Quantitative EEG analysis in typical absence seizures: unveiling spectral dynamics and entropy patterns.

A typical absence seizure is a generalized epileptic event characterized by a sudden, brief alteration of consciousness that serves as a hallmark for various generalized epilepsy syndromes. Distinguishing between similar interictal and ictal electroencephalographic (EEG) epileptiform patterns poses a challenge. However, quantitative EEG, particularly spectral analysis focused on EEG rhythms, shows potential for differentiation. This study was designed to investigate discernible differences in EEG spectral dynamics and entropy patterns during the pre-ictal and post-ictal periods compared to the interictal state. We analyzed 20 EEG ictal patterns from 11 patients with confirmed typical absence seizures, and assessed recordings made during the pre-ictal, post-ictal, and interictal intervals. Power spectral density (PSD) was used for the quantitative analysis that focused on the delta, theta, alpha, and beta bands. In addition, we measured EEG signal regularity using approximate (ApEn) and multi-scale sample entropy (MSE). Findings demonstrate a significant increase in delta and theta power in the pre-ictal and post-ictal intervals compared to the interictal interval, especially in the posterior brain region. We also observed a notable decrease in entropy in the pre-ictal and post-ictal intervals, with a more pronounced effect in anterior brain regions. These results provide valuable information that can potentially aid in differentiating epileptiform patterns in typical absence seizures. The implications of our findings are promising for precision medicine approaches to epilepsy diagnoses and patient management. In conclusion, our quantitative analysis of EEG data suggests that PSD and entropy measures hold promise as potential biomarkers for distinguishing ictal from interictal epileptiform patterns in patients with confirmed or suspected typical absence seizures.

Interictal Dysphoric Disorder: A disorder with distinct nosography or atypical symptomatology of mood disorders in people with epilepsy? Results from a systematic review.

INTRODUCTION: Mood disorders are the most frequent comorbidities in people with epilepsy. The term Interictal Dysphoric Disorder (IDD) has been used to describe a condition where at least three out of eight symptoms must be present for diagnosis. Symptoms are grouped into three symptom clusters of four "labile depressive" symptoms (anergia, depressed mood, insomnia, and pain), two "labile affective" symptoms (anxiety and fear), and two specific symptoms (euphoric moods and paroxysmal irritability), which are described and can be present in people with epilepsy. There is debate about whether IDD is a distinct disease, or if it is simply a special manifestation of mood disorders in epilepsy. For instance, it may represent an atypical presentation of depression in this population. METHODS: We conducted a systematic review of the literature in 3 databases with the terms "Interictal Dysphoric Disorder" and "mood disorder". A total of 130 articles were selected and, after removing the duplicated applying eligibility criteria, 12 articles were included. RESULTS: Six articles showed positive evidence for the validation of IDD as an independent nosological entity; in contrast, five articles reported inconclusive findings regarding the question; one explicitly questioned significant differences between IDD and mood disorders as nosological constructs. The data available and presented in this systematic review is insufficient to confirm IDD as a distinct diagnostic category. Nevertheless, it is worth noting other researchers have found some validity in this concept, highlighting the strong connection between mood disorders and epilepsy. CONCLUSION: Further research in this area is needed, and additional systematic reviews focusing on other aspects of the construct, such as neurobiological mechanisms, may prove to be helpful.

Calcitonin gene-related peptide (CGRP) concentrations outside migraine attacks in peripheral blood as a potential biomarker for chronic migraine / Concentrações de peptídeo relacionado ao gene da calcitonina (CGRP) fora dos ataques de enxaqueca no sangue periférico como um potencial biomarcador para enxaqueca crônica

Introduction: Chronic migraine is a debilitating condition that affects a significant portion of the population. Accurate diagnosis and treatment of chronic migraine remain a challenge due to the lack of objective biomarkers. Calcitonin gene-related peptide (CGRP) is a neuropeptide involved in the pathophysiology of migraine and has been proposed as a potential biomarker for migraine. Methods: We measured CGRP levels in peripheral blood samples collected from 142 participants with chronic or episodic migraine and 24 healthy controls during ictal periods, i.e., outside migraine attacks. We compared CGRP levels between the three groups and assessed the correlation between CGRP levels and clinical features of chronic migraine. Conclusion: Our study provides evidence that CGRP levels in peripheral blood during ictal periods may serve as a potential biomarker for chronic migraine. Further studies are needed to validate these findings and to explore the clinical utility of CGRP as a biomarker for chronic migraine.

