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 (21, 22, 23, 24) for measuring a physical parameter, and a signal interface; wherein the rod-shaped hollow body has a first region 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 that is arranged proximally from the first region, wherein the second region is designed to lie in the region of the cerebral mass in the applied state; wherein the first region 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 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 (21, 22, 23, 24) for measuring a physical parameter, and a signal interface; wherein the rod-shaped hollow body has a first region 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 that is arranged proximally from the first region, wherein the second region is designed to lie in the region of the cerebral mass in the applied state; wherein the first region 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 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.