Navegando por Palavras-chave "EEG"

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    Age-related changes during a paradigm of chronic sleep restriction
    (Elsevier B.V., 2010-12-10) Souza, Luciane de [UNIFESP]; Andersen, Monica L. [UNIFESP]; Smaili, Soraya Soubhi [UNIFESP]; Lopes, Guiomar S. [UNIFESP]; Ho, Priscila S. [UNIFESP]; Papale, Ligia A. [UNIFESP]; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Fragmented and restricted sleep is a common problem for the human elderly. There is evidence that aging impairs sleep in animals as well. After sleep deprivation, older animals have less sleep rebound. Despite increasing complaints of reduced time for sleep in contemporary society, few studies have examined chronic sleep restriction protocols in animals. Therefore, the aim of the present study was to evaluate the effects of chronic sleep restriction on the sleep patterns of aged rats. Using the single platform method, 22-month-old male rats were submitted to 18 h of sleep restriction followed by 6 h of total sleep opportunity. the sleep-wake cycles of these rats were recorded for 6 h/day throughout the 12-day procedure. the results showed that total sleep time and NREM sleep were reduced during the 12-day sleep restriction period. However, rebound REM sleep was only significant on day 6. A negative rebound was also seen, particularly during the last days of the chronic sleep restriction period. Furthermore, sleep latency and mean wake bout length progressively increased during the protocol. These findings indicate that older rats have an inability to restore their sleep patterns during extended sleep deprivation. (C) 2010 Elsevier B.V. All rights reserved.
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    Analysis of clinical characteristics and risk factors for mortality in human status epilepticus
    (W B Saunders Co Ltd, 2003-09-01) Garzon, Eliana [UNIFESP]; Fernandes, Regina Maria França; Sakamoto, Américo Ceiki [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    Purpose: To analyse clinical data including aetiology, age, antecedents, classification and mortality in human status epilepticus (SE), and to assess prognostic factors for mortality.Methods: A prospective study was performed, including detailed analysis of clinical and laboratorial data of SE in individuals of any age. except neonates.Results: One hundred and eleven SE were included, with patients' age ranging from 3 months to 98 years. SE incidence peaked in the first year of life, and 59.4% of the individuals had previous epilepsy while 40.6% had not. the main underlying causes were noncompliance to treatment in the first group, and CNS infection, stroke and metabolic disturbances in the second group. Overall mortality was 19.8%. and deaths were correlated to aetiology and patient's age. Refractory SE affected 11.7% of the cases. Clinical types included focal, secondarily generalised and generalised SE. Clinical and clinicoelectrographic classifications were convergent, but EEG was essential for the diagnosis in 4.5% of the cases.Conclusions: Epileptic patients are at greater risk to develop SE, however, individuals with no prior history of epilepsy and acute neurological problems can also present SE. Aetiology varies with patient's age, and mortality is high and related to age and underlying causes. Clinical and clinicoelectrographic classifications are usually convergent, but in some cases the diagnosis of SE would not be established without the EEG. (C) 2003 BEA Trading Ltd. Published by Elsevier B.V. All rights reserved.
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    Atypical clinical and electroencephalographic pattern in a patient with subacute sclerosing panencephalitis
    (Academia Brasileira de Neurologia - ABNEURO, 1995-06-01) Silva, Délrio F. [UNIFESP]; Lima, Márcia Marques; Anghinah, Renato; Zanoteli, Edmar [UNIFESP]; Lima, José Geraldo Camargo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    We describe an atypical clinical and electroencephalographic (EEG) pattern observed during the course of subacute sclerosing panencephalitis in a 14 year-old boy. In this patient with a two weeks history of partial complex seizures, the atypical EEG pattern was characterized by an initial left temporal focus which evolved to periodic lateralized epileptiform discharges (PLEDs) and, only during the 3rd and 4th weeks the typical bilateral and generalized periodic complexes appeared.
