Cognitive Motor Dissociation: Gap Analysis and Future Directions.

BACKGROUND: Patients with disorders of consciousness who are behaviorally unresponsive may demonstrate volitional brain responses to motor imagery or motor commands detectable on functional magnetic resonance imaging or electroencephalography. This state of cognitive motor dissociation (CMD) may have prognostic significance. METHODS: The Neurocritical Care Society's Curing Coma Campaign identified an international group of experts who convened in a series of monthly online meetings between September 2021 and April 2023 to examine the science of CMD and identify key knowledge gaps and unmet needs. RESULTS: The group identified major knowledge gaps in CMD research: (1) lack of information about patient experiences and caregiver accounts of CMD, (2) limited epidemiological data on CMD, (3) uncertainty about underlying mechanisms of CMD, (4) methodological variability that limits testing of CMD as a biomarker for prognostication and treatment trials, (5) educational gaps for health care personnel about the incidence and potential prognostic relevance of CMD, and (6) challenges related to identification of patients with CMD who may be able to communicate using brain-computer interfaces. CONCLUSIONS: To improve the management of patients with disorders of consciousness, research efforts should address these mechanistic, epidemiological, bioengineering, and educational gaps to enable large-scale implementation of CMD assessment in clinical practice.

Modeling the effect of cerebral capillary blood flow on neuronal firing.

Adequate cerebral blood flow has long been recognized as essential for the maintenance of the neuronal function while interruption of cerebral blood flow for durations as short as minutes can result in permanent brain damage. A primary goal of this work is to determine how a neuron's ability to respond to synaptic input depends on parameters that control cerebral blood flow. A complex mathematical model is constructed that integrates detailed biophysical models of neuronal action potentials, mitochondrial ATP production and cerebral capillary blood flow. The model also provides insights of the role of astrocytes in maintaining neuronal responses, as well as the impact of elevated cytosolic calcium, due to increased synaptic activity, on mitochondrial ATP production. Both dynamical systems analysis and numerical simulations are used to determine how the maximum frequency at which the neurons can respond to synaptic input depends on capillary blow flow, as well as the ability of astrocytes to buffer extracellular potassium and cytosolic calcium handling. Results are presented for both the cases of homogenous and heterogeneous capillary networks. These results demonstrate, through this interconnected model, that heterogeneity of the capillary flow results in a decrease in the ability of neurons to respond to synaptic stimulation and that intact glial function provides a further protective role for the neurons.

Collateral status, hyperglycemia, and functional outcome after acute ischemic stroke.

BACKGROUND: Mixed data exist regarding the association between hyperglycemia and functional outcome after acute ischemic stroke when accounting for the impact of leptomeningeal collateral flow. We sought to determine whether collateral status modifies the association between treatment group and functional outcome in a subset of patients with large vessel occlusion enrolled in the Stroke Hyperglycemia Insulin Network Effort (SHINE) trial. METHODS: In this post-hoc analysis, we analyzed patients enrolled into the SHINE trial with anterior circulation large vessel occlusion who underwent imaging with CT angiography prior to glucose control treatment group assignment. The primary analysis assessed the degree to which collateral status modified the effect between treatment group and functional outcome as defined by the 90-day modified Rankin Scale score. Logistic regression was used to model the data, with adjustments made for thrombectomy status, age, post-perfusion thrombolysis in cerebral infarction (TICI) score, tissue plasminogen activator (tPA) use, and baseline National Institutes of Health Stroke Scale (NIHSS) score. Five SHINE trial centers contributed data for this analysis. Statistical significance was defined as a p-value < 0.05. RESULTS: Among the 1151 patients in the SHINE trial, 57 with angiographic data were included in this sub-analysis, of whom 19 had poor collaterals and 38 had good collaterals. While collateral status had no effect (p = 0.855) on the association between glucose control treatment group and functional outcome, patients with good collaterals were more likely to have a favorable functional outcome (p = 0.001, OR 5.02; 95% CI 1.37-16.0). CONCLUSIONS: In a post-hoc analysis using a subset of patients with angiographic data enrolled in the SHINE trial, collateral status did not modify the association between glucose control treatment group and functional outcome. However, consistent with prior studies, there was a significant association between good collateral status and favorable outcome in patients with large vessel occlusion stroke. TRIAL REGISTRATION: ClinicalTrials.gov Identifier is NCT01369069. Registration date is June 8, 2011.

