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1.
Nervenarzt ; 95(3): 283-290, 2024 Mar.
Article De | MEDLINE | ID: mdl-38416181

With increasing life expectancy, the prevalence of dementia is increasing worldwide. Dementia is among the greatest challenges for healthcare and social systems of the future. Approximately 40% of newly diagnosed cases of dementia are associated with risk factors that can potentially be influenced by preventive measures. Based on the evidence from longitudinal studies, systematic reviews and meta-analyses, the Lancet commission on dementia prevention, intervention and care has defined 12 risk factors that are associated with an increased risk for dementia: low level of education, hearing impairment, traumatic brain injury, arterial hypertension, diabetes mellitus, smoking, excessive alcohol consumption, depression, obesity, social isolation, and air pollution.


Dementia , Humans , Dementia/diagnosis , Dementia/prevention & control , Risk Factors , Longitudinal Studies , Educational Status
2.
Z Gerontol Geriatr ; 56(3): 227-234, 2023 May.
Article De | MEDLINE | ID: mdl-37097299

With increasing life expectancy, the prevalence of dementia is increasing worldwide. Dementia is among the greatest challenges for healthcare and social systems of the future. Approximately 40% of newly diagnosed cases of dementia are associated with risk factors that can potentially be influenced by preventive measures. Based on the evidence from longitudinal studies, systematic reviews and meta-analyses, the Lancet commission on dementia prevention, intervention and care has defined 12 risk factors that are associated with an increased risk for dementia: low level of education, hearing impairment, traumatic brain injury, arterial hypertension, diabetes mellitus, smoking, excessive alcohol consumption, depression, obesity, social isolation, and air pollution.


Dementia , Diabetes Mellitus , Humans , Dementia/epidemiology , Dementia/prevention & control , Risk Factors , Smoking/epidemiology , Longitudinal Studies
3.
Sleep ; 45(7)2022 07 11.
Article En | MEDLINE | ID: mdl-35290446

STUDY OBJECTIVES: While light therapy has proven effective in re-entraining circadian rhythms, the potential of such an intervention has not been evaluated systematically in post-comatose patients with disorders of consciousness (DOC), who often have strongly altered circadian rhythms. METHODS: We recorded skin temperature over 7-8 days in patients with DOC in each of two conditions: habitual light (HL), and dynamic daylight (DDL) condition. While patients were in a room with usual clinic lighting in the HL condition, they were in an otherwise comparable room with biodynamic lighting (i.e. higher illuminance and dynamic changes in spectral characteristics during the day) in the DDL condition. To detect rhythmicity in the patients' temperature data, we computed Lomb-Scargle periodograms and analyzed normalized power, and peak period. Furthermore, we computed interdaily stability and intradaily variability, which provide information about rhythm entrainment and fragmentation. RESULTS: We analyzed data from 17 patients with DOC (i.e. unresponsive wakefulness syndrome [n = 15] and minimally conscious state [n = 2]). The period length of the patients' temperature rhythms was closer to 24 h in the DDL as compared to the HL condition (median median deviation from 24 h: DDL = 0.52 h, HL = 3.62 h). Specifically, in 11/17 (65%) patients the period length was closer to 24 h in the DDL condition. Furthermore, the patients' rhythm was more pronounced, more stable, and less variable in the DDL condition. CONCLUSIONS: Our results indicate that DDL stimulation entrains and stabilizes circadian rhythms. This highlights the importance of adequate room lighting as an adjunct therapeutic approach for improving circadian rhythms in severely brain-injured patients. TRIAL REGISTRATION INFORMATION: German Clinical Trials Register (DRKS00016041); registration: 18.01.2019; recording start: 04.06.2019 https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00016041.


