Interictal Period Research Articles

Post-Ictal Mania: A Case Report with Literature Revue

IntroductionWhile postictal mania is a well-recognized clinical condition, it has received less research attention compared to other postictal manifestations.ObjectivesDrawing upon an analysis of a case report that underscores the clinical and therapeutic challenges associated with comorbid epilepsy and mania, a literature review was carried out to investigate the connection between these two disorders.MethodsWe illustrate a case of comorbidity between mania and epilepsy and provide a concise review of the literature summarizing the key characteristics of this association.ResultsThis case pertains to Mr. M, a 44-year-old male with a history of frontal epilepsy characterized by secondary partial generalization, which was partially controlled with sodium valproate. He was admitted to our service due to acute agitation following a loss of consciousness lasting a few minutes.Upon admission, the patient exhibited symptoms of mental confusion. A neurological examination did not uncover any abnormalities. Brain computed tomography revealed mild frontal atrophy. Video electroencephalography conducted during the interictal period and outside the episodes of confusion did not reveal any abnormalities. The patient was restarted on sodium valproate (20 mg/kg/day) and clonazepam (2 mg/day). Following a lucid interval of ten days, the patient started to manifest psychiatric symptoms, which included irritability, hostility towards his spouse, increased talkativeness, thought pressure, and an unusual sense of familiarity, raising suspicion of post-ictal mania.ConclusionsBased on this clinical case and the existing scientific literature, post-ictal mania occupies a distinct position among the mental disorders observed in the post-ictal period. Therefore, clinicians must be aware of these conditions to facilitate accurate diagnosis and appropriate management.Disclosure of InterestNone Declared

What Cluster Headache Patients Would Like Their Relatives to Know: Results from a Qualitative Study

Many patients with cluster headaches report that their relatives do not understand what they are going through. This qualitative study aimed to collect patients’ recommendations and wishes on how others should respond to those suffering from cluster headaches. We recruited 22 patients with episodic or chronic cluster headaches for this cross-sectional study. They responded to seven questions that assessed the disease’s impact on their relationships with relatives and their wishes for others’ behaviour towards them. Seven recommendations for relatives emerged: (i) withdraw during attacks, (ii) respect post-ictal exhaustion, (iii) do not insist on discussing the disorder, (iv) help the patient to lead a “normal” life, (v) support preserving social contacts, (vi) show being aware of the disease severity, and (vii) expect the disease to take up space in patients’ lives and minds. Two recommendations for the interictal period indicate avoidance, which is considered a negative coping strategy. Conversely, the suggestion to support preserving social contacts might mean confronting the disease, which is likely associated with more favourable outcomes. Still, adhering to all patients’ requests might increase suffering instead of reducing it. Thus, further research is needed to develop strategies suited to improve well-being.

Exploring PGE2 and LXA4 Levels in Migraine Patients: The Potential of LXA4-Based Therapies.

Neurogenic inflammation plays a significant role in the pathogenesis of migraines. This study aimed to investigate the serum levels of prostaglandin E2 (PGE2), lipoxin A4 (LXA4), and other inflammatory biomarkers (C-reactive protein, fibrinogen) in migraine patients. In total, 53 migraine patients and 53 healthy controls were evaluated. Blood serum samples were collected during both attack and interictal periods and compared with the control group. In both the attack and interictal periods, PGE2 and LXA4 values were significantly lower in migraine patients compared to the control group (p < 0.001). Additionally, PGE2 values during the attack period were significantly higher than those during the interictal period (p = 0.016). Patients experiencing migraine attacks lasting ≥ 12 h had significantly lower serum PGE2 and LXA4 levels compared to those with attacks lasting < 12 h (p = 0.028 and p = 0.009, respectively). In ROC analysis, cut-off values of 332.7 pg/mL for PGE2 and 27.2 ng/mL for LXA4 were determined with 70-80% sensitivity and specificity. In conclusion, PGE2 and LXA4 levels are significantly lower in migraine patients during both interictal and attack periods. Additionally, the levels of LXA4 and PGE2 decrease more with the prolongation of migraine attack duration. Our findings provide a basis for future treatment planning.

