“…In the occipital route, the burr hole location is established in a standard fashion, located 60-80 mm above the inion and 30-40 mm lateral to the midline. 4,7,10,11,14,18) On the other hand, the external aim point has been variously described in surgical textbooks, especially with reference to the sagittal plane, as the nasion, 18) the tip of the top of the ear, 11) or not specified 14) for cerebrospinal fluid sampling or temporary drainage; and the middle of forehead, 10,16) 10 mm above the nasion, 4) and the medial canthus 7,10,15) for shunt placement. This situation is confusing for trainee neurosurgeons and standard manual puncture sometimes results in incorrect ventricular catheter placement.…”