The Postural Effect of Lesions of the Vestibular Nuclei: A Note on Species Differences Among Primates

T HE pathology of human spasmodic torticollis 1,12,14,15,~3 has not been convincingly demonstrated and therefore the recent papers 13,16 on abnormalities of head posture resulting from experimental lesions in the brain stem have evoked considerable interest. Lately I have had an opportunity during the course of a study of the primate central vestibular connections 24 to observe 10 Macaques, a baboon, and a chimpanzee with experimental lesions of the vestibular nuclei. Lesions of similar extent produced strikingly different postural effects in the species examined. The data indicate that lesions in the central nervous system that are responsible for abnormalities of posture in monkeys may have quite different effects on the posture of the higher primates.