Consciousness transitions during epilepsy seizures through the lens of integrated information theory

Consciousness is one of the most complex aspects of human experience. Studying the mechanisms involved in the transitions among different levels of consciousness remains as one of the greatest challenges in neuroscience. In this study we use a measure of integrated information (ΦAR) to evaluate dynamic changes during consciousness transitions. We applied the measure to intracranial electroencephalography (SEEG) recordings collected from 6 patients that suffer from refractory epilepsy, taking into account inter-ictal, pre-ictal and ictal periods. We analyzed the dynamical evolution of ΦAR in groups of electrode contacts outside the epileptogenic region and compared it with the Consciousness Seizure Scale (CCS). We show that changes on ΦAR are significantly correlated with changes in the reported states of consciousness.

Presence of Spontaneous Nystagmus, Benign Paroxysmal Positional Vertigo, and Tumarkin Fall in Patients With Primary Headache and Their Responses to Caloric and Video Head Impulse Tests.

Migraine, vestibular migraine (VM) and tension-type headache (TTH) are the most common disorders in dizziness and headache clinics, associated with dizziness or vertigo and postural imbalance, causing a substantial burden on the individual and the society. The objective of this research was to examine the presence of spontaneous nystagmus, comorbidity of benign paroxysmal positional vertigo (BPPV), and Tumarkin fall in patients; additionally, the study focused on assessing the patients' responses to bithermal caloric irrigation and video head impulse test (vHIT). Consecutive patients diagnosed with migraine, VM, and TTH according to the International Classification of Headache Disorders, third edition (beta version (ICHD-3β)), who were referred to Dizziness and Headache Clinic were enrolled. BPPV and Tumarkin fall were assessed by questionnaires. The presence of BPPV was further evaluated through Dix-Hallpike or head roll maneuver, while spontaneous nystagmus was monitored using video-oculography during interictal period. Lastly, patients' responses to bithermal caloric irrigation and vHIT were analyzed. There was a significantly higher incidence of spontaneous nystagmus in VM compared to both migraine and TTH. The drop attack episodes were slightly more frequent in VM than in TTH and migraine, though not statistically significant. The prevalence of BPPV was significantly higher in VM than in migraine and TTH. Unilateral vestibular paresis was more common in the VM group than in migraine and TTH. There was profound unilateral weakness (UW) in VM patients than in migraine, but no significant difference was found between VM and TTH. In VM, the percentage of saccades along with reduced vHIT gain was significantly higher than in migraine. Lastly, the percentage of abnormal response in vHIT was significantly lower than the percentage of abnormal UW in caloric irrigation across all groups. In VM patients, the prevalences of decompensated peripheral damage and BPPV were higher than in migraine and TTH patients as disclosed by the presence of peripheral spontaneous nystagmus and abnormal vHIT during the interictal period. Our findings suggest that the peripheral vestibular system acts as a significant mechanism in the pathogenesis of VM, and it might also be involved in migraine and TTH cases without vertigo symptoms.

Diagnostic value of high frequency oscillation in localization of type Ⅱ focal cortical dysplasia epilepsy

Retrospective analysis was conducted on 9 patients with type Ⅱ focal cortical dysplasia (FCD) who underwent stereo-electroencephalography (SEEG) implantation in the Department of Neurosurgery of the First Affiliated Hospital of Fujian Medical University from November 2020 to February 2023. The onset area, onset time, and frequency of high-frequency oscillations (HFO) were analyzed and the correlation of HFOs with interictal, preictal, and ictal periods. SEEG recordings of 80-500 Hz HFOs were observed in both interictal and ictal periods in 9 patients, with 6 patients exhibiting fast ripples (FR) in the range of 250-500 Hz. Surgical resection of the seizure onset area and FR-generating electrodes was performed, and postoperative follow-up for over 2 years indicated Engel I in 5 cases. 6 patients showed continuous discharge during the preictal period, and the distribution index of continuous discharge was positively correlated with seizure frequency. HFOs in the range of 80-500 Hz were present in all four seizure onset patterns during the ictal period. The onset area and FR-emitting electrode were surgically removed in 6 patients with continuous discharge and overlapping HFOs during the preictal period, with 5 cases of Engel I. Type Ⅱ FCD discharges exhibited complexity, high discharge indices, and a close association with HFOs. Compared with the spike wave, the electrode range of HF is more limited, and the incidence of HF before attack is significantly increased, which is closely correlated with the onset area. The simultaneous occurrence of HFO and the spike waves has higher diagnostic value than the individual occurrence, effectively enhancing surgical efficacy.

