Time‐dependent effects of isoflurane and dexmedetomidine on functional connectivity,spectral characteristics,and spatial distribution of spontaneous BOLD fluctuations

Anesthesia is often necessary to perform fMRI experiments in the rodent model; however, commonly used anesthetic protocols may manifest changing brain conditions over the duration of the study. This possibility was explored in the current work. Eleven rats were anesthetized with 2% isoflurane anesthesia; four rats were anesthetized for a short period (30 min, simulating induction and fMRI setup) and seven rats were anesthetized for a long period (3 h, simulating surgical preparation). Following the initial anesthetic period, isoflurane was discontinued, and a dexmedetomidine bolus (0.025 mg/kg) and continuous subcutaneous infusion (0.05 mg/kg/h) were administered. Blood‐oxygen‐level dependent resting state imaging was performed every 30 min from 0.75 h post dexmedetomidine bolus until 5.75 h post‐bolus. Evaluation of power spectra obtained from time courses in the primary somatosensory cortex revealed, in general, a monotonic increase in low‐frequency power (0.05–0.3 Hz) in both groups over the duration of resting state imaging. Greater low‐band spectral power (0.05–0.15 Hz) is present in the short isoflurane group for the first 2.75 h, but the spectra become highly uniform at 3.25 h. The emergence of a ~0.18 Hz peak, beginning at the 3.75 h time point, exists in both groups and evolves similarly, increasing in strength as the duration of dexmedetomidine sedation (and time since isoflurane cessation) extends. In the long isoflurane group only, bilateral functional connectivity strengthens with anesthetic duration, and correlation is linearly linked to low‐band spectral power. Convergence of connectivity and spectral metrics between the short and long isoflurane groups occurs at ~3.25 h, suggesting the effects of isoflurane have subsided. Researchers using dexmedetomidine following isoflurane for functional studies should be aware of the duration specific effects of the pre‐scan isoflurane durations as well as the continuing influences of long‐term imaging under dexmedetomidine. Copyright © 2014 John Wiley & Sons, Ltd.     

Dissemination of Misinformative and Biased Information about Prostate Cancer on YouTube

YouTube is a social media platform with more than 1 billion users and >600 000 videos about prostate cancer. Two small studies examined the quality of prostate cancer videos on YouTube, but did not use validated instruments, examine user interactions, or characterize the spread of misinformation. We performed the largest, most comprehensive examination of prostate cancer information on YouTube to date, including the first 150 videos on screening and treatment. We used the validated DISCERN quality criteria for consumer health information and the Patient Education Materials Assessment Tool, and compared results for user engagement. The videos in our sample had up to 1.3 million views (average 45 223) and the overall quality of information was moderate. More videos described benefits (75%) than harms (53%), and only 50% promoted shared decision-making as recommended in current guidelines. Only 54% of the videos defined medical terms and few provided summaries or references. There was a significant negative correlation between scientific quality and viewer engagement (views/month p = 0.004; thumbs up/views p = 0.015). The comments section underneath some videos contained advertising and peer-to-peer medical advice. A total of 115 videos (77%) contained potentially misinformative and/or biased content within the video or comments section, with a total reach of >6 million viewers.

Modified Cognitive Behavioral Therapy for Insomnia in Depressed Adolescents: A Pilot Study

Objective/Background: The purpose of the study was to pilot a five-week insomnia treatment in adolescents with major depressive disorder (MDD) and insomnia. This was an open-label trial of a modified-group cognitive behavioral therapy for insomnia (CBTI). Participants: Adolescents with MDD (n = 16; mean age = 17.3 +/– 1.7), characterized by the Children’s Depression Rating Scale–Revised T-score ≥ 55 and insomnia, characterized by > 30 min to fall or return to sleep and an Insomnia Severity Index (ISI) score of ≥ 7 participated. Methods: Sleep diaries, actigraphy, weekly ISI, Quick Inventory of Depressive Symptomatology (QIDS), and Multidimensional Fatigue Inventory (MFI) were completed. Results: Paired t-tests comparing pre- and posttreatment revealed a decrease in sleep onset latency from 41 min +/– 14 min to 18 min +/– 8.9 min (t = 5.9, p = .004). Linear mixed modeling across sessions revealed that ISI (B = 11.0, SE = 0.94, p < .001), QIDS (B = 11.3, SE = 0.96, p < .001), and MFI (B = 30.0, SE = 4.4, p < .001) improved across treatment. Daily sleep diaries showed decreased wake during the night (B = 22.8, SE = 7.19, p = .008), increased sleep time (B = 382.4, SE = 71.89, p < .001), and increased quality of sleep (B = 3.7, SE = 0.37, p < .001). When asked whether group members would recommend this group, 27% responded “yes” and 73% responded “definitely yes.” Conclusions: Additional controlled studies utilizing sleep-focused therapy in depressed adolescents with insomnia are warranted.     

Parkinson’s disease and the Stroop color word test: processing speed and interference algorithms

Objective: Processing speed alters the traditional Stroop calculations of interference. Consequently, alternative algorithms for calculating Stroop interference have been introduced to control for processing speed, and have done so in a multiple sclerosis sample. This study examined how these processing speed correction algorithms change interference scores for individuals with idiopathic Parkinson’s disease (PD, n = 58) and non-PD peers (n = 68). Method: Linear regressions controlling for demographics predicted group (PD vs. non-PD) differences for Jensen’s, Golden’s, relative, ratio, and residualized interference scores. To examine convergent and divergent validity, interference scores were correlated with standardized measures of processing speed and executive function. Results: PD–non-PD differences were found for Jensen’s interference score, but not Golden’s score, or the relative, ratio, and residualized interference scores. Jensen’s score correlated significantly with standardized processing speed but not executive function measures. Relative, ratio, and residualized scores correlated with executive function but not processing speed measures. Golden’s score did not correlate with any other standardized measures. Conclusions: The relative, ratio, and residualized scores were comparable for measuring Stroop interference in processing speed-impaired populations. Overall, the ratio interference score may be the most useful calculation method to control for processing speed in this population.