Brain Injuries , Circadian Rhythm , Circadian Rhythm/physiology , Humans , Lighting , Skin Temperature , Wakefulness
4.
Brain Sci ; 12(3)2022 Mar 11.
Article En | MEDLINE | ID: mdl-35326331

The current study investigated heart rate (HR) and heart rate variability (HRV) across day and night in patients with disorders of consciousness (DOC). We recorded 24-h electrocardiography in 26 patients with DOC (i.e., unresponsive wakefulness syndrome (UWS; n = 16) and (exit) minimally conscious state ((E)MCS; n = 10)). To examine diurnal variations, HR and HRV indices in the time, frequency, and entropy domains were computed for periods of clear day- (forenoon: 8 a.m.-2 p.m.; afternoon: 2 p.m.-8 p.m.) and nighttime (11 p.m.-5 a.m.). The results indicate that patients' interbeat intervals (IBIs) were larger during the night than during the day, indicating HR slowing. The patients in UWS showed larger IBIs compared to the patients in (E)MCS, and the patients with non-traumatic brain injury showed lower HRV entropy than the patients with traumatic brain injury. Additionally, higher HRV entropy was associated with higher EEG entropy during the night. Thus, cardiac activity varies with a diurnal pattern in patients with DOC and can differentiate between patients' diagnoses and etiologies. Moreover, the interaction of heart and brain appears to follow a diurnal rhythm. Thus, HR and HRV seem to mirror the integrity of brain functioning and, consequently, might serve as supplementary measures for improving the validity of assessments in patients with DOC.

5.
Procare ; 26(8): 44-47, 2021.
Article De | MEDLINE | ID: mdl-34728907

Researchers from various fields of medicine, health sciences, social sciences, cultural studies, history, literature, and education seek to develop new perspectives on medicine and the humanities, thus connecting these two fields with each other. In this interdisciplinary field of research, the so-called Medical Humanities, a wide spectrum of research approaches has emerged. Among other questions, the Medical Humanities are concerned with how literature and art provide insights into human conditions and how one can gain a better and more holistic understanding of a disease, such as dementia. Specific examples of application illustrate what the Medical Humanities can contribute to science and society.

6.
BMC Geriatr ; 20(1): 248, 2020 07 20.
Article En | MEDLINE | ID: mdl-32690030

BACKGROUND: Dementia is an increasing public health threat worldwide. The pathogenesis of dementia has not been fully elucidated yet. Inflammatory processes are hypothesized to play an important role as a driver for cognitive decline but the origin of inflammation is not clear. We hypothesize that disturbances in gut microbiome composition, gut barrier dysfunction, bacterial translocation and resulting inflammation are associated with cognitive dysfunction in dementia. METHODS: To test this hypothesis, a cohort of 23 patients with dementia and 18 age and sex matched controls without cognitive impairments were studied. Gut microbiome composition, gut barrier dysfunction, bacterial translocation and inflammation were assessed from stool and serum samples. Malnutrition was assessed by Mini Nutritional Assessment Short Form (MNA-SF), detailed information on drug use was collected. Microbiome composition was assessed by 16S rRNA sequencing, QIIME 2 and Calypso 7.14 tools. RESULTS: Dementia was associated with dysbiosis characterized by differences in beta diversity and changes in taxonomic composition. Gut permeability was increased as evidenced by increased serum diamine oxidase (DAO) levels and systemic inflammation was confirmed by increased soluble cluster of differentiation 14 levels (sCD14). BMI and statin use had the strongest impact on microbiome composition. CONCLUSION: Dementia is associated with changes in gut microbiome composition and increased biomarkers of gut permeability and inflammation. Lachnospiraceae NK4A136 group as potential butyrate producer was reduced in dementia. Malnutrition and drug intake were factors, that impact on microbiome composition. Increasing butyrate producing bacteria and targeting malnutrition may be promising therapeutic targets in dementia. TRIAL REGISTRATION: NCT03167983 .


