Abstract
We thank Hariz and colleagues for their letter concerning the new European Academy of Neurology/Movement Disorder Society-European Section (EAN/MDS-ES) guideline (GL) on "invasive treatment of Parkinson disease". Their comments and concerns give us the opportunity to explain more deeply, and discuss the value of, GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) GLs.
These colleagues list several possible "inaccuracies" of the EAN/MDS-ES GL for lesional surgery, especially regarding posteroventral pallidotomy. Most concerns relate to misunderstandings of the methodology adopted for our GL.
Our two organizations (EAN and MDS-ES) decided upfront to use GRADE methodology for this GL. This represents a major difference from former methodological approaches to support conclusions and make treatment recommendations.