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    Atypical EEG pattern in children with absence seizures
    (Academia Brasileira de Neurologia - ABNEURO, 1995-06-01) Silva, Délrio F. [UNIFESP]; Lima, Márcia Marques; Anghinah, Renato; Zanoteli, Edmar [UNIFESP]; Lima, José Geraldo Camargo; Universidade Federal de São Paulo (UNIFESP)
    We studied four children with diagnosis of absence seizures (generalized primary epilepsy), and with a generalized delta activity on the EEG during clinical attacks provoked by hyperventilation. The lack of ictal generalized spike-and-wave discharges with a frequency of 3 Hz in our patients, makes this an atypical pattern. All children had complete control of their seizures and disappearance of the EEG changes with valproate. We concluded that generalized delta activity observed on EEG during the hyperventilation in children should not always be considered as a normal finding for age, since it could be an ictal event of an absence seizure.
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    Atypical pattern related to 14 Hz positive spikes
    (Academia Brasileira de Neurologia - ABNEURO, 1995-06-01) Silva, Délrio F. [UNIFESP]; Lima, Márcia Marques; Kanda, Paulo M.; Anghinah, Renato; Zanoteli, Edmar [UNIFESP]; Lima, José Geraldo C. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    We studied two children with a history of headache and a normal physical and neurological examination whose EEG showed an electroencephalographic pattern recently published, the N-shape potential associated with the 14 Hz positive spikes. This graphoelement was observed only during the asleep state.
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    Background and paroxystic activities on AIDS patients' EEG: relation with urea and creatinine seric concentration
    (Academia Brasileira de Neurologia - ABNEURO, 1998-09-01) Prado, Gilmar Fernandes do [UNIFESP]; Silva, Ademir Baptista [UNIFESP]; Coelho, João Fernando Guimbra Simões; Braga, Nádia Iandoli Oliveira; Accetturi, Conceicao Aparecida [UNIFESP]; Lima, José Geraldo de Camargo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Instituto de Infectologia Emílio Ribas
    The HIV is responsible for important metabolic and structural alterations of the brain. This affected brain must react to continuous systemic metabolic fluctuations. We search for possibly resulting cerebral electric disturbance that could be found by EEG exploration. Sixty-three AIDS patients ranked as CDC group IV had their EEG background rhythm measured, and were appointed to mutually exclusiding groups delimited by medians' values of urea (24 mg/dl) and creatinine (0.9 mg/dl) seric concentrations. These groups were independently formed for each of the parameters utilized, and each data pair generated therefrom were compared between themselves to verify whether there were differences in background rhythm and the occurrence of paroxysmal activity. Background rhythm and paroxysmal activities have not statistically differed between the group whose creatinine values were lower than 0.9 mg/dl and the group whose creatinine values were equal or higher than 0.9 mg/dl. Background rhythm has not statistically differed between the group whose ures values were <24 mg/dl and the group whose urea values were =24 mg/dl; contrariwise, the occurrence of paroxysmal activities in these groups has significatively differed, being higher in the patient group whose otherwise normal urea values exceeded 24 mg/dl (p=0.02).
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    Brain-Derived Neurotrophic Factor Gene Polymorphism Predicts Interindividual Variation in the Sleep Electroencephalogram
    (Wiley-Blackwell, 2014-08-01) Guindalini, Camila [UNIFESP]; Mazzotti, Diego R. [UNIFESP]; Castro, Laura S. [UNIFESP]; D'Aurea, Carolina V. R. [UNIFESP]; Andersen, Monica L. [UNIFESP]; Poyares, Dalva [UNIFESP]; Bittencourt, Lia R. A. [UNIFESP]; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Previous studies have suggested that brain-derived neurotrophic factor (BDNF) participates in the homeostatic regulation of sleep. the objective of this study was to investigate the influence of the Val66Met functional polymorphism of the BDNF gene on sleep and sleep EEG parameters in a large population-based sample. in total 337 individuals participating in the São Paulo Epidemiologic Sleep Study were selected for analysis. None of the participants had indications of a sleep disorder, as measured by full-night polysomnography and questionnaire. Spectral analysis of the EEG was carried out in all individuals using fast Fourier transformation of the oscillatory signals for each EEG electrode. Sleep and sleep EEG parameters in individuals with the Val/Val genotype were compared with those in Met carriers (Val/Met and Met/Met genotypes). After correction for multiple comparisons and for potential confounding factors, Met carriers showed decreased spectral power in the alpha band in stage one and decreased theta power in stages two and three of nonrapid-eye-movement sleep, at the central recording electrode. No significant influence on sleep macrostructure was observed among the genotype groups. Thus, the Val66Met polymorphism seems to modulate the electrical activity of the brain, predicting interindividual variation of sleep EEG parameters. Further studies of this and other polymorphic variants in potential candidate genes will help the characterization of the molecular basis of sleep. (C) 2014 Wiley Periodicals, Inc.