Dementia , Gastrointestinal Microbiome , Bacteria , Dysbiosis , Feces , Humans , Inflammation , Pilot Projects , RNA, Ribosomal, 16S/genetics
7.
Nutrients ; 12(6)2020 May 28.
Article En | MEDLINE | ID: mdl-32481668

Residents in long-term care facilities (LTCFs) are frequently colonized by multidrug-resistant Gram-negative bacteria, putting them at risk for subsequent infections. We aimed to evaluate the effect of the multispecies probiotic Omnibiotic10AAD® on the intestinal and inguinal skin colonization of patients by multidrug-resistant Gram-negative bacteria in LTCFs. Patients colonized by multidrug-resistant Gram-negative bacteria received a 12 week oral course of Omnibiotic10AAD®. Inguinal swabs and stool samples were collected during and after treatment for microbiological and microbiome analysis. The median age of patients was 76 years. Twelve patients completed the pilot study. Intestinal colonization was reduced to 42% of patients 8 weeks after the end of treatment, but increased to 66% 24 weeks after the end of probiotic treatment. Colonization of inguinal skin was lowest during probiotic treatment and increased thereafter. Fecal microbiome analysis revealed statistically significant increases of the genus Enterococcus comparing start and end of probiotic treatment. In conclusion, a 12 week course of a multispecies probiotic led to a transient reduction of intestinal colonization 8 weeks after the end of treatment. The findings of our pilot study warrant further research in the area of probiotics and intestinal colonization by multidrug-resistant bacteria.


Gram-Negative Bacteria/drug effects , Intestines/microbiology , Long-Term Care , Probiotics/pharmacology , Skilled Nursing Facilities , Skin/microbiology , Adult , Aged , Aged, 80 and over , Drug Resistance, Multiple, Bacterial , Enterococcus/genetics , Enterococcus/isolation & purification , Female , Gram-Negative Bacteria/isolation & purification , Humans , Male , Middle Aged , Young Adult
8.
BMC Med ; 18(1): 106, 2020 05 12.
Article En | MEDLINE | ID: mdl-32393256

BACKGROUND: Actigraphy has received increasing attention in classifying rest-activity cycles. However, in patients with disorders of consciousness (DOC), actigraphy data may be considerably confounded by passive movements, such as nursing activities and therapies. Consequently, this study verified whether circadian rhythmicity is (still) visible in actigraphy data from patients with DOC after correcting for passive movements. METHODS: Wrist actigraphy was recorded over 7-8 consecutive days in patients with DOC (diagnosed with unresponsive wakefulness syndrome [UWS; n = 19] and [exit] minimally conscious state [MCS/EMCS; n = 11]). The presence and actions of clinical and research staff as well as visitors were indicated using a tablet in the patient's room. Following removal and interpolation of passive movements, non-parametric rank-based tests were computed to identify differences between circadian parameters of uncorrected and corrected actigraphy data. RESULTS: Uncorrected actigraphy data overestimated the interdaily stability and intradaily variability of patients' activity and underestimated the deviation from a circadian 24-h rhythm. Only 5/30 (17%) patients deviated more than 1 h from 24 h in the uncorrected data, whereas this was the case for 17/30 (57%) patients in the corrected data. When contrasting diagnoses based on the corrected dataset, stronger circadian rhythms and higher activity levels were observed in MCS/EMCS as compared to UWS patients. Day-to-night differences in activity were evident for both patient groups. CONCLUSION: Our findings indicate that uncorrected actigraphy data overestimates the circadian rhythmicity of patients' activity, as nursing activities, therapies, and visits by relatives follow a circadian pattern itself. Therefore, we suggest correcting actigraphy data from patients with reduced mobility.


