The system (1) has an implantable brain parameter sensor with a wireless sensor transponder for measuring a brain parameter i.e. intracranial pressure. A receiving unit (8) with an antenna is in wireless signal communication with the sensor transponder. A data reader module (18) is in signal communication with the antenna. A data processing and display device (20) is in signal communication with the data reader module. The receiving unit is fixed on a head cap (14) by a hook and loop fastener for predefining a relative position with respect to the sensor transponder.