Abstract: A device for inserting a thin measurement probe into brain tissue, the device including a skull screw, a guide hose, and a compressive screw connection. The skull screw defines a longitudinal borehole through which the guide hose and a measurement probe extend. The compressive screw connection radially seals, by compression, the measurement probe and the guide hose relative to the skull screw. The guide hose serves as a protective sleeve enclosing the measurement probe and connecting the skull screw to a probe hookup. The guide hose includes further and separate lumina to receive further measurement probes and associated probe hookups, and the guide hose supports the probe hookups.