Actigraphy/methods , Brain Injuries/diagnostic imaging , Circadian Rhythm/physiology , Neuropsychological Tests/standards , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult
9.
Am J Infect Control ; 48(10): 1144-1147, 2020 10.
Article En | MEDLINE | ID: mdl-31917013

BACKGROUND: We aimed to determine the prevalence of asymptomatic colonization by C. difficile in stool of residents in four long-term care facilities (LTCFs) in Graz, Austria and to identify factors associated with colonization. METHODS: We conducted a point-prevalence study in March 2018. Stool samples were examined by GDH enzyme immunoassay and when positive a toxin A/B-enzyme immunoassay was carried out. Additionally, all samples were tested by toxin A and B PCR and were plated manually as well as in automated fashion onto selective C. difficile agar. RESULTS: In 4/144 (2.8%) residents the GDH assay was positive. Each resident was colonized by a different C. difficile ribotype. C. difficile was not detected in any of the environmental samples. Significantly more colonized residents (60%) had stayed at a hospital in the 3 months previous to the study compared to 10% of non-colonized patients (p=0.01). CONCLUSIONS: The prevalence of colonization by toxigenic C. difficile was 2.8% in patients in LTCFs in Graz, Austria.


Clostridioides difficile , Clostridium Infections , Austria/epidemiology , Clostridium Infections/epidemiology , Cross-Sectional Studies , Feces , Humans , Long-Term Care , Prevalence
10.
Z Gerontol Geriatr ; 53(4): 310-317, 2020 Jul.
Article De | MEDLINE | ID: mdl-31701238

BACKGROUND: Acute hospitals are generally not designed for people with dementia. Behavioral issues pose the greatest challenge. This article reports on the results of a prospective controlled study designed to assess whether dementia patients benefit from a remobilization strategy in a memory clinic (IG-MA) following hospital discharge. METHODS: Between January and September 2018 patients with moderate to severe dementia discharged from hospital following acute episodes were admitted to an IG-MA for remobilization. The IG-MA unit provides specially qualified personnel and an adapted environment. Control groups were formed from the standard remobilization unit (KG1-AGR) and four care homes (KG2-PWH). RESULTS: Patients in the IG-MA (n = 22) had a worse functional status at admission according to the Barthel index (BI), the timed "up and go" test (TUG) and the Esslinger transfer scale (ETS) than patients in the KG1-AGR (n = 59). Outcomes significantly improved in both groups (IG-MA and KG1-AGR) without a clear difference between groups: IG-MA (BI from 35 to 57.8 points, TUG from 30.8 s to 23 s, ETS from 2.1 to 1.1 points) vs. KG1-AGR (BI from 44.7 to 62.4 points, TUG from 28.6 s to 20.2 s, ETS from 1.7 to 0.9 points). There were differences in cognitive ability at admission (mini mental state examination, MMSE: IG-MA 13.6 points vs. KG1-AGR 20 points). The length of stay in the IG-MA was on average 5 days longer. Early discharge was mostly the result of complications and transfer to acute hospitals in the IG-MA group (22.7%) and in the KG1-AGR group this was mostly due to care issues (27.1%). The KG2-PWH group did not show any significant functional improvements in the first 4 weeks as measured by the BI. CONCLUSION: Moderate to severely affected dementia patients with behavioral problems benefited from treatment in a specially designed remobilization unit following hospital discharge after an acute event.


Dementia/rehabilitation , Inpatients , Patient Discharge , Physical Therapy Modalities , Hospitalization , Humans , Prospective Studies , Recovery of Function , Treatment Outcome
11.
Brain Cogn ; 125: 78-87, 2018 08.
Article En | MEDLINE | ID: mdl-29909026

BACKGROUND: Recently, fNIRS has been proposed as a promising approach for awareness detection, and a possible method to establish basic communication in patients with disorders of consciousness (DOC). AIM: Using fNIRS, the present study evaluated the applicability of auditory presented mental-arithmetic tasks in this respect. METHODS: We investigated the applicability of active attention to serial subtractions for awareness detection in ten healthy controls (HC, 21-32 y/o), by comparing the measured patterns to patterns induced by self-performance of the same task. Furthermore, we examined the suitability of ignoring the given task as additional control signal to implement a two-class brain-computer interface (BCI) paradigm. Finally, we compared our findings in HC with recordings in one DOC patient (78 y/o). RESULTS AND CONCLUSION: Results of the HC revealed no differences between the self-performance and the attention condition, making the attention task suitable for awareness detection. However, there was no general difference between the ignore and attend condition, making the tasks less suitable for BCI control. Despite inconsistent correlations between the patient data and the HC group, single runs of the patient recordings revealed task-synchronous patterns - however, we cannot conclude whether the measured activation derives from instruction based task performance and thus awareness.


