THE NATURAL-HISTORY OF PARKINSONS-DISEASE

There are still insufficient data on the natural course of Parkinson's disease (PD) owing to lack of standardized longitudinal follow-up stu dies. Reported progression rates in early PD vary considerably by a fa ctor of 2 to 3. Similarly, data from sequential [F-18] dopa PET studie s in PD patients have produced variable decline rates of PET indices r anging between 7 and 70% per decade. Risk factors fro rapid progressio n include old age at onset, concomitant major depression, dementia, an dakinetic-rigid symptoms presentation. The introduction of levodopa in to the routine treatment of PD patients had a dramatic impact on sympt omatic control without affecting the underlying rate of disease progre ssion. By contrast, monoamine oxidase (MAO) B inhibition by deprenyl m onotherapy in early PD was shown to delay the need for levodopa by aro und 9 months. However, the neuroprotective action disappeared after 2 years of follow-up. Furthermore, deprenyl also failed to influence the subsequent development of levodopa-induced motor complications. Avail able studies on mortality in PD provide heterogeneous mortality rates, probably because of discrepancies between patient populations with re spect to co-morbidity, disease stage at study entry, and diagnostic ac curacy. However, the most recent follow-up from the DATATOP cohort sug gests normal life expectancy in carefully selected patients without si gnificant co-morbidity and with adequate treatment and expert follow-u p.