Measurable transitions during seizures in intracranial EEG: A stereoelectroencephalography and SPECT study

ObjectiveIctal Single Photon Emission Computed Tomography (SPECT) and stereo-electroencephalography (SEEG) are diagnostic techniques used for the management of patients with drug-resistant focal epilepsies. While hyperperfusion patterns in ictal SPECT studies reveal seizure onset and propagation pathways, the role of ictal hypoperfusion remains poorly understood. The goal of this study was to systematically characterize the spatio-temporal information flow dynamics between differently perfused brain regions using stereo-EEG recordings. MethodsWe identified seizure-free patients after resective epilepsy surgery who had prior ictal SPECT and SEEG investigations. We estimated directional connectivity between the epileptogenic-zone (EZ), non-resected areas of hyperperfusion, hypoperfusion, and baseline perfusion during the interictal, preictal, ictal, and postictal periods. ResultsCompared to the background, we noted significant information flow (1) during the preictal period from the EZ to the baseline and hyperperfused regions, (2) during the ictal onset from the EZ to all three regions, and (3) during the period of seizure evolution from the area of hypoperfusion to all three regions. ConclusionsHypoperfused brain regions were found to indirectly interact with the EZ during the ictal period. SignificanceOur unique study, combining intracranial electrophysiology and perfusion imaging, presents compelling evidence of dynamic changes in directional connectivity between brain regions during the transition from interictal to ictal states.

The effect of epilepsy and antiseizure medications on cardiac autonomic functions in children with epilepsy

ABSTRACT Background Autonomic manifestations have been frequently studied in adults with epilepsy. Here, we evaluated cardiac autonomic (ANS) functions in children with epilepsy in the interictal period and determined the risks for their dysfunctions. Research design and methods This study included 60 patients (boys = 25; girls = 35 age: 14.53 ± 2.54 yrs) and 25 controls. Patients were well-controlled on antiseizure medications (ASMs). The battery of testing included measuring resting heart rate (HR) and blood pressure (BP), 30:15 ratio, HR variability (HRV) response to deep breathing, Valsalva ratio and BP changes in response to standing, isometric exercise and cold. Results Dizziness was reported in 25%. Autonomic dysfunctions were found in 45% (n = 27). Manifestations included high frequencies of abnormal 30:15 ratio (22%), HRV responses to deep breathing (45%), Valsalava ratio (45%), and BP responses to standing (35%), isometric exercise (27%) and cold (27%), indicating parasympathetic and sympathetic hypofunctions. There were positive correlations between parasympathetic and sympathetic dysfunctions. Logistic analysis showed that the durations of epilepsy and ASMs therapy were associated with ANS dysfunctions [95% CI: 0.895–4.719, p = 0.004]. Conclusions Parasympathetic and sympathetic autonomic hypofunctions are common in children with epilepsy. This could be due to the depressant effect of sodium channel blocker ASMs on central and/or cardiac autonomic systems.

Influence of idiopathic epilepsy on blood pressure and electrocardiography in dogs treated with phenobarbital.

Dogs with idiopathic epilepsy (IE) experience a shortened lifespan, neurobehavioral changes, and an increased risk of comorbidities during the interictal period. There have been several reports of sudden death in humans with epilepsy, suggesting changes in cardiac rhythm secondary to seizures. In veterinary medicine, there are still no such conclusive studies. The present study aimed to evaluate blood pressure values, electrocardiographic findings, and laboratory parameters in dogs with IE treated with phenobarbital and to correlate these findings with possible cardiac alterations. Twenty-one dogs were divided into 11 healthy dogs and 10 idiopathic epileptic dogs for blood analysis, computerized electrocardiogram, and oscillometer-based blood pressure measurement. QRS complex and S-T interval values differed significantly between groups, but blood pressure values were not significantly different. IE can occur with alterations in cardiac conduction and is a pathological condition.

