Motor cortex extirpation (1886-1950): The influence of Sir Victor Horsley

OBJECTIVE: To delineate Sir Victor Horsley's influence on neurosurgeons who subsequently reported (through 1950) on the effects of motor cortex extirpation surgery. METHODS: We used the available literature to divide Horsley's influence into five categories, i.e., direct trainee, via a trainee or colleague, via personal contact and publications, via publications only, and no evidence of influence. RESULTS: Of 15 later neurosurgeons who reported results through 1950, the numbers corresponding to the five categories were 1, 6, 2, 3, and 3, respectively. CONCLUSION: Horsley's influence on neurosurgeons who performed motor cortex extirpation surgery was primarily indirect, with most influence occurring via trainees of his students or colleagues. Although indirectly associated with Horsley, Paul Bucy was his truest disciple.