Mathematical modeling of cerebral capillary blood flow heterogeneity and its effect on brain tissue oxygen levels.

Maintaining cerebral blood flow is critical for adequate neuronal function. Previous computational models of brain capillary networks have predicted that heterogeneous cerebral capillary flow patterns result in lower brain tissue partial oxygen pressures PO2). However, these previous models have often considered simple capillary networks in terms of their geometric properties. In this current work, we developed and analyzed computational models of brain capillary networks to determine how perturbations of network properties impact tissue oxygen levels. The models include variabilities in both their geometric (segment lengths and diameters) and three-dimensional, topological structure. Two classes of capillary network models are considered. The first consists of equations for the oxygen partial pressure, PO2, in both a capillary network and the surrounding tissue. In order to gain insight into the behavior of this detailed model, we also consider a reduced model for changes in PO2 in just the capillary network. The main result is that for a general class of networks, random perturbations of either segment diameters or conductances will always, on average, decrease the average tissue oxygen levels. This result is supported through both simulations of the models and mathematical analysis. Our results promise to expand our understanding of cerebral capillary blood flow and its impact on the brain function in health and disease.

White Matter Injury Is Associated with Reduced Manual Dexterity and Elevated Serum Ceramides in Subjects with Cerebral Small Vessel Disease.

INTRODUCTION: We have demonstrated that asymptomatic cerebral small vessel disease (cSVD) measured by white matter hyperintensity volume is associated with reduced manipulative manual dexterity on the Grooved Peg Board Test (GPBT) in middle-aged healthy individuals with a family history of early coronary artery disease. In this current study, we aim to identify the association of subcortical white matter microstructural impairment measured by diffusion tensor imaging, manual dexterity measured by GPBT and circulating serums ceramide, another marker for white matter injury. We hypothesize that lower regional fractional anisotropy (rFA) is associated with worse performance on GPBT and elevated serum ceramides in the same study population. METHODS: rFA of 48 regions representing the subcortical white matters were analyzed in GeneSTAR participants in addition to serum ceramides and GPBT scores. Unadjusted univariable analyses with Bonferroni correction for multiple comparisons were completed using Spearman correlation for testing the associations between ceramides, rFA of subcortical white matter, and GPBT performance. Subsequently, sensitivity analyses were performed after excluding the participants that had any physical limitation that may influence their performance on GPBT. Finally, in the adjusted analysis using generalized estimating equation, linear regression models were performed for the areas that met significance threshold in the unadjusted analyses. RESULTS: 112 subjects (age [49 ± 11], 51% female, 39.3% African American) were included. Adjusted analyses for the significant correlations that met the Bonferroni correction threshold in the unadjusted univariable analyses identified significant negative associations between rFA of the right fornix (RF) and log-GPBT score (ß = -0.497, p = 0.037). In addition, rFA of RF negatively correlated with log serum ceramide levels (C18: ß = -0.03, p = 0.003, C20: ß = -0.0002, p = 0.004) and rFA of left genu of corpus callosum negatively correlated with log C18 level (ß = -0.0103, p = 0.027). CONCLUSIONS: These results demonstrate that subcortical microstructural white matter disruption is associated with elevated serum ceramides and reduced manual dexterity in a population with cSVD. These findings suggest that injury to white matter tracts undermines neural networks, with functional consequences in a middle-aged population with cardiovascular risk factors.

Early Functional Connectome Integrity and 1-Year Recovery in Comatose Survivors of Cardiac Arrest.

