Peripheral blood BDNF and soluble CAM proteins as possible markers of prolonged disorders of consciousness: a pilot study

Although clinical examination still represents the gold standard for the differential diagnosis of prolonged disorders of consciousness (pDoC), the introduction of innovative markers is essential for diagnosis and prognosis, due to the problem of covert cognition. We evaluated the brain-derived neurotrophic factor protein (BDNF) and the soluble cell adhesion molecules proteins (CAMs) in a cohort of prolonged disorders of consciousness patients to identify a possible application in the clinical context. Furthermore, peripheral blood determinations were correlated with imaging parameters such as white matter hyperintensities (WMH), cranial standardized uptake value (cSUV), electroencephalography (EEG) data and clinical setting. Our results, although preliminary, identify BDNF as a possible blood marker for the diagnosis of pDoC (p value 0.001), the soluble CAMs proteins CD44, Vcam-1, E-selectin (p value < 0.01) and Icam-3 (p value < 0.05) showed a higher peripheral blood value in pDoC compared with control. Finally, soluble Ncam protein could find useful applications in the clinical evolution of the pDoC, showing high levels in the MCS and EMCS subgroups (p value < 0. 001) compared to VS/UWS.

Phenotyping Superagers Using Resting-State fMRI

BACKGROUND AND PURPOSE

Superagers are defined as older adults with episodic memory performance similar or superior to that in middle-aged adults. This study aimed to investigate the key differences in discriminative networks and their main nodes between superagers and cognitively average elderly controls. In addition, we sought to explore differences in sensitivity in detecting these functional activities across the networks at 3T and 7T MR imaging fields.

MATERIALS AND METHODS

Fifty-five subjects 80 years of age or older were screened using a detailed neuropsychological protocol, and 31 participants, comprising 14 superagers and 17 cognitively average elderly controls, were included for analysis. Participants underwent resting-state-fMRI at 3T and 7T MR imaging. A prediction classification algorithm using a penalized regression model on the measurements of the network was used to calculate the probabilities of a healthy older adult being a superager. Additionally, ORs quantified the influence of each node across preselected networks.

RESULTS

The key networks that differentiated superagers and elderly controls were the default mode, salience, and language networks. The most discriminative nodes (ORs > 1) in superagers encompassed areas in the precuneus posterior cingulate cortex, prefrontal cortex, temporoparietal junction, temporal pole, extrastriate superior cortex, and insula. The prediction classification model for being a superager showed better performance using the 7T compared with 3T resting-state-fMRI data set.

CONCLUSIONS

Our findings suggest that the functional connectivity in the default mode, salience, and language networks can provide potential imaging biomarkers for predicting superagers. The 7T field holds promise for the most appropriate study setting to accurately detect the functional connectivity patterns in superagers.

An innovative approach for the evaluation of prolonged disorders of consciousness using NF-L and GFAP biomarkers: a pivotal study

Behavioral assessments during the clinical evaluation in prolonged disorders of consciousness patients could be not sufficient for a correct diagnosis and prognostication. To this aim, we used an innovative approach, involving the ultra-sensitive determination of biological markers, correlating them with imaging parameters to investigate the prolonged disorders of consciousness (pDoC).We assessed the serum concentration of neurofilament light chain(NF-L) and glial fibrillary acidic protein (GFAP) in pDoC (n = 16), and healthy controls (HC, n = 6) as well as several clinical imaging parameters such as Fractional Anisotropy (FA), Whole Brain SUV, and White Matter Hyperintensities volumes (WMH) using PET-MRI acquisition. As for differential diagnosis task, only the imaging WMH volume was able to discriminate between vegetative state/unresponsive wakefulness syndrome (VS/UWS), and minimally conscious state (MCS) patients (p-value < 0.01), while all selected markers (both imaging and in vitro) were able to differentiate between pDoC patients and HC. At subject level, serum NF-L concentrations significantly differ according to clinical progression and consciousness recovery (p-value < 0.01), highlighting a potential play for the longitudinal management of these patients.