Introdução: A enxaqueca crônica é uma condição debilitante que afeta uma parcela significativa da população. O diagnóstico preciso e o tratamento da enxaqueca crónica continuam a ser um desafio devido à falta de biomarcadores objetivos. O peptídeo relacionado ao gene da calcitonina (CGRP) é um neuropeptídeo envolvido na fisiopatologia da enxaqueca e foi proposto como um potencial biomarcador para enxaqueca. Métodos: Medimos os níveis de CGRP em amostras de sangue periférico coletadas de 142 participantes com enxaqueca crônica ou episódica e 24 controles saudáveis ​​durante períodos ictais, ou seja, fora das crises de enxaqueca. Comparamos os níveis de CGRP entre os três grupos e avaliamos a correlação entre os níveis de CGRP e as características clínicas da enxaqueca crônica. Conclusão: Nosso estudo fornece evidências de que os níveis de CGRP no sangue periférico durante os períodos ictais podem servir como um potencial biomarcador para enxaqueca crônica. Mais estudos são necessários para validar estes resultados e explorar a utilidade clínica do CGRP como biomarcador para enxaqueca crónica.

Relation of Brain Perfusion Patterns to Sudden Unexpected Death Risk Stratification: A Study in Drug Resistant Focal Epilepsy.

To explore the role of the interictal and ictal SPECT to identity functional neuroimaging biomarkers for SUDEP risk stratification in patients with drug-resistant focal epilepsy (DRFE). Twenty-nine interictal-ictal Single photon emission computed tomography (SPECT) scans were obtained from nine DRFE patients. A methodology for the relative quantification of cerebral blood flow of 74 cortical and sub-cortical structures was employed. The optimal number of clusters (K) was estimated using a modified v-fold cross-validation for the use of K means algorithm. The two regions of interest (ROIs) that represent the hypoperfused and hyperperfused areas were identified. To select the structures related to the SUDEP-7 inventory score, a data mining method that computes an automatic feature selection was used. During the interictal and ictal state, the hyperperfused ROIs in the largest part of patients were the bilateral rectus gyrus, putamen as well as globus pallidus ipsilateral to the seizure onset zone. The hypoperfused ROIs included the red nucleus, substantia nigra, medulla, and entorhinal area. The findings indicated that the nearly invariability in the perfusion pattern during the interictal to ictal transition observed in the ipsi-lateral putamen F = 12.60, p = 0.03, entorhinal area F = 25.80, p = 0.01, and temporal middle gyrus F = 12.60, p = 0.03 is a potential biomarker of SUDEP risk. The results presented in this paper allowed identifying hypo- and hyperperfused brain regions during the ictal and interictal state potentially related to SUDEP risk stratification.

Common Ictal and Interictal Perfusion Patterns: A Window into the Epileptogenic Network and SUDEP Mechanism in Drug-Resistant Focal Epilepsy.

BACKGROUND: Focal epilepsies have been described as a network disease. Noninvasive investigative techniques have been used to characterize epileptogenic networks. OBJECTIVE: This study aimed to describe ictal and interictal cortical and subcortical perfusion patterns using single- photon emission computed tomography (SPECT) in patients with drug-resistant epilepsy (DRE). METHODS: Thirty-five interictal-ictal SPECT scans were obtained from 15 patients with DRE. A methodology was developed to get a relative perfusion index (PI) of 74 cortical and sub-cortical brain structures. K-means algorithm, together with modified v-fold cross-validation, was used to identify the two regions of interest (ROIs) that represent hypoperfused and hyperperfused areas. RESULTS: In common with the individual analysis, the statistical analysis evidenced that the hyperperfusion ROIs resulting from group analysis during interictal and ictal involved mainly the cingulate gyrus, cuneus, lingual gyrus, and gyrus rectus as well as the putamen. ROIs hypoperfused included the red nucleus, the substantia nigra, and the medulla. The medians of the group analysis of the hypoperfusion and hyperperfusion ROIs were 0.601-0.565 and 1.133-1.119 for the ictal and interictal states, correspondingly. A group of mostly cortical structures involved in the hyperperfused ROIs in both interictal and ictal states showed no change or negative change in the transition from interictal to ictal state (mean change of -0.002). On the other hand, the brain stem, basal ganglia, red nucleus, and thalamus revealed a mean global change of 0.19, indicating a mild increase in the PI. However, some of these structures (red nucleus, substantia nigra, and medulla oblongata) remained hypoperfused during the interictal to ictal transition. CONCLUSION: The methodology employed made it possible to identify common cortical and subcortical perfusion patterns not directly linked to epileptogenicity, for a better epileptogenic network and sudden unexpected death (SUDEP) mechanism in DRE.

Independent risk factors for seizures in critically ill patients on continuous EEG.

