An apparatus for delivery of medication to the ventricles within the brain of a patient, the apparatus comprising: a flexible delivery member having a proximal end, a distal end, and a lumen for advancement of a solid form medication element through the delivery member, the medication element comprising at least one drug, wherein the delivery member is configured to be advanced into a selected ventricle of the brain from a site outside the brain; and a diffusion chamber coupled to the distal end of the delivery member; the diffusion chamber having a wall and an interior volume for receiving the medication element and at least one diffusion section positioned in the wall allowing cerebrospinal fluid to enter and exit the chamber; characterized in that i) an interior volume of the diffusion chamber retains a medication element received from the delivery member; ii) the diffusion chamber includes at least one opening configured to allow CSF fluid to enter the chamber to dissolve the medication element in fluid within the interior volume to form a drug solutions÷ and wherein, in use, drug diffuses from the drug solution through the at least one diffusion section to CSF within the selected ventricle of the brain; and wherein the diffusion chamber and the delivery member have a flexibility configured such that during advancement of the apparatus into the ventricles of the brain, the diffusion chamber can to bend up to about 30 degrees to allow the apparatus to conform to a shape of the selected ventricle. a flexible delivery member having a proximal end, a distal end, and a lumen for advancement of a solid form medication element through the delivery member, the medication element comprising at least one drug, wherein the delivery member is configured to be advanced into a selected ventricle of the brain from a site outside the brain; and a diffusion chamber coupled to the distal end of the delivery member; the diffusion chamber having a wall and an interior volume for receiving the medication element and at least one diffusion section positioned in the wall allowing cerebrospinal fluid to enter and exit the chamber; characterized in that i) an interior volume of the diffusion chamber retains a medication element received from the delivery member; ii) the diffusion chamber includes at least one opening configured to allow CSF fluid to enter the chamber to dissolve the medication element in fluid within the interior volume to form a drug solutions÷ and wherein, in use, i) an interior volume of the diffusion chamber retains a medication element received from the delivery member; ii) the diffusion chamber includes at least one opening configured to allow CSF fluid to enter the chamber to dissolve the medication element in fluid within the interior volume to form a drug solutions÷ and wherein, in use, drug diffuses from the drug solution through the at least one diffusion section to CSF within the selected ventricle of the brain; and wherein the diffusion chamber and the delivery member have a flexibility configured such that during advancement of the apparatus into the ventricles of the brain, the diffusion chamber can to bend up to about 30 degrees to allow the apparatus to conform to a shape of the selected ventricle.