[Guidelines for the Neuropsychological Assessment of Patients with Parkinson's Disease]

Presence of mild cognitive impairment is currently the best predictor for the development of Parkinson's disease dementia. Diagnostic criteria for both Parkinson's with mild cognitive impairment and Parkinson's disease dementia have been suggested by the Movement Disorder Society. However, not all cognitive tests recommended are available in the German language with proper standard values.

To define evidence-based guidelines for neuropsychological assessment of patients with Parkinson's disease in German.

Two systematic literature searches were conducted. First, articles that presented international guidelines (consensus papers or reviews) for the application of standardized neuropsychological assessments for the diagnosis of cognitive impairment in Parkinson's disease were selected. Of those, only neuropsychological assessments in German language with normative values referring either to a German, Austrian, or Swiss population were considered. Second, articles comparing test performances of healthy controls vs. Parkinson's disease and/or different cognitive Parkinson's disease subtypes (e.g. no cognitive impairment, Parkinson's with mild cognitive impairment, Parkinson's disease dementia) were selected. Effect sizes for group differentiation were calculated.

Out of 127 full-text articles reviewed, 48 tests were identified during the first literature search. In the second search, 1716 articles were reviewed and 23 papers selected. The strongest effect sizes for group discrimination were revealed for tests assessing executive function, attention, and visuo-cognitive abilities. Based on the results of the two literature searches, consensus guidelines were defined by the authors, allowing for Level-II diagnosis for Parkinson's with mild cognitive impairment and Parkinson's disease dementia.

The presented guidelines may have the potential to standardize and improve the neuropsychological assessment of Parkinson's disease patients in German speaking countries.