The types of sensation described as "hyperaffectivity," "hyperpathia," "central pain," "spontaneous pain" and "dysesthesia" have been the topic of many contributions. All of these sensations were first described by Dejerine1 as forming the syndrome thalamique, and the subject was elaborated on later by his pupil Roussy2 in the well known monograph entitled "La couche optique." According to Roussy the syndrome is characterized by "spontaneous pain," hemianesthesia, little or no hemiplegia, hemiataxia and choreo-athetoid movements. Of these symptoms "spontaneous pain" has received the most consideration. Head and Holmes3 and others have shown that the acute paroxysmal pains, frequently intolerable and not amenable to any form of treatment, are caused by lesions of the lateral nucleus of the thalamus. The other symptoms are produced by lesions in the structures adjacent to the thalamus.
In 1911 Head and Holmes expressed the belief that "the feeling tone of somatic or visceral