A brain drainage device with a rod-shaped hollow body with an inner drainage channel for insertion through the cranium into the brain , a first sensor arrangement with at least one sensor for measuring a physical parameter, and a signal interface ; wherein the rod-shaped hollow body has a first region (A) that, in the applied state, is designed to protrude into a ventricle situated in the brain; wherein the rod-shaped hollow body has a second region (B) that is arranged proximally from the first region (A), wherein the second region (B) is designed to lie in the region of the cerebral mass in the applied state; wherein the first region (A) has a drainage opening arrangement connected to the drainage channel through which liquor can be drained from the ventricle into the drainage channel in the applied state; wherein the first sensor arrangement is arranged in the second region (B) to measure a physical parameter of the cerebral mass ; wherein the first sensor arrangement is connected to the signal interface to transmit measurement data determined by the first sensor arrangement to a measuring system that is to be connected, wherein the first sensor arrangement has at least one sensor for detecting an oxygen content and/or an oxygen saturation in the region of the cerebral mass or the ventricle , wherein the sensor has at least one light source for light with at least a first wavelength and a second wavelength, as well as at least one first light sensor associated with the light source and sensitive to the first wavelength and a second light sensor associated with the light source and sensitive to the second wavelength. a rod-shaped hollow body with an inner drainage channel for insertion through the cranium into the brain , a first sensor arrangement with at least one sensor for measuring a physical parameter, and a signal interface ; wherein the rod-shaped hollow body has a first region (A) that, in the applied state, is designed to protrude into a ventricle situated in the brain; wherein the rod-shaped hollow body has a second region (B) that is arranged proximally from the first region (A), wherein the second region (B) is designed to lie in the region of the cerebral mass in the applied state; wherein the first region (A) has a drainage opening arrangement connected to the drainage channel through which liquor can be drained from the ventricle into the drainage channel in the applied state; wherein the first sensor arrangement is arranged in the second region (B) to measure a physical parameter of the cerebral mass ; wherein the first sensor arrangement is connected to the signal interface to transmit measurement data determined by the first sensor arrangement to a measuring system that is to be connected, wherein the first sensor arrangement has at least one sensor for detecting an oxygen content and/or an oxygen saturation in the region of the cerebral mass or the ventricle , wherein the sensor has at least one light source for light with at least a first wavelength and a second wavelength, as well as at least one first light sensor associated with the light source and sensitive to the first wavelength and a second light sensor associated with the light source and sensitive to the second wavelength. <EOS>