Prevalence and Determinants of Insomnia After a Myocardial Infarction.

OBJECTIVES: This study analyzed cross-sectional data to examine the prevalence of insomnia and to identify factors associated with insomnia after a myocardial infarction (MI). METHODS: The participants were 209 individuals with a recent MI. At approximately 5 weeks post-MI, participants completed standardized self-report measures assessing insomnia (Insomnia Severity Index) and various sociodemographic, clinical, behavioral, and psychosocial variables, including stressful life events, depressive symptoms, and dysfunctional beliefs about sleep. RESULTS: Overall, 36% of the sample reported clinical symptoms of insomnia (Insomnia Severity Index score ≥ 10) and an additional 9% reported milder/subthreshold symptoms (Insomnia Severity Index score ≥ 8). Among patients with insomnia, a much higher proportion (62.7%) were experiencing symptoms consistent with depressed mood compared to good sleepers (13.4%). Multivariate linear regression showed that younger age, use of prescribed medication for sleep, more depressive symptoms, and greater dysfunctional beliefs about sleep were associated with insomnia severity. CONCLUSIONS: Many patients after MI experience insomnia, which may increase the illness burden and hamper recovery during the cardiac rehabilitation phase. Our findings provide a theoretical basis for evaluating cognitive-behavioral approaches for the management of insomnia in patients after MI.

Summary of the 1st Schizophrenia International Research Society Conference oral sessions, Venice, Italy, June 21-25, 2008: the rapporteur reports.

The Schizophrenia International Research Society held its first scientific conference in Venice, Italy, June 21 to 25th, 2008. A wide range of controversial topics were presented in overlapping and plenary oral sessions. These included new genetic studies, controversies about early detection of schizophrenia and the prodrome, treatment issues, clinical characteristics, cognition, neuropathology and neurophysiology, other etiological considerations, substance abuse co-morbidity, and animal models for investigating disease etiology and for use as targets in drug studies. Young investigators in the field were awarded travel grants to participate in the congress and one of their roles was to summarize the oral sessions and subsequent discussions. The reports that follow are the culmination of this work produced by 30 young investigators who attended the congress. It is hoped that these summaries will be useful synopses of what actually occurred at the congress for those who did not attend each session or were unable to be present. The abstracts of all presentations, as submitted by the authors a few months prior, were previously published as supplement 2 to volume 102/1-3, June 2008.

Functional MRI involving painful stimulation of the ankle and the effect of physiotherapy joint mobilization.

We examined whether cerebral activation due to secondary hyperalgesia resulting from intrajoint capsaicin injection could be detected using functional magnetic resonance imaging (fMRI) in alpha-chloralose anesthetized rats. We also examined whether we could detect analgesic changes in the central nervous system response to pain as a result of physiotherapy joint manipulation. Robust activation of areas of the brain known to be associated with the processing of pain, namely the anterior cingulate (bilateral), frontal cortex (bilateral) and sensory motor cortex (contralateral), was found in all animals following injection of 25 microl of capsaicin (128 microg/ml in 7.5% DMSO) into the plantar surface of the rat hindpaw (n = 7) and 75 microL into the ankle joint (n = 13). Significantly greater activation was observed when capsaicin was injected into the plantar surface of the hindpaw compared to the ankle joint. Mechanical allodynia and secondary hyperalgesia following capsaicin injection into the ankle joint also resulted in activation of the same brain regions. Trends toward decreased areas of activation in brain regions associated with pain in animals following physiotherapy joint mobilization were observed.

Effects of methylphenidate on basic and higher-order oculomotor functions.

Eye movements are sensitive indicators of pharmacological effects on sensorimotor and cognitive processing. Methylphenidate (MPH) is one of the most prescribed medications in psychiatry. It is increasingly used as a cognitive enhancer by healthy individuals. However, little is known of its effect on healthy cognition. Here we used oculomotor tests to evaluate the effects of MPH on basic oculomotor and executive functions. Twenty-nine males were given 20mg of MPH orally in a double-blind placebo-controlled crossover design. Participants performed visually-guided saccades, sinusoidal smooth pursuit, predictive saccades and antisaccades one hour post-capsule administration. Heart rate and blood pressure were assessed prior to capsule administration, and again before and after task performance. Visually-guided saccade latency decreased with MPH (p<0.004). Smooth pursuit gain increased on MPH (p<0.001) and number of saccades during pursuit decreased (p<0.001). Proportion of predictive saccades increased on MPH (p<0.004), specifically in conditions with predictable timing. Peak velocity of predictive saccades increased with MPH (p<0.01). Antisaccade errors and latency were unaffected. Physiological variables were also unaffected. The effects on visually-guided saccade latency and peak velocity are consistent with MPH effects on dopamine in basal ganglia. The improvements in predictive saccade conditions and smooth pursuit suggest effects on timing functions.