Brain-Computer Interfaces , Cognition/physiology , Consciousness Disorders/diagnostic imaging , Consciousness/physiology , Functional Neuroimaging/methods , Problem Solving/physiology , Spectroscopy, Near-Infrared/methods , Adult , Aged , Awareness/physiology , Brain/diagnostic imaging , Brain/physiopathology , Consciousness Disorders/physiopathology , Female , Humans , Male , Mathematics
12.
PLoS One ; 13(1): e0190458, 2018.
Article En | MEDLINE | ID: mdl-29293607

Sleep has been proposed to indicate preserved residual brain functioning in patients suffering from disorders of consciousness (DOC) after awakening from coma. However, a reliable characterization of sleep patterns in this clinical population continues to be challenging given severely altered brain oscillations, frequent and extended artifacts in clinical recordings and the absence of established staging criteria. In the present study, we try to address these issues and investigate the usefulness of a multivariate machine learning technique based on permutation entropy, a complexity measure. Specifically, we used long-term polysomnography (PSG), along with video recordings in day and night periods in a sample of 23 DOC; 12 patients were diagnosed as Unresponsive Wakefulness Syndrome (UWS) and 11 were diagnosed as Minimally Conscious State (MCS). Eight hour PSG recordings of healthy sleepers (N = 26) were additionally used for training and setting parameters of supervised and unsupervised model, respectively. In DOC, the supervised classification (wake, N1, N2, N3 or REM) was validated using simultaneous videos which identified periods with prolonged eye opening or eye closure.The supervised classification revealed that out of the 23 subjects, 11 patients (5 MCS and 6 UWS) yielded highly accurate classification with an average F1-score of 0.87 representing high overlap between the classifier predicting sleep (i.e. one of the 4 sleep stages) and closed eyes. Furthermore, the unsupervised approach revealed a more complex pattern of sleep-wake stages during the night period in the MCS group, as evidenced by the presence of several distinct clusters. In contrast, in UWS patients no such clustering was found. Altogether, we present a novel data-driven method, based on machine learning that can be used to gain new and unambiguous insights into sleep organization and residual brain functioning of patients with DOC.


Consciousness Disorders/physiopathology , Machine Learning , Sleep , Adult , Female , Humans , Male , Middle Aged
13.
Am J Infect Control ; 46(1): 76-80, 2018 Jan.
Article En | MEDLINE | ID: mdl-28844492

BACKGROUND: Residents in long-term care facilities (LTCFs) are increasingly found to be an important reservoir of multidrug-resistant gram-negative (MRGN) bacteria. AIMS: We aimed to determine colonization by MRGN bacteria over 6 months in LTCFs and geriatric wards in Graz, Austria, and to evaluate risk factors for such colonization. METHODS: During August 2015, we conducted a point-prevalence survey at LTCFs and geriatric wards of the Geriatric Health Centers of the City of Graz. Inguinal and perianal swabs were taken from 137 patients and screened for MRGN using standard procedures. Six months after the initial investigation all colonized patients were sampled again and use of antibiotics, hospital admissions, and mortality was registered. Genetic relatedness of MRGN bacteria was evaluated. RESULTS: We detected 12 patients harboring MRGN isolates (prevalence, 8.7%). Overall inguinal colonization was 5.1%. After 6 months, only 2 out of 12 patients were still colonized. Presence of a urinary catheter was associated with a higher risk of MRGN colonization (odds ratio [OR], 17.5; 95% CI, 1.6-192). Chronic wounds and gastrostomy were also risk factors of MRGN colonization (OR, 10.7; 95% CI, 1.6-69.3 and OR, 18.3; 95% CI, 2.4-139.4, respectively). There was no difference in mortality between colonized and noncolonized patients. CONCLUSIONS: Prevalence of colonization with MRGN bacteria was low in patients in LTCFs and geriatric wards in Graz, Austria.