Purpose To assess whether early brain functional connectivity is associated with functional recovery 1 year after cardiac arrest (CA). Materials and Methods Enrolled in this prospective multicenter cohort were 46 patients who were comatose after CA. Principal outcome was cerebral performance category at 12 months, with favorable outcome (FO) defined as cerebral performance category 1 or 2. All participants underwent multiparametric structural and functional magnetic resonance (MR) imaging less than 4 weeks after CA. Within- and between-network connectivity was measured in dorsal attention network (DAN), default-mode network (DMN), salience network (SN), and executive control network (ECN) by using seed-based analysis of resting-state functional MR imaging data. Structural changes identified with fluid-attenuated inversion recovery and diffusion-weighted imaging sequences were analyzed by using validated morphologic scales. The association between connectivity measures, structural changes, and the principal outcome was explored with multivariable modeling. Results Patients underwent MR imaging a mean 12.6 days ± 5.6 (standard deviation) after CA. At 12 months, 11 patients had an FO. Patients with FO had higher within-DMN connectivity and greater anticorrelation between SN and DMN and between SN and ECN compared with patients with unfavorable outcome, an effect that was maintained after multivariable adjustment. Anticorrelation of SN-DMN predicted outcomes with higher accuracy than fluid-attenuated inversion recovery or diffusion-weighted imaging scores (area under the receiver operating characteristic curves, respectively, 0.88, 0.74, and 0.71). Conclusion MR imaging-based measures of cerebral functional network connectivity obtained in the acute phase of CA were independently associated with FO at 1 year, warranting validation as early markers of long-term recovery potential in patients with anoxic-ischemic encephalopathy. © RSNA, 2017.

Herniation despite Decompressive Hemicraniectomy in Large Hemispherical Ischemic Strokes.

BACKGROUND: Despite decompressive hemicraniectomy (DHC), progressive herniation resulting in death has been reported following middle cerebral artery (MCA) strokes. We aimed to determine the surgical parameters measured on brain computed tomography (CT) scan that are associated with progressive herniation despite DHC in large MCA strokes. METHODS: Retrospective chart review of medical records of patients with malignant hemispheric infarction who underwent DHC for cerebral edema was performed. Infarct volume was calculated on CT scans obtained within 24 hours of ictus. Radiological parameters of craniectomy bone flap size, brain volume protruding out of the skull, adequate centering of the craniectomy over the stroke bed, and the infarct volume outside the craniectomy bed (volume not centered [VNC]) were measured on the postoperative brain CT. RESULTS: Of 41 patients who underwent DHC, 7 had progressive herniation leading to death. Radiographic parameters significantly associated with progressive herniation included insufficient centering of craniectomy bed on the stroke bed (P = .03), VNC (P = .011), additional anterior cerebral artery infarction (P = .047), and smaller craniectomy length (P = .05). Multivariate logistic regression analysis for progressive herniation using craniectomy length and VNC as independent variables demonstrated that a higher VNC was significantly associated with progressive herniation despite surgery (P = .029). CONCLUSIONS: In large MCA strokes, identification of large infarct volume outside the craniectomy bed was associated with progressive herniation despite surgery. These results will need to be verified in larger prospective studies.

Mapping the Connectome Following Traumatic Brain Injury.

There is a paucity of accurate and reliable biomarkers to detect traumatic brain injury, grade its severity, and model post-traumatic brain injury (TBI) recovery. This gap could be addressed via advances in brain mapping which define injury signatures and enable tracking of post-injury trajectories at the individual level. Mapping of molecular and anatomical changes and of modifications in functional activation supports the conceptual paradigm of TBI as a disorder of large-scale neural connectivity. Imaging approaches with particular relevance are magnetic resonance techniques (diffusion weighted imaging, diffusion tensor imaging, susceptibility weighted imaging, magnetic resonance spectroscopy, functional magnetic resonance imaging, and positron emission tomographic methods including molecular neuroimaging). Inferences from mapping represent unique endophenotypes which have the potential to transform classification and treatment of patients with TBI. Limitations of these methods, as well as future research directions, are highlighted.

Abnormal movements in critical care patients with brain injury: a diagnostic approach.