Effect of D-amphetamine on inhibition and motor planning as a function of baseline performance.

RATIONALE: Baseline performance has been reported to predict dopamine (DA) effects on working memory, following an inverted-U pattern. This pattern may hold true for other executive functions that are DA-sensitive. OBJECTIVES: The objective of this study is to investigate the effect of D: -amphetamine, an indirect DA agonist, on two other putatively DA-sensitive executive functions, inhibition and motor planning, as a function of baseline performance. METHODS: Participants with no prior stimulant exposure participated in a double-blind crossover study of a single dose of 0.3 mg/kg, p.o. of D: -amphetamine and placebo. Participants were divided into high and low groups, based on their performance on the antisaccade and predictive saccade tasks on the baseline day. Executive functions, mood states, heart rate and blood pressure were assessed before (T0) and after drug administration, at 1.5 (T1), 2.5 (T2) and 3.5 h (T3) post-drug. RESULTS: Antisaccade errors decreased with D: -amphetamine irrespective of baseline performance (p = 0.025). For antisaccade latency, participants who generated short-latency antisaccades at baseline had longer latencies on D: -amphetamine than placebo, while those with long-latency antisaccades at baseline had shorter latencies on D: -amphetamine than placebo (drug x group, p = 0.04). D: -amphetamine did not affect motor planning. Ratings of mood improved on D: -amphetamine (p < 0.001). Magnitude of D: -amphetamine-induced changes in elation was related to baseline reaction time variability. CONCLUSIONS: D: -amphetamine reduced antisaccade error rates in healthy controls, replicating and extending findings with DA agonists in clinical populations. D: -amphetamine had baseline-dependent effects on antisaccade latency, consistent with an inverted-U relationship between performance and DA activity.

Functional MRI characteristics of a focal region of cortical malformation not associated with seizure onset.

Neuroimaging studies have demonstrated that heterotopic tissue of patients with "double cortex" is activated during motor and somatosensory tasks. Activation in patients with malformations of cortical development (MCD) has been variable, likely due to the heterogeneity of the disorder. We examined clinical, electroencephalography (EEG), neuropsychological, and functional MRI findings in a patient with intractable epilepsy secondary to MCD in the left temporal cortex. Invasive EEG monitoring revealed that the dysplastic tissue was not involved in ictal onset of seizures. Functional MRI tests of motion and object processing, memory encoding, and language demonstrated no activation within dysplastic tissue. Hemispheric asymmetries in activation for motion and object processing were evident, favoring the right hemisphere--a pattern not evident in controls. These weaker activations in the patient were present in tissue proximal to the seizure focus. Thus, nonepileptogenic dysplastic tissue may not support cognitive functions, with abnormal processing evident in epileptogenic tissue.

Time flies when you're having fun: temporal estimation and the experience of boredom.

Boredom is a common experience in healthy individuals and may be elevated in various neurological or psychiatric conditions. As yet, very little is known about the cognitive or neural bases of the subjective experience of boredom. We examined temporal perception and the temporal allocation of attention in healthy individuals reporting high- or low-levels of boredom. We found no difference in high- or low-boredom-prone individuals in the temporal allocation of attention, while individuals who experienced low-levels of boredom tended to underestimate time more so than high-boredom-prone individuals. Furthermore, high-boredom-prone individuals demonstrated higher error values when estimating time indicating that the subjective perception of the passage of time may be a critical component to the experience of boredom.

Evaluation of spatial working memory function in children and adults with fetal alcohol spectrum disorders: a functional magnetic resonance imaging study.

Magnetic resonance imaging (MRI) and functional MRI studies involving n-back spatial working memory (WM) tasks were conducted in adults and children with Fetal Alcohol Spectrum Disorders (FASD), and in age- and sex-matched controls. FMRI experiments demonstrated consistent activations in regions of the brain associated with working memory. Children with FASD displayed greater inferior-middle frontal lobe activity, while greater superior frontal and parietal lobe activity was observed in controls. Control children also showed an overall increase in frontal lobe activity with increasing task difficulty, while children with FASD showed decreased activity. FASD adults demonstrated less functional brain activity overall, but greater inferior-middle frontal lobe activity during the simpler tasks, relative to controls. Control adults demonstrated greater inferior frontal activity with increasing task difficulty, while this pattern was not consistently observed in FASD adults. All four groups showed increasing activity with increases in task difficulty in the parietal and frontal regions at more superior slice levels. The results suggest impairment in spatial working memory in those with FASD that does not improve with age, and that fMRI may be useful in evaluation of brain function in these individuals.