Drug Resistance, Multiple, Bacterial , Gram-Negative Bacteria/drug effects , Aged , Austria/epidemiology , Carrier State , Gram-Negative Bacteria/genetics , Humans , Long-Term Care , Phylogeny , Residential Facilities , Risk Factors
14.
J Vis Exp ; (126)2017 08 01.
Article En | MEDLINE | ID: mdl-28809822

In this experiment, we demonstrate a suite of hybrid Brain-Computer Interface (BCI)-based paradigms that are designed for two applications: assessing the level of consciousness of people unable to provide motor response and, in a second stage, establishing a communication channel for these people that enables them to answer questions with either 'yes' or 'no'. The suite of paradigms is designed to test basic responses in the first step and to continue to more comprehensive tasks if the first tests are successful. The latter tasks require more cognitive functions, but they could provide communication, which is not possible with the basic tests. All assessment tests produce accuracy plots that show whether the algorithms were able to detect the patient's brain's response to the given tasks. If the accuracy level is beyond the significance level, we assume that the subject understood the task and was able to follow the sequence of commands presented via earphones to the subject. The tasks require users to concentrate on certain stimuli or to imagine moving either the left or right hand. All tasks are designed around the assumption that the user is unable to use the visual modality, and thus, all stimuli presented to the user (including instructions, cues, and feedback) are auditory or tactile.


Brain-Computer Interfaces , Communication , Consciousness Disorders/physiopathology , Algorithms , Brain/physiology , Consciousness Disorders/diagnosis , Cues , Electroencephalography , Equipment Design , Hand , Humans , Imagination
15.
Article En | MEDLINE | ID: mdl-28515905

BACKGROUND: We aimed to determine the prevalence of colonization by multidrug-resistant Gram-negative bacteria including ESBL-producing enterobacteriaceae, carbapenem-resistant enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii at two wards caring long term for patients with disorder of consciousness at the Geriatric Health Centers Graz, Austria. During our study we detected two A. baumannii outbreaks. METHODS: In August 2015, we conducted a point-prevalence study. Inguinal and perianal swabs were taken from 38 patients and screened for multidrug-resistant Gram-negative rods using standard procedures. Six months after the initial investigation all patients were sampled again and use of antibiotics during the past 6 months and mortality was registered. Genetic relatedness of bacteria was evaluated by DiversiLab system. RESULTS: Fifty percent of patients were colonized by multidrug-resistant Gram-negative isolates. Five patients harboured ESBL-producing enterobacteriaceae. No carbapenem-resistant enterobacteriaceae were detected. 13/38 patients were colonized by A. baumannii isolates (resistant to ciprofloxacin but susceptible to carbapenems). There was a significant difference in the prevalence of colonization by A. baumannii between ward 2 and ward 1 (60% vs. 5.6%, p < 0.001). Two clusters of A. baumannii isolates were identified including one isolate detected on a chair in a patient's room. CONCLUSIONS: We detected a high prevalence of two multidrug-resistant A. baumannii strains in patients with disorder of consciousness at a LTCF in Graz, Austria. Our findings strongly suggest nosocomial cross-transmission between patients. An active surveillance strategy is warranted to avoid missing newly emerging pathogens.

