Stereotactic and Functional Neurosurgery Convection-Enhanced Delivery of Autologous Cerebrospinal Fluid Enhances Basal Ganglia Visualization during MRI-Guided Deep Brain Stimulation Surgery.

INTRODUCTION: The aim of this study was to determine the safety and feasibility of convection-enhanced delivery of autologous cerebrospinal fluid (CSF) for enhancing intraoperative magnetic resonance imaging (MRI) of the basal ganglia during stereotactic neurosurgery. METHODS: This pilot study was conducted in 4 patients with Parkinson\u27s disease (PD) who underwent MRI-guided deep brain stimulation of the globus pallidus internus (GPi). CSF was obtained via lumbar puncture after general anesthesia and prior to incision. A frameless stereotaxy system was installed, and an infusion catheter was inserted to the GPi using intraoperative MRI. Infusion of autologous CSF was performed at a convective rate of 5 µL/min with a maximum volume of infusion (Vi) of 500 mL. T2-weighted MRI scans were obtained every 15 min up to a maximum of 105 min in order to calculate the volume of distribution (Vd). Safety was assessed with adverse event monitoring, and clinical outcomes were measured with changes in unmedicated UPDRS part III and PDQ-39 scores from baseline to 6 months postoperatively. RESULTS: All four infusions were safe and without adverse events. The mean unmedicated UPDRS part III and PDQ-39 scores improved by 24% and 26%, respectively. The Vd:Vi ratio ranged from 2.2 to 2.8 and peaked 45 min from the onset of infusion, which is when the borders of the GPi could generally be visualized based on T2-weighted MRI. Two patients underwent refinement of the stereotactic targeting based on infusion-enhanced images. CONCLUSIONS: The convective administration of autologous CSF to deep brain structures appears safe and feasible for enhancing intraoperative MRI during stereotactic procedures. Infusion-enhanced imaging with target-specific infusates could be developed to visualize neurochemical circuits or cellular regions that currently are not seen with anatomic/structural MRI

Neurological Surgery Training Abroad as a Progression to the Final Year of Training and Transition to Independent Practice

BACKGROUND: Residents at the University of Virginia spend 1 year abroad at a neurological surgery program prior to their chief year. The Accreditation Council for Graduate Medical Education (ACGME) considers international rotations elective experiences and does not count them toward clinical accreditation. OBJECTIVE: We compared clinical training obtained in New Zealand (NZ) to data from US ACGME-accredited programs to see if it was reasonable to reconsider the former as clinical training. METHODS: We compared US national average chief case volumes to those performed by University of Virginia residents rotating in NZ over the past 3 years, using case volume comparisons and a survey of the residents' experience. RESULTS: The mean number of cases performed in NZ was above the 50th percentile for US averages for adult cranial cases, including the 70th to 90th percentile for aneurysms and 50th to 70th percentile for tumors. The average number of cases performed in 1 year in NZ satisfied the cranial case quota for 4 of 6 adult and 2 of 3 pediatric areas over the entire residency. The rotation doubled the cranial exposure of graduating residents at the chief level without diluting the experience of residents in the core program. All residents reported being “very satisfied” with the experience, noting it facilitated their transition to chief year and independent practice. CONCLUSIONS: Clinical training obtained during an international rotation in NZ is comparable to that attained in the United States. The international experience in NZ facilitated advancement in all 6 competencies, and should be considered adequate for clinical neurological surgery education