Hardware improvement in cold pressor test and Peltier system for measurement of hemodynamic response to pain by fNIR spectroscopy

Functional Near-Infrared (fNIR) spectroscopy is a relatively new imaging technology which allows a continuous and non-invasive monitoring of changes in cerebral hemodynamics and blood oxygenation. A number of studies have reported changes in the hemodynamic activity in response to experimental pain in human subjects using several imaging modalities, including fMRI and laser Doppler sonography/flowmetry. In our lab (CONQUER CollabOrative, Drexel University) fNIR is employed to study the changes in hemodynamic responses to acute cold pain. The hemodynamic response to different levels of pain has been investigated at our lab by delivering cold noxious stimuli by limb immersion in cold water a.ka. cold pressor test (CPT) and through ceramic plates (Peltier device) respectively. Two configurations of ‘far’ and ‘near’ optode spacing were used to investigate both pain-related cortical as well as systemic hemodynamic changes. However, the existing sensor used for capturing the fNIR recording needed some further hardware improvement to eliminate the glitches in smooth experimentation. Moreover, there was a critical need for developing corresponding adapter circuit for the control circuit used for operating the light sources and photo-detectors of the fNIR sensors. Furthermore, optimum parameters to be used for delivering cold noxious stimuli needed to be investigated for the existing peltier device setup. This thesis addresses these hardware designs and development concerns done to achieve better experimentation. Results from tolerance tests using CPT suggest that the systemic change in the blood flow in response to acute episodes of cold painful stimuli can be objectively monitored and assessed through the biological marker measured by fNIR spetroscopy. Results from Peltier study suggest that noxious cold stimuli evoke a less generalized hemodynamic response when compared with CPTs, which is yet detectable with fNIR spectroscopy.M.S., Biomedical Engineering -- Drexel University, 201

Non-invasive Assessment of Cerebral Blood Flow and Oxygen Metabolism in Neonates during Hypothermic Cardiopulmonary Bypass: Feasibility and Clinical Implications

The neonatal brain is extremely vulnerable to injury during periods of hypoxia and/or ischemia. Risk of brain injury is increased during neonatal cardiac surgery, where pre-existing hemodynamic instability and metabolic abnormalities are combined with long periods of low cerebral blood flow and/or circulatory arrest. Our understanding of events associated with cerebral hypoxia-ischemia during cardiopulmonary bypass (CPB) remains limited, largely due to inadequate tools to quantify cerebral oxygen delivery and consumption non-invasively and in real-time. This pilot study aims to evaluate cerebral blood flow (CBF) and oxygen metabolism (CMRO2) intraoperatively in neonates by combining two novel non-invasive optical techniques: frequency-domain near-infrared spectroscopy (FD-NIRS) and diffuse correlation spectroscopy (DCS). CBF and CMRO2 were quantified before, during and after deep hypothermic cardiopulmonary bypass (CPB) in nine neonates. Our results show significantly decreased CBF and CMRO2 during hypothermic CPB. More interestingly, a change of coupling between both variables is observed during deep hypothermic CPB in all subjects. Our results are consistent with previous studies using invasive techniques, supporting the concept of FD-NIRS/DCS as a promising technology to monitor cerebral physiology in neonates providing the potential for individual optimization of surgical management

Florid expansile cemento-osseous dysplasia of the jaws: Cone beam computed tomography study and review of the literature

An interesting case of florid expansile cemento-osseous dysplasia (FECOD) of the maxilla and mandible in a 36-year-old female is being presented. The patient presented for consultation for orthognathic surgery and was unaware of these lesions. Upon clinical and radiographic examination, including cone beam computed tomography, massive cemento-osseous lesions in all quadrants were observed. The radiographic appearance of the lesions was consistent with cemento-osseous dysplasia (COD), the key difference being extreme expansion. Expansion, although not a new phenomenon, is present in all quadrants. These radiographic features suggest a variation of florid cemento-osseous dysplasia and is more aptly termed FECOD. This name is proposed for its diagnostic relevance based on the radiographic features. As with similar CODs, unless the lesions are disfiguring, conservative management is the preferred approach. Biopsy was not indicated unless there are additional associated complications. A detailed review of the pertinent literature was undertaken

Optimizing Unanesthetized Cerebral Oxygen Consumption Measures: Comparison of NIRS and MRI Approaches in Neonates with Congenital Heart Disease

Cerebral perfusion in neonates with congenital heart disease is a clinical concern. Combined measures of MRI and NIRS can provide complementary information to improve monitoring. We compare multimodal measures of cerebral hemodynamics in this group

