Implantable medical device for delivery of pharmacological agents to the deep brain structures

An intrathecal drug delivery system comprising:

• an intrathecal drug delivery device to intrathecally diffuse a pharmaceutical agent into a cerebrospinal fluid (CSF) within a spinal canal of a patient;
• and
• a deep brain catheter comprising an elongated body extending from a proximal end to a distal end and defining an inner lumen, wherein when the system is implanted in the patient, the distal end is implanted within a deep brain structure of the patient and the proximal end is positioned within a subarachnoid space directly adjacent to a brain of the patient to provide a fluid passageway between the subarachnoid space and the deep brain structure,
• wherein the proximal end of the deep brain catheter is not coupled to the intrathecal drug delivery device;
• and
• wherein the drug delivery system relies only on a natural pulsatile flow of the CSF to transport the pharmaceutical agent from the spinal canal to the subarachnoid space, through the deep brain catheter, and to the deep brain structure.