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    A comparison between averaged spikes and individual visually-analyzed spikes in rolandic epileptiform discharges
    (Academia Brasileira de Neurologia - ABNEURO, 2002-09-01) Braga, Nadia I.o. [UNIFESP]; Manzano, Gilberto Mastrocola [UNIFESP]; Nóbrega, João Antonio Maciel [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    PURPOSE:This study compared some morphological features of individual rolandic epileptiform discharges, used to obtain an averaged estimate, with those of the resulting estimate. METHOD: Twenty-four averaged discharges from EEGs of 24 children showing rolandic spikes were compared with 480 individual discharges used in the averaging. The analysis was based on the occurrence of tangential dipole and double spike patterns. RESULTS: In 15 averaged discharges the tangential dipole pattern was found. Individual spikes used in the averaging process displayed the same pattern in 35-100% of them; in the remaining 9 averaged discharges, up to 20% of the individual spikes showed the same pattern, although this was not found in the averaged waveforms. Double spike pattern was found in 11 of the averaged waveforms and was recognized in 50-100% of its individual discharges, whereas up to 45% of individual spikes showed this pattern without expression in the averaged waveform. CONCLUSION: When visually analyzing an EEG with rolandic spikes, caution should be exercised in characterizing these patterns, since a few discharges showing them may not be expressed in the averaged waveform and the clinical correlations proposed for these patterns may not apply.
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    Complex partial status epilepticus in a child
    (Academia Brasileira de Neurologia - ABNEURO, 1995-06-01) Silva, Délrio F. [UNIFESP]; Zanoteli, Edmar [UNIFESP]; Lima, Márcia Marques; Anghinah, Renato; Lima, José Geraldo Camargo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Complex partial status epilepticus (SE) has been reported rarely in children. We describe the clinical case of a 14 year-old girl with complex partial seizures (CPS) since age 10 who developed a complex partial SE probably because she was not adherent to treatment. The neurologic examination and computed tomography scan were normal. During the SE she received diazepam and phenytoin and became free of the seizures after 5 minutes. The ictal EEG showed spikes and slow waves over the right temporal region.
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    Cyclooxygenase-2/PGE(2) pathway facilitates pentylenetetrazol-induced seizures
    (Elsevier B.V., 2008-03-01) Oliveira, Mauro Schneider; Furian, Ana Flavia; Freire Royes, Luiz Fernando; Fighera, Michele Rechia; Fiorenza, Natalia Gindri; Castelli, Marcelo; Machado, Pablo; Bohrer, Denise; Veiga, Marlei; Ferreira, Juliano; Cavalheiro, Esper Abraao [UNIFESP]; Mello, Carlos Fernando; Universidade Federal de Sergipe (UFS); Univ Fed Rio Grande do Sul; Universidade Federal de São Paulo (UNIFESP)
    Cyclooxygenases (CCXs) are rate-limiting enzymes in the metabolic pathways in which arachidonic acid is converted to prostaglandins. COX-2 is the isoform induced at injury/inflammation sites and expressed constitutively in a few tissues, such as the central nervous system, and plays a rote in neurodegenerative diseases associated with increased excitatory activity. However, the role of COX-2 and its main product, prostaglandin E-2 (PGE(2)), in the convulsive states is not fully established. in this study we showed that the selective COX-2 inhibitor, celecoxib (at the dose of 2mg/kg, but not at the doses of 0.2 or 20mg/kg, p.o.), protects against the seizures induced by pentylenetetrazol (PTZ, 60 mg/kg, i.p.). the role of PGE2 in the convulsions induced by PTZ was further investigated by administering anti-PGE(2) antibodies (4 mu g/2 mu l, i.c.v.), and assessing electroencephatographic changes induced by PTZ (PTZ, 60 mg/kg, i.p.). Anti-PGE(2) antibodies attenuated PTZ-induced seizures in rats. in addition, combining PGE(2) (100 ng/2 mu l, i.c.v.) with a subconvulsant dose of PTZ (20 mg/kg, i.p.) caused seizures, further supporting a role for this prostaglandin in the convulsions induced by PTZ. Finally, we showed that the anticonvulsant action of celecoxib (2 mg/kg, p.o.) was reversed by the intracerebroventricular administration of PGE(2) (10 ng/2 mu l, i.c.v.). These data constitute strong converging pharmacological evidence supporting a facilitatory role for the COX-2/PGE2 pathway in the seizures induced by PTZ. However, whether selective COX-2 inhibitors are safer anti-inflammatory drugs for epileptic patients than nonspecific inhibitors remains to be determined. (c) 2008 Elsevier B.V. All rights reserved.
