Sympathetic functions in parkinsonism treated with stereotactic surgery: observations in ten patients

Ipsilateral sympathetic deficits, that is symptoms and signs consistent with a diagnosis of Horner's syndrome, have been described in patients who have undergone thalamotomy for dyskinesia as well as for parkinsonism. The present patient material consists of 10 patients with parkinsonism who had undergone stereotactic surgery. Since anhidrosis and miosis are two integral components of Horner's syndrome, forehead sweating and pupillometric response to sympathicomimetic agents have been investigated in this preliminary work. The tests were carried out a considerable time postoperatively. Sweating was stimulated in two different ways: by body heating and by parenterally administered pilocarpine. OH-amphetamine and phenylephrine (an indirectly and a directly acting sympathicomimetic agent) were used in the pupillometric tests. The results were compared with those obtained in a healthy control group. With the OH-amphetamine test, there were some indications of a changed sympathetic activity on the surgical side. However, when comparing these results with those obtained by the phenylephrine test, the inference seems to be allowable that parkinsonian patients operated in this way (target area: ventro-oral thalamic nuclei (Voa and Vop) and the reticular thalamic nucleus) show no definite sympathetic supersensitivity at the late postoperative stage. Our data suggest that the response pattern of the pupils and the sweat glands may be related to the surgical method used and/or to the interval from operation to investigation.