Impact of the Anticholinergic Burden on Disease-Specific Symptoms in Parkinsonian Syndromes

<b>Background</b>: Anticholinergic adverse effects pose a relevant threat to patients, in particular elderly and cognitively impaired patients. Patients with Parkinsonian syndromes are especially at risk from anticholinergic adverse effects due to the often-required complex drug therapy. <b>Aims</b>: The aim of this study was to evaluate the potential effect of the anticholinergic burden on motor and non-motor symptoms in Parkinson's disease and atypical Parkinsonian syndromes. <b>Methods:</b> This cross-sectional, monocentric retrospective data analysis included 151 patients with Parkinson's disease (PD), 63 with progressive supranuclear palsy (PSP), and 36 with multiple system atrophy (MSA). The anticholinergic burden of patients' medications was determined using two established scores: the Anticholinergic Drug Scale (ADS) and the German Anticholinergic Burden Scale (GABS). These scores were compared between the different diseases and correlated with several disease-specific scores. <b>Results</b>: Anticholinergic burden was higher in patients with PD, in particular, compared to PSP. In the PD group, anticholinergic burden showed a weak correlation with almost all analyzed clinical scores and the number of administered drugs. The UMSARS I and II showed a significant correlation with the anticholinergic burden in MSA patients. In general, the GABS-measured anticholinergic burden was significantly higher compared to the ADS-measured. <b>Conclusions</b>: The calculated anticholinergic burden affected motor and non-motor symptoms in patients with various Parkinsonian syndromes poorly. Since the GABS also contains basic anti-parkinsonian drugs, this score tended to overestimate the anticholinergic burden in patients with Parkinsonian syndromes and, therefore, seemed less appropriate for this application.