Abