Clinical criteria for the switch of treatment strategies in XXXX .

@entity1 @entity191
Along the years the treatment of @entity191 with L-dopa has revealed unfavorable effects in general after 5-10 years. This has led to the present criteria for treatment of de novo @entity1 that mainly relay on the age, the general strategy being to delay the use of L-dopa as long as possible. However, this practical approach lacks a scientific basis. In a retrospective study data of 155 @entity1 with @entity191 were analyzed with the goal of finding a clinical marker for the critical time point when L-dopa needs to be administrated. The clinical stage of the @entity1 was assessed using the Hoehn and Yahr (H_Y) scale and the severity of the symptoms was measured using the UPDRS score. The results show that there was no relationship between the age of the @entity1 and the therapy (L-dopa vs. no L-dopa) with regard to the clinical outcome. A significant interaction was found however, between the clinical stage (H_Y) and the therapy. Further analysis of this interaction showed that in the H_Y Stages 1-2.5 the UPDRS scores were lower in the @entity1 groups treated without L-dopa. Remarkably, in the H_Y stages 3 and higher the UPDRS scores were lower in the @entity1 groups treated with L-dopa. These results suggest that the clinical stage of the disease (H_Y) might be a better criterion than the age for the time point when L-dopa needs to be administered in de novo @entity1 .
