Objective: This study aims to identify if oscillations at frequencies higher than the traditional EEG can be recorded on the scalp EEG of patients with focal epilepsy and to analyze the association of these oscillations with interictal discharges and the seizure onset zone (SOZ). Methods:The scalp EEG of 15 patients with focal epilepsy was studied. We analyzed the rates of gamma (40-80 Hz) and ripple (Ͼ80 Hz) oscillations, their co-occurrence with spikes, the number of channels with fast oscillations inside and outside the SOZ, and the specificity, sensitivity, and accuracy of gamma, ripples, and spikes to determine the SOZ.Results: Gamma and ripples frequently co-occurred with spikes (77.5% and 63% of cases). For all events, the proportion of channels with events was consistently higher inside than outside the SOZ: spikes (100% vs 70%), gamma (82% vs 33%), and ripples (48% vs 11%); p Ͻ 0.0001. The mean rates (events/min) were higher inside than outside the SOZ: spikes (2.64 Ϯ 1.70 vs 0.69 Ϯ 0.26, p ϭ 0.02), gamma (0.77 Ϯ 0.71 vs 0.20 Ϯ 0.25, p ϭ 0.02), and ripples (0.08 Ϯ 0.12 vs 0.04 Ϯ 0.09, p ϭ 0.04). The sensitivity to identify the SOZ was spikes 100%, gamma 82%, and ripples 48%; the specificity was spikes 30%, gamma 68%, and ripples 89%; and the accuracy was spikes 43%, gamma 70%, and ripples 81%. Conclusion:The rates and the proportion of channels with gamma and ripple fast oscillations are higher inside the SOZ, indicating that they can be used as interictal scalp EEG markers for the SOZ. These fast oscillations are less sensitive but much more specific and accurate than spikes to delineate the SOZ. Neurology The conventional range of EEG analysis usually involves frequencies below 40 Hz. Studies over the last decade suggest, however, that high-frequency oscillations (HFOs) may have an essential role in normal and pathologic brain function. Reports using microelectrodes combined with depth EEG electrodes showed the presence of HFOs in epileptic patients.

SUMMARYPurpose: Removal of areas generating high-frequency oscillations (HFOs) recorded from the intracerebral electroencephalography (iEEG) of patients with medically intractable epilepsy has been found to be correlated with improved surgical outcome. However, whether differences exist according to the type of epilepsy is largely unknown. We performed a comparative assessment of the impact of removing HFO-generating tissue on surgical outcome between temporal lobe epilepsy (TLE) and extratemporal lobe epilepsy (ETLE). We also assessed the relationship between the extent of surgical resection and surgical outcome. Methods: We studied 30 patients with drug-resistant focal epilepsy, 21 with TLE and 9 with ETLE. Two thirds of the patients were included in a previous report and for these, clinical and imaging data were updated and followup was extended. All patients underwent iEEG investigations (500 Hz high-pass filter and 2,000 Hz sampling rate), surgical resection, and postoperative magnetic resonance imaging (MRI). HFOs (ripples, 80-250 Hz; fast ripples, >250 Hz) were identified visually on a 5-10 min interictal iEEG sample. HFO rates inside versus outside the seizure-onset zone (SOZ), in resected versus nonresected tissue, and their association with surgical outcome (ILAE classification) were assessed in the entire cohort, and in the TLE and ETLE subgroups. We also tested the correlation of resected brain hippocampal and amygdala volumes (as measured on postoperative MRIs) with surgical outcome. Key Findings: HFO rates were significantly higher inside the SOZ than outside in the entire cohort and TLE subgroup, but not in the ETLE subgroup. In all groups, HFO rates did not differ significantly between resected and nonresected tissue. Surgical outcome was better when higher HFO rates were included in the surgical resection in the entire cohort and TLE subgroup, but not in the ETLE subgroup. Resected brain hippocampal and amygdala volumes were not correlated with surgical outcome. Significance: In TLE, removal of HFO-generating areas may lead to improved surgical outcome. Less consistent findings emerge from ETLE, but these may be related to sample size limitations of this study. Size of resection, a factor that was ignored and that could have affected results of earlier studies did not influence results.