Abnormal movements are frequently encountered in patients with brain injury hospitalized in intensive care units (ICUs), yet characterization of these movements and their underlying pathophysiology is difficult due to the comatose or uncooperative state of the patient. In addition, the available diagnostic approaches are largely derived from outpatients with neurodegenerative or developmental disorders frequently encountered in the outpatient setting, thereby limiting the applicability to inpatients with acute brain injuries. Thus, we reviewed the available literature regarding abnormal movements encountered in acutely ill patients with brain injuries. We classified the brain injury into the following categories: anoxic, vascular, infectious, inflammatory, traumatic, toxic-metabolic, tumor-related and seizures. Then, we identified the abnormal movements seen in each category as well as their epidemiologic, semiologic and clinicopathologic correlates. We propose a practical paradigm that can be applied at the bedside for diagnosing abnormal movements in the ICU. This model seeks to classify observed abnormal movements in light of various patient-specific factors. It begins with classifying the patient's level of consciousness. Then, it integrates the frequency and type of each movement with the availability of ancillary diagnostic tests and the specific etiology of brain injury.

MRI for coma emergence and recovery.

PURPOSE OF REVIEW: Data from MRI can be used to generate detailed maps of central nervous system anatomy and functional activation. Here, we review new research that integrates advanced MRI acquisition and analysis to predict and track recovery following severe traumatic brain injury (TBI) or anoxic ischemic encephalopathy (AIE) following cardiac arrest. RECENT FINDINGS: Diffusion tensor MRI studies of comatose TBI patients demonstrate specific distributions of white matter damage that are robustly associated with long-term functional outcomes. In unconscious patients with AIE, whole brain diffusion restriction has prognostic significance, as do regional changes in diffusion restriction or anisotropy. Results using functional MRI suggest that coma following TBI and cardiac arrest is associated with disconnections within cerebral architectures associated with arousal and conscious perception. The relation between these disconnections and postinjury recovery is being explored in ongoing cohorts. SUMMARY: MRI of the brain is feasible in critically ill patients following TBI or cardiac arrest, revealing patterns of structural damage and functional disconnection that can help predict outcome in the long term. Prospective studies are needed to validate these findings and to identify relationships between MRI-defined alterations and specific postinjury cognitive and behavioural phenotypes.

Prevalence of Electrographic Seizures in Hospitalized Patients With Altered Mental Status With No Significant Seizure Risk Factors Who Underwent Continuous EEG Monitoring: A Retrospective Study.

OBJECTIVES: The objective of this study is to evaluate the prevalence of electrographic seizures in hospitalized patients with altered mental status and no significant risk factors for seizures. METHODS: We retrospectively reviewed over a six-year period (2013-2019) the medical records of all adults admitted at Ohio State University Wexner Medical Center (OSUWMC), who underwent continuous electroencephalography (cEEG) monitoring for > 48 hours. Our primary objective was to identify the prevalence of electrographic seizures in patients with altered mental status and no significant acute or remote risk factors for seizures. RESULTS: A total of 1966 patients were screened for the study, 1892 were excluded (96.2%) and 74 patients met inclusion criteria. Electrographic seizures were identified in seven of 74 patients (9.45%). We found a significant correlation between electrographic seizures and a history of hepatic cirrhosis, n= 4 (57%), (p=0.035), acute chronic hepatic failure during admission, 71% (n=5), (p=0.027), and hyperammonemia (p =0.009). CONCLUSION: In this retrospective study of patients with altered mental status and no significant acute or remote risk factors for seizures who underwent cEEG monitoring for > 48 hours, electrographic seizures were identified in 9.45%. Electrographic seizures were associated with hepatic dysfunction and hyperammonemia. Based on our results, cEEG monitoring should be considered in patients with altered mental status and hepatic dysfunction even in the absence of other seizure risk factors.

Intravenous Odatroltide for Acute Ischemic Stroke Within 24 Hours of Onset: A Phase 2, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study.

