[Parkinson's disease: from pallidotomy to L-dopa and back to pallidotomy].
Until the introduction of L-dopa in the therapeutics of idiopathic Parkinson's disease (IPD) at the end of the 60's, treatment was essentially limited to anticholinergic drugs and surgical procedures devised to produce discrete lesions in the pallidum, ansa lenticularis and thalamus. L-dopa, associated with dopa decarboxylase inhibitors and dopaminergic agonists, gave rise to an almost complete standstill of surgical procedures. Nevertheless, natural progression of IPD with motor fluctuations and the appearance of L-dopa related abnormal involuntary movements caused surgery to reappear as a primary treatment option. The MPTP epidemic in heroin addicts was responsible for obtaining an experimental model of IPD and became the starting point for a wealth of information concerning the physiopathology of basal ganglia circuitry, neurotransmitters and specific dopaminergic, gabaergic and glutamaergic receptor subtypes involved in motor control. This information, in the context of new stereotactic techniques with modern neuroimaging, enabled old surgical procedures on the internal globus pallidus (Gpi) and thalamus to be reformulated. Additional neurophysiological guidance further improved accuracy in target finding thereby giving rise to impressive results in the symptomatic improvement of IPD including L-dopa induced dyskinesias.