Addressing Pain for a Proper Rehabilitation Process in Patients With Severe Disorders of Consciousness

Consciousness constitutes a fundamental prerequisite in the individual appraisal and experience of pain. In the same way, a person needs to be able to report on pain perception. Patients who suffered a severe brain injury with disorders of consciousness (DOC) represent a spectrum of pathologies affecting patients' capacity to interact with the external world. In these patients, the most relevant aspects in response to pain are physiologic and behavioral. The treatments and management of pain are challenging issues in these patients, arising serious ethical concerns and bringing emotional load among medical staff, caregivers, and relatives. In this review, we report the importance of having a correct pain management in DOC patients, to individuate the best pharmacological treatment that can make the difference in detecting a behavioral response, indicative of a change in the level of consciousness, and in planning a more effective rehabilitative approach.

What impact can hospitalization environment produce on the ANS functioning in patients with Unresponsive Wakefulness Syndrome? - 24-hour monitoring

Objectives: Studies showed that the recovery of patients with Unresponsive Wakefulness Syndrome (UWS) is also correlated to the recovery of circadian rhythms. In this study, we observed the correlations between patients with UWS biometrical and ambient parameters. Methods: A dedicated monitoring system was realized to record and correlate the level of noise and luminosity with biometric Heart Rate (HR), Heart Rate Variability (HRV) and Breath Rate (BR) parameters. Eleven patients with UWS were recruited and monitored for 13 ± 7 days. Correlation of ambient and biometric parameters was analyzed by Spearman's test. Wilcoxon's test was used to compare the biometric parameters in two different moments of daily activity in the rehabilitation unit (night and day). Patients showed a moderate negative or positive correlation between biometric and ambient parameters. Results: Significant differences between night and morning (0.0001 < p ≤ 0.001) were found for HR, HRV and BR in seven, five and four patients, respectively, at Wilcoxon's test. HR and BR were higher during the night while HRV was lower. Conclusion: In patients with UWS, lower HRV and higher HR and BR during the night might be indicative of interference in sleep/wake cycles. The modifications of the environment surrounding the patient due to the unit procedures of the staff and/or some interaction modalities of the relatives may have an effect on residual endogenous mechanisms of self-regulation. However, differences between night and day in the biometrical parameters are not necessarily linked to the changes in the environment care unit.

Screening for metabolic syndrome in older patients with severe mental illness: Two-years observational study

Introduction

Patients with serious psychiatric illness (SMI) have a reduced quality of life and life expectancy than the general population. Metabolic syndrome (MS) is a clinical aspect determining who should be considered to reduce the risk of serious and chronic organic factors, even more significant in the elderly.

Objectives

To evaluate metabolic screening of elderly patients with severe mental illness (SMI).

Aims

To evaluate the importance of routine screening of metabolic parameters in elderly guests of residential facilities with or without SMI; metabolic screening at baseline and after two of hospitalization.

Methods

Elderly inpatients (44 Tot) with Severe Mental Illness (SMI: bipolar disorder: 34%; schizophrenia: 46%; other: 20%) vs elderly inpatients (78 Tot). Data collected at baseline: psychiatric diagnosis; any previous diagnosis of hypertension, diabetes, dyslipidemia; ECG. At baseline and for two years were administered following scale: BPRS; PANSS; Qli; MMSE, ADL.

Results

After two years metabolic screening has recorded at least one of the new interactions between the five factors of MS (ATP III) in 50% of patients with: one (34%); two (21%); three (11%); four (3%) new altered parameters. In MS inpatients, 53% of new metabolic alterations were recorded in 53% (MS inpatients) vs 23% without MS after two years.