Dynamics and concordance alterations of regional brain function indices in vestibular migraine: a resting-state fMRI study

BackgroundPrior MRI studies on vestibular migraine (VM) have revealed abnormalities in static regional intrinsic brain activity (iBA) and dynamic functional connectivity between brain regions or networks. However, the temporal variation and concordance of regional iBA measures remain to be explored.Methods57 VM patients during the interictal period were compared to 88 healthy controls (HC) in this resting-state functional magnetic resonance imaging (fMRI) study. The dynamics and concordance of regional iBA indices, including amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo), were examined by utilizing sliding time-window analysis. Partial correlation analyses were performed between clinical parameters and resting-state fMRI indices in brain areas showing significant group differences.ResultsThe VM group showed increased ALFF and ReHo dynamics, as well as increased temporal concordance between ALFF and ReHo in the bilateral paracentral lobule and supplementary motor area relative to the HC group. We also found decreased ReHo dynamics in the right temporal pole, and decreased ALFF dynamics in the right cerebellum posterior lobe, bilateral angular gyrus and middle occipital gyrus (MOG) in the VM group compared with the HC group. Moreover, a positive correlation was observed between ALFF dynamics in the left MOG and vertigo disease duration across all VM patients.ConclusionTemporal dynamics and concordance of regional iBA indices were altered in the motor cortex, cerebellum, occipital and temporoparietal cortex, which may contribute to disrupted multisensory processing and vestibular control in patients with VM. ALFF dynamics in the left MOG may be useful biomarker for evaluating vertigo burden in this disorder.

Anti-saccade as a tool to evaluate cognitive impairment in vestibular migraine.

Vestibular migraine (VM), an intricate subtype of migraine, amalgamates the dual attributes of migraine and vestibular disorders. In clinical settings, individuals with VM frequently articulate concerns regarding the manifestation of subjective cognitive impairment. This cognitive dysfunction is intricately linked with diminished mobility, heightened susceptibility to falls, and increased absenteeism in afflicted patients. Consequently, comprehending the features of cognitive impairment in VM patients holds potential clinical significance. The pursuit of rapid and objective methods for detection and assessment is foundational and prerequisite for efficacious cognitive management of VM patients. The study encompassed 50 patients diagnosed with vestibular migraine and recruited 50 age-sex matched healthy controls. All participants underwent anti-saccade tasks, and cognitive evaluation was performed using the MMSE and MoCA to assess overall cognitive function. Additionally, RBANS scales were employed to measure specific cognitive domains. The VM patients and normal controls demonstrated statistical parity in terms of age, gender, education, weight, and BMI, with no significant differences observed. Analysis of cognitive scores divulged a marked increase in the incidence of Mild Cognitive Impairment (MCI) in VM patients compared to Healthy Controls (HCs). Both MMSE and MoCA scores were notably lower in VM patients compared to their healthy counterparts. The RBANS cognitive test indicated significant impairment in immediate memory, visuospatial construction, language, attention, and delayed memory among VM patients. Notably, the Trail Making Test and Stroop Color-Word Test revealed compromised processing speed and executive function cognitive domains. The anti-saccadic task highlighted significantly elevated anti-saccadic latency and frequency of direction errors in vestibular migraine patients. Symptom severity, illness duration, and episode frequency in VM patients positively correlated with counter-scanning errors and negatively correlated with cognitive performance across diverse cognitive domains. VM patients exhibit cognitive decline across multiple cognitive domains during the interictal period. This cognitive impairment may not be fully reversible, underscoring its potential clinical significance for cognitive management in VM patients. The sensitivity of anti-saccade tasks to the cognitive status of VM patients positions them as promising objective indicators for diagnosis, intervention, and evaluation of cognitive impairment effects in VM in future applications.

Poor creativity in interictal migraine: A case–control pilot study

Background/Hypothesis: Creativity is a cognitive process that affects the performance of many daily life activities. This process, in turn, is influenced not only by various environmental factors but also by numerous individual aspects. Chronic pain is one of the factors that has proven to negatively affect creativity. Our hypothesis is that people with migraine in the interictal phase also have lower levels of creativity than the control group. Methods: We collected data from participants with migraine ( n = 31) in the interictal phase and from a non-migraine control group ( n = 30). We used the Alternative Uses Task (AUT) test and the Creative Intelligence Test (CREA) to evaluate creativity. Results: Our results revealed lower creativity in participants with migraine. This was confirmed by both the AUT (fluency: controls 7.4 (4.35) vs. participants with migraine 4.4 (2.9); p &lt; 0.001; originality: controls 2.353 (0.457) vs. participants with migraine 2.07 (0.278); p &lt; 0.001; flexibility: controls 3.4 (1.55) vs. participants with migraine 2.0 (1.0); p &lt; 0.001) and CREA (controls 14.0 (9.875) vs. participants with migraine 9.5 (5.0); p = 0.004) tests. Interpretation: The present pilot study provides evidence that migraine, even in the interictal period, reduces creative ideation and this may impact the quality of life of these individuals.