Purpose: Odatroltide (LT3001), a novel small synthetic peptide molecule designed to recanalize occluded blood vessels and reduce reperfusion injury, is safe and efficacious in multiple embolic stroke animal models. This study aimed to investigate the safety and tolerability of intravenous administration of odatroltide in patients with acute ischemic stroke within 24 hours of onset. Patients and Methods: Patients with National Institutes of Health Stroke Scale (NIHSS 4-30) who were untreated with intravenous thrombolysis or endovascular thrombectomy were randomized (2:1) to receive a single dose of odatroltide (0.025 mg/kg) or placebo within 24 hours of stroke symptom onset. The primary safety outcome was symptomatic intracranial hemorrhage (sICH) occurrence within 36 hours. Results: Twenty-four patients were enrolled and randomized; of these 16 and 8 received intravenous odatroltide infusion and placebo, respectively. sICH did not occur in both groups, and other safety measures were comparable between the groups. The rate of excellent functional outcome (modified Rankin Scale score, 0-1, at 90 days) was 21% and 14% in the odatroltide and placebo groups, respectively. Furthermore, 47% and 14% of patients in the odatroltide and placebo groups, respectively, showed major neurological improvement (NIHSS improvement ≥4 points from baseline to 30 days). Among the 9 odatroltide-treated patients with baseline NIHSS ≥6, 78% showed major neurological improvement. Conclusion: Compared with placebo, treatment with intravenous odatroltide within 24 hours following onset of ischemic stroke appears to be safe and may be associated with better neurological and functional outcomes. However, the efficacy and safety of odatroltide requires further confirmation in the next phase of clinical trials. Clinical Trial Registration: Clinicaltrials.gov identifier: NCT04091945.

Premorbid Blood Pressure Control Modifies Risk of DWI Lesions With Acute Blood Pressure Reduction in Intracerebral Hemorrhage.

BACKGROUND: Hypoperfusion due to blood pressure (BP) reduction is a potential mechanism of cerebral ischemia after intracerebral hemorrhage. However, prior evaluations of the relationship between BP reduction and ischemia have been conflicting. Untreated chronic hypertension is common in intracerebral hemorrhage and alters cerebral autoregulation. We hypothesized that the risk of diffusion-weighted imaging (DWI) hyperintensities from acute BP reduction is modified by premorbid BP control. METHODS: Individuals enrolled in the ERICH study (Ethnic/Racial Variations of Intracerebral Hemorrhage) from 2010 to 2015 were categorized as untreated, treated, or nonhypertensive based on preintracerebral hemorrhage diagnosis and antihypertensive medication use. The percent reduction of systolic BP (SBP) was calculated between presentation and 24 hours from admission. The primary outcome was the presence of DWI lesions. Using logistic regression, we tested the association between chronic hypertension status, SBP reduction, and their interaction with DWI lesion presence. RESULTS: From 3000 participants, 877 with available magnetic resonance imaging met inclusion (mean age, 60.5±13.3 years; 42.5% women). DWI lesions were detected in 25.9%. Untreated, treated, and no hypertension accounted for 32.6%, 47.9%, and 19.5% of cases, respectively. SBP reduction was not directly associated with DWI lesions; however, an interaction effect was observed between SBP reduction and chronic hypertension status (P=0.036). Nonhypertensive subjects demonstrated a linear risk of DWI lesion presence with greater SBP reduction, whereas untreated hypertension demonstrated a stable risk across a wide range of SBP reduction (P=0.023). CONCLUSIONS: Premorbid BP control, especially untreated hypertension, may influence the relationship between DWI lesions and acute BP reduction after intracerebral hemorrhage. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01202864.

Stroke-associated pneumonia: major advances and obstacles.