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    Dipole reversal: an ictal feature in a patient with benign partial epilepsy of childhood with centrotemporal spike
    (Academia Brasileira de Neurologia - ABNEURO, 1995-06-01) Silva, Délrio F. [UNIFESP]; Lima, Márcia Marques; Anghinah, Renato; Zanoteli, Edmar [UNIFESP]; Lima, José Geraldo C. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    We describe the case of a 15-year-old boy who had the diagnosis of benign partial epilepsy of childhood with centrotemporal spike. During the EEG a subclinical electrographic seizure was recorded. The discharges were clearly electropositive in T4 with positive phase reversal between derivations F8-T4 and T4-T6. The whole episode lasted less than one minute (45 sec). The interictal right medio-temporal spikes reemerged after 60 sec and were electronegative in the same location after the end of the electrographic seizures. The mechanisms underlying this uncommon pattern on EEG is not well stablished.
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    Effects of sleep loss on sleep architecture in Wistar rats: Gender-specific rebound sleep
    (Elsevier B.V., 2008-05-15) Andersen, M. L. [UNIFESP]; Antunes, I. B. [UNIFESP]; Silva, A. [UNIFESP]; Alvarenga, T. A. F. [UNIFESP]; Baracat, E. C. [UNIFESP]; Tufik, S. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    This study was designed to examine the influence of gender on sleep rebound architecture after a 4-day paradoxical sleep deprivation period. After a 5-day baseline sleep recording, both male and female rats in different phases of the estrus cycle were submitted to paradoxical sleep deprivation for 96 h. After this period, the sleep rebound recording was evaluated for 5 days (one estrus cycle). the findings revealed that after paradoxical sleep deprivation, sleep efficiency and paradoxical sleep returned to baseline values on the second day of the light period, for all except the proestrus group. During the dark rebound period, only the female groups presented increased sleep efficiency on the first day. Paradoxical sleep returned to baseline values on the third day, except for males and the cycling females submitted to paradoxical sleep deprivation in the diestrus phase, whose baseline values returned to normal on the second day of rebound period. Thus, the females and males displayed distinct patterns as a result of sleep disruption. (C) 2008 Elsevier Inc. All rights reserved.
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    Electroencephalogram base rhythm in AIDS patients
    (Academia Brasileira de Neurologia - ABNEURO, 1993-06-01) Prado, Gilmar Fernandes do [UNIFESP]; Silva, A. Baptista da [UNIFESP]; Lima, J.g. Camargo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    We studied the EEG of 73 patients diagnosed with HIV infection, with or without secondary complications. Sixty-eight belonged to CDC (Center for Disease Control) group IV and 38 presented signs or symptoms of encephalic neurological impairment. Rhytms constituting base activity were alpha (65.75%), beta (13.70%), theta (12.33%), and delta (8.22%). The alpha rhythm presented two modes: slow (8 to 9 Hz) in 25/48 or 52.08% of the cases and not-slow (>9 to 13 Hz) in 23/48 or 47.92% of the cases. The alpha slow-mode has been observed in about 10 to 15% of the normal population, with the 8 Hz frequency being found in only 1% of the normal adult population, which suggests that in some manner HIV is implicated in the slowing-down of the EEG base rhythm in AIDS patients. The patients from CDC group IV with encephalic neurological involvement presented a base rhythm significantly lower than those with non-encephalic involvement or the absence of neurological impairment.
