A series of experimental surgery for advanced Parkinson's disease by foetal mesencephalic transplantation.

12 patients with advanced Parkinson's Disease who had right caudate implantations of late stage foetal mesencephalon have been followed up for 1 to 2 years with extensive clinical and physiological assessments. Three patients failed to comply and were excluded. Seven of the remaining 9 patients showed substantial initial improvement which was well maintained in 4. Two of the 3 remaining patients of this group maintained lesser improvement. One returned to pre-operative state. Two patients with greatly advanced disease had only slight but brief improvement. A series of 24 matched patients have been treated and continue under investigation.