Development and validation of a prediction nomogram for depressive symptoms in gout patients.

The objective of the study was to explore the risk factors for depressive symptoms in patients with gout and to construct and validate a nomogram model. From October 2022 to July 2023, a total of 469 gout patients from a Class iii Grade A hospital in Northeast China were selected as the research objects by the convenience sampling method. The General Information Questionnaire, Self-Rating Depression Scale, Gout Knowledge Questionnaire, Self-Efficacy Scale for Managing Chronic Disease (SEMCD), and Social Support Rating Scale were used to conduct the survey. Univariate and multivariate logistic regression analyses were used to establish a depression risk prediction model and construct a nomogram. The bootstrap method was used to verify the performance of the model. The detection rate of depressive symptoms in gout patients was 25.16%. Binary logistic regression analysis showed that male, the number of tophi, acute attack period, lack of knowledge about gout, the number of attacks in the past year, and the duration of the last attack were independent risk factors for post-gout depression. Female, interictal period, chronic arthritis period, knowledge of gout, and social support were protective factors for post-gout depression (p < 0.05). The calibration (χ2 = 11.348, p = 0.183, p > 0.05) and discrimination (AUC = 0.858, 95%CI: 0.818-0.897) of the nomogram model for depressive symptoms in gout patients were good. The prevalence of depressive symptoms in gout patients is high, and it is affected by gender, current disease stage, number of tophi, gout knowledge level, the number of attacks in the past year, and the last attack days. The nomogram model is scientific and practical for predicting the occurrence of depressive symptoms in gout patients.

Disentanglement of Resting State Brain Networks for Localizing Epileptogenic Zone in Focal Epilepsy.

The objective of this study is to extract pathological brain networks from interictal period of E/MEG recordings to localize epileptic foci for presurgical evaluation. We proposed here a resting state E/MEG analysis framework, to disentangle brain functional networks represented by neural oscillations. By using an Embedded Hidden Markov Model, we constructed a state space for resting state recordings consisting of brain states with different spatiotemporal patterns. Functional connectivity analysis along with graph theory was applied on the extracted brain states to quantify the network features of the extracted brain states, based on which the source location of pathological states is determined. The method is evaluated by computer simulations and our simulation results revealed the proposed framework can extract brain states with high accuracy regarding both spatial and temporal profiles. We further evaluated the framework as compared with intracranial EEG defined seizure onset zone in 10 patients with drug-resistant focal epilepsy who underwent MEG recordings and were seizure free after surgical resection. The real patient data analysis showed very good localization results using the extracted pathological brain states in 6/10 patients, with localization error of about 15mm as compared to the seizure onset zone. We show that the pathological brain networks can be disentangled from the resting-state electromagnetic recording and could be identified based on the connectivity features. The framework can serve as a useful tool in extracting brain functional networks from noninvasive resting state electromagnetic recordings, and promises to offer an alternative to aid presurgical evaluation guiding intracranial EEG electrodes implantation.

Brain functional connectivity patterns associated with symptoms of vestibular migraine.

Several functional magnetic resonance imaging (fMRI) investigations of patients with vestibular migraine (VM) have revealed abnormal functionality in different networks, indicating that VM is related to alterations in brain function. We sought to investigate the resting-state functional connectivity (FC) patterns during the interictal period in VM by combining data-driven voxel-wise degree centrality (DC) calculations and seed-based FC analyses, and thereby determine the associations between cerebral function and clinical symptoms. Thirty-eight patients with VM and 33 matched normal controls were recruited. DC was calculated and compared between the groups, and the FC of locations showing DC alterations was further tested using a seed-based technique. The participants' clinical indicators were correlated with the DC and FC values of the brain areas. In contrast to the control group, the VM group showed considerably lower DC values in the bilateral medial prefrontal cortex (mPFC) and significantly higher DC values in the right occipital lobe. In the seed-based FC analyses, patients with VM demonstrated fewer connections of the bilateral mPFC with the bilateral posterior cingulate cortex, right parahippocampus, right cerebellar posterior lobe, bilateral cuneus, and left precuneus. In addition, clinical data from patients, such as pain intensity, episode frequency, and the Dizziness Handicap Inventory score, were negatively related to these FC and DC impairments. Our findings showed changes in the default mode network and visual cortex in patients with VM, providing further insights into the complexity of the mechanisms underlying VM.