Objective-We aim to automatically detect fast oscillations (40-200 Hz) related to epilepsy on scalp EEG recordings.Methods-The detector first finds localized increments of the signal power in narrow frequency bands. A simple classification based on two features, a narrowband to wideband signal amplitude ratio and an absolute narrowband signal amplitude, then allows for an important reduction in the number of false positives.Results-When compared to an expert, the performance in 15 focal epilepsy patients resulted in 3.6 false positives per minute at 95% sensitivity, with at least 40% of the detected events being true positives. In most of the patients the channels showing the highest number of events according to the expert and the automatic detector were the same.Conclusions-A high sensitivity is achieved with the proposed automatic detector, but results should be reviewed by an expert to remove false positives.Significance-The time required to mark fast oscillations on scalp EEG recordings is drastically reduced with the use of the proposed detector. Thus, the automatic detector is a useful tool in studies aiming to create a better understanding of the fast oscillations visible on the scalp.

Objective To estimate the incidence of epilepsy in children with Zika‐related microcephaly in the first 24 months of life; to characterize the associated clinical and electrographic findings; and to summarize the treatment responses. Methods We followed a cohort of children, born during the 2015‐2016 Zika virus (ZIKV) epidemic in Brazil, with congenital microcephaly and evidence of congenital ZIKV infection on neuroimaging and/or laboratory testing. Neurological assessments were performed at ≤3, 6, 12, 15, 18, 21, and 24 months of life. Serial electroencephalograms were performed over the first 24 months. Results We evaluated 91 children, of whom 48 were female. In this study sample, the cumulative incidence of epilepsy was 71.4% in the first 24 months, and the main type of seizure was infantile spasms (83.1%). The highest incidence of seizures occurred between 3 and 9 months of age, and the risk remained high until 15 months of age. The incidence of infantile spasms peaked between 4 and 7 months and was followed by an increased incidence of focal epilepsy cases after 12 months of age. Neuroimaging results were available for all children, and 100% were abnormal. Cortical abnormalities were identified in 78.4% of the 74 children evaluated by computed tomography and 100% of the 53 children evaluated by magnetic resonance imaging. Overall, only 46.1% of the 65 children with epilepsy responded to treatment. The most commonly used medication was sodium valproate with or without benzodiazepines, levetiracetam, phenobarbital, and vigabatrin. Significance Zika‐related microcephaly was associated with high risk of early epilepsy. Seizures typically began after the third month of life, usually as infantile spasms, with atypical electroencephalographic abnormalities. The seizure control rate was low. The onset of seizures in the second year was less frequent and, when it occurred, presented as focal epilepsy.

Analysis of interictal HFOs during 5-10 min of sleep recording is a good tool to localize the SOZ in patients with epilepsy and normal MRI, and could potentially reduce the duration of chronic intracerebral EEG recordings.

Thunderclap headache attributed to reversible cerebral vasoconstriction (THARCV) is a syndrome observed in a number of reported cases. In this article we reviewed this new headache entity (idiopathic form) using the clinical-radiological findings of 25 reported patients. In this series of patients 72% were women, the mean age at the onset of first headache episode was 39.4 ± 2.3 years. In addition to the sine qua non condition of being abrupt and severe (thunderclap) at the onset, the headache was usually described as being explosive, excruciating, or crushing. The feature of pulsatility, accompanied or not by nausea was described by 80% of the patients. Forty percent of the cases manifested vomiting and 24% photophobia. Usually the headache was generalized, and in three cases it was unilateral at least at the onset. In 21 of 25 patients (84%) there was at least one recurrence or a sudden increase in the intensity of the headache. A past history of migraine was present in 52% of the patients. Precipitating factors were identified in 56% of the patients. Sexual intercourse was described by six patients. Of the 25 patients with THARCV syndrome studied, 12 (48%) developed focal neurological signs, transitory ischemic attack (n = 1), or ischemic stroke (n = 11, 44%), and two (8%) of them manifested seizures. The THARCV syndrome is a neurological disturbance perhaps more frequent than expected, preferentially affecting middle aged female migraineurs, and having an unpredictable prognosis, either showing a benign course or leading to stroke.