Conclusions

Our results showed a higher frequency of MS in patients with SMI than comparison subjects. Haloperidol was the antipsychotic medication that caused minor impact on the development of metabolic disorders.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Is climate change a threat for water uses in the Mediterranean region? Results from a survey at local scale

Water scarcity and water security are linked, not only through the direct effects of water shortages on each water users' access to water, but also because of water conflicts generated. Climate change is predicted to raise temperatures in the Mediterranean region and reduce rainfall, leading to a reduction in water yield and possibly worsening the situation of water resource shortages that Mediterranean regions are already experiencing. In its dissemination strategy, the EU FP7 CLIMB project addressed water security threats through an analysis of water uses and water use rivalries within a few target catchments distributed over the Mediterranean region. The present work explores whether climate change is locally perceived by stakeholders (water users and managers) as a key issue for their water uses and water security. Individual interviews, meetings, and compilation of questionnaires were conducted at five sites located in the Mediterranean region. The methodology permitted an analysis of water use and its evolution in the water management context, an identification of the state of awareness of local stakeholders and of the pressures on water use and water use rivalries, and a prioritization of water uses. Currently, the main response to increasing water demand in the Mediterranean region, while not yet considering climate change as a driving force, is a progressive externalization of water resources, with limits represented by national borders and technological possibilities. Overall, 'climate change' was not mentioned by stakeholders during both interviews and in answers to the questionnaires. Even the prospect of decreasing precipitation was not considered a relevant or threatening issue in the coming 20years. This confirms the need to continue all efforts to disseminate the state of knowledge on climate change impacts in the Mediterranean region, such as water scarcity, especially to local water managers, as initiated by various research programs of the European Commission.

Highlighting the structure-function relationship of the brain with the Ising model and graph theory

With the advent of neuroimaging techniques, it becomes feasible to explore the structure-function relationships in the brain. When the brain is not involved in any cognitive task or stimulated by any external output, it preserves important activities which follow well-defined spatial distribution patterns. Understanding the self-organization of the brain from its anatomical structure, it has been recently suggested to model the observed functional pattern from the structure of white matter fiber bundles. Different models which study synchronization (e.g., the Kuramoto model) or global dynamics (e.g., the Ising model) have shown success in capturing fundamental properties of the brain. In particular, these models can explain the competition between modularity and specialization and the need for integration in the brain. Graphing the functional and structural brain organization supports the model and can also highlight the strategy used to process and organize large amount of information traveling between the different modules. How the flow of information can be prevented or partially destroyed in pathological states, like in severe brain injured patients with disorders of consciousness or by pharmacological induction like in anaesthesia, will also help us to better understand how global or integrated behavior can emerge from local and modular interactions.

An independent SSVEP-based brain-computer interface in locked-in syndrome

OBJECTIVE

Steady-state visually evoked potential (SSVEP)-based brain-computer interfaces (BCIs) allow healthy subjects to communicate. However, their dependence on gaze control prevents their use with severely disabled patients. Gaze-independent SSVEP-BCIs have been designed but have shown a drop in accuracy and have not been tested in brain-injured patients. In the present paper, we propose a novel independent SSVEP-BCI based on covert attention with an improved classification rate. We study the influence of feature extraction algorithms and the number of harmonics. Finally, we test online communication on healthy volunteers and patients with locked-in syndrome (LIS).

APPROACH

Twenty-four healthy subjects and six LIS patients participated in this study. An independent covert two-class SSVEP paradigm was used with a newly developed portable light emitting diode-based 'interlaced squares' stimulation pattern.

MAIN RESULTS

Mean offline and online accuracies on healthy subjects were respectively 85 ± 2% and 74 ± 13%, with eight out of twelve subjects succeeding to communicate efficiently with 80 ± 9% accuracy. Two out of six LIS patients reached an offline accuracy above the chance level, illustrating a response to a command. One out of four LIS patients could communicate online.