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    Electrophysiological correlates of sleep disturbance induced by acute and chronic administration of D-amphetamine
    (Elsevier B.V., 2009-01-16) Andersen, Monica L. [UNIFESP]; Margis, Regina; Frey, Benicio N.; Giglio, Larriany M. F.; Kapczinski, Flavio; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Fed Rio Grande do Sul; McMaster Univ
    Sleep disturbance is the strongest predictor of manic relapse and is considered one of the most important objective measures of treatment response in bipolar disorder (BD). However, the neurobiological mechanisms underlying sleep disturbance in BD are poorly understood. the administration of psycho stimulants to rodents can trigger a number of manic-like behaviors. Therefore, the present study aims to investigate the effects of single and repeated D-amphetamine (AMPH) administration on sleep patterns in rats. Sleep was continuously monitored during light periods after single and repeated (7 days) injections of AMPH (2 mg/kg, i.p.) or saline in adult Wistar rats using electrocorticogram and electromyographic recordings. Acute injections of AMPH suppressed sleep for the first 2 h, and were followed by a gradual increase in the amount of sleep. Both slow wave sleep (SWS) and paradoxical sleep (PS) were compromised. Repeated exposure to AMPH led to a drastic disruption of the sleep-wake cycle that was mainly characterized by a decrease of PS during all time-points recorded in comparison to the saline group. Furthermore, both acute and chronic AMPH administration induced longer latencies to both SWS and PS. These findings suggest that AMPH produces profound sleep disturbances and decreases PS sleep. Given that some of these abnormalities are observed in individuals with BD, this animal model can provide a means to investigate neurobiological aspects of sleep disturbance in BD, as well as their response to mood stabilizers. (C) 2008 Elsevier B.V. All rights reserved.
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    Emprego da análise de componentes de grupo relacionadas à tarefa na decomposição de potenciais relacionados a eventos
    (Universidade Federal de São Paulo, 2023-08-16) Couto, Bruno Andry Nascimento [UNIFESP]; Casali, Adenauer Girardi [UNIFESP]; http://lattes.cnpq.br/1928873015717140; http://lattes.cnpq.br/1955823300418515
    Este estudo tem como objetivo explorar a eficácia do método de Análise de Componentes de Grupo Relacionadas à Tarefa (gTRCA) na extração de componentes reprodutíveis a partir de dados de Potenciais Relacionados a Eventos (ERPs) e na interpretação da natureza complexa das formas de onda dos ERPs. O estudo é conduzido em três fases, cada uma focando em um aspecto diferente da aplicação do método. A primeira fase consiste na análise e validação da gTRCA usando conjuntos de dados simulados, revelando detalhes sobre o funcionamento do método e sua robustez em vários cenários. Nesta etapa, um novo teste estatístico, implementado a partir do deslocamento circular dos sinais de cada indivíduo, também foi introduzido para medir a reprodutibilidade a nível de grupo das componentes, provando-se útil na análise dos ERPs. A segunda fase envolve a aplicação da gTRCA a conjuntos de dados reais de ERPs, obtidos de 40 indivíduos submetidos a um protocolo de Mismatch Negativity (MMN) auditivo passivo do tipo oddball. O objetivo era investigar o potencial do método na implementação de classificadores para tipos de potenciais distintos: padrão e desviante. A terceira fase estende a aplicação a outro conjunto de dados reais de 16 sujeitos submetidos a um protocolo de Estimulação Magnética Transcraniana (TMS) no córtex motor esquerdo, visando caracterizar os Potenciais Evocados por TMS (TEPs). Como resultado, na primeira fase mostramos - em dados simulados - que o método é capaz de identificar as componentes que são reprodutíveis intra e entre sujeitos desde que seja combinado a técnicas estatísticas apropriadas. Na segunda fase, encontramos que a gTRCA foi capaz de extrair componentes dos potenciais auditivos MMN de forma a discriminar os diferentes tipos de estímulo com alta acurácia (mediana de 90%). Finalmente, mostramos que a técnica identifica múltiplas componentes reprodutíveis em nível de grupo em TEPs motores e que possuem características nos domínios do espaço, tempo e frequência coerentes com a literatura descrevendo tais potenciais. Deste modo, esta investigação multifacetada não só aprofunda nossa compreensão dos ERPs como ferramentas de investigação em neurociências, mas também destaca o potencial de técnicas de aprendizado de máquina como a gTRCA na análise de ERPs. Os resultados deste trabalho ilustram a robustez e aplicabilidade da gTRCA, posicionando-a como uma ferramenta valiosa na análise e interpretação de ERPs.
