Although neurosurgery has a long history it was thanks to brave pioneering neurosurgeons such as Harvey Cushing in the United States — and in Sweden Herbert Olivecrona — that the speciality made huge progress during the first half of the 20th century. However, around 1950, the possibility to reveal pathological processes taking place inside the closed skull, was still very restricted. The only available rapid procedure was the neurological examination of the patient. X-ray of the skull is of restricted value, pneumo-encephalography was much too complicated and time-consuming for acute situations, and angiography was still in its infancy. Thus the neurosurgeon, receiving an acute patient with a suspected intracranial haematoma, had to make a qualified guess about where to start placing his trephine on the skull in order to save the life of the patient — often within minutes in the case of a bleeding between the skull bone and the dura. The mortality in those days was 40 % , often because the diagnosis was made too late. Thanks to an ingenious Swedish neurosurgeon, Lars Leksell, working at Lund University Hospital, a new approach to reveal the secrets inside the skull was introduced in clinical praxis — echoencephalography. Lars Leksell graduated from the Karolinska Institute (KI) and received his neurosurgical training in Herbert Olivecrona’s department from 1935. He volunteered as a neurosurgeon in the Finnish winter war in 1940 in Karelia. His team could operate on 24 head injuries per 24 hours and already by this point, Leksell showed his creative mind in constructing the double-action rongeur for more efficient removal of shell-splinters from the vicinity of the spinal cord. In 1941 he joined Professor Ragnar Granit (1967 Nobel laureate in Medicine) at the Institute of Neurophysiology where he presented his thesis on gamma nerve fibres in 1945. In 1946 he became the chief of the new neurosurgical unit in Lund and in 1958 he was appointed the first Professor of Neurosurgery at Lund University. In 1960 he succeeded Olivecrona as Professor and Chairman of the Neurosurgical Department at the Karolinska Institute/Hospital.