Teresa Paiva

Schizophrenia patients with predominantly positive symptoms have more disturbed sleep-wake cycles measured by actigraphy

Sleep disturbances are widespread in schizophrenia, and one important concern is to determine the impact of this disruption on self-reported sleep quality and quality of life (QoL). Our aim was to evaluate the sleep-wake cycle in a sample of patients with schizophrenia (SZ), and whether sleep patterns differ between patients with predominantly negative versus predominantly positive symptoms, as well as its impact on sleep quality and QoL. Twenty-three SZ outpatients were studied with 24 h continuous wrist-actigraphy during 7 days. The quality of sleep was assessed with the Pittsburgh Sleep Quality Index (PSQI), and the self-reported QoL was evaluated with the World Health Organization Quality of Life - Abbreviated version (WHOQOL-Bref). About half of the studied population presented an irregular sleep-wake cycle. We found a trend for more disrupted sleep-wake patterns in patients with predominantly positive symptoms, who also had a trend self-reported worse quality of sleep and worse QoL in all domains. Overall, patients with worse self-reported QoL demonstrated worse sleep quality. Our findings suggest that SZ patients are frequently affected with sleep and circadian rhythm disruptions; these may have a negative impact on rehabilitation strategies. Moreover, poor sleep may play a role in sustaining poor quality of life in SZ patients.

Sleep-wake patterns in schizophrenia patients compared to healthy controls.

Abstract Objectives. The aim of this study was to examine the differences between a sample of patients with schizophrenia and a sample of healthy controls in terms of sleep patterns and self-reported sleep quality and quality of life (QoL). Methods. Thirty-four schizophrenia outpatients (SP), 12 women and 22 men and 34 healthy subjects (HS), 15 women and 19 men, participated in this study. Wrist-actigraphy recordings and a sleep diary were used for sleep–wake cycle assessment. The quality of sleep was measured using the Pittsburgh Sleep Quality Index (PSQI), the QoL was evaluated using the World Health Organization Quality of Life – Abbreviated version (WHOQOL-Bref). The Positive and Negative Syndrome Scale (PANSS) was used for psychopathology assessment. Results. Patients sleep more at night, but have poorer sleep efficiency, than HS. Sleep latency and nighttime awakenings were significantly higher in SP. Self-reported QoL scores were significantly higher, in all four domains, in HS. Scores on PSQI were significantly higher in SP, indicating a worse quality of sleep. Two disturbed patterns of sleep–wake phase were found in SP: advance sleep-phase syndrome (ASPS) (N = 3) and irregular sleep–wake rhythm (N = 3). Conclusion. Schizophrenia patients have more disturbed sleep–wake patterns and poor sleep quality and quality of life compared with healthy controls.

Dream features in the early stages of Parkinson’s Disease

Few studies have investigated the relation between dream features and cognition in Parkinson’s disease (PD), although vivid dreams, hallucinations and cognitive decline have been proposed as successive steps of a pathological continuum. Our objectives were therefore to characterize the dreams of early stage PD and to study the relation between dream characteristics, cognitive function, motor status, depression, dopaminergic treatment, and the presence of REM sleep behaviour disorder (RBD) and hallucinations. Dreams of 19 male PD patients and 21 matched control subjects were classified according to Hall and van de Castle system. h statistics was used to compare the dream content between patients and controls. We tested the relation between patients’ dreams characteristics and cognitive function (Frontal assessment battery (FAB) and Mini-Mental State Examination tests) depression (Beck depression inventory), motor function (UPDRS), dopaminergic treatment, the presence of RBD (according to clinical criteria) and hallucinations, using general linear model statistics. Patients and controls differed only on FAB scores. Relevant differences in the Hall and van de Castle scale were found between patient’s dreams and those of the control group, regarding animals, aggression/friendliness, physical aggression, befriender (higher in the patient group) and aggressor and bodily misfortunes (lower in the patient group) features. Cognitive and particularly frontal dysfunction had a significant influence on the frequency of physical aggression and animal related features, while dopaminergic doses, depressive symptoms, hallucinations and RBD did not. We found a pattern of dream alteration characterized by heightened aggressiveness and the presence of animals. These were related to more severe frontal dysfunction, which could be the origin of such changes.

