency oscillations. At T2, all visual stimulation-induced changes of somatosensory processing had vanished. These results suggest a malfunctioning multisensory integration process, which could be favoured by an abnormal excitability level of thalamo-cortical loops.

Restless Legs Syndrome: Known Knowns and Known Unknowns.

Although restless legs syndrome (RLS) is a common neurological disorder, it remains poorly understood from both clinical and pathophysiological perspectives. RLS is classified among sleep-related movement disorders, namely, conditions characterized by simple, often stereotyped movements occurring during sleep. However, several clinical, neurophysiological and neuroimaging observations question this view. The aim of the present review is to summarize and query some of the current concepts (known knowns) and to identify open questions (known unknowns) on RLS pathophysiology. Based on several lines of evidence, we propose that RLS should be viewed as a disorder of sensorimotor interaction with a typical circadian pattern of occurrence, possibly arising from neurochemical dysfunction and abnormal excitability in different brain structures.

Study of the Involvement of the P2Y12 Receptor in Chronic Itching in Type 2 Diabetes Mellitus.

Itching is a common clinical symptom in diabetic patients. This research is to carry out experiments on the pathological changes in the P2Y12 receptor in type 2 diabetes mellitus complicated with chronic itching. Changes in body weight, fasting blood glucose (FBG), thermal hyperalgesia, cold hyperalgesia, spontaneous itching, and sciatic nerve conduction velocity were detected. The content of reactive oxygen species (ROS) in the dorsal root ganglion was detected by chemical fluorescence. The expression of the P2Y12 receptor, NLRP3, ASC, interleukin-1β (IL-1β), and IL-18 was detected by Western blotting, real-time quantitative PCR, immunofluorescence double labelling, and enzyme-linked immunosorbent assay. Itching and pain behaviours of the mice in the type 2 diabetes mellitus + itch group were significantly increased, and the expression of P2Y12 and NLRP3 as well as the content of ROS increased, and these changes were significantly reversed by treatment with P2Y12 short hairpin RNA (shRNA) or P2Y12 antagonist ticagrelor. Upregulated P2Y12 receptor expression after the activation of satellite glial cells contributes to the increase in ROS content in vivo, followed by NLRP3 inflammasome activation, increased inflammatory cytokine release, and damage to peripheral nerves, which leads to chronic itching. Treatment with P2Y12 shRNA or ticagrelor can inhibit these pathological changes, thus improving itching behaviour. Development mechanism of diabetes mellitus complicated with chronic itching. Notes: The upregulation of P2Y12 receptor expression and the activation of SGCs lead to the increase of ROS content in vivo, followed by the activation of NLRP3 inflammasome, the increase of inflammatory cytokine release, the abnormal excitation of DRG neurons, and the damage of peripheral nerves, resulting in chronic itching. P2Y12 receptor-related inflammatory injury involves chronic itching in type 2 diabetes mellitus. Treatment with P2Y12 receptor shRNA or P2Y12 antagonist ticagrelor can inhibit these pathological changes and improve itching behaviour.

Utilization of EEG in A Teaching Hospital: A Descriptive Cross-Sectional Study

INTRODUCTION Electroencephalography is a safe, convenient, non-invasive, and inexpensive technique that allows assessment of cerebral function and detects physiological manifestations of abnormal cortical excitability. Published literature about its utilization and application is sparse from this part of the world. &#x0D; METHODOLOGY It is a descriptive, cross-sectional study conducted in Nepalgunj Medical College, Kohalpur, Nepal. All the subjects referred for EEG evaluation from January 2019 to December 2020 (two years) were enrolled and EEG was performed. A self-designed proforma was used to record different variables and data was analyzed using Statistical Package for the Social Sciences version 21.0 for Windows.&#x0D; RESULT Of total 246 subjects, 53.3% were male and 58.9% of the subjects were 20 years or younger by age. Maximum (35.8%) number of referrals came from the department of psychiatry. Generalized seizure discharge was the most common EEG diagnosis and presence of seizure activity was noted in 37%of patients.&#x0D; CONCLUSION EEG is utilized by different specialities commonly for seizure disorder, psychiatric disorders and headaches.

