Medical device having non-filtered csf withdrawal pathway

An implantable medical device for withdrawing cerebrospinal fluid (CSF) from a CSF-containing space of a subject and for infusing fluid into the subject, the device comprising:

• a first inlet configured to be accessed by a needle of an aspiration device;
• a first outlet;
• a first fluid pathway extending from the first inlet to the first outlet;
• a second inlet;
• a second outlet;
• a second fluid pathway extending from the second inlet to the second outlet;
• and
• one or more CSF catheters comprising a first lumen, a first distal opening in fluid communication with the first lumen, a second lumen and a second distal opening in fluid communication with the second lumen,
• wherein the first lumen is in fluid communication with, or is configured to be placed in fluid communication with the first fluid pathway,
• wherein the second lumen is in fluid communication with, or is configured to be placed in fluid communication with the second fluid pathway,
• wherein the first distal opening is configured to be placed in the CSF-containing space of the subject, and
• wherein the first fluid pathway is free of a filter configured to prevent passage of a microbe.