SIGNIFICANCE

We have demonstrated the feasibility of online communication with a covert SSVEP paradigm that is truly independent of all neuromuscular functions. The potential clinical use of the presented BCI system as a diagnostic (i.e., detecting command-following) and communication tool for severely brain-injured patients will need to be further explored.

A default mode of brain function in altered states of consciousness

Using modern brain imaging techniques, new discoveries are being made concerning the spontaneous activity of the brain when it is devoid of attention-demanding tasks. Spatially separated patches of neuronal assemblies have been found to show synchronized oscillatory activity behavior and are said to be functionally connected. One of the most robust of these is the default mode network, which is associated with intrinsic processes like mind wandering and self-projection. Furthermore, activity in this network is anticorrelated with activity in a network that is linked to attention to external stimuli. The integrity of both networks is disturbed in altered states of consciousness, like sleep, general anesthesia and hypnosis. In coma and related disorders of consciousness, encompassing the vegetative state (unresponsive wakefulness syndrome) and minimally conscious state, default mode network integrity correlates with the level of remaining consciousness, offering the possibility of using this information for diagnostic and prognostic purposes. Functional brain imaging is currently being validated as a valuable addition to the standardized behavioral assessments that are already in use.

DTI BASED STRUCTURAL DAMAGE CHARACTERIZATION FOR DISORDERS OF CONSCIOUSNESS

MRI Diffusion Tensor Imaging (DTI) has been recently proposed as a highly discriminative measurement to detect structural damages in Disorders of Consciousness patients (Vegetative State/Unresponsive Wakefulness Syndrome-(VS/UWS) and Minimally Consciousness State-MCS). In the DTI analysis, certain tensor features are often used as simplified scalar indices to represent these alterations. Those characteristics are mathematically and statistically more tractable than the full tensors. Nevertheless, most of these quantities are based on a tensor diffusivity estimation, the arithmetic average among the different strengths of the tensor orthogonal directions, which is supported on a symmetric linear relationship among the three directions, an unrealistic assumption for severely damaged brains. In this paper, we propose a new family of scalar quantities based on Generalized Ordered Weighted Aggregations (GOWA) to characterize morphological damages. The main idea is to compute a tensor diffusitivity estimation that captures the deviations in the water diffusivity associated to damaged tissue. This estimation is performed by weighting and combining differently each tensor orthogonal strength. Using these new scalar quantities we construct an affine invariant DTI tensor feature using regional tissue histograms. An evaluation of these new scalar quantities on 48 patients (23 VS/UWS and 25 MCS) was conducted. Our experiments demonstrate that this new representation outperforms state-of-the-art tensor based scalar representations for characterization and classification problems.

Hypnotic modulation of resting state fMRI default mode and extrinsic network connectivity

Resting state fMRI (functional magnetic resonance imaging) acquisitions are characterized by low-frequency spontaneous activity in a default mode network (encompassing medial brain areas and linked to self-related processes) and an anticorrelated "extrinsic" system (encompassing lateral frontoparietal areas and modulated via external sensory stimulation). In order to better determine the functional contribution of these networks to conscious awareness, we here sought to transiently modulate their relationship by means of hypnosis. We used independent component analysis (ICA) on resting state fMRI acquisitions during normal wakefulness, under hypnotic state, and during a control condition of autobiographical mental imagery. As compared to mental imagery, hypnosis-induced modulation of resting state fMRI networks resulted in a reduced "extrinsic" lateral frontoparietal cortical connectivity, possibly reflecting a decreased sensory awareness. The default mode network showed an increased connectivity in bilateral angular and middle frontal gyri, whereas its posterior midline and parahippocampal structures decreased their connectivity during hypnosis, supposedly related to an altered "self" awareness and posthypnotic amnesia. In our view, fMRI resting state studies of physiological (e.g., sleep or hypnosis), pharmacological (e.g., sedation or anesthesia), and pathological modulation (e.g., coma or related states) of "intrinsic" default mode and anticorrelated "extrinsic" sensory networks, and their interaction with other cerebral networks, will further improve our understanding of the neural correlates of subjective awareness.

