NEUROSURGICAL PROCEDURES FOR THE TREATMEN T OF PARKINSONS-DISEASE - CURRENT STATUS

There is a world-wide renaissance of neurosurgical treatments of Parki nson's disease (PD), based on substantial progress in basic sciences. A model of parallel motor circuitry has identified potential targets f or lesioning by clarifying the pathophysiological role of the basal ga nglia in PD. The internal globus pallidus (Gpi) is an essential player as it connects to thalamocortical projections and can be disinhibited by overactivity of the nucleus subthalamicus (Nst). Lesioning of thes e targets has been successful in MPTP damaged primates. There is clini cal use of destructive as well as restorative and stimulative technics . Pallidotomy and thalamatomy have evolved by the use of better neuror adiological and electrophysiological targeting. The first technic is u sed for treatment of rigidity, hypokinesia and dyskinesias, the latter one has proven to be efficient for tremor. Dopaminergic reinnervation and increased dopaminergic output of the striatum has only been seen after transplantation of fetal cells; this method however carries immu nological and ethical problems. The continuous high frequency stimulat ion of basal ganglia is the newest technic; it is highly adaptable to the patient's need and carries a low morbidity profile. Thalamic stimu lation is used for the treatment of tremor. The stimulation of Nst and Gpi are proposed for dyskinesias and on/off phenomena. Animal researc h further focuses on xenotransplantation and implantation of genetical ly transformed cells or pluripotent precursor cells. - In summary neur osurgical procedures seem to be verey promising; however longterm comp arison studies are needed to define the best (combination) treatment(s ) for the future.