OBJECTIVE: The objective of this study was to characterize the independent risk factors for seizures in critically ill patients monitored with continuous EEG (cEEG). METHODS: We retrospectively investigated variables associated with cEEG seizures, first in the entire cohort of 156 patients and, subsequently, in the subgroup without seizures in the first 30 minutes of monitoring. RESULTS: Seizures were observed in 19.2% of recordings, and in 50% of these, seizures occurred in the first 30 minutes. In the entire cohort, epilepsy, acute seizures prior to cEEG, interictal epileptiform discharges (IEDs), lateralized periodic discharges (LPDs), and brief potentially ictal rhythmic discharges (BIRDs) were associated with a higher incidence of cEEG seizures, whereas coma, intravenous anaesthetic drugs, and generalized periodic discharges (GPDs) were associated with a lower incidence of seizures. On multivariate analysis, this association was maintained for acute seizures before cEEG (OR: 5.92) and IEDs (OR: 6.81). Excluding patients with seizures at the beginning of monitoring, acute seizures before cEEG, IEDs, LPDs, and BIRDs were associated with an increased risk of seizures. The presence of IEDs or LPDs in the first 30 minutes was associated with a 4.14-fold greater chance of seizures on cEEG. On multivariate analysis, acute seizures prior to recording (OR 7.29) and LPDs (OR: 5.38) remained associated with seizures on cEEG. Due to the sample size, BIRDs were not included in multivariate models. SIGNIFICANCE: Acute seizures prior to monitoring, IEDs, LPDs and BIRDs are important risk factors for cEEG seizures in critically ill patients.

Peri-Ictal and Para-Ictal Psychiatric Phenomena: A Relatively Common Yet Unrecognized Disorder.

Patients with epilepsy can experience different neuropsychiatric symptoms related (peri-ictal) or not (interictal) with seizures. Peri-ictal symptoms can precede (pre-ictal) or follow (post-ictal) the seizure, or even be the expression of the seizure activity (ictal). Neuropsychiatric symptoms, such as irritability and apathy, are among the most frequent pre-ictal manifestations. Ictal fear is reported by around 10% of patients with focal seizures, and sometimes can be difficult to differentiate from panic attacks. Post-ictal anxiety, mood and psychotic symptoms are also frequently reported by patients. Peri-ictal phenomena can occur as isolated symptom or as a cluster of symptoms, sometimes resembling a full-blown psychiatric syndrome. Actually, peri-ictal and interictal neuropsychiatric manifestations seem to be closely associated.

Cognitive tasks as provocation methods in routine EEG: a multicentre field study.

This study aimed to analyse the effect of neuropsychological activation methods on interictal epileptiform discharges, compared to standard activation methods, for both focal and generalized epilepsies. This was a multicentre, prospective study including 429 consecutive EEG recordings of individuals with confirmed or suspected diagnosis of epilepsy. Neuropsychological activation included reading aloud in foreign and native language, praxis and a letter cancelation task (each with a duration of three minutes). After counting interictal discharges in three-minute time windows, activation and inhibition were assessed for each procedure, accounting for spontaneous fluctuations (95% CI) and compared to the baseline condition with eyes closed. Differences between generalized and focal epilepsies were explored. Interictal epileptiform discharges were present in 59.4% of the recordings. Activation was seen during hyperventilation in 31%, in at least one neuropsychological activation method in 15.4%), during intermittent photic simulation in 13.1% and in the resting condition with eyes open in 9.9%. The most frequent single cognitive task eliciting activation was praxis (10.3%). Lasting activation responses were found in 18-25%. Significant inhibition was found in 88/98 patients with baseline interictal epileptiform discharges, and was not task-specific. Adding a brief neuropsychological activation protocol to the standard EEG slightly increased its sensitivity in patients with either focal or generalized epilepsy. However, in unselected epilepsy patients, this effect seems only exceptionally to result in ultimate diagnostic gain, compared to standard procedures. From a diagnostic perspective, cognitive tasks should be reserved for patients with a suspicion of cognitive reflex epilepsy/seizures and probably require longer exposure times. Further research is needed to explore potential therapeutic applications of the observed inhibition of interictal epileptiform discharges by cognitive tasks in some patients.

Hijacking of hippocampal-cortical oscillatory coupling during sleep in temporal lobe epilepsy.

Memory impairment is the most common cognitive deficit in patients with temporal lobe epilepsy (TLE). This type of epilepsy is currently regarded as a network disease because of its brain-wide alterations in functional connectivity between temporal and extra-temporal regions. In patients with TLE, network dysfunctions can be observed during ictal states, but are also described interictally during rest or sleep. Here, we examined the available literature supporting the hypothesis that hippocampal-cortical coupling during sleep is hijacked in TLE. First, we look at studies showing that the coordination between hippocampal sharp-wave ripples (100-200 Hz), corticothalamic spindles (9-16 Hz), and cortical delta waves (1-4 Hz) during nonrapid eye movement (NREM) sleep is critical for spatial memory consolidation. Then, we reviewed studies showing that animal models of TLE display precise coordination between hippocampal interictal epileptiform discharges (IEDs) and spindle oscillations in the prefrontal cortex. This aberrant oscillatory coupling seems to surpass the physiological ripple-delta-spindle coordination, which could underlie memory consolidation impairments. We also discuss the role of rapid eye movement (REM) sleep for local synaptic plasticity and memory. Sleep episodes of REM provide windows of opportunity for reactivation of expression of immediate early genes (i.e., zif-268 and Arc). Besides, hippocampal theta oscillations during REM sleep seem to be critical for memory consolidation of novel object place recognition task. However, it is still unclear which extend this particular phase of sleep is affected in TLE. In this context, we show some preliminary results from our group, suggesting that hippocampal theta-gamma phase-amplitude coupling is exacerbated during REM in a model of basolateral amygdala fast kindling. In conclusion, there is an increasing body of evidence suggesting that circuits responsible for memory consolidation during sleep seem to be gradually coopted and degraded in TLE. This article is part of the Special Issue "NEWroscience 2018".

