Safety and tolerability through assessment of adverse events, ECGs, vital signs, clinical laboratory variables, MRI of brain and spinal cord, CSF sampling, and device performance as characterized by catheter tip placement and infusion accuracy. Multiple over 3 months [clinicaltrials_resource:089d96cdf1290d7478e93151bab4ca93]

Continuous ICV infusion for two weeks at one of three dose levels

Safety and tolerability through assessment of adverse events, ECGs, vital signs, clinical laboratory variables, MRI of brain and spinal cord, CSF sampling, and device performance as characterized by catheter tip placement and infusion accuracy. Multiple over 3 months [clinicaltrials_resource:089d96cdf1290d7478e93151bab4ca93]

Continuous ICV infusion for two weeks at one of three dose levels