Alterations in brain network functional connectivity and topological properties in DRE patients.

The study aimed to find the difference in functional network topology on interictal electroencephalographic (EEG) between patients with drug-resistant epilepsy (DRE) and healthy people. We retrospectively analyzed the medical records as well as EEG data of ten patients with DRE and recruited five sex-age-matched healthy controls (HC group). Each participant remained awake while undergoing video-electroencephalography (vEEG) monitoring. After excluding data that contained abnormal discharges, we screened EEG segments that were free of artifacts and put them together into 20-min segments. The screened data was bandpass filtered to different frequency bands (delta, theta, alpha, beta, and gamma). The weighted phase lag index (wPLI) and the network properties were calculated to evaluate changes in the topology of the functional network. Finally, the results were statistically analyzed, and the false discovery rate (FDR) was used to correct for differences after multiple comparisons. In the full frequency band (0.5-45 Hz), the functional connectivity in the DRE group during the interictal period was significantly lower than that in the HC group (p < 0.05). Compared to the HC group, in the full frequency band, the DRE group exhibited significantly decreased clustering coefficient (CC), node degree (D), and global efficiency (GE), while the characteristic path length (CPL) significantly increased (p < 0.05). In the sub-frequency bands, the functional connectivity of the DRE group was significantly lower than that of the HC group in the delta band but higher in the alpha, beta, and gamma bands (p < 0.05). The statistical results of network properties revealed that in the delta band, the DRE group had significantly decreased values for D, CC, and GE, but in the alpha, beta, and gamma bands, these values were significantly increased (p < 0.05). Additionally, the CPL of the DRE group significantly increased in the delta and theta bands but significantly decreased in the alpha, beta, and gamma bands (p < 0.05). The topology structure of the functional network in DRE patients was significantly changed compared with healthy people, which was reflected in different frequency bands. It provided a theoretical basis for understanding the pathological network alterations of DRE.

PREDICTION OF EPILEPSY BASED ON EEMD AND LSSVM DOUBLE CLASSIFICATION

Epilepsy seizures are caused by abnormal, excessive, or synchronized neuronal activity in the brain, which is difficult to treat and is extremely stubborn. Therefore, studying the activity of epilepsy can greatly contribute to its diagnosis and treatment. The original signal is decomposed into IMFs and residual by ensemble empirical mode decomposition (EEMD), and then the first three intrinsic mode functions (IMF) are selected to replace the original signal, and the nonlinear and non-stationary problems of the original signal are solved. The Least Squares Support Vector Machine (LSSVM) was used as the classifier, its parameters (gam and sig2) are optimized by Particle Swarm Optimization (PSO). The experiment used the EEG database published by the University of Bonn (UoB) to realize the classification of normal, interictal and ictal periods. When PSO was employed, the recognition accuracy of the test set was 93.33%, with a classification time of 0.035 s and the Information Transfer Rate (ITR) of 3.77 bpm in training 70 classes with 100 samples each. In contrast, without PSO, the recognition accuracy of the test set was 92%, with a classification time of 0.039 s and the ITR of 2.88 bpm without PSO in training 70 classes with 100 samples each. The experimental results show that EEMD and LSSVM can effectively implement the three-classification problem and provide an effective means for the onset prediction of epilepsy patients.