16.
Neurology ; 88(20): 1933-1941, 2017 05 16.
Article En | MEDLINE | ID: mdl-28424270

OBJECTIVE: To investigate the relationship between the presence of a circadian body temperature rhythm and behaviorally assessed consciousness levels in patients with disorders of consciousness (DOC; i.e., vegetative state/unresponsive wakefulness syndrome or minimally conscious state). METHODS: In a cross-sectional study, we investigated the presence of circadian temperature rhythms across 6 to 7 days using external skin temperature sensors in 18 patients with DOC. Beyond this, we examined the relationship between behaviorally assessed consciousness levels and circadian rhythmicity. RESULTS: Analyses with Lomb-Scargle periodograms revealed significant circadian rhythmicity in all patients (range 23.5-26.3 hours). We found that especially scores on the arousal subscale of the Coma Recovery Scale-Revised were closely linked to the integrity of circadian variations in body temperature. Finally, we piloted whether bright light stimulation could boost circadian rhythmicity and found positive evidence in 2 out of 8 patients. CONCLUSION: The study provides evidence for an association between circadian body temperature rhythms and arousal as a necessary precondition for consciousness. Our findings also make a case for circadian rhythms as a target for treatment as well as the application of diagnostic and therapeutic means at times when cognitive performance is expected to peak.


Brain Injuries/physiopathology , Circadian Rhythm/physiology , Consciousness Disorders/physiopathology , Skin Temperature/physiology , Adolescent , Adult , Aged , Brain Injuries/complications , Brain Injuries/therapy , Consciousness/physiology , Consciousness Disorders/etiology , Consciousness Disorders/therapy , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Periodicity , Phototherapy , Pilot Projects , Trauma Severity Indices , Young Adult
17.
Sci Rep ; 7(1): 266, 2017 03 21.
Article En | MEDLINE | ID: mdl-28325926

Brain injuries substantially change the entire landscape of oscillatory dynamics and render detection of typical sleep patterns difficult. Yet, sleep is characterized not only by specific EEG waveforms, but also by its circadian organization. In the present study we investigated whether brain dynamics of patients with disorders of consciousness systematically change between day and night. We recorded ~24 h EEG at the bedside of 18 patients diagnosed to be vigilant but unaware (Unresponsive Wakefulness Syndrome) and 17 patients revealing signs of fluctuating consciousness (Minimally Conscious State). The day-to-night changes in (i) spectral power, (ii) sleep-specific oscillatory patterns and (iii) signal complexity were analyzed and compared to 26 healthy control subjects. Surprisingly, the prevalence of sleep spindles and slow waves did not systematically vary between day and night in patients, whereas day-night changes in EEG power spectra and signal complexity were revealed in minimally conscious but not unaware patients.


Circadian Rhythm , Consciousness Disorders/complications , Sleep , Wakefulness , Electroencephalography , Humans
18.
Parasitology ; 144(6): 747-759, 2017 05.
Article En | MEDLINE | ID: mdl-27938439

Xanthohumol (Xan) is a natural constituent of human nutrition. Little is known about its actions on leishmanial parasites and their mitochondria as putative target. Therefore, we determined the antileishmanial activity of Xan and resveratrol (Res, as alternative compound with antileishmanial activity) with respect to mitochondria in Leishmania amazonensis promastigotes/amastigotes (LaP/LaA) in comparison with their activity in peritoneal macrophages from mouse (PMM) and macrophage cell line J774A.1 (J774). Mechanistic studies were conducted in Leishmania tarentolae promastigotes (LtP) and mitochondrial fractions isolated from LtP. Xan and Res demonstrated antileishmanial activity in LaA [half inhibitory concentration (IC50): Xan 7 µ m, Res 14 µ m]; while they had less influence on the viability of PMM (IC50: Xan 70 µ m, Res >438 µ m). In contrast to Res, Xan strongly inhibited oxygen consumption in Leishmania (LtP) but not in J774 cells. This was based on the inhibition of the mitochondrial electron transfer complex II/III by Xan, which was less pronounced with Res. Neither Xan nor Res increased mitochondrial superoxide release in LtP, while both decreased the mitochondrial membrane potential in LtP. Bioenergetic studies showed that LtP mitochondria have no spare respiratory capacity in contrast to mitochondria in J774 cells and can therefore much less adapt to stress by mitochondrial inhibitors, such as Xan. These data show that Xan may have antileishmanial activity, which is mediated by mitochondrial inhibition.