RESUMO -O objetivo deste estudo foi analisar aspectos clínicos, epidemiológicos e evolutivos da paralisia facial periférica idiopática em 180 pacientes. Houve ligeiro predomínio do sexo feminino (66,7%). Quanto à faixa etária mais acometida, foram observados dois picos de incidência um nas terceira e quarta décadas, e o outro na sexta década de vida. Nos 180 pacientes houve 198 episódios de paralisia facial periférica, sendo 17 recorrências e em um paciente a paralisia foi de instalação inicial bilateral. Em 15 pacientes (8,3%) houve recidiva da paralisia facial, em dois casos a paralisia se repetindo por mais duas vezes. Em 12 casos (70,6%) a recidiva ocorreu no mesmo lado da paralisia anterior. O lado esquerdo da face estava envolvido em 55,6% dos casos. Em oito pacientes a paralisia aconteceu na gestação (n=5) ou no pós-parto (n=3). Quatro das pacientes grávidas apresentaram paralisia de Bell no terceiro trimestre. Uma paciente com 18 anos de idade desenvolveu paralisia facial do lado direito no sétimo mês da gravidez, havendo recidiva da paralisia no mesmo lado aos 23 anos de idade, no 15º dia pós-parto. Como condicões associadas encontramos hipertensão arterial sistêmica (11,7%), diabete mélito (11,1%), gravidez ou pós-parto imediato (4,4%; 6,7% nas mulheres) e neurocisticercose (1,1%). Em 72,8% dos casos não encontramos associação com outras afecções. Em 22,8% dos pacientes observou-se uma das seguintes sequelas: espasmo hemifacial (12,8%), recuperação parcial do déficit motor (10,6%), síndrome das lágrimas do crocodilo (3,3%), contrações sincinéticas (2,8%), lacrimejamento (1,1%) e fenômeno de Marcus Gunn invertido (1,1%). Concluíndo, no estudo foi demonstrado que a paralisia facial periférica idiopática pode provocar sequelas importantes, cosméticas ou funcionais, em mais de 20% dos pacientes.PALAVRAS-CHAVE: paralisia facial periférica, hipertensão arterial, diabete mélito, gravidez, sequela. Idiopathic facial paralysis (Bell´s palsy): a study of 180 patientsAbstract -The objective of this study was to analyze some clinical and epidemiologic aspects, as well as the follow up of 180 patients with Bell´s palsy. In the study population there was a predominance of female (66.7%). Two peaks of incidence in the age distribution were identified: third-fourth and sixth decades of life. In the group of 180 patients there were 198 events of facial paralysis, 17 recurrences and in one patient the paralysis was bilateral at the onset. In 15 patients (8.3%) there were recurrences of the facial paralysis, in 12 cases (70.6%) the recurrences were ipsilateral. The left side of the face was involved in 55.6% of the cases. In eight patients the paralysis ocurred during pregnancy (n=5) or puerperium (n=3). As associated conditions we found: arterial hypertension (11.7%), diabetes mellitus (11.1%), pregnancy or puerperium (4.4%; 6.7% in the women), and neurocysticercosis (1.1%). In 72.8% of the cases no association with such conditions was found. In 22.8% of the patients some kind of sequelae were identified: hemifacial spa...

SUMMARYHippocampi from all patients were processed for Nissl/HE and Timm's stainings. Both groups were compared for clinical variables, hippocampal cell densities, and intensity of supragranular mossy fiber staining. Results: There were no significant differences between FMTLE and SMTLE groups in the following: age at the surgery, age of first usual epileptic seizure, history of initial precipitating injury (IPI), age of IPI, latent period, ictal and interictal video-EEG patterns, presence of hippocampal atrophy and signal changes at MRI, and postoperative outcome. In addition, no differences were found in cell densities in hippocampal cornu ammonis subfields (CA1, CA2, CA3, CA4), fascia dentata, polymorphic region, subiculum, prosubiculum, and presubiculum. However, patients with SMTLE had greater intensity of mossy fiber Timm's staining in the fascia dentata-inner molecular layer (p< 0.05). Discussion: Patients with intractable FMTLE present a clinical profile and most histological findings comparable to patients with SMTLE. Interestingly, mossy fiber sprouting was less pronounced in patients with FMTLE, suggesting that, when compared to SMTLE, patients with FMTLE respond differently to plastic changes plausibly induced by cell loss, neuronal deafferentation, or epileptic seizures.