virtual-reality-tools-for-assessing-unilateral-spatial-neglect-novel

Virtual Reality Tools for Assessing Unilateral Spatial Neglect: A Novel Opportunity for Data Collection

Unilateral spatial neglect (USN) is a syndrome characterized by inattention to or inaction in one side of space and affects between 23-46% of acute stroke ...

University of Pennsylvania

The early postoperative period following neonatal cardiac surgery is a time of increased risk for brain injury, yet the mechanisms underlying this risk are unknown. To understand these risks more completely, we quantified changes in postoperative cerebral metabolic rate of oxygen (CMRO(2)), oxygen extraction fraction (OEF), and cerebral blood flow (CBF) compared with preoperative levels by using noninvasive optical modalities.

Early postoperative changes in cerebral oxygen metabolism following neonatal cardiac surgery: effects of surgical duration.

Sodium bicarbonate (NaHCO3) is a common treatment for metabolic acidemia; however, little definitive information exists regarding its treatment efficacy and cerebral hemodynamic effects. This pilot observational study quantifies relative changes in cerebral blood flow (Î”rCBF) and oxy- and deoxyhemoglobin concentrations (Î”HbO2 and Î”Hb) due to bolus administration of NaHCO3 in patients with mild base deficits.

Sodium bicarbonate causes dose-dependent increases in cerebral blood flow in infants and children with single-ventricle physiology.

To develop a valid, reliable, and simple-to-use semiquantitative visual scale of fetal brain maturation for use in clinical fetal MR imaging assessment and interpretation.

Development and validation of a semiquantitative brain maturation score on fetal MR images: initial results.

Neonatal congenital heart disease (CHD) is associated with altered cerebral hemodynamics and increased risk of brain injury. Two novel noninvasive techniques, magnetic resonance imaging (MRI) and diffuse optical and correlation spectroscopies (diffuse optical spectroscopy (DOS), diffuse correlation spectroscopy (DCS)), were employed to quantify cerebral blood flow (CBF) and oxygen metabolism (CMRO(2)) of 32 anesthetized CHD neonates at rest and during hypercapnia. Cerebral venous oxygen saturation (S(v)O(2)) and CBF were measured simultaneously with MRI in the superior sagittal sinus, yielding global oxygen extraction fraction (OEF) and global CMRO(2) in physiologic units. In addition, microvascular tissue oxygenation (StO(2)) and indices of microvascular CBF (BFI) and CMRO(2) (CMRO(2)(i)) in the frontal cortex were determined by DOS/DCS. Median resting-state MRI-measured OEF, CBF, and CMRO(2) were 0.38, 9.7 mL/minute per 100 g and 0.52 mL O(2)/minute per 100 g, respectively. These CBF and CMRO(2) values are lower than literature reports for healthy term neonates (which are sparse and quantified using different methods) and resemble values reported for premature infants. Comparison of MRI measurements of global S(v)O(2), CBF, and CMRO(2) with corresponding local DOS/DCS measurements demonstrated strong linear correlations (R(2)=0.69, 0.67, 0.67; P<0.001), permitting calibration of DOS/DCS indices. The results suggest that MRI and optics offer new tools to evaluate cerebral hemodynamics and metabolism in CHD neonates.

Cerebral oxygen metabolism in neonates with congenital heart disease quantified by MRI and optics.

Cerebral oxygen extraction, defined as the difference between arterial and venous oxygen saturations (SaO2 and SvO2), is a critical parameter for managing intensive care patients at risk for neurological collapse. Although quantification of SaO2 is easily performed with pulse oximetry or moderately invasive arterial blood draws in peripheral vessels, cerebral SvO2 is frequently not monitored because of the invasiveness and risk associated with obtaining jugular bulb or super vena cava (SVC) blood samples.

Noninvasive optical quantification of cerebral venous oxygen saturation in humans.

Hypoxic-ischemic white mater brain injury commonly occurs in neonates with hypoplastic left heart syndrome (HLHS). Approximately one half of HLHS survivors will exhibit neurobehavioral symptoms believed to be associated with this injury, although the exact timing of the injury is unknown.

Time to surgery and preoperative cerebral hemodynamics predict postoperative white matter injury in neonates with hypoplastic left heart syndrome.

Single-ventricle patients undergoing surgical reconstruction experience a high rate of brain injury. Incidental findings on preoperative brain scans may result in safety considerations involving hemorrhage extension during cardiopulmonary bypass that result in surgical postponement.

Brain magnetic resonance immediately before surgery in single ventricles and surgical postponement.

Currently two magnetic resonance imaging (MRI) methods have been used to assess periventricular leukomalacia (PVL) severity in infants with congenital heart disease: manual volumetric lesion segmentation and an observational categorical scale. Volumetric classification is labor intensive and the categorical scale is quick but unreliable. We propose the quartered point system (QPS) as a novel, intuitive, time-efficient metric with high interrater agreement.

Scoring system for periventricular leukomalacia in infants with congenital heart disease.

Patients with a single ventricle experience a high rate of brain injury and adverse neurodevelopmental outcome; however, the incidence of brain abnormalities throughout surgical reconstruction and their relationship with cerebral blood flow, oxygen delivery, and carbon dioxide reactivity remain unknown.

Article	Year
Early postoperative changes in cerebral oxygen metabolism following neonatal cardiac surgery: effects of surgical duration. The Journal of thoracic and cardiovascular surgery\| PubMed ID: 23111021	2013
Sodium bicarbonate causes dose-dependent increases in cerebral blood flow in infants and children with single-ventricle physiology. Pediatric research\| PubMed ID: 23403802	2013
Development and validation of a semiquantitative brain maturation score on fetal MR images: initial results. Radiology\| PubMed ID: 23440324	2013
Cerebral oxygen metabolism in neonates with congenital heart disease quantified by MRI and optics. Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism\| PubMed ID: 24326385	2014
Noninvasive optical quantification of cerebral venous oxygen saturation in humans. Academic radiology\| PubMed ID: 24439329	2014
Time to surgery and preoperative cerebral hemodynamics predict postoperative white matter injury in neonates with hypoplastic left heart syndrome. The Journal of thoracic and cardiovascular surgery\| PubMed ID: 25109755	2014
Brain magnetic resonance immediately before surgery in single ventricles and surgical postponement. The Annals of thoracic surgery\| PubMed ID: 25149046	2014
Scoring system for periventricular leukomalacia in infants with congenital heart disease. Pediatric research\| PubMed ID: 25996891	2015
Neurological Injury and Cerebral Blood Flow in Single Ventricles Throughout Staged Surgical Reconstruction. Circulation\| PubMed ID: 28031423	2017

Peter J. Schwab

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