Quantitative assessment of cortical excitability in Alzheimer’s dementia and its association with clinical symptoms: A systematic review and meta‐analyses

AbstractBackgroundAlzheimer’s Disease (AD) is characterized by cognitive and neuropsychiatric symptoms (NPS). Studies using electroencephalography (EEG) have shown increased epileptiform and epileptic activity in AD. Transcranial magnetic stimulation (TMS) studies have also shown abnormal cortical excitability in AD, however findings have been inconsistent. Further, relationship between cortical excitability and clinical symptoms of AD is not clear. This review and meta‐analyses aims to synthesize the existing evidence for abnormal cortical excitability in AD and its relationship with clinical symptoms.MethodWe systematically searched and reviewed publications that quantitatively assessed cortical excitability, using TMS resting motor threshold (rMT), active motor threshold (aMT), motor evoked potential (MEP) or directly from the cortex using TMS‐EEG via TMS‐evoked potential (TEP). Effect sizes and 95% confidence intervals (CI) of rMT and aMT were calculated using Hedges’ g and meta‐analyzed using a random effects model. Heterogeneity among studies was assessed by Cochran’s Q and I2 statistic.ResultWe identified 895 publications out of which 68 were reviewed in full‐text and 37 were included in the final review. Thirty studies using rMT and seven using aMT were included in the meta‐analyses. The AD group had reduced rMT (Hedges’ g = ‐0.99, 95% CI [‐1.29, ‐0.68], p &lt; 0.00001) and aMT (Hedges’ g = ‐0.87, 95% CI [‐1.50, ‐0.24], p &lt; 0.00001) as compared with control groups, indicative of higher cortical excitability. Evidence of considerable heterogeneity was found across the studies (Q (29) = 85.68, p &lt; 0.00001, I2 =81%). Qualitative review of the literature showed some evidence of increased MEP amplitude (n = 2 studies), however findings related to TEP were inconsistent. Further, there was some evidence (n = 4 studies) supporting an inverse association between cortical excitability and global cognition. No publications reported on the relationship between cortical excitability and neuropsychiatric symptoms (NPS).ConclusionThere is strong evidence of increased motor cortex excitability in AD and some evidence of an inverse association between excitability and cognition. Future studies should assess cortical excitability from non‐motor areas and examine its relationship with cognition and NPS.

A test to determine the site of abnormal neuromuscular refractoriness

ObjectiveThe relative refractory period (RRP) of motor axons is an important parameter in nerve excitability tests of the recovery cycle (RC). Abnormalities may have a site in the axonal membrane, the neuromuscular junction, or in a dysfunction of the muscle. We aimed in this study to determine the site of abnormality, using a modified protocol of the conventional RC test, whereby an additional supramaximal stimulus is added at the same interstimulus interval as in RC recordings (RCSM). MethodsTwenty-four healthy subjects aged 37.8 ± 2.4 years (mean ± SE) were examined with median nerve excitability testing using RC and RCSM protocols at normal temperature (34.1 ± 0.2 °C). The recordings were repeated in 12 subjects after selective cooling of the thenar muscle (25.2 ± 0.7 °C) and in 12 subjects after cooling the nerve trunk at the wrist (24.9 ± 0.3 °C). ResultsAfter cooling the nerve, RRP measured with RC and RCSM were prolonged similarly (medians by 1.8 ms, and 2.1 ms respectively). In contrast, cooling the muscle prolonged RRP measured with RC (by 1.3 ms), but did not significantly prolong RRP measured with RCSM. RRPs measured by RC and RCSM were significantly different when cooling was at the muscle (P = 5.10-4), but not when cooling was at the nerve (P = 0.57). ConclusionsA difference between RC and RCSM indicates abnormal excitability distal to the axonal membrane under the stimulating electrode. SignificanceCombining RCSM with the conventional RC protocol should help to localize the site of abnormal neuromuscular refractoriness.