Sleep-promoting action of the endogenous melatonin in schizophrenia compared to healthy controls

Abstract Objective. The aim of this study was to compare the endogenous melatonin sleep-promoting effect in schizophrenic patients to a sample of healthy controls. Methods. Thirty-four schizophrenia outpatients (SP) and 34 healthy subjects (HS) participated in this study. Wrist-actigraphy recordings and a sleep diary were used for sleep–wake cycle assessment. The quality and patterns of sleep were measured with the Pittsburgh Sleep Quality Index (PSQI) and the Positive and Negative Syndrome Scale (PANSS) was used for psychopathology assessment. To quantify and assess nocturnal melatonin profiles, saliva samples were collected for one night under dim light conditions (<50 lux) hourly from 20:00 h to 23:00 h. Results. Scores on PSQI were significantly higher in SP as compared to HS, indicating a worse quality of sleep. Patients sleep more at night, but have poorer sleep efficiency, than HS. Sleep latency and nighttime awakenings were significant higher in SP. Melatonin levels were negatively correlated with sleep latency, total sleep time and positively correlated with sleep efficiency in HS but not in SP. Conclusion. The results of the present study indicate that endogenous melatonin sleep-promoting action seems to be compromised in schizophrenia.

Epileptic manifestations in stroke patients treated with intravenous alteplase

Intravenous alteplase (rtPA) may be associated with seizures and epileptic activity in the electroencephalogram (EEG). The aim of this work was to compare the frequency of seizures and EEG abnormalities between stroke patients treated and not treated with rtPA.

An actigraphy heterogeneous mixture model for sleep assessment

Wrist actigraphy is a well established procedure to monitor human activity. Among other areas, it has a special relevance in sleep studies where its lightweight and non-intrusive nature make it a valuable tool to access the circadian cycle. While there are several methods to extract information from the data, the differentiation between sleep and wakefulness states is still an open discussion. In this paper, the characteristics of the movements in the different states are assumed to be intrinsically different. These differences are not simply related with magnitude and movement counting, but due to real differences on the statistical distributions describing the actigraphy data. Thus it is possible to refine the discrimination level when detecting these states. The proposed methodology to characterize the actigraphy data is based on a mixture of three canonical distributions; i)Exponential, ii)Rayleigh and iii)Gaussian. It is shown that the weights and parameters estimated in each state are organized into almost separable clusters on the feature space. This suggests the ability of the method to discriminate these states based only on the movements recorded on actigraphy data.

Topographic EEG brain mapping before, during and after obstructive sleep apnea episodes

Obstructive Sleep Apnea Syndrome (OSAS) is a very common sleep disorder that is associated with several neurocognitive impairments. The present study aims to assess the electroencephalographic (EEG) power before, during and after obstructive apnea episodes, in four frequency bands: delta (δ), theta (θ), alpha α and beta (β). For that propose, continuous wavelet transform was applied to the EEG signals obtained with polysomnography, and topographic EEG brain mapping to visualize the power differences across the whole brain. The results demonstrate that there is a significant decrease in the EEG δ power during OSAS that does not totally recover immediately after the episode. Since δ waves are linked to learning and plasticity processes, it is hypothesized that decreased δ power during the episode may contribute to the cognitive deterioration in patients with OSAS.

Sleep/Wakefulness State from Actigraphy

In this paper a definition of the activity (ACT) variable is proposed and a method to estimate it from the noisy actigraph output sensor data is described. A statistical model for the actigraph data generation process is suggested based on its working physical principles and on physiological considerations about human activity. The purposeless nature of the sleeping movements is used to discriminate the Sleep and Wakefulness (SW) states. n nThe estimated ACT signal from the actigraph output signal is correlated with the data from a Sleep Diary to validate the SW oscillations, computed from the ACT. A Sleep electronic Diary (SeD) was implemented in the scope of this work to make it possible an accurate register of the patient activities relevant for the diagnosis of sleep disorders. n nExamples using real data, illustrating the application of the method, have shown high correlation between the output of the proposed algorithm that characterizes the activity and the data registered in the SeD.

Dreaming and cognition in patients with frontotemporal dysfunction

Individuals with Parkinsons disease (PD) and temporal lobe epilepsy (TLE) have hallucinations and mild cognitive dysfunction. The objective of this work was to study dreams in PD and TLE patients using a common functional model of dream production involving the limbic and paralimbic structures. Dreams were characterised in early-stage PD (19 males) and TLE patients (52) with dream diaries classified by the Hall van de Castle system and were compared with matched controls. In PD, there were significant differences between patients dreams and those of controls: animals, physical aggression, and a befriender were more common in patients, and aggressor and bodily misfortunes were less common. The dreams of patients with frontal dysfunction showed more aggressive features. TLE patients had lower recall than PD patients and a higher proportion of dreams involving family and familiar settings, lower proportions involving success, and a higher incidence of frontal dysfunction. The dreams of PD and TLE patients share important features.

Epilepsia partialis continua after an anterior circulation ischaemic stroke

Although cerebrovascular disorders are the main cause of epilepsia partialis continua (EPC) in adulthood, the frequency of EPC after stroke is unknown. The aim was to prospectively ascertain its frequency 1 year after an ischaemic stroke.