Olfactory stimulation induces delayed responses in epilepsy

Precipitation and inhibition of seizures and epileptic discharges by sensory stimuli are receiving increasing attention because they provide insight into natural seizure generation in human epilepsies and can identify potential nonpharmacological therapies. We aimed to investigate modulation (provocation or inhibition) of epileptiform discharges (EDs) in mesial temporal lobe epilepsy (MTLE) versus idiopathic generalized epilepsy (IGE) by olfactory stimulation (OS) compared with standard provocation methods. The underlying hypothesis was that any response would be more likely to occur in MTLE, considering the anatomical connections of the temporal lobe to the olfactory system. This multicenter, international study recruited patients with either MTLE or IGE who were systematically compared for responses to OS using an EEG/video-EEG protocol including a 30-min baseline, twice 3-min olfactory stimulation with ylang-ylang, hyperventilation, and intermittent photic stimulation. The 95% confidence interval (CI) for the baseline EDs in each patient was calculated, and modulation was assumed when the number of EDs during any 3-min test period was outside this CI. A total of 134 subjects (55 with MTLE, 53 with IGE, and 26 healthy controls) were included. Epileptiform discharges were inhibited during OS in about half the patients with both MTLE and IGE, whereas following OS, provocation was seen in 29.1% of patients with MTLE and inhibition in 28.3% of patients with IGE. Olfactory stimulation was less provocative than standard activation methods. The frequent subclinical modulation of epileptic activity in both MTLE and IGE is in striking contrast with the rarity of reports of olfactory seizure precipitation and arrest. Inhibition during OS can be explained by nonspecific arousal. The delayed responses seem to be related to processing of olfactory stimuli in the temporal lobe, thalamus, and frontal cortex.

Hippocampal proteomic profile in temporal lobe epilepsy

In this study we used proteomics approaches to obtain the protein profile of human epileptic hippocampi (N=6) and control hippocampi obtained from autopsy (N=6). We used two-dimensional gel electrophoresis (2-D) coupled to HPLC and Mass spectroscopy (MALDI-TOF) to identify proteins differentially expressed. Nine proteins were differentially expressed comparing the hippocampus of patients with the hippocampus of control. Proteins that were increased in the hippocampus of patients with TLE were: isoform 1 of serum albumin, HSP 70, dihydropyrimidinase-related protein 2, isoform 1 of myelin basic protein, proton ATPase catalytic subunit A, and dihydrolipoyllysine-residue acethyltransferase component of pyruvate dehydrogenase complex. The expression of isoform 3 of spectrin alpha chain (fodrin) was down-regulated while the proteins glutathione S-transferase P and the DJ-1 (PARK7) were detected only in the hippocampus of patients with TLE. Taken together, our results provide evidence supporting a direct link between metabolic disturb and oxidative damage related to pathophysiology of TLE. Besides, indicates biomarkers for further investigations as therapies targeted to epilepsy.

Sign of the Cross (Signum Crucis): observation of an uncommon ictal manifestation of mesial temporal lobe epilepsy

The objective of the study was to describe the clinical characteristics and determine the lateralizing value of ictal Sign of the Cross (SC) as a complex hand automatism (CHA) in patients evaluated by video/EEG monitoring in a comprehensive epilepsy unit. We reviewed video/EEG data of 530 patients with epilepsy recorded in a tertiary epilepsy center from 2002 to 2008. Four patients were found to have manifested a CHA similar to the SC at least once during their complex partial seizures. All patients had unilateral right mesial temporal lobe epilepsy (TLE) refractory to medical treatment. The limbic system is often suggested as the critical site of religious experience. Moreover, it may be localized predominantly to the temporal regions of the right hemisphere. However, this rare and peculiar ictal manifestation may be related not only to the neural substrate and personality characteristics of TLE, but also to the general religious convictions of Brazilians.

Can intraoperative electrocorticography patterns predict surgical outcome in patients with temporal lobe epilepsy secondary to unilateral mesial temporal sclerosis?

INTRODUCTION

Intraoperative electrocorticography (ECoG) can be performed in cases of temporal lobe epilepsy due to hippocampal sclerosis (TLE-HS). However, its significance and correlation with surgical outcome are still controversial.

OBJECTIVES

To analyze the electrophysiological characteristics of temporal lobe structures during ECoG of patients with TLE-HS, with emphasis on the comparison between pre- and post-resection recordings and surgical outcome.