Deficits in central auditory processing among migraine patients

BackgroundMigraine is a neurological disease associated with abnormal excitability in visual, somatosensory, and motor cortex. This study aimed to verify and compare auditory processing performance in migraine patients with and without dizziness and healthy controls.ResultsSixty subjects were divided into 3 groups: control group, twenty normal healthy subjects, and study group I (twenty subjects diagnosed with migraine) and study group II (twenty subjects diagnosed with vestibular migraine). They were evaluated using the Central Auditory Processing Questionnaire for adults, tympanometry, pure tone audiometry, Psychophysical Central Auditory Tests, including Arabic Speech Intelligibility in Noise Test for adults, Arabic Dichotic Digit Test [version II], Gap in Noise Test, Duration Pattern Test, and Arabic Memory Tests. No significant difference was found between the two study groups I and II, but the significant difference was found between the study groups and the control group in all central auditory test results. Statistically significant difference was found between the control group and study groups I and II regarding all memory tests. The highest percentage of abnormality was present in temporal resolution and selective auditory attention in both study groups. There was no significant statistical correlation between the number of attacks/month and central auditory test results. There was no significant statistical correlation between the frequency of attacks in VM patients and central auditory test results.ConclusionsPatients with migraine and vestibular migraine had an inferior performance in all psychophysical central auditory tests when compared with control. Also, there was no significant difference between the 2 study groups regarding central auditory test results which may support that both migraine with and without dizziness have the same pathophysiology.

Deep brain stimulation in primary Meige’s syndrome: a successful case report

Introduction: Meige’s Syndrome is a rare focal dystonia disorder characterized mainly by blepharospasm and orofacial dystonia. Dystonia is identified as a movement disorder, with abnormal involuntary movements and postures, caused by sustained or intermittent muscle contractions. Its pathophysiology is not fully elucidated, but it is known that its evolution is due to an abnormal excitability of the sensorimotor cortex and the interneural pathways of the brainstem, a genetic predisposition and environmental factors. Treatment includes various interventions, ranging from conservative approaches to invasive surgical procedures. Oral medications such as anticholinergics, dopamine antagonists and GABA receptor agonists shows positive results, also botulinum A injection can be used as treatment. If any of those conservative alternatives are not providing the required results, deep brain stimulation (DBS) of globus pallidus interna (GPi) provides an invasive neuromodulation that has been presenting improvement of symptoms in individuals with previous failure in other forms of treatment. Objectives: The purpose of this case report is to show the effectiveness of treatment with deep brain stimulation of GPi in a patient with Meige Syndrome that has undergone several other approaches previously. Because it is a surgical procedure, there are risks of adverse effects, but most of them can be minimized or even stopped by the correct programming of the intracerebral electrodes. This case report shows that the deep brain stimulation of Gpi is more efficient than other treatments when well indicated, besides having a better index of improvement when compared to the stimulation of the subthalamic nucleus. The authors do not have any conflict of interests. Case report: A 66-years-old man started suffering involuntary contractions of the orofacial muscles associated with blepharospasm that impaired his quality of life. He was diagnosed with Meige syndrome by a neurologist specialized in movement disorders. Before starting the treatment, he was extremely depressed with suicidal ideas and his psycho-affective relationship with family deteriorated since those symptoms started. Therefore, he was under follow-up with a psychologist and psychiatrist, who prescribed antidepressants Duloxetin 30 mg 12/12 oral and Nortriptyline 25 mg 12/12 oral. The patient was unresponsive to the conventional treatment. He had pharmacological treatment with Levodopa, Trazodone and Lorazepam without benefits. He also underwent several botulinum toxin applications for one year and two eyelid lift surgeries, also without success. He was referred to a functional neurosurgeon, who proceeded with the Gpi-DBS implantation in the patient, in February 2021, with an ActivRC generator. The surgery was performed with the patient awake and bilateral microrecording was used to help locate the target. After 4 weeks of surgery and correct programming of the electrodes - 3387 from Medtronic, 130 Hz, 90 PW, 2.5 mA, 1.5 mm2 contact area and 1.5 mm interelectrode spacing, with rechargeable battery -, the patient evolved with an improvement of 80% of the symptoms he presented before the surgical procedure.

Basic study of epileptic seizure detection using a single-channel frontal EEG and a pre-trained ResNet.