Increased Breastfeeding Proportion Is Associated with Improved Gross Motor Skills at 3–5 Years of Age: A Pilot Study

Breastmilk provides key nutrients and bio-active factors that contribute to infant neurodevelopment. Optimizing maternal nutrition could provide further benefit to psychomotor outcomes. Our observational cohort pilot study aims to determine if breastfeeding extent and breastmilk nutrients correlate with psychomotor outcomes at school age. The breastfeeding proportion at 3 months of age and neurodevelopmental outcomes at 3–5 years of age were recorded for 33 typically developing newborns born after uncomplicated pregnancies. The association between categorical breastfeeding proportion and neurodevelopmental outcome scores was determined for the cohort using a Spearman correlation with and without the inclusion of parental factors. Vitamin E and carotenoid levels were determined in breastmilk samples from 14 of the mothers. After the inclusion of parental education and income as covariates, motor skill scores positively correlated with breastmilk contents of α-tocopherol (Spearman coefficient 0.88, p-value = 0.02), translutein (0.98, p-value = 0.0007), total lutein (0.92, p-value = 0.01), and zeaxanthin (0.93, p-value = 0.0068). Problem solving skills negatively correlated with the levels of the RSR enantiomer of α-tocopherol (−0.86, p-value = 0.03). Overall, higher exposure to breastfeeding was associated with improved gross motor and problem-solving skills at 3–5 years of age. The potential of α-tocopherol, lutein, and zeaxanthin intake to provide neurodevelopmental benefit is worthy of further investigation

Assessment of Maternal Macular Pigment Optical Density (MPOD) as a Potential Marker for Dietary Carotenoid Intake during Lactation in Humans

Pregnancy and lactation can change the maternal nutrient reserve. Non-invasive, quantitative markers of maternal nutrient intake could enable personalized dietary recommendations that improve health outcomes in mothers and infants. Macular pigment optical density (MPOD) is a candidate marker, as MPOD values generally reflect carotenoid intake. We evaluated the association of MPOD with dietary and breastmilk carotenoids in postpartum women. MPOD measurements and dietary intake of five carotenoids were obtained from 80 mothers in the first three months postpartum. Breastmilk samples from a subset of mothers were analyzed to determine their nutrient composition. The association between MPOD and dietary or breastmilk carotenoids was quantitatively assessed to better understand the availability and mobilization of carotenoids. Our results showed that dietary α-carotene was positively correlated with MPOD. Of the breastmilk carotenoids, 13-cis-lutein and trans-lutein were correlated with MPOD when controlled for the total lutein in breastmilk. Other carotenoids in breastmilk were not associated with MPOD. Maternal MPOD is positively correlated with dietary intake of α-carotene in the early postpartum period, as well as with the breastmilk content of lutein. MPOD may serve as a potential marker for the intake of carotenoids, especially α-carotene, in mothers in the early postpartum period

Improving Infant Hydrocephalus Outcomes in Uganda: A Longitudinal Prospective Study Protocol for Predicting Developmental Outcomes and Identifying Patients at Risk for Early Treatment Failure after ETV/CPC

Infant hydrocephalus poses a severe global health burden; 80% of cases occur in the developing world where patients have limited access to neurosurgical care. Surgical treatment combining endoscopic third ventriculostomy and choroid plexus cauterization (ETV/CPC), first practiced at CURE Children’s Hospital of Uganda (CCHU), is as effective as standard ventriculoperitoneal shunt (VPS) placement while requiring fewer resources and less post-operative care. Although treatment focuses on controlling ventricle size, this has little association with treatment failure or long-term outcome. This study aims to monitor the progression of hydrocephalus and treatment response, and investigate the association between cerebral physiology, brain growth, and neurodevelopmental outcomes following surgery. We will enroll 300 infants admitted to CCHU for treatment. All patients will receive pre/post-operative measurements of cerebral tissue oxygenation (SO2), cerebral blood flow (CBF), and cerebral metabolic rate of oxygen consumption (CMRO2) using frequency-domain near-infrared combined with diffuse correlation spectroscopies (FDNIRS-DCS). Infants will also receive brain imaging, to monitor tissue/ventricle volume, and neurodevelopmental assessments until two years of age. This study will provide a foundation for implementing cerebral physiological monitoring to establish evidence-based guidelines for hydrocephalus treatment. This paper outlines the protocol, clinical workflow, data management, and analysis plan of this international, multi-center trial