PATIENTS AND METHODS

Seventeen patients with refractory TLE-HS submitted to corticoamigdalohipocampectomy were included in the study. Clinical variables included age at the onset, duration of epilepsy and seizure outcome. The post-operative follow-up ranged from 24 to 36 months. According to outcome subjects were divided in two subgroups: (A) individuals free of seizures (Engel 1A), and (B) individuals not-free of seizures (Engel 1B-IV). Four patterns of ECoG findings were identified: isolated discharges; high frequency spikes (HFS); continuous discharges; combination of isolated discharges and HFS. According to predominant topography ECoG was classified as mediobasal, lateral (or neocortical), mediobasal and lateral.

RESULTS

The progressive removal of the temporal pole and the hippocampus was associated with significant decrease of neocortical spikes. No correlation between clinical variables and seizure outcome was observed. Patients who only had isolated spikes on intraoperative ECoG presented a statistical trend for excellent surgical control. Patients who presented temporal pole blurring on MRI also had better post-surgical seizure outcome.

CONCLUSIONS

This study showed that out of diverse clinical and laboratory variables, only isolated discharges on intraoperative ECoG and temporal pole blurring on MRI predicted excellent post-surgical seizure outcome. However, other studies with larger number of patients are still necessary to confirm these findings.

Occipital intermittent rhythmic delta activity in absence epilepsy

Occipital intermittent rhythmic delta activity (OIRDA) is considered good prognostic factor in typical absences (TA). We report electroclinical evolution in 14 patients with TA and OIRDA, which performed video-EEG. Seven patients were female; 9 had childhood absence epilepsy and the others did not present electroclinical characteristics for syndromic classification according to ILAE's classification (1989). Pyknolepsy was referred to in 13; TA was the only seizure type in 13; one had generalized tonic-clonic seizures (GTCS) and three had myoclonic jerks during TA. VPA monotherapy controlled seizures in 11, diVPA and ESM, in one each. After seizure control EEG normalized in 10 while in three, spike-wave complexes (SWC) persisted, accompanied by OIRDA in one. Finally in another, seizures were not controlled and SWC and OIRDA persisted. In conclusion, we observed in this series of TA and OIRDA with onset before 10 years, pyknolepsy as common finding and few GTCS. VPA controlled seizures in most cases and EEG normalized in 76.92%. We suggest that OIRDA could be considered good prognostic factor in TA associated with SWC and of epileptiform nature leading to appropriate investigation.

Neuropsychiatric profiles of patients with juvenile myoclonic epilepsy treated with valproate or topiramate

In this cross-sectional study, the neuropsychiatric profiles of 42 patients with juvenile myoclonic epilepsy (JME) who were treated with valproate (VPA) or topiramate (TPM) in monotherapy were compared with the aim of verifying the relationship between cognitive dysfunction, psychiatric disorders, and factors related to epilepsy. Patients with JME taking VPA 500-1750 mg/day or TPM 50-175 mg/day were selected. For all patients, psychiatric profiles were evaluated with the Scheduled Clinical Interview, axes I and II (SCID I and SCID II), or the Brazilian version of the Schedule for Affective Disorders and Schizophrenia for School-Aged Children (K-SADS-PL). Neuropsychological measures included intellectual functions, attention, memory, executive functions, and language. Patients taking TPM exhibited worse neuropsychological performance on attention, short-term memory, processing speed, and verbal fluency functions related to frontal lobes, which may be dysfunctional in JME. Anxiety disorders were associated with lack of seizure control and having had more than 20 lifetime generalized tonic-clonic seizures.

Mutation in filamin A causes periventricular heterotopia, developmental regression, and West syndrome in males

PURPOSE

Familial periventricular heterotopia (PH) represents a disorder of neuronal migration resulting in multiple gray-matter nodules along the lateral ventricular walls. Prior studies have shown that mutations in the filamin A (FLNA) gene can cause PH through an X-linked dominant pattern. Heterozygotic female patients usually remain asymptomatic until the second or third decade of life, when they may have predominantly focal seizures, whereas hemizygotic male fetuses typically die in utero. Recent studies have also reported mutations in FLNA in male patients with PH who are cognitively normal. We describe PH in three male siblings with PH due to FLNA, severe developmental regression, and West syndrome.

METHODS

The study includes the three affected brothers and their parents. Video-EEG recordings and magnetic resonance image (MRI) scanning were performed on all individuals. Mutations for FLNA were detected by using polymerase chain reaction (PCR) on genomic DNA followed by single-stranded conformational polymorphism (SSCP) analysis or sequencing.

