The classical freehand technique uses anatomical landmarks and the catheter is placed in the anterior horn of the lateral ventricle through a burr hole just anterior to the coronal suture in the pupillary line (at the level of Kocher`s point, a point on the surface of the cranium 2.5 cm from the midline and 1 cm anterior to the coronal suture). The target is the ipsilateral frontal horn just anterior to the foramen of Monroe to avoid the chorioid plexus. The right nondominant side is preferred. The catheter is directed freehand using external landmarks in the coronar plane towards the ipsilateral medial canthus and in the sagittal plane through the external auditory meatus. A post-procedural CT scan of the brain is performed within 24 hours as part of standard care for postoperative control or earlier in case of postoperative CSF drainage problems.