Cerebrospinal fluid treatment

Provided, among other things, is a method of treating cerebral spinal fluid comprising: (a) utilizing a channel of a pump to draw CSF from a subject's subarachnoid space of the subject's brain or spinal column; (b) subjecting the drawn CSF to membrane dialysis against a dialysate fluid to reduce immune or inflammatory mediators; and (c) utilizing a second channel of the synchronized dual channel pump to return the dialyzed CSF to the subarachnoid space of the subject's brain or spinal column. For example, the pump can be a synchronized dual channel pump. In one embodiment, the method further comprises: (d) removing cellular matter from the CSF to produce reduced cell content CSF, wherein the reduced cell content CSF is subjected to membrane dialysis.