Atypical Structural Connectivity and Integrity in Children with Hydrocephalus and its Relation to Executive Function

Infants with hydrocephalus are a high-risk group for adverse neurodevelopmental outcomes, including impairments in executive functions such as goal-directed behaviour, focusing, and shifting attention. The current pilot study aimed to profile white matter and executive dysfunction in school-aged children with ventriculoperitoneal (VP) shunted hydrocephalus and age-matched healthy controls using the Behaviour Rating Inventory for Executive Functions and diffusion tensor imaging. To assess the degree of similarity between patient structural networks and controls, probabilistic streamlines between striatal and cortical regions and their respective diffusivity metrics were assessed. For a number of patients with hydrocephalus, white matter in the striatal-executive network showed significant deviation from a healthy control profile. Patients with higher global executive dysfunction also had lower correlations of striatal-executive fractional anisotropy with the healthy control profile. Future studies with larger samples can explore factors such as etiology that are likely to contribute to aberrant white matter and executive dysfunction

3D Ultrasound in the Management of Post Hemorrhagic Ventricle Dilatation

Enlargement of the cerebral ventricles is relatively common among extremely preterm neonates born before 28 weeks gestational age. One common cause of ventricle dilatation is post hemorrhagic ventricle dilatation following a bleed in the cerebral ventricles. While many neonates with PHVD will have spontaneous resolution of the condition, severe, persistent PHVD is associated with a greater risk of brain injury and morbidity later in life and left untreated can cause death. The current clinical management strategy consists of daily measurements of head circumference and qualitative interpretation of two-dimensional US images to detect ventricular enlargement and monitoring vital signs for indications increased intracranial pressure (i.e. apnea, bradycardia). Despite the widespread clinical use of these indicators, they do not have the specificity to reliably indicate when an intervention to remove some CSF is required to prevent brain damage. Early recognition of interventional necessity using quantitative measurements could help with the management of the disease, and could lead to better care in the future. Our objective was to develop and validate a three-dimensional ultrasound system for use within an incubator of neonates with PHVD in order to accurately measure the cerebral ventricle volume. This system was validated against known geometric phantoms as well as a custom ventricle-like phantom. Once validated, the system was used in a clinical study of 70 neonates with PHVD to measure the ventricle size. In addition to three-dimensional ultrasound, clinical ultrasound images, and MRIs were attained. Clinical measurements of the ventricles and three-dimensional ultrasound ventricle volumes were used to determine thresholds between neonates with PHVD who did and did not receive interventions based on current clinical management. We determined image based thresholds for intervention for both neonates who will receive an initial intervention, as well as those who will receive multiple interventions. Three-dimensional ultrasound based ventricle volume measurements had high sensitivity and specificity as patients with persistent PHVD have ventricles that increase in size faster than those who undergo resolution. This allowed for delineation between interventional and non-interventional patients within the first week of life. While this is still a small sample size study, these results can give rise to larger studies that would be able to determine if earlier intervention can result in better neurodevelopmental outcomes later in life