BACKGROUND: Stroke-associated pneumonia (SAP) has been implicated in the morbidity, mortality and increased medical cost after acute ischemic stroke. The annual cost of SAP during hospitalization in the United States approaches USD 459 million. The incidence and prognosis of SAP among intensive care unit (ICU) patients have not been thoroughly investigated. We reviewed the pathophysiology, microbiology, incidence, risk factors, outcomes and prophylaxis of SAP with special attention to ICU studies. METHODS: To determine the incidence, risk factors and prognosis of acute SAP, PubMed was searched using the terms 'pneumonia' AND 'neurology intensive unit' and the MeSH terms 'stroke' AND 'pneumonia'. Non-English literature, case reports and chronic SAP studies were excluded. Studies were classified into 5 categories according to the setting they were performed in: neurological intensive care units (NICUs), medical intensive care units (MICUs), stroke units, mixed studies combining more than one setting or when the settings were not specified and rehabilitation studies. RESULTS: The incidences of SAP in the following settings were: NICUs 4.1-56.6%, MICUs 17-50%, stroke units 3.9-44%, mixed studies 3.9-23.8% and rehabilitation 3.2-11%. The majority of NICU and MICU studies were heterogeneous including different neurovascular diseases, which partly explains the wide range of SAP incidence. The higher incidence in the majority of ICU studies compared to stroke units or acute floor studies is likely explained by the presence of mechanical ventilation, higher stroke severity causing higher rates of aspiration and stroke-induced immunodepression among ICU patients. The short-term mortality of SAP was increased among the mixed and stroke unit studies ranging between 10.1 and 37.3%. SAP was associated with worse functional outcome in the majority of stroke unit and floor studies. Mortality was less consistent among NICU and MICU studies. This difference could be due to the heterogeneity of ICU studies and the effect of small sample size or other independent risk factors for mortality such as the larger neurological deficit, mechanical ventilation, and age, which may simultaneously increase the risk of SAP and mortality confounding the outcomes of SAP itself. The pathophysiology of SAP is likely explained by aspiration combined with stroke-induced immunodepression through complex humeral and neural pathways that include the hypothalamic-pituitary-adrenal axis, parasympathetic and sympathetic systems. CONCLUSIONS: A unified definition of SAP, strict inclusion criteria, and the presence of a long-term follow-up need to be applied to the future prospective studies to better identify the incidence and prognosis of SAP, especially among ICU patients.

Cerebral Small Vessel Disease: a Review of the Pathophysiological Mechanisms.

Cerebral small vessel disease (cSVD) refers to the age-dependent pathological processes involving the brain small vessels and leading to vascular cognitive impairment, intracerebral hemorrhage, and acute lacunar ischemic stroke. Despite the significant public health burden of cSVD, disease-specific therapeutics remain unavailable due to the incomplete understanding of the underlying pathophysiological mechanisms. Recent advances in neuroimaging acquisition and processing capabilities as well as findings from cSVD animal models have revealed critical roles of several age-dependent processes in cSVD pathogenesis including arterial stiffness, vascular oxidative stress, low-grade systemic inflammation, gut dysbiosis, and increased salt intake. These factors interact to cause a state of endothelial cell dysfunction impairing cerebral blood flow regulation and breaking the blood brain barrier. Neuroinflammation follows resulting in neuronal injury and cSVD clinical manifestations. Impairment of the cerebral waste clearance through the glymphatic system is another potential process that has been recently highlighted contributing to the cognitive decline. This review details these mechanisms and attempts to explain their complex interactions. In addition, the relevant knowledge gaps in cSVD mechanistic understanding are identified and a systematic approach to future translational and early phase clinical research is proposed in order to reveal new cSVD mechanisms and develop disease-specific therapeutics.

Characterizing CD38 Expression and Enzymatic Activity in the Brain of Spontaneously Hypertensive Stroke-Prone Rats.

Background: CD38 is a transmembrane glycoprotein that catabolizes nicotinamide adenine dinucleotide (NAD+) and is the main source for the age-dependent decrease in NAD+ levels. Increased CD38 enzymatic activity has been implicated in several neurological diseases. However, its role in the pathogenesis of cerebral small vessel disease (CSVD) remains unknown. We aimed to characterize CD38 expression and enzymatic activity in the brain of spontaneously hypertensive stroke-prone rats (SHRSP), a genetic model for hypertension and human CSVD, in comparison to age-matched normotensive Wistar Kyoto rats (WKY). Materials and Methods: Age-matched male 7- and 24-week-old WKY and SHRSP were studied. CD38 enzymatic activity was determined in the brain homogenate. Immunohistochemistry and Western Blotting (WB) were used to characterize CD38 expression and localize it in the different cell types within the brain. In addition, expression of nitric oxide synthase (NOS) isoforms and the levels of nitric oxide (NO), superoxide, nicotinamide dinucleotide (phosphate) NAD(P)H were measured the brain of in WKY and SHRSP. Results: CD38 expression and enzymatic activity were increased in SHRSP brains compared to age matched WKY starting at 7 weeks of age. CD38 expression was localized to the endothelial cells, astrocytes, and microglia. We also identified increased CD38 expression using WB with age in SHRSP and WKY. CD38 enzymatic activity was also increased in 24-week SHRSP compared to 7-week SHRSP. In association, we identified evidence of oxidative stress, reduced NO level, reduced NAD(P)H level and endothelial NOS expression in SHRSP compared to age matched WKY. NAD(P)H also decreased with age in WKY and SHRSP. Additionally, activation of astrocytes and microglia were present in SHRSP compared to WKY. Conclusions: CD38 is overexpressed, and its enzymatic activity is increased in SHRSP, a genetic model for marked hypertension and human CSVD. Our results suggest a potential role for CD38 enzymatic activation in the pathogenesis of CSVD and points to the need for future mechanistic and pharmacological studies.

