Influence of bromazepam on cortical interhemispheric coherence

Abstract

-Benzodiazepines are among the most commonly prescribed medications due to their therapeutic efficacy in reducing anxiety and inducing sleep. Consequently, they have been widely employed in the pharmacological treatment of several disorders. Nevertheless, few studies have analyzed the effects of bromazepam in electroencephalographic activity (EEG). The present study aimed at investigating the modulatory effects of this drug on brain dynamics. Specifically, the effects of bromazepam (3mg) on EEG coherence were tested in a double-blind experiment. The sample, consisting of 10 healthy subjects (5 male and 5 female), was submitted to ten minutes of EEG recording. The electrophysiological measure (coherence) was analyzed across three experimental conditions: bromazepam, placebo 1, and placebo 2. Results indicate that bromazepam significantly increases cortical interhemispheric coherence.KEY WORDS: bromazepam, qEEG. Influência do bromazepam na coerência cortical inter-hemisféricaRESUMO -Benzodiazepínicos estão entre as medicações mais comumente prescritas devido à sua eficácia terapêutica para reduzir ansiedade e induzir sono. Conseqüentemente, eles têm sido amplamente empregados no tratamento de diversas desordens. No entanto, poucos estudos têm analisado os efeitos do bromazepam na atividade eletrencefalográfica (EEG). Assim, o presente estudo teve por objetivo investigar os efeitos modulatórios desta droga na dinâmica cerebral. Especificamente, os efeitos de 3 mg de bromazepam na coerência eletrocortical foram analisados em um experimento duplo-cego. A amostra consistiu de 10 sujeitos sadios (5 homens e 5 mulheres), submetidos a dez minutos de captação do sinal de EEG. A medida eletrofisiológica (coerência) foi analisada em três condições experimentais: bromazepam, placebo 1 e placebo 2. Os resultados sugerem que o bromazepam aumenta significativamente a coerên-cia cortical inter-hemisférica. PALAVRAS-CHAVE: bromazepam, EEGq.

Cross-conditional entropy and coherence analysis of pharmaco-EEG changes induced by alprazolam

“…Thus, the linear connectivity correlated with plasma concentrations was focused on the anterior half of the brain and the decrease of linear couplings was consistent with the hypothesis of GABAergic inhibitory action and the results obtained in (Alonso et al 2010). However, these results do not match the increase in interhemispheric coherence shown in the alpha and beta bands found in Sampaio et al (2007).…”

“…Benzodiazepine effects on the EEG have been studied by means of several techniques such as classical spectral analysis (Tan et al 1998), coherence (Romano et al 2002;Sampaio et al 2007), structural synchrony (Fingelkurts et al 2004) and cross-mutual information (Alonso et al 2010). In this last study, interesting drug-related changes were obtained and they were not bounded to any specific region of the scalp.…”

“…Traditionally, the EEG is recorded using the 10/20 electrode placement convention, but some connectivity studies have only taken into account interhemispheric pairs of channels (see, for instance, Sampaio et al 2007). The present study analyzed all possible pairs of channels, and an evaluation of the electrophysiological effects of alprazolam on cerebral connectivity was presented.…”

“…Coherence is one of the most common indicators of EEG coupling reported in the literature (Tauscher et al 1998;Achermann and Borbély 1998;Weiss and Rappelsberger 2000;Abraham and Duffy 2001;Zavaglia et al 2008;Wendling et al 2009) and represents a measurement of linear covariation in the frequency domain. Some authors have proposed alternative measures based on more sophisticated techniques (Lachaux et al 1999;Nolte et al 2004) to overcome the limitations of coherence, but it is still widely used, as shown by recent studies concerning EEG effects after benzodiazepine administration (Romano et al 2002;Sampaio et al 2007).…”

Neuropsychiatric pharmaceuticals and illicit drugs in wastewater treatment plants: a review

“…[46] (Table 6). [47][48][49][50][51][52][53][54][55][56] The presence of flunitrazepam in environmental and biological samples is commonly confirmed by measuring 7-aminoflunitrazepam, a pharmacologically active in vivo metabolite and in vitro degradation product (Table 6). [52,53] Nordiazepam and oxazepam are used as drugs, but they are also formed as metabolites of diazepam.…”