Red blood cell-derived parameters as a potential tool in the differential diagnosis of parkinsonian syndromes.

Atypical parkinsonian syndromes account for a small but clinically important proportion of parkinsonism cases. Compared with Parkinson's disease (PD), these disorders are characterized by more rapid deterioration and more pronounced deficits. Progressive supranuclear palsy (PSP) is the most common form of atypical parkinsonism. Due to the overlapping clinical features of PSP and PD, there is a clear need for the development of practical supplementary diagnostic tools. The study included 30 patients with a clinical diagnosis of PD, 29 with PSP-Richardson's Syndrome (PSP-RS), 17 with PSP-Parkinsonism Predominant (PSP-P), and 23 healthy controls. Each participant underwent blood sample analysis, including morphological evaluation. Analysis of blood parameters revealed that red cell distribution width-coefficient of variation (RDW-CV) has differential diagnostic potential. Elevated RDW-CV values were associated with PSP-RS and showed significant differences compared with all other groups. No other blood parameters demonstrated statistically significant values for differential diagnosis. The results of this study suggest that red blood cell-derived parameters may serve as useful supplementary tools for differentiating symptomatically overlapping parkinsonian syndromes. These findings highlight the importance of further research into factors affecting red blood cells in patients with parkinsonian syndromes.