RESULTS

Two of the siblings are monozygotic twins, and all had West syndrome with hypsarrhythmia on EEG. MRI of the brain revealed periventricular nodules of cerebral gray-matter intensity, typical for PH. Mutational analyses demonstrated a cytosine-to-thymidine missense mutation (c. C1286T), resulting in a threonine-to-methionine amino acid substitution in exon 9 of the FLNA gene.

CONCLUSIONS

The association between PH and West syndrome, to our knowledge, has not been previously reported. Males with PH have been known to harbor FLNA mutations, although uniformly, they either show early lethality or survive and have a normal intellect. The current studies show that FLNA mutations can cause periventricular heterotopia, developmental regression, and West syndrome in male patients, suggesting that this type of FLNA mutation may contribute to severe neurologic deficits.

Hyperventilation revisited: physiological effects and efficacy on focal seizure activation in the era of video-EEG monitoring

PURPOSE

Hyperventilation is an activation method that provokes physiological slowing of brain rhythms, interictal discharges, and seizures, especially in generalized idiopathic epilepsies. In this study we assessed its effectiveness in inducing focal seizures during video-EEG monitoring.

METHODS

We analyzed the effects of hyperventilation (HV) during video-EEG monitoring (video-EEG) of patients with medically intractable focal epilepsies. We excluded children younger than 10 years, mentally retarded patients, and individuals with frequent seizures.

RESULTS

We analyzed 97 patients; 24 had positive seizure activation (PSA), and 73 had negative seizure activation (NSA). No differences were found between groups regarding sex, age, age at epilepsy onset, duration of epilepsy, frequency of seizures, and etiology. Temporal lobe epilepsies were significantly more activated than frontal lobe epilepsies. Spontaneous and activated seizures did not differ in terms of their clinical characteristics, and the activation did not affect the performance of ictal single-photon emission computed tomography (SPECT).

CONCLUSIONS

HV is a safe and effective method of seizure activation during monitoring. It does not modify any of the characteristics of the seizures and allows the obtaining of valuable ictal SPECTs. This observation is clinically relevant and suggests the effectiveness and the potential of HV in shortening the presurgical evaluation, especially of temporal lobe epilepsy patients, consequently reducing its costs and increasing the number of candidates for epilepsy surgery.

Urban prevalence of epilepsy: populational study in São José do Rio Preto, a medium-sized city in Brazil

The aim of this study was to determine the prevalence of epilepsy in the urban population of São José do Rio Preto. This is a medium-sized city of 336000 inhabitants, located in the northwest of the state of São Paulo, Brazil. METHOD: A crosssectional epidemiological investigation with a randomized sample was performed in two phases, a screening phase and a confirmation of the diagnosis phase. The gold standard was a clinical investigation and neurological examination. The chi-square test was used in analysis of the results and p-value value < 0.05 was considered significant. Prevalence was calculated with 95% confidence interval. RESULTS: The study sample size was 17293 individuals, with distributions of gender, age, and race similar to the general population. The prevalence per 1000 inhabitants of epilepsy was 18.6, of these 8.2 were active, defined as at least one seizure within the last two years. The prevalence per 1000 inhabitants for the age groups (years) was 4.9 (04), 11.7 (514), 20.3 (1564) and 32.8 (65 or over). CONCLUSION: Prevalence of both accumulated and active epilepsy was elevated, comparable to other developing nations, in particular those of Latin America. However, the prevalence of epilepsy in childhood was low, whilst in aged individuals it was high similar to industrialized nations.

Syndromic classification of patients with typical absence seizures

The aim of this study is to compare ILAE classification (1989) and Panayiotopoulos' criteria (1997) for absence epilepsies. We studied 455 typical absences (ILAE, 1981) by video-EEG in 43 patients with normal neurological and neuroradiological examinations and interictal EEG with spike-wave complexes higher than 2.5Hz. Syndromic diagnosis was possible in 60.5% and 67.4% of the patients using ILAE classification and Panayiotopoulos' proposal, respectively. According to ILAE criteria 19 patients had childhood absence epilepsy (CAE), five juvenile absence epilepsy (JAE), one juvenile myoclonic epilepsy (JME) and one epilepsy with specific modes of seizure precipitation. According to Panayiotopoulos' proposal, 10 had CAE, 14 JAE, one JME, three myoclonic absence epilepsy and one eyelid myoclonia with absences. We conclude that Panayiotopoulos' criteria and ILAE classification for absence epilepsies, which did not allow for the classification of 32.6% and 39.5% of cases, respectively, were still insufficient to classify all patients under specific diagnosis.