The present invention provides methods and systems for conditioning 
cerebrospinal fluid (CSF). The methods provide for efficiently removing target compounds from CSF. The systems provide for a multilumen flow path and exchange of a majority volume portion of CSF in the CSF space. The removal and / or delivery of specific compounds can be tailored to the 
pathology of the specific 
disease. The removal is targeted and specific, for example, through the use of specific size-exclusion thresholds, antibodies against specific toxins, and other chromatographic techniques, as well as delivery and / or removal of targeted therapeutic agents. The invention finds use as a diagnostic, therapeutic and 
drug delivery platform for a variety of diseases affecting the CNS by accessing the CSF space. Exemplified 
disease conditions treatable by the present CSF 
processing systems and methods include, but are not limited to: 
Cerebral Vasospasm, Guillain Bane Syndrome, illustrating multi-lumen 
lumbar approach Alzheimer's, Parkinson's, Huntington's, 
Multiple Sclerosis, 
Amyotrophic Lateral Sclerosis, 
Spinal Cord Injury, 
Traumatic Brain Injury, 
Stroke, 
Cancer affecting the brain or 
spinal cord, Prion 
disease, 
Encephalitis from various causes, 
Meningitis from various causes, diseases secondary to enzymatic or metabolic imbalances, 
Biological Warfare, etc. For the first time, the present invention offers patients a disease-modifying, disruptive technology treatment platform that addresses the known 
disease pathogenesis of a number of neurologic conditions to which there are presently limited and ineffective 
treatment options.