Antiprotozoal Agents/pharmacology , Flavonoids/pharmacology , Leishmania/drug effects , Mitochondria/drug effects , Propiophenones/pharmacology , Animals , Antiprotozoal Agents/chemistry , Cattle , Cell Line , Electron Transport/drug effects , Electron Transport Complex III/drug effects , Female , Flavonoids/chemistry , Inhibitory Concentration 50 , Leishmania/metabolism , Leishmania/ultrastructure , Macrophages, Peritoneal/parasitology , Membrane Potential, Mitochondrial/drug effects , Mice , Mice, Inbred BALB C , Oxidative Phosphorylation/drug effects , Oxygen Consumption/drug effects , Propiophenones/chemistry , Resveratrol , Stilbenes/chemistry , Stilbenes/pharmacology , Superoxides/metabolism , Yeasts/drug effects , Yeasts/ultrastructure
19.
Conscious Cogn ; 44: 51-60, 2016 08.
Article En | MEDLINE | ID: mdl-27351782

Emotional and self-relevant stimuli are able to automatically attract attention and their use in patients suffering from disorders of consciousness (DOC) might help detecting otherwise hidden signs of cognition. We here recorded EEG in three Locked-in syndrome (LIS) and four Vegetative State/Unresponsive Wakefulness Syndrome (VS/UWS) patients while they listened to the voice of a family member or an unfamiliar voice during a passive. Data indicate that, in a passive listening condition, the familiar voice induces stronger alpha desynchronization than the unfamiliar one. In an active condition, the target evoked stronger alpha desynchronization in controls, two LIS patients and one VS/UWS patient. Results suggest that self-relevant familiar voice stimuli can engage additional attentional resources and might allow the detection of otherwise hidden signs of instruction-following and thus residual awareness. Further studies are necessary to find sensitive paradigms that are suited to find subtle signs of cognition and awareness in DOC patients.


Acoustic Stimulation/methods , Attention/physiology , Brain/physiopathology , Consciousness Disorders/physiopathology , Electroencephalography , Recognition, Psychology/physiology , Adult , Brain Mapping/methods , Female , Humans , Male
20.
J Neurol ; 263(8): 1530-43, 2016 Aug.
Article En | MEDLINE | ID: mdl-27216625

Estimating cognitive abilities in patients suffering from Disorders of Consciousness remains challenging. One cognitive task to address this issue is the so-called own name paradigm, in which subjects are presented with first names including the own name. In the active condition, a specific target name has to be silently counted. We recorded EEG during this task in 24 healthy controls, 8 patients suffering from Unresponsive Wakefulness Syndrome (UWS) and 7 minimally conscious (MCS) patients. EEG was analysed with respect to amplitude as well as phase modulations and connectivity. Results showed that general reactivity in the delta, theta and alpha frequency (event-related de-synchronisation, ERS/ERD, and phase locking between trials and electrodes) toward auditory stimulation was higher in controls than in patients. In controls, delta ERS and lower alpha ERD indexed the focus of attention in both conditions, late theta ERS only in the active condition. Additionally, phase locking between trials and delta phase connectivity was highest for own names in the passive and targets in the active condition. In patients, clear stimulus-specific differences could not be detected. However, MCS patients could reliably be differentiated from UWS patients based on their general event-related delta and theta increase independent of the type of stimulus. In conclusion, the EEG signature of the active own name paradigm revealed instruction-following in healthy participants. On the other hand, DOC patients did not show clear stimulus-specific processing. General reactivity toward any auditory input, however, allowed for a reliable differentiation between MCS and UWS patients.


Attention/physiology , Brain Waves/physiology , Cognition Disorders/diagnosis , Names , Self Concept , Acoustic Stimulation , Adult , Aged , Analysis of Variance , Brain Mapping , Cognition Disorders/etiology , Consciousness Disorders/complications , Electroencephalography , Female , Humans , Male , Middle Aged , Young Adult
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