Bispectral index correlates with regional cerebral blood flow during sleep in distinct cortical and subcortical structures in humans

The relationship between the Bispectral Index (BIS), an EEG-based monitor of anesthesia, and brain activity is still unclear. This study aimed at investigating the relationship between changes in BIS values during natural sleep and regional cerebral blood flow (rCBF) variations, as measured by Positron Emission Tomography (PET). Data were obtained from six young, healthy, right-handed, male volunteers (20-30 years old) using the H2(15)O infusion method. PET scans were performed both during waking and various stages of sleep. BIS values were monitored continuously and recorded during each PET scan. Positive correlations were detected between BIS and rCBF values in dorsolateral prefontal, parietal, anterior and posterior cingulate, precuneal, mesiofrontal, mesiotemporal and insular cortices. These areas belong to a frontoparietal network known to be related to awareness of self conscious sensory perception, attention and memory. BIS values also positively correlated with activity in brainstem and thalami, both structures known to be involved in arousal and wakefulness. These results show that BIS changes associated with physiological sleep depth co-vary with the activity of specific cortical and subcortical areas. The latter are known to modulate arousal, which in turn allows sustained thalamo-cortical enhancement of activity in a specific frontoparietal network known to be related to the content of consciousness. Thus, although mainly derived from frontal EEG, BIS could represent a wider index of cerebral activity.

[MRI in coma survivors]

Traumatic and non-traumatic brain injured disorders of consciousness patients are still challenging for diagnosis, prognosis, ethical and socio-economic reasons. Currently, there remains a high rate of misdiagnosis of the vegetative state (Schnakers, et al. 2009). Recent advances in MRI techniques (diffusion tensor, magnetic resonance spectroscopy and functional imaging) provide data that could improve the diagnostic and prognostic evaluation and management of these patients.

Estimated glomerular filtration rate, albuminuria and mortality in type 2 diabetes: the Casale Monferrato study

AIMS/HYPOTHESIS

Estimated glomerular filtration rate (eGFR) predicts mortality in non-diabetic populations, but its role in people with type 2 diabetes is unknown. We assessed to what extent a reduction in eGFR in people with type 2 diabetes predicts 11-year all-cause and cardiovascular mortality, independently of AER and other cardiovascular risk factors.

MATERIALS AND METHODS

The study population was the population-based cohort (n = 1,538; median age 68.9 years) of the Casale Monferrato Study. GFR was estimated by the abbreviated Modification of Diet in Renal Disease Study equation.

RESULTS

At baseline, the prevalence of chronic kidney disease (eGFR <60 ml min(-1) 1.73 m(-2)) was 34.3% (95% CI 33.0-36.8). There were 670 deaths in 10,708 person-years of observation. Hazard ratios of 1.23 (95% CI 1.03-1.47) for all-cause mortality and 1.18 (95% CI 0.92-1.52) for cardiovascular mortality were observed after adjusting for cardiovascular risk factors and AER. When five levels of eGFR were analysed we found that most risk was conferred by eGFR 15-29 ml min(-1) 1.73 m(-2), whereas no increased risk was evident in people with eGFR values between 30 and 59 ml min(-1) 1.73 m(-2). In an analysis stratified by AER categories, a significant increasing trend in risk with decreasing eGFR was evident only in people with macroalbuminuria.

CONCLUSIONS/INTERPRETATION

Our study suggests that in type 2 diabetes macroalbuminuria is the main predictor of mortality, independently of both eGFR and cardiovascular risk factors, whereas eGFR provides no further information in normoalbuminuric people.

Estimated glomerular filtration rate, albuminuria and mortality in type 2 diabetes: the Casale Monferrato study

AIMS/HYPOTHESIS

Estimated glomerular filtration rate (eGFR) predicts mortality in non-diabetic populations, but its role in people with type 2 diabetes is unknown. We assessed to what extent a reduction in eGFR in people with type 2 diabetes predicts 11-year all-cause and cardiovascular mortality, independently of AER and other cardiovascular risk factors.

