SPASMODIC torticollis is clinically defined as abnormal involuntary innervation of muscles of the neck resulting in more or less sustained movements or in deviation from the normal of the posture of the head. Both types of motor abnormality may be present in the same case.
Compensatory movements in certain types of oculomotor and vestibular disorders, as well as structural abnormalities of muscles or bones of the neck, may cause a change in the normal position of the head. Neither, however, is the result of abnormal involuntary activity, as is spasmodic torticollis, to which entity this study is limited.
Forty-three patients with spasmodic torticollis were seen at the Neurological Institute of New York between 1930 and 1944. A clinical analysis of the neurologic and psychiatric observations in this group and an evaluation of the results of various forms of operative treatment in 18 of them will be published separately.
HERZ E, HOEFER PFA. SPASMODIC TORTICOLLIS1. Physiologic Analysis of Involuntary Motor Activity. Arch NeurPsych. 1949;61(2):129-136. doi:10.1001/archneurpsyc.1949.02310080033002