Rediscovering patient M: Justo Gonzalo Rodriguez-Leal and his theory of the brain dynamics

Introduction. During the Spanish Civil War, Justo Gonzalo Rodriguez-Leal visited patient M at the Military Healthcare Hospital in Godella (Valencia). This meeting marked the beginning of a long relationship between the two, which gave Justo Gonzalo the opportunity to study the functional organisation of the brain and to develop an original conception of neurophysiology based on the laws of nervous excitability. The aim of this work is to rediscover patient M and the physiological interpretation of Gonzalo's brain dynamics. Development. Taking patient M as the cornerstone, Gonzalo postulated that the effect of a cortical lesion depends on its magnitude and position: the magnitude conditions the intensity of the disorder, whereas the position determines the type of disorder. Between 1945 and 1950 he developed these and other hypotheses in depth, based on clinical observations, in his work Dinamica cerebral. La actividad cerebral en funcion de las condiciones dinamicas de la excitabilidad nerviosa (Vol. 1, 1945; Vol. 2, 1950). From 1952 onwards he provided an expanded version of his theory of brain dynamics, basing it not only on physiological concepts, but also on the idea of brain gradients, and introducing the concepts of similarity and allometry of dynamic systems. Conclusions. For centuries, knowledge about the functional organisation of the brain has been based on single case studies. Patient M is a further example of this tradition that helps to establish the basis of the theory of brain dynamics developed by Justo Gonzalo.