Detection of interictal epileptiform discharge in focal seizures

Introduction: Many factors underlying basic epileptic conditions determine the characteristics of epileptic seizures and the therapeutic outcome. Visual obvious abnormalities in resting baseline EEG are cardinal but incompletely understood like feature of seizure onset zone in focal epilepsy and interictal epileptiform discharge. Present study is an attempt to diagnose that evidence of epileptic discharge in temporal lobe epilepsy (TLE), would persist during interictal period in absence of abnormalities in baseline EEG, which could increase the impact of automatic analysis of EEG waves for clinical relevance.&#x0D; Material and Methods: By using 10-20 system, functional connectivity was estimated in the 20 channels of delta, theta, alpha, beta and gamma frequency bands of EEG, from 16 diagnosed focal epileptic seizure patients and 16 age and sex matched controls. To observe the dynamics of the healthy brain, differ from the brain of dynamically focal epileptic patients during interictal period treated with anti-epileptic drugs in the context of resting state during eye close session of EEG. Such differences can be observed by using absolute spectral power from BESS ((Brain Electro Scan Software) of the Axxonet System and statistically measure by applied unpaired student t -test.&#x0D; Result: The high significance results in slow frequency EEG waves (delta and theta) in power spectral analysis were observed that demonstrates the potential epileptic discharge occurring during interictal period without visible pathological activity for helping in the diagnosis and lateralization of TLE.&#x0D; Conclusion: The detailed spectral analysis of EEG waves offers novel insight into focal epileptic patients when visually EEG findings were normal. This linear analysis helpful in extracting information from EEG signals in diagnosing specific neuronal correlates for TLE. Present findings concluded that epileptic discharges occur at different topographical regions of brain during interictal period and power spectral analysis plays a new insight in diagnosis of focal discharge.

Long-term outcome of epileptic dogs treated with implantable vagus nerve stimulators.

The long-term effect of implantable vagus nerve stimulators (VNS) on seizures has not been evaluated in epileptic dogs. Report seizure frequency in medication-resistant epileptic dogs before and after VNS implantation. Twelve client-owned dogs with idiopathic epilepsy and >1 seizure day per 3 weeks despite 3 months of appropriate use of 2 antiseizure medications and seizure diaries maintained 6 months before and >12 months after VNS implantation. Uncontrolled, open-label, before and after study. Mean monthly seizures and inter-seizure periods obtained from contemporaneous seizure diaries in the 6 months before implantation were compared with 0 to 6 months, 7 to 12 months, and subsequent 12-month periods after implantation. The number of dogs with >50% decrease in seizure frequency, >3 times increase in inter-ictal period interval, and seizure freedom for >3 months at the time of death or last follow-up were recorded. Five of 12 dogs were euthanized <12 months after implantation. All 7 remaining dogs showed >50% decrease in seizure frequency until last follow-up, starting at a median of 37 to 48 months after implantation (range, 0-6 to 61-72 months) and a >3-fold increase in mean inter-seizure interval starting a median of 25 to 36 months after implantation (range, 0-6 months to 49-60 months), 3/7 dogs were seizure-free at death or last follow-up. Monthly seizure frequencies decreased and inter-seizure intervals increased in all dogs 2 to 3 years after VNS implantation, but a high proportion were euthanized before this time point. Prospective clinical trials are required to establish causality and the magnitude of this association.

B - 91 Cognition as a Premonitory Symptom of Migraine.

Migraine is often accompanied by premonitory symptoms (neurologic symptoms preceding migraine pain) which serve as "warning signs." Cognition changes are commonly described during the premonitory period (period preceding pain onset). Ecological momentary assessment can be utilized to understand if perceived cognitive changes are a symptom patients use as an indicator of the premonitory period. Participants with episodic migraine were recruited through a large urban health system and online advertising (n = 43). Individuals participated in a three-month, three-times-a-day electronic diary answering questions regarding migraine attack symptoms, including perception of being in a premonitory period, and the presence of premonitory symptoms, including "difficulty thinking or concentrating." The frequency of perceived cognitive difficulties was analyzed during the perceived premonitory period (endorsing "I think I might get a headache") vs. the perceived interictal period (endorsing "I do not anticipate a headache"). Cross tabs evaluated the frequencies of perceived cognitive difficulties during different migraine phases. Participants were predominantly White (n = 33, 76.7%), non-Hispanic (n = 33, 76.7%) women (n = 36, 83.7%). Thirty-three participants endorsed subjective cognitive difficulties at least once during the premonitory phase (n = 33; 76.75%). Difficulty thinking and concentrating was endorsed 35.16% of the time when participates also reported anticipating a headache in the morning and only 8.36% of the time when participants reported not anticipating a headache. Participants perceived cognitive decline as a premonitory symptom. Difficulty concentrating and thinking was endorsed more when participants anticipated getting a headache vs. when not. Assessing subjective cognitive decline as a premonitory symptom can guide individualized interventions for migraine and elucidate the relationship between cognition and migraine.