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    Epilepsy with continuous spike-waves during slow wave sleep: a clinical and electroencephalographic study
    (Academia Brasileira de Neurologia - ABNEURO, 1995-06-01) Silva, Délrio F. [UNIFESP]; Lima, Márcia Marques; Gonzalez, Luzinete V.a.t.; Lopez, Odyna J. Lr.; Anghinah, Renato; Zanoteli, Edmar [UNIFESP]; Lima, José Geraldo C. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    We report four children with epilepsy with continuous spike-waves during slow wave sleep (CSWSS). The main clinical features were partial motor seizures, mental retardation and motor deficit. The EEG findings were characterized by nearly continuous (>85%) diffuse slow spike and wave activity in two patients, and localized to one hemisphere in two other cases during non-REM sleep. The treatment was effective in improving the clinical seizures, but not the EEG pattern. We believe that this epileptic syndrome has been overlooked and routine sleep EEG studies on epileptic children may disclose more cases of CSWSS.
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    Flunitrazepam-induced changes in neurophysiological, behavioural, and subjective measures used to assess sedation
    (Elsevier B.V., 2003-05-01) Lucchesi, Lígia M. [UNIFESP]; Pompeia, Sabine [UNIFESP]; Manzano, Gilberto M. [UNIFESP]; Kohn, A. F.; Galduroz, José CF [UNIFESP]; Bueno, Orlando FA [UNIFESP]; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    Introduction: Certain features of event-related potentials (ERPs), electroencephalographic (EEG), and behavioural measures vary with differing states of alertness and/or sedation. Purpose: This study was conducted to investigate changes in several measures usually viewed as reflecting states of sedation/sleepiness associated with the use of a range of doses of the hypnotic benzodiazepine (BZD) flunitrazepam (FNZ). Methods: This was a double blind, independent group design study of the effects of acute oral doses of FNZ in young healthy volunteers. Forty-eight subjects were randomly allocated to one of four groups-FNZ (0.6, 0.8, and 1.0 mg) and placebo (PLAC)-and tested prior to treatment and then in a posttreatment session close to the theoretical peak plasma concentration. ERP latencies and amplitudes were measured at midfrontal (Fz), midcentral (Cz), and midparietal (Pz) using a standard auditory oddball paradigm. EEG changes were assessed at Pz. Behavioural measures included the digit-symbol substitution test (DSST), a cancellation task (CT), and subjective ratings of alertness and attentiveness by the subjects (SUB) and the experimenter (EXP). Results: FNZ led to psychomotor impairments and decreased alertness and attention; these effects were consistent with previous findings. A progressive, dose-related increase in P3 latency occurred in Fz, Cz, and Pz, and there was an increase in N1 (Fz, Cz) and N2 (Fz). N2-P3 amplitude decreased in Fz. EEG power bands beta 1 increased for the two highest doses, but no significant differences were noted in theta, delta, and alpha bands. P3 latencies, experimenter-rated levels of alertness, and DSST scores differentiated all three doses of FNZ from PLAC. Conclusion: the most sensitive measures used were P3 latencies of the ERPs (which varied with FNZ dose), DSST, and the experimenter-rated levels of alertness. However, we found no evidence for the assumption that one single phenomenon was reflected in all measures and different mechanisms were probably involved. Further experiments will be needed for more in-depth probing of the finer mechanisms underlying sedation/sleepiness and how they affect behavioural and eletrophysiological measures of the central nervous system (CNS) function. (C) 2003 Elsevier Science Inc. All rights reserved.