Epilepsy is a neurological disorder that causes sudden seizures due to abnormal excitation of neurons in the brain. Approximately 30 % of patients cannot control their seizures using medication. In addition, since seizures can occur anywhere and at any time, caregivers must always be with the patient. Various researchers have developed seizure detection methods using multichannel EEG to improve the quality of life of patients and caregivers. However, the large size of the measurement device impedes transportation. We believe that a portable measurement device with a small number of channels is suitable for detecting seizures in daily life. Therefore, we need a system that can detect seizures using a small number of channels. The purpose of this research is to develop a seizure detection algorithm using a single-channel frontal EEG and to confirm its basic performance. We used EEG signals from a single electrode position (Fp1-F7, Fp2-F8), which is a bipolar derivation of the frontal region. We segmented the EEG using a 2 s sliding window with 50 % overlap and converted the segments into images. After preprocessing, we fine-tuned ResNet18, pre-trained on ImageNet, and developed an ensemble classification method. In the experiments with 10 epileptic patients (3 - 19 years old) registered in the CHB-MIT scalp EEG database, the results showed that the average sensitivity was 88.73 %, the average specificity was 98.98 %, and the average detection latency time was 7.39 s. In conclusion, the developed algorithm was validated as sufficiently accurate to detect epileptic seizures.Clinical Relevance- This establishes an image recognition algorithm that can detect epileptic seizures using a single- channel frontal EEG.

A new, sensitive biomarker for abnormal cortical excitability: Single trial based synchronization and desynchronization with cortical myoclonus

Giant somatosensory evoked potentials (SEPs), i.e., enlarged cortical components of SEPs, represent abnormal cortical excitability such as cortical myoclonus (CM). Recently, we reported high-frequency oscillations (HFOs) with a part of giant SEPs specifically observed in benign adult familial myoclonus epilepsy (Tojima et al., 2021). However, no clear HFOs after N33 were observed. We herein hypothesized, in CM patients, late cortical abnormal excitability may be poorly synchronized in average method and thus only detectable by single trial, event-related synchronization (ERS) and desynchronization (ERD). We also compared ERS/ERD between CM patients and healthy controls (HCs).

Evaluation Of Central Auditory Function In Migraine Patients

Abstract Background Migraine is a neurological disease associated with abnormal excitability in visual, somatosensory and motor cortex. Previous researches reported abnormalities in the auditory brainstem response (ABR) and in vestibular functions. These results are an indicator of impending auditory malfunction in Migraine and disruption of central auditory processing mechanisms. Objectives This study aimed to assess and compare central auditory processing (CAP) performance in migraine patients with and without dizziness and healthy controls. Subjects and method Sixty subjects aged between18 and 60 years divided into 3 groups; control group (twenty normal healthy subjects), study group I (twenty subject diagnosed with migraine) and study group II (twenty subjects diagnosed with vestibular migraine). They were subjected to a headache sheet, central auditory processing questionnaire and Psychophysical central auditory tests: including Arabic Speech Intelligibility In Noise (SPIN) test for adults, Arabic Dichotic digit test, Gap In Noise (GIN) test, Duration pattern test and Arabic memory tests. Results Statistically significant difference was found between the 2 study groups and control group regarding right dichotic (p = 0.004),right and left duration pattern tests (p = 0.01) with highly statistically significant difference(p &amp;lt; 0.001) Gap In Noise (GIN) test, left dichotic digit test, right and left speech in noise. But there was no statistically significant difference between the two study groups regarding all tests. Conclusions Patients with migraine and vestibular migraine had poor performance in all central auditory tests when compared with control this mean that migraine lead to impaired central auditory processing in adults. Also, there was no significant difference between the 2 study groups regarding central auditory test results which may support that both migraine with and without dizziness have the same pathophysiology.

Cyclic changes of visual cortical excitability across migraine phases: A study with sound induced flash illusions

Abnormal cortical excitability has a role in migraine but the link with beginning and stop of migraine attacks remains unclear. Critical insight could come by excitability changes across the migraine cycle. Here we explore it through sound induced flash illusions (SIFI). SIFI are cross-modal illusory percepts critically dependent on visual cortical excitability (less illusions = increased excitability) that have been found to be altered in episodic and chronic migraine(1–2).