Neurosurgical convection-enhanced delivery of treatments for Parkinson’s disease

Convection-enhanced delivery (CED) is a promising neurosurgical technique for the delivery of potential therapeutic agents to the Parkinson’s disease (PD)-affected striatum. CED utilises stereotactic insertion of a catheter to the striatum and continuous infusion to distribute agents in the brain parenchyma. Insufficient attention to the details of CED may have contributed to early failures of translating candidate therapeutic agents from the laboratory to PD patients. A literature review was performed to examine the factors that govern CED in the laboratory as well as translation in PD and we found that although there have been significant developments in implant design, infusion parameters and infusate composition, there have not been enough comparative trials of different technologies. Further optimisation of CED is required before it can be applied in the clinical setting and this will require a step-by-step breakdown of the different elements of delivery for independent testing. We conclude that CED is a promising technique for delivering therapeutic agents to the striatum for the treatment of PD but further refinements are necessary for successful clinical translation. The risk is that early clinical translation of exciting new therapies may lead to therapeutic failure which is not due to the agent in question but simply the neurosurgical delivery.