Treatment of Parkinson's Disease by Streotactic Thalamotomy and Pallidotomy

ABSTRACT

The authors report the surgical results of thalamotomy and pallidotomy, performed at our hospital between 1983 and 1993 for the treatment of Parkinson's disease. The series included a retrospective analysis of 156 patients with this condition by stereotactic ventrolateral(VL) thalamotomy(126 patients, 138 thalamotomies) and posterolateral pallidotomy(30 patients, 30 pallidotomies). Each patient was followed up postoperatively, for one year. Among those who underwent the stereotactic VL thalamotomy, 136/138 procedures(99%) led to improvement of tremor, and 83/138(60%) resulted in reduced rigidity. Stereotactic posterolateral pallidotomy, led to improvement of bradykinesia after 27/30 procedures(90%), of rigidity after 22/30(73%) and of tremor after 13/30(43%). Drug-induced dyskinesia showed a 42% improvement in the thalamotomy series and a 93% improvement in the pallidotomy series; the difference between the two series was significant(p0.557). In addition, for groups with greater preoperative disability(Hoehn & Yahr staging, groups III and IV), improvement was more likely after pallidotomy than after thalamotomy. In the pallidotomy series, dysphasia was the only serious complication and this was seen after 20% of procedures. In the thalamotomy series, however, complications included hypotonia(24%), transient confusion(19%), transient dysphasia(11%), permanent dysarthria(7%), subjective numbness(4%) and epileptic seizure(3%). The authors believe that posterolateral pallidotomy is much more effective than VL thalamotomy for the control of Parkinsonian bradykinesia and rigidity, but that thalamotomy is still a useful surgical option for the control of Parkinsonian tremor.