Since 1958, 61 patients with spasmodic torticollis, 46 of whom did not develop other kinds of involuntary movements, have been experienced in our neurosurgical clinic. The course of these 46 patients was followed for more than one year. The retrospective analysis revealed 25 patients were treated conservatively, and 21 patients were treated surgically. Surgical treatment consisted of stereotactic ventrolateral thalamotomy in 19 patients, and Olivecrona's operation in the other 2. The long-term outcome of conservative therapy was compared to that of surgical therapy. One patient with severe retrocollis with horizontal components was treated successfully but transiently by implantation of stimulating electrodes in the cervical epidural spinal cord. The peak incidence of the onset of the disease was in the fourth decade; however, the time of onset ranged from 7 to 55 years of age. The period from disease onset to the final evaluation in the follow-up was 9.3 years (mean) in the conservative group, and 8.5 years in the surgically treated group (no significant difference). There were no significant differences between the groups in the interval from the time of disease onset to the initial evaluation in our clinic, stage determined at evaluation, and follow-up period after the initial evaluation. Of the 25 conservatively treated patients, symptoms and signs remained unchanged in 8, deteriorated in one, but improved significantly in most of the remaining patients. Many of the surgically treated patients showed improvement one week after surgery, but the long-term outcome was not significantly better than that of the conservatively treated patients.(ABSTRACT TRUNCATED AT 250 WORDS)