Freud uses the term innervation throughout his work, both with and without reference to hysterical conversion. We find it in its physiological and anatomical meaning as an efferent or afferent mode of action of the nervous system and/or distribution of nerves in a region of the body: "sensation of innervation," "voluntary or involuntary innervation of the muscles," "innervation of the brain," "body innervation." But we also find, more rarely: "innervation (tears)," "sensation of the innervation of the word," "sensation of speech innervation," "innervation of images of movement."
For Freud the theory of conversion took shape within the very broad framework of these meanings: "the inhibited antithetic idea can put itself into effect by innervation of the body" (1892-93a, p. 122). As soon as the term conversion appeared, it was often linked to innervation. Two examples: "The affect that is torn [from the repressed idea] would be used for a somatic innervation. (That is, the excitation is 'converted'.)" (1895d, p. 285), and "in the case of conversion hysteria the ciruitous route led to the somatic innervation; the repressed impulse broke its way through at some point or other and produced symptoms " (1925d, p. 33).
The notion is not much used by psychoanalysts today. Although linked to Freud's earliest paraneurological speculations, it has nevertheless been retained in relation to hysteria, for example, as a reaffirmation in Freud's opinion of a correspondence or an indissoluble continuity between the psychical and the physical.
See also: Conversion; Hysterical paralysis; Mnemic symbol; Psychosomatic limit/boundary; Sum of excitation; Symptom
Freud, Sigmund. (1892-93a). A case of successful treatment by hypnotism. SE, 1: 115-128.
——. (1895d). Studies on hysteria. SE, 2: 48-106.
——. (1940e ). Splitting of the ego in the process of defence.SE, 23: 271-278.