The Horsley–Clarke stereotaxic apparatus

Abstract

Robert Henry Clarke was responsible for the application of mathematical principles to neurophysiology and the invention and construction of an apparatus which would allow Sir Victor Horsley to make electrolytic lesions in the roof nuclei of the cerebellum. In order to be able to make lesions at any other desired point of the brain of a cat or monkey, Clarke and Horsley constructed an atlas based on photographs of sections to be used in conjunction with the instrument. The original apparatus was made in 1905 and papers on its use and on the atlas were published in 1908, 1911 and 1914. This advance was the basis of modern stereotaxic surgery and of a very large part of the work on neurophysiology that is carried out today. Clarke gave his original apparatus to F. J. F. Barrington, genitourinary surgeon at University College Hospital and neurophysiologist. It was lent to various other workers in Oxford and elsewhere and was last used by Barrington in 1953 or 1954. It then disappeared following his sudden death in 1956. Various other pieces of apparatus were built, some of which are of historical importance in their own right, and these are referred to in the paper. Some parts of Clarke's apparatus, including a special grid for trnsferring measurements from the atlas to the instrument and a spinal stereotaxic instrument, were found and described by E. R. Hitchcock in 1960. One of us (W. R. M.) succeeded in locating the original apparatus in 1970. It is now in the museum of University College Hospital, London.