Ictal fear is associated with anxiety symptoms and interictal dysphoric disorder in drug-resistant mesial temporal lobe epilepsy.

Interictal dysphoric disorder (IDD) is a poorly understood psychiatric disorder of epilepsy patients. Interictal dysphoric disorder is characterized by depressive, somatoform, and affective symptoms observed in up to 5.9% of drug-resistant mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). This study aimed to evaluate the association between ictal fear (IF) and the psychiatric symptoms and diagnosis in MTLE-HS patients. We included 116 (54.3% male) consecutive adult patients (36 ±â€¯11 years) with MTLE-HS. Anxiety and depression symptoms were evaluated by the Hospital Anxiety and Depression Scale (HADS) and the psychiatric diagnosis were according to Fourth Edition of the Diagnosis and Statistical Manual of Mental Disorders (DSM-IV). The independent association between the occurrence of IF aura and the psychiatric diagnosis was determined by binary regression. When compared to those with other auras or without aura, patients reporting IF have higher HADS anxiety, but not HADS depression, scores. Ictal fear was independently associated with the diagnosis of interictal dysphoric disorder (OR, IC 95% = 7.6, 1.3-43.2, p = 0.02), but not with the diagnosis of anxiety (OR, CI 95% = 0.72, 0.08-6.0, p = 0.73), depression (OR, CI 95% = 0.94, 0.19-4.8, p = 0.94) or psychotic disorders (p = 0.99). Only patients with drug-resistant MTLE-HS were included and the small number of cases with DD diagnosis in the sample. In MTLE-HS patients, the occurrence of IF is associated with higher levels of anxiety symptoms and IDD. The results provide insights about fear-related neural network connections with anxiety symptoms and the IDD in MTLE-HS.

Electroencephalographic Patterns During Routine Polysomnography in Childhood and Association With Future Epilepsy Diagnosis.

STUDY OBJECTIVES: Evaluate the frequency of abnormal electroencephalograph (EEG) records during pediatric polysomnography (PSG) at a tertiary referral center and determine frequency with which these records may predict future seizures and a diagnosis of epilepsy. METHODS: Retrospective review of all pediatric PSG reports from 2013 was performed. Demographics, medical history, indications, diagnoses, and EEG reports were collected. Patients were evaluated for follow-up of future diagnosis of seizure or epilepsy over a 30-month period. RESULTS: A total of 1,969 studies (56.9% males, median age 7 years) were analyzed. Abnormal EEG results were detected in 314 studies (15.9%); abnormalities included slowing in 75 (3.8%) and interictal epileptiform discharges (IEDs) in 239 (12.1%). Incidental abnormal EEG recordings were found in 186 patients (9.4%) without a prior diagnosis of seizure or epilepsy. Incidental IEDs were recorded in 126 (6.4%) and were most commonly focal (66.7%). Ten patients received follow-up EEG without clinical follow-up, 68 received clinical follow-up without follow-up EEG, and 29 received both within a 30-month period. Follow-up EEG was normal in only 30.8% of cases. Thirteen patients in the 30-month window received a new diagnosis of epilepsy. Each new diagnosis occurred in patients with preexisting neurodevelopmental disorders at high risk for seizures. CONCLUSIONS: Abnormal EEG during pediatric PSG without additional history of seizure is a poor prognosticator for a future diagnosis of epilepsy. Abnormalities detected on PSG did not always portend abnormal diagnostic EEG and thus its utility to corroborate findings does not appear to be supported without additional clinical context concerning for seizure.

Long-Term Electroclinical and Employment Follow up in Temporal Lobe Epilepsy Surgery. A Cuban Comprehensive Epilepsy Surgery Program.

