Metamemória em adultos e em pacientes pós-acidente vascular cerebral

Este trabalho investigou processos metamnemônicos de monitoramento e controle, bem como conhecimento e desempenho de memória em diversas condições. O Capítulo I apresenta um paradigma experimental de aprendizado associativo de pares de palavras para avaliação da metamemória. No Capítulo II observou-se que julgamentos de aprendizagem (JOL) tardios foram mais precisos do que imediatos, porém apenas para adultos jovens, em comparação a adultos de idade intermediária. Adultos jovens contaram mais com seus JOLs e seu desempenho de memória prévios para alocação de tempo de estudo (STA), porém apenas na condição JOLs tardios. No Capítulo III, os grupos de pacientes pós-acidente vascular cerebral e controles não se diferenciaram significativamente quanto ao funcionamento metamnemônico. Contudo, uma análise de séries de casos revelou heterogeneidade dos casos e associações e dissociações funcionais entre memória e metamemória, além de uma dissociação dupla entre monitoramento e controle de memória, indicando que lesões à esquerda comprometem o monitoramento, enquanto lesões à direita o controle.This work investigated metamemory processes of memory monitoring, control, as well as memory knowledge and performance in several conditions. Chapter I presents a paired-words associative learning experimental paradigm to assess metamemory. In Chapter II we observed that delayed judgements of learning (JOLs) were more accurate than immediate JOLs, however only for young adults compared to intermediate age adults. Young adults relied more on theirs previous JOLs and memory performance for the allocation of study-time (STA), though only in the delayed JOLs condition. In Chapter III a group analysis showed no significant differences for metamnemônic measures between stroke patients and controls. Nevertheless, a case series analysis revealed inter-case heterogeneity and functional associations and dissociations between memory and metamemory, in addition to a double dissociation between memory monitoring and control, which suggested that left hemisphere lesions impair the monitoring while right hemisphere lesions impair the control

The mapping of cortical activation by near infra-red spectroscopy might be a biomarker related to the severity of fibromyalgia

The delta value of oxyhemoglobin (Δ-HbO) determined by functional near-infrared spectroscopy at prefrontal cortex (PFC) and motor cortex (MC) based on primary (25 °C) and secondary (5 °C) thermal stimuli presented a larger peak latency at left MC in fibromyalgia than in controls. The difference between HbO concentration 15 s after the thermal stimuli ending and HbO concentration before the thermal stimuli onset (Δ-HbO*) at left PFC increased 47.82% in fibromyalgia and 76.66% in controls. This value had satisfactory discriminatory properties to differentiate cortical activation in fibromyalgia versus controls. A receiver operator characteristics (ROC) analysis showed the Δ-HbO* cutoffs of − 0.175 at left PFC and − 0.205 at right PFC offer sensitivity and specificity of at least 80% in screening fibromyalgia from controls. In fibromyalgia, a ROC analysis showed that these cutoffs could discriminate those with higher disability due to pain and more severe central sensitization symptoms (CSS). The ROC with the best discriminatory profile was the CSS score with the Δ-HbO* at left PFC (area under the curve = 0.82, 95% confidence interval = 0.61–100). These results indicate that cortical activation based on Δ-HbO* at left PFC might be a sensitive marker to identify fibromyalgia subjects with more severe clinical symptoms

Spectral power density analysis of the resting-state as a marker of the central effects of opioid use in fibromyalgia

Spectral power density (SPD) indexed by electroencephalogram (EEG) recordings has recently gained attention in elucidating neural mechanisms of chronic pain syndromes and medication use. We compared SPD variations between 15 fibromyalgia (FM) women in use of opioid in the last three months (73.33% used tramadol) with 32 non-users. EEG data were obtained with Eyes Open (EO) and Eyes Closed (EC) resting state. SPD peak amplitudes between EO-EC were smaller in opioid users in central theta, central beta, and parietal beta, and at parietal delta. However, these variations were positive for opioid users. Multivariate analyses of variance (ANOVAs) revealed that EO-EC variations in parietal delta were negatively correlated with the disability due to pain, and central and parietal beta activity variations were positively correlated with worse sleep quality. These clinical variables explained from 12.5 to 17.2% of SPD variance. In addition, central beta showed 67% sensitivity / 72% specificity and parietal beta showed 73% sensitivity/62% specificity in discriminating opioid users from non-users. These findings suggest oscillations in EEG might be a sensitive surrogate marker to screen FM opioid users and a promising tool to understand the effects of opioid use and how these effects relate to functional and sleep-related symptoms