Neuronal activity and NIBS in developmental myelination and remyelination - Current state of knowledge.

Oligodendrocytes are responsible for myelinating central nervous system (CNS) axons and rapid electrical transmission through saltatory conduction of action potentials. Myelination and myelin repair rely partially on oligodendrogenesis, which comprises oligodendrocyte precursor cell (OPC) migration, maturation, and differentiation into oligodendrocytes (OL). In multiple sclerosis (MS), demyelination occurs due to an inflammatory cascade with auto-reactive T-cells. When oligodendrogenesis fails, remyelination becomes aberrant and conduction impairments are no longer restored. Although current disease modifying therapies have achieved results in modulating the faulty immune response, disease progression continues because of chronic inflammation, neurodegeneration, and failure of remyelination. Therapies have been tried to promote remyelination. Modulation of neuronal activity seems to be a very promising strategy in preclinical studies. Additionally, studies in people with MS (pwMS) have shown symptom improvement following non-invasive brain stimulation. (NIBS) techniques. The aforementioned mechanisms are yet unknown and probably involve both the activation of neurons and glial cells. Noting neuronal activity contributes to myelin plasticity and that NIBS modulates neuronal activity; we argue that NIBS is a promising research horizon for demyelinating diseases. We review the hypothesized pathways through which NIBS may affect both neuronal activity in the CNS and how the resulting activity can affect oligodendrogenesis and myelination.

Comparison of Bioelectrical Impedance Analysis (BIA)-Derived Parameters in Healthy Volunteers and Critically Ill Patients.

OBJECTIVE: To compare bioelectrical impedance analysis (BIA)-derived parameters in healthy volunteers and critically ill patients and to assess its prognostic value in an ICU patient cohort. DESIGN: Retrospective, observational data analysis. SETTING: Single centre, tertiary-level ICU (Ziekenhuis Netwerk Antwerpen, ZNA Stuivenberg Hospital). PATIENTS: 101 patients and 101 healthy subjects, participants of International Fluid Academy Days. MEASUREMENTS AND MAIN RESULTS: Compared to healthy volunteers, both male and female ICU patients had significantly higher values for total body water (TBW), extracellular water (ECW), extracellular fluid (ECF), plasma, and interstitial fluid volumes. The phase angle was significantly lower and the malnutrition index was significantly higher in ICU patients, regardless of gender. Non-survivors in the ICU had significantly higher extracellular water content (ECW, 50.7 ± 5.1 vs. 48.9 ± 4.3%, p = 0.047) and accordingly significantly lower intracellular water (ICW, 49.2 ± 5.1 vs. 51.1 ± 4.3%, p = 0.047). The malnutrition index was also significantly higher in non-survivors compared to survivors (0.94 ± 0.17 vs. 0.87 ± 0.16, p = 0.048), as was the capillary leak index (ECW/ICW). CONCLUSIONS: Compared to healthy volunteers, this study observed a higher malnutrition index and TBW in ICU patients with an accumulation of fluids in the extracellular compartment. ICU non-survivors showed similar results, indicating that ICU patients and a fortiori non-survivors are generally overhydrated, with increased TBW and ECW, and more undernourished, as indicated by a higher malnutrition index.

Neutrophil-to-lymphocyte ratio predicts delirium after stroke.

BACKGROUND: Delirium is an underdiagnosed and possibly preventable complication in acute stroke and is linked to poor outcome. Neutrophil-to-lymphocyte ratio (NLR), a marker of systemic inflammation, is also associated with poor outcome after acute ischemic stroke. AIM: To determine whether NLR is a predictor of post-stroke delirium (PSD). METHODS: We reviewed the UZ Brussel stroke database and included 514 patients with acute ischemic stroke within 24 hours from stroke onset between February 2009 and December 2014. The presence of delirium was evaluated by two raters based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria, using a retrospective chart review method. When no consensus was reached, a third evaluator was consulted. Patients were divided into two groups: those who developed delirium within the first week after stroke onset (n = 201; 39%) and those who did not (n = 313; 61%). Receiver operating characteristics (ROC) and multiple logistic regression analysis (MLRA) were used to identify predictors of PSD. RESULTS: MLRA showed that NLR (odds ratio (OR) 1.14; 95% confidence interval (CI) 1.04-1.26), age (OR 1.05; 95% CI 1.03-1.07), National Institutes of Health Stroke Scale (NIHSS; OR 1.14; 95% CI 1.10-1.18), premorbid modified Rankin Scale (mRS) (OR 1.35; 95% CI 1.05-1.74) and premorbid cognitive dysfunction (OR 3.16; 95% CI 1.26-7.92) predicted PSD. ROC curve of a prediction model including NLR, age, NIHSS and premorbid cognitive dysfunction showed an area under the curve of 0.84 (95% CI = 0.81-0.88). CONCLUSIONS: Besides age, stroke severity, premorbid mRS and cognitive impairment, NLR is a predictor of PSD, even independent of the development of pneumonia or urinary tract infection.

Prognostic value of bioelectrical impedance analysis for assessment of fluid overload in ICU patients: a pilot study.

INTRODUCTION: The non-invasive analysis of body fluid composition with bio-electrical impedance analysis (BIA) provides additional information allowing for more persona-lised therapy to improve outcomes. The aim of this study is to assess the prognostic value of fluid overload (FO) in the first week of intensive care unit (ICU) stay. MATERIAL AND METHODS: A retrospective, observational analysis of 101 ICU patients. Whole-body BIA measurements were performed, and FO was defined as a 5% increase in volume excess from baseline body weight. RESULTS: Baseline demographic data, including severity scores, were similar in both the fluid overload-positive (FO+, n = 49) patients and in patients without fluid overload (FO-, n = 52). Patients with FO+ had significantly higher cumulative fluid balance during their ICU stay compared to those without FO (8.8 ± 7.0 vs. 5.5 ± 5.4 litres; P = 0.009), VE (9.9 ± 6.5 vs. 1.5 ± 1.5 litres; P < 0.001), total body water (63.0 ± 9.5 vs. 52.8 ± 8.1%; P < 0.001), and extracellular water (27.0 ± 7.3 vs. 19.6 ± 3.7 litres; P < 0.001). The presence of 5%, 7.5%, and 10% fluid overload was directly associated with increased ICU mortality rates. The percentage fluid overload (P = 0.039) was an independent predictor for hospital mortality. CONCLUSIONS: A higher mortality rate in ICU-patients with FO was observed. FO is an independent prognostic factor because neither APACHE-II, SOFA, nor SAPS-II significantly differed on admission between survivors and non-survivors. Further research is needed to confirm these data prospectively and to evaluate whether BIA-guided deresuscitation in the subacute phase will improve mortality rates.