The purpose of this paper is to present a long- term electroclinical and employment follow up in temporal lobe epilepsy (TLE) patients in a comprehensive epilepsy surgery program. Forty adult patients with pharmacoresistant TLE underwent detailed presurgical evaluation. Electroencephalogram (EEG) and clinical follow up assessment for each patient were carried out. The occurrence of interictal epileptiform activity (IEA) and absolute spike frequency (ASF) were tabulated before and after 1, 6, 12, 24 and 72 months surgical treatment. Employment status pre- to post-surgery at the last evaluated period was also examined. Engel scores follow-up was described as follows: at 12 months 70% (28) class I, 10% (4) class II and 19% (8) class III-IV; at 24 months after surgery 55.2% (21) of the patients were class I, 28.9% (11) class II and 15.1% (6) class III-IV. After one- year follow up 23 (57.7%) patients were seizure and aura-free (Engel class IA). These figures changed to 47.3%, and 48.6% respectively two and five years following surgery whereas 50% maintained this condition in the last follow up period. A decline in the ASF was observed from the first year until the sixth year after surgery in relation to the preoperative EEG. The ASF one year after surgery allowed to distinguish "satisfactory" from "unsatisfactory" seizure relief outcome at the last follow up. An adequate social functioning in terms of education and employment in more than 50% of the patients was also found. Results revealed the feasibility of conducting a successful epilepsy surgery program with favorable long term electroclinical and psychosocial functioning outcomes in a developing country as well.

Clinical and sociodemographic variables associated with interictal dysphoric disorder and interictal personality in patients with drug-resistant temporal lobe epilepsy: A controlled study.

Psychiatric disorders (PD) have an elevated prevalence and an important negative impact on patients with epilepsy (PWE) since they are associated with lower quality of life and clinical refractoriness. However, it is also necessary to identify behavioral conditions possibly associated with epilepsy that are not part of the standard psychiatric classifications, such as Interictal Dysphoric Disorder (IDD) and Interictal Personality (IP). The frequency of IDD and IP in patients with drug-resistant temporal lobe epilepsy and mesial temporal sclerosis (TLE-MTS) was assessed. The Brazilian versions of the Neurobehavioral Inventory (NBI) and Interictal Dysphoric Disorder Inventory (IDDI) were applied to patients and to a control group. Psychiatric standard assessment was conducted through the Diagnostic and Statistical Manual for Psychiatric Disorders - 5th edition (DSM-5). The value of p considered significant was <0.05. Ninety-five patients (51 women; 53.6%) and 50 controls (29 women; 58.0%) were assessed. Axis I PD were observed in 41 patients (43.1%). Interictal Dysphoric Disorder was observed in 18 patients (18.4%) and IP in 36 (37.9%). Interictal Dysphoric Disorder was associated with left-sided MTS (OR=3.22; p=0.008), previous psychiatric treatment (OR=4.29; p=0.007), and more than one AED used (OR=2.73; p=0.02) while presence of bilateral MTS (OR=3.27; p=0.008), longer disease duration (OR=3.39; p=0.006), and presence of Major Depressive Disorder (OR=4.73; p=0.004) were associated with IP. In the present study, there was a high prevalence of IDD and IP in patients with drug-resistant TLE-MTS; studies should be conducted to identify the presence of behavioral conditions that are not present in the conventional psychiatric classifications.

An unaware agenda: interictal consciousness impairments in epileptic patients.

Consciousness impairments have been described as a cornerstone of epilepsy. Generalized seizures are usually characterized by a complete loss of consciousness, whereas focal seizures have more variable degrees of responsiveness. In addition to these impairments that occur during ictal episodes, alterations of consciousness have also been repeatedly observed between seizures (i.e. during interictal periods). In this opinion article, we review evidence supporting the novel hypothesis that epilepsy produces consciousness impairments which remain present interictally. Then, we discuss therapies aimed to reduce seizure frequency, which may modulate consciousness between epileptic seizures. We conclude with a consideration of relevant pathophysiological mechanisms. In particular, the thalamocortical network seems to be involved in both seizure generation and interictal consciousness impairments, which could inaugurate a promising translational agenda for epilepsy studies.

How do people with drug-resistant mesial temporal lobe epilepsy sleep? A clinical and video-EEG with EOG and submental EMG for sleep staging study.

This study aimed to assess subjective and objective sleep parameters in a homogeneous group of drug-resistant mesial temporal lobe epilepsy (MTLE) patients through internationally validated clinical questionnaires, video-electroencephalographic (VEEG) and polysomnographic (PSG) studies. Fifty-six patients with definite diagnosis of MTLE who were candidates for epilepsy surgery underwent a detailed clinical history, the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Stanford Sleepiness Scale (SSS), neurological examination, 1.5 T brain magnetic resonance imaging, VEEG and PSG. Sixteen percent of patients reported significant daytime sleepiness as measured by ESS and 27% reported low levels of sleep quality as measured by PSQI. Patients with medically resistant epilepsy by MTLE showed increased wakefulness after sleep onset (WASO) with mean ± standard deviation of 17.4 ± 15.6, longer non-rapid eye movement (NREM) 1 (7.5 ± 4.6%) and NREM3 sleep (26.6 ± 11.8%), abnormal rapid eye movement (REM) latency in 30/56 patients, shorter REM sleep (16.7 ± 6.6%), and abnormal alpha delta patterns were observed in 41/56 patients. The analysis of interictal epileptic discharges (IEDs) evidenced highest spiking rate during NREM3 sleep and higher concordance with imaging data when IEDs were recorded in sleep, mainly during REM sleep. We concluded that patients with MTLE showed disrupted sleep architecture that may result in daytime dysfunction and sleep complaints. Furthermore, NREM sleep activated focal IEDs and them - when recorded during sleep - had higher localizing value.