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    Generalized periodic EEG activity in two cases of neurosyphilis
    (Academia Brasileira de Neurologia - ABNEURO, 2006-03-01) Anghinah, Renato; Camargo, Érica C.s.; Braga, Nádia I. [UNIFESP]; Waksman, Simone; Nitrini, Ricardo; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    Neurosyphilis is a recognized cause of epileptic seizures and cognitive impairment, but is not usually associated with the finding of generalized periodic activity in the EEG. We report two similar cases characterized by progressive cognitive impairment followed by partial complex seizures, in whom the EEG showed generalized periodic activity. Both cerebrospinal fluid and the response to penicillin therapy confirmed the diagnoses of neurosyphilis in the two cases. The finding of EEG generalized periodic activity in patients with cognitive or behavioral disorders is usually associated with Creutzfeldt-Jakob disease, although there are other conditions, some of them potentially reversible, which may also present this EEG abnormality. Neurosyphilis has tended not to be included among them, and our present findings support the importance of first ruling out neurosyphilis in those patients with cognitive or behavioral disorders associated with generalized periodic epileptiform discharges.
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    GMI ganglioside prevents seizures, Na+,K+-ATPase activity inhibition and oxidative stress induced by glutaric acid and pentylenetetrazole
    (Elsevier B.V., 2006-06-01) Fighera, M. R.; Royes, LFF; Furian, A. F.; Oliveira, M. S.; Fiorenza, N. G.; Frussa, R.; Petry, J. C.; Coelho, R. C.; Mello, C. F.; Universidade Federal de Sergipe (UFS); Universidade Federal de São Paulo (UNIFESP)
    Monosialoganglioside (GM1) is a glycosphingolipid that protects against some neurological conditions, such as seizures and ischemia. Glutaric acidemia type I (GA-I) is an inherited disease characterized by striatal degeneration, seizures, and accumulation of glutaric acid (GA). in this study, we show that GA inhibits Na+,K+-ATPase activity and increases oxidative damage markers (total protein carbonylation and thiobarbituric acid-reactive substances-TBARS) production in striatal homogenates from rats in vitro and ex vivo. It is also shown that GM1 (50 mg/kg, i.p., twice) protects against GA-induced (4 mu mol/striatum) seizures, protein carbonylation, TBARS increase, and inhibition of Na+,K+-ATI`ase activity ex vivo. Convulsive episodes induced by GA strongly correlated with Na+,K+-ATPase activity inhibition in the injected striatum but not with oxidative stress marker measures. Muscimol (46 pmol/striatum), but not MK-801 (3 nmol/ striatum) and DNQX (8 nmol/striatum) prevented GA-induced convulsions, increase of TBARS and protein carbonylation and inhibition of Na+,K+-ATPase activity. the protection of GM1 and muscimol against GA-induced seizures strongly correlated with Na+,K+-ATPase activity maintenance ex vivo. in addition, GM1 (50-200 mu M) protected against Na+K+-ATPase inhibition induced by GA (6 mM) but not against oxidative damage in vitro. GM1 also decreased pentylenetetrazole (PTZ)-induced (1.8 mu mol/striatum) seizures, Na+,K+-ATPase inhibition, and increase of TBARS and protein carbonyl in the striatum. These data suggest that Na+,K+-ATPase and GABA(A) receptor-mediated mechanisms may play important roles in GA-induced seizures and in their prevention by GM1. (c) 2006 Elsevier Inc. All rights reserved.
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    Hyperventilation revisited: Physiological effects and efficacy on focal seizure activation in the era of video-EEG monitoring
    (Blackwell Publishing Inc, 2005-01-01) Guaranha, Mirian SB; Garzon, Eliana [UNIFESP]; Buchpiguel, Carlos A.; Tazima, Sergio; Yacubian, Elza Márcia Targas [UNIFESP]; Sakamoto, Américo C. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    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.