Navegando por Palavras-chave "P300"

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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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    P300 em sujeitos com perda auditiva
    (Pró-Fono Produtos Especializados para Fonoaudiologia Ltda., 2007-04-01) Reis, Ana Cláudia Mirândola Barbosa; Iorio, Maria Cecilia Martinelli [UNIFESP]; Universidade de Franca Curso de Fonoaudiologia; Universidade Federal de São Paulo (UNIFESP)
    BACKGROUND: behavioral and electrophysiological evaluations contribute to the understanding of the hearing system and to the intervention process. AIM: to investigate the occurrence of P300 in subjects with congenital severe to profound hearing loss, according to the variables of gender, age and hearing loss level. METHOD: the design of this research is a descriptive transversal study. Twenty-nine subjects, 15 male and 14 female, ranging in age from 11 to 42 years, were evaluated. Inclusion criteria were: to have at least 11 years of age and no more than 45 years; to have the diagnosis of congenital severe to profound sensorineural hearing loss; to have no other disorder; and absence of central hearing loss or any other auditory conductive disorder. The first stage consisted of an auditory behavioral and physiological evaluation, including: pure tone audiometry (air and bone conduction measures), speech audiometry, SDT (Speech Detection Threshold) and functional gain measures for the subjects using hearing aids, and immittance measures - tympanometry and acoustic reflexes thresholds; transient evoked otoacoustic emissions (TEOAE); distortion product otoacoustic emissions (DPOAE). The electrophysiological evaluation was the fourth stage of the study and included: auditory brainstem response (ABR) and late latency response (P300). RESULTS: P300 was obtained for 17 out of the 29 subjects. Mean latency and amplitude were 326.97 ms and 3.76 V, respectively. A statistical significant difference was observed for latency when considering the variable age (electrode CzA2 p < 0.003 and CzA1 p < 0.02) and for amplitude when considering the variable hearing loss level (p < 0.0015). CONCLUSION: P300 can be recorded in subjects with hearing loss.
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    Potenciais auditivos de longa latência para avaliação do tratamento medicamentoso do zumbido
    (Universidade Federal de São Paulo (UNIFESP), 2018-10-30) Azevedo, Andreia Aparecida de [UNIFESP]; Penido, Norma de Oliveira [UNIFESP]; Munhoz, Mário Sérgio Lei [UNIFESP]; http://lattes.cnpq.br/2089248518093645; http://lattes.cnpq.br/7060786297081212; Universidade Federal de São Paulo (UNIFESP)
    Objective: To verify if the Event related Potentials (ERP´s)) present changes in their latency and or amplitude that may help to measure, with the THI (Tinnitus Handicap Inventory) and the VAS (VisualAnalogue Scale) questionnaire, any characteristics objectives of a drug treatment for tinnitus. Method: Eightyeight patients complaining of tinnitus were randomized into two groups of drugs: Central drugs with different mechanisms of action in the neurotransmitters involved in the auditory pathways and a drug with Peripheric. Its effects on the negative reaction of the tinnitus symptom were evaluated by the eventrelated auditory potentials at three moments: premedication (T1), at the end of the drug treatment (T2) and after a washout period (T3) and compared with the results of the EVA and the THI questionnaire Results: Measurement of ERP´s waves in central and peripheral drugs did not show significant differences during the 03 evaluated moments (p = 0.53), despite the significant improvement in the evaluation of the THI questionnaire and in the EVA for tinnitus volume and annoyance (p< 0.0001). Conclusion: The use of ERP´s in patients with chronic tinnitus subjected to drug treatment of both central and peripheral action did not present changes in latency and amplitude of waves N1, P2, N2 and P3 throughout the treatment drugs when compared to Tinnitus handicap Inventory and the analog visual scale. The amplitude and latency parameters of Event Related Potentials can´t be considered as a criterion for evaluate the evolution of drug treatment in tinnitus complaint.