Interictal dysphoric disorder: a frequent psychiatric comorbidity among patients with epilepsy who were followed in two tertiary centers / Transtorno disforico interictal: uma comorbidade psiquiatrica frequente entre pacientes com epilepsia acompanhados em dois servicos terciarios

Psychiatric disorders are frequent among patients with epilepsy. Data in the literature have shown a heterogeneous clinical presentation of psychiatric disorders in patients with epilepsy. Interictal dysphoric disorder could be a specific psychiatric comorbidity associated with epilepsy, primarily in patients treated in tertiary centers. Objective The present study aimed to determine the prevalence of interictal dysphoric disorder among patients with epilepsy who were followed in two tertiary epilepsy services in Brazil. Method Sixty-five patients with epilepsy completed the Portuguese version of the Interictal Dysphoric Disorder Inventory. Results Thirty-three (50.7%) patients fulfilled the diagnostic criteria for interictal dysphoric disorder, although all participants answered positively to having at least one key symptom. Conclusion The high rate of patients with epilepsy who fulfilled the diagnosis of interictal dysphoric disorder confirms an association between epilepsy and psychiatric disorders. However, there is clearly a need to improve diagnostic tools to allow better differentiation between interictal dysphoric disorder and other psychiatric disorders. .

Transtornos psiquiátricos são frequentes entre pacientes com epilepsia. Estudos evidenciam apresentações clínicas heterogêneas neste grupo. O transtorno disfórico interictal pode um transtorno específico destes pacientes, particularmente naqueles acompanhados em centros terciários. Objetivo Determinar a prevalência de transtorno disfórico interictal entre pacientes com epilepsia atendidos em dois serviços terciários de epilepsia do Brasil. Método Sessenta e cinco pacientes foram convidados a responder a versão brasileira do Interictal Dysphoric Disorder Inventory adaptado e validado para o Português. Resultados Trinta e três pacientes (50,7%) preencheram critérios para transtorno disfórico interictal, embora todos os entrevistados tenham afirmado que são acometidos por ao menos um dos sintomas-chave. Conclusão A alta prevalência de transtorno disfórico interictal em pacientes com epilepsia pode ser um indício da associação entre epilepsia e transtornos psiquiátricos. No entanto, é necessário melhorar a acurácia dos instrumentos de diagnóstico para poder diferenciar casos de transtorno disfórico interictal de outros transtornos psiquiátricos. .

Correlações clínicas entre as epilepsias e transtornos psiquiátricos: considerações da literatura / Clinical correlations between epilepsy and psychiatric disorders: considerations from the literature

Objective: Make some notes in the light of current knowledge about psychiatric disorders in the interface between epilepsy, from the medical literature. Method: Review and confrontation of works related to the theme of non-systematic way, with emphasis on recent journal articles and book chapters. Results: The epilepsies are prevalent chronic neurological conditions, with significant psychiatric comorbidity. This connection can be characterized by unfavorable repercussions on emotional, social and professional levels. The prevalence rates of psychiatric disorders in patients with epilepsy vary considerably between studies, often conducted in hospital populations, whose results are difficult to extrapolate to other clinical settings. Mood disorders, anxiety disorders, psychotic disorders and other behavioral interictal dysfunctions represent a common occurrence in this population, although they are often undiagnosed. Conclusions: The mere acceptance of these entities as 'disorders secondary to an organic cause' seems not to favor one more goal in deepening their understanding and, as in the past, correlations between psychiatric disorders and epilepsy remain in need of further clarification. Additional studies are needed on a non-hospital population basis, attending to the influences of personal development and variables related to epilepsy, in the set of psychopathology of these manifestations...

Objetivo: Esboçar algumas considerações à luz dos conhecimentos atuais sobre transtornos psiquiátricos em interface com as epilepsias, a partir da literatura médica. Método: Revisão e confrontação de trabalhos pertinentes ao tema, de maneira não sistemática, com ênfase em artigos recentes de periódicos e capítulos de livros. Resultados: As epilepsias constituem condições neurológicas crônicas, relativamente prevalentes, que cursam com significativa comorbidade psiquiátrica. Essa conexão pode ser marcada por repercussões desfavoráveis em níveis afetivos, profissionais e sociais. As taxas de prevalência dos transtornos psiquiátricos em pacientes com epilepsia variam consideravelmente entre os estudos, muitas vezes realizados em populações hospitalares, com difícil extrapolação de resultados para outros contextos. Transtornos do humor, de ansiedade, transtornos psicóticos e outras disfunções comportamentais observadas no período interictal figuram entre ocorrências comuns nessa população, ainda que sejam frequentemente subdiagnosticados. Conclusões: A mera aceitação dessas entidades como 'transtornos secundários a uma causa orgânica' parece não favorecer um aprofundamento mais objetivo em sua compreensão e, como no passado, correlações entre transtornos psiquiátricos e epilepsias permanecem carentes de maiores esclarecimentos. Estudos adicionais são necessários em bases populacionais não hospitalares, atentando-se para as influências do desenvolvimento pessoal e de variáveis ligadas à epilepsia, no conjunto psicopatológico dessas manifestações...