Evaluation of energy intake compared with indirect calorimetry requirements in critically ill patients with acute brain injury.

BACKGROUND: Nutrition support in critically ill patients with acute brain injury is vitally important because of known hypermetabolism. We aimed to describe energy and protein intake within the first 72 h in a broad neurocritical care population and compare energy intake with the indirect calorimetry (IC) resting energy expenditure (REE) target. METHODS: IC data, daily energy, and protein intake were collected through chart review over the first 7 days of hospital admission. We evaluated the type and amount of tube-feed product received, volume of propofol (1.1 kcal/ml) and clevidipine (2 kcal/ml), and amount of supplemental protein received. RESULTS: Ninety-one patients were included, with the majority presenting with either intracerebral hemorrhage (35.2%) or acute ischemic stroke (26.4%). The median day of admission on which IC was completed and enteral nutrition was initiated was day 3 (2-5) and day 1 (1-2), respectively. The difference in kilocalories received compared with IC REE target within the first 72 h was significantly different (2831 kcal [1663-4072] vs 4275 kcal [3450-5811]; Z = -6.469; P < .001). The median kilocalories received as tube feeds during the first 72 h was 88% (55%-99%), and the mean protein received in the first 72 h was 0.7 ± 0.5 g/kg/day. CONCLUSION: In this population, patients had lower energy intake compared with their energy needs determined by IC during the first 72 h of admission but attained 7-day goals. Future studies should investigate barriers to improve energy delivery in this patient population.

Association of Vascular Properties With the Brain White Matter Hyperintensity in Middle-Aged Population.

Background The periventricular white matter is more sensitive to the systemic hemodynamic alterations than the deep white matter because of differences in its vascular structure and systemic circulation relationship. We hypothesize that periventricular white matter hyperintensity (PVWMH) volume shows greater association than deep white matter hyperintensity (DWMH) volume with vascular properties (VPs) reflecting arterial stiffness and cardiovascular remodeling, indicators of the systemic circulation. Methods and Results A total of 426 participants (age, 59.0±6.1 years; 57.5% women; and 39.7% Black race) in the Genetic Study of Atherosclerosis Risk who were aged ≥50 years and had brain magnetic resonance imaging were studied. VPs included pulse pressure, hypertensive response to exercise, diastolic brachial artery diameter, diastolic common carotid artery diameter, common carotid artery distensibility coefficient, and left ventricular function. The relative associations of VPs with PVWMH and DWMH as multiple measures within the same individual were determined using multilevel linear models. We also determined if age modified the differences in VPs associations with PVWMH and DWMH. Our findings indicated that, within the same subject, PVWMH volume had greater association than DWMH volume with pulse pressure (P=0.002), hypertensive response to exercise (P=0.04), diastolic brachial artery diameter (P=0.012), and diastolic common carotid artery diameter (P=0.04), independent of age and cardiovascular risk factors. The differences of PVWMH versus DWMH associations with VPs did not differ at any age threshold. Conclusions We show, for the first time, that PVWMH has greater association than DWMH, independent of age, with vascular measurements of arterial stiffness and cardiovascular remodeling suggesting that changes in the systemic circulation affect the PVWMH and DWMH differently.