MATERIALS AND METHODS

The study population was the population-based cohort (n = 1,538; median age 68.9 years) of the Casale Monferrato Study. GFR was estimated by the abbreviated Modification of Diet in Renal Disease Study equation.

RESULTS

At baseline, the prevalence of chronic kidney disease (eGFR <60 ml min(-1) 1.73 m(-2)) was 34.3% (95% CI 33.0-36.8). There were 670 deaths in 10,708 person-years of observation. Hazard ratios of 1.23 (95% CI 1.03-1.47) for all-cause mortality and 1.18 (95% CI 0.92-1.52) for cardiovascular mortality were observed after adjusting for cardiovascular risk factors and AER. When five levels of eGFR were analysed we found that most risk was conferred by eGFR 15-29 ml min(-1) 1.73 m(-2), whereas no increased risk was evident in people with eGFR values between 30 and 59 ml min(-1) 1.73 m(-2). In an analysis stratified by AER categories, a significant increasing trend in risk with decreasing eGFR was evident only in people with macroalbuminuria.

CONCLUSIONS/INTERPRETATION

Our study suggests that in type 2 diabetes macroalbuminuria is the main predictor of mortality, independently of both eGFR and cardiovascular risk factors, whereas eGFR provides no further information in normoalbuminuric people.

Longitudinal study of cognitive dysfunction in multiple sclerosis: neuropsychological, neuroradiological, and neurophysiological findings

OBJECTIVE

(1) To assess cognitive function and cerebral magnetic resonance imaging (MRI) involvement in relapsing-remitting multiple sclerosis; (2) to monitor disease evolution, cognitive dysfunction, and cerebral lesion burden over time (mean 8.5 year follow up period); (3) to study the relation between clinical, neuropsychological, and MRI data. On follow up assessment, visual and auditory oddball event related potentials (ERPs) were recorded as psychophysiological evaluation of cognitive status. Correlations between neuropsychological, MRI, and ERP data were also analysed.

METHODS

Neuropsychological study assessed verbal and non-verbal IQ, deterioration index (DI) from WAIS subtests, conceptual reasoning, attention, verbal and visuospatial short-term and long term memory. MRI assessment detected presence of demyelinating lesions by using a semiquantitative method as well as cortical and subcortical atrophy over time.

RESULTS

Attention, short-term and long term visuospatial memory were mildly impaired at baseline and remained unaltered longitudinally. At retesting a significant worsening of verbal long term memory (p=0.023), DI presence (p=0.041) and the increase of supratentorial and subtentorial MRI lesions load (p=0.001) emerged. Expanded disability status scale score correlated significantly with total lesion burden at both evaluations (p=0.043 and p=0.024 respectively). Temporal, occipital, and frontal horn lesions as well as cortical atrophy correlated significantly with attention and memory tests at baseline. Follow up assessment revealed significant correlation between cortical atrophy and attention as well as visuospatial short-term memory; spatial long term memory correlated significantly with lesions in body of lateral ventricle and frontal lobe. ERP study showed P300 latency abnormalities in 75% of patients, involving specifically more visual P300 (58.4 % of cases) than auditory wave (41.6 %). Visual P300 latency and amplitude correlated significantly with DI and auditory P300 latency with frontal horn and brain stem lesions.

CONCLUSIONS

These findings revealed mild cognitive impairment in MS patients particularly consistent with slowing information processing over time. Increased MRI lesions do not correlate with the clinical course of the disease and cognitive deficit evolution. Thus, cognitive dysfunction could be related to disease peculiarity and not to the time course. Correlations between P300, neuropsychological, and MRI findings provide further information about ERP application to examine cognitive impairment in MS and probably to investigate their neural origin.