Pathophysiology of mood disorders in temporal lobe epilepsy / Fisiopatologia dos transtornos de humor na epilepsia do lobo temporal

OBJECTIVE: There is accumulating evidence that the limbic system is pathologically involved in cases of psychiatric comorbidities in temporal lobe epilepsy (TLE) patients. Our objective was to develop a conceptual framework describing how neuropathological, neurochemical and electrophysiological aspects might contribute to the development of psychiatric symptoms in TLE and the putative neurobiological mechanisms that cause mood disorders in this patient subgroup. METHODS: In this review, clinical, experimental and neuropathological findings, as well as neurochemical features of the limbic system were examined together to enhance our understanding of the association between TLE and psychiatric comorbidities. Finally, the value of animal models in epilepsy and mood disorders was discussed. CONCLUSIONS:TLE and psychiatric symptoms coexist more frequently than chance would predict. Alterations and neurotransmission disturbance among critical anatomical networks, and impaired or aberrant plastic changes might predispose patients with TLE to mood disorders. Clinical and experimental studies of the effects of seizures on behavior and electrophysiological patterns may offer a model of how limbic seizures increase the vulnerability of TLE patients to precipitants of psychiatric symptoms.

OBJETIVO: Há evidências crescentes do envolvimento do sistema límbico nas comorbidades psiquiátricas associadas à epilepsia do lobo temporal (ELT). Nosso objetivo foi descrever o panorama atual das alterações neuropatológicas, neuroquímicas e eletrofisiológicas que podem contribuir para o desenvolvimento de sintomas psiquiátricos na ELT e explorar possíveis mecanismos neurobiológicos que podem levar ao aparecimento das desordens de humor nesse subgrupo de pacientes. MÉTODOS: Achados clínicos, de modelos experimentais e neuropatológicos foram revistos, assim como características neuroquímicas do sistema límbico foram examinadas em conjunto para auxiliar nossa compreensão sobre a associação entre ELT e transtornos de humor. CONCLUSÕES: A ELT e os sintomas psiquiátricos coexistem numa frequência muito maior do que o acaso poderia sugerir. Alterações e desregulação de redes anatômicas essenciais, além de mudanças plásticas aberrantes ou deficientes, podem predispor o cérebro de pacientes com ELT a transtornos de humor. Estudos experimentais e clínicos sobre o efeito das crises no comportamento e nos padrões eletrofisiológicos podem oferecer um modelo de como as crises límbicas aumentam a vulnerabilidade a sintomas psiquiátricos em pacientes com ELT.

Hemispheric assymetry of abnormal focal EEG findings / Assimetria hemisférica de anormalidades eletrencefalográficas focais

Left and right cerebral hemispheres are morphologically similar, although they are functionally different. Focal EEG abnormalities should appear with an equal frequency in both of them, but the literature has reported a left predominance. We presented the first Latin American study on lateralization of focal EEG abnormalities. METHOD: We retrospectively studied 10,408 EEGs from April 2001 to April 2010. They were separated by age and gender to estimate the frequency of left-sided versus right-sided focal abnormalities (discharges or slow waves). Associated clinical features were also accessed. RESULTS: Discharges were more prevalent in left cerebral hemisphere, in temporal lobe, and a stronger lateralization was found among adults. Right-sided discharges occurred more in frontal lobe. Slow waves were also more prevalent in the left cerebral hemisphere and among adults. Among left-sided slow waves group, women were more prevalent. Contrarily, men were more observed among right-sided slow waves EEGs. Left-sided slow waves were more prevalent in temporal and parietal lobes. Contrarily, right-sided slow waves occurred more in frontal and occipital lobes. Epilepsy was the most frequent disease among the patients with focal discharges in both cerebral hemispheres. Right-sided slow waves were more associated to epilepsy, and left-sided slow waves were more associated to headache. CONCLUSION: There were significant differences between cerebral hemispheres on focal EEG abnormalities, considering lateralization, gender, age and clinical features. These results suggest a neurofuncional asymmetry between cerebral hemispheres which may be explained by different specificities, as well as by cerebral neuroplasticity.

Embora sejam morfologicamente semelhantes, os hemisférios cerebrais apresentam diferenças funcionais geneticamente determinadas. Ainda assim, anormalidades eletrencefalográficas focais deveriam ocorrer simetricamente numa população geral, embora a literatura tenha referido um predomínio à esquerda. Nosso objetivo é relatar o primeiro estudo latino-americano sobre uma grande série de EEGs, no intuito de observar se há lateralização de anormalidades focais. MÉTODO: Foram estudados retrospectivamente 10.408 EEGs, realizados de abril de 2001 a abril de 2010, os quais foram classificados de acordo com a presença de anormalidades focais específicas (descargas) e inespecíficas (ondas lentas focais). Os EEGs foram divididos de acordo com o gênero e a idade, e foram analisados achados clínicos associados. RESULTADOS: As descargas foram mais prevalentes no hemisfério cerebral esquerdo, no lobo temporal, observando-se uma lateralização mais forte entre os adultos. À direita, elas prevaleceram no lobo frontal. Ondas lentas focais prevaleceram também à esquerda e no lobo temporal, especialmente entre os adultos. Entre os que apresentaram ondas lentas à esquerda, observou-se maior prevalência entre as mulheres. Os homens prevaleceram entre os que apresentaram ondas lentas à direita. À esquerda, ondas lentas prevaleceram nos lobos temporal e parietal. À direita, nos lobos frontal e occipital. Epilepsia foi o achado clínico mais associado à presença de descargas em ambos os hemisférios cerebrais. Ondas lentas à direita foram mais associadas a epilepsia, enquanto que, à esquerda, elas foram mais associadas a cefaleia. CONCLUSÃO: Houve diferenças entre os hemisférios cerebrais quanto à lateralização das anormalidades focais, assim como entre os gêneros, faixas etárias analisadas e quadro clínico associado.

Tradução e adaptação transcultural do Interictal Dysphoric Disorder Inventory (IDDI) para o Brasil / Translation and cross-cultural adaptation of the Interictal Dysphoric Disorder Inventory (IDDI)

INTRODUÇÃO: O transtorno disfórico interictal (TDI) se constitui em uma síndrome comportamental descrita principalmente em pacientes com epilepsia. A apresentação pleomófica e inespecífica dos seus sintomas, no entanto, dificulta seu diagnóstico. O Interictal Dysphoric Disorder Inventory (IDDI) é um instrumento recentemente criado com a finalidade de facilitar o diagnóstico do TDI entre os pacientes com epilepsia. OBJETIVO: Tradução e adaptação cultural do Interictal Dysphoric Disorder Inventory (IDD) MÉTODOS: Vinte e um pacientes em acompanhamento regular no ambulatório de Epilepsia do Departamento de Neurologia e Neurocirurgia da Universidade Federal de São Paulo - UNIFESP responderam ao questionário. A versão original foi obtida com um dos autores da escala (Marco Mula) que concedeu a versão original em inglês para a tradução. Dois professores de inglês nativos fizeram a retrotradução. As versões em português e a retrotraduzida foram comparadas à original e após consenso foi obtida a versão final. RESULTADOS: Dos pacientes entrevistados, 17 (81 por cento) eram do sexo feminino, com média de idade de 32,3 anos. Sete completaram o ensino fundamental, enquanto quatro completaram o ensino médio e dois, o ensino superior. Após a aplicação dos 21 questionários apenas a questão D do Apêndice não foi compreendida por três pacientes, tendo sido reescrita. CONCLUSÃO: o ITDI demonstrou-se uma escala de fácil aplicação na população brasileira, constituindo-se de grande utilidade para a avaliação do TDI em pacientes com epilepsia.

INTRODUCTION: Interictal dysphoric disorder (IDD) is a behavioral syndrome described mainly in epileptic patients. The pleomorphic and unspecific nature of its symptoms makes difficult its recognition. The Interictal Dysphoric Disorder Inventory (IDDI) is an instrument specifically created to evaluate IDD symptoms and to facilitate its diagnosis. PURPOSE: Translation and cross-cultural adaptation of the Interictal Dysphoric Disorder Inventory (IDDI). METHODS: Twenty-one patients regularly accompanied in the outpatient epilepsy clinic of Universidade Federal de São Paulo - UNIFESP answered the questionnaire. The original version in English for translation was obtained with one of the authors (Marco Mula). Later, two independent native English-speaking teachers fluent in Portuguese translated this consensus version back into English. Comparison of the back-translation with the original English version showed only a few discrepancies and the English and Portuguese versions were considered conceptually equivalents. RESULTS: Seventeen female (81 percent) and four male (19 percent) answered the questionnaire. The mean age was of 32.3 years and seven had primary school, four had completed secondary and two, higher education. After patients had answered the 21 questionnaires, only three of them did not understand question D of the Appendix section, which had to be rewritten. CONCLUSION: Brazilian patients easily understood the questions of IDDI. We believe that after finishing validation of its psychometric properties this instrument will be very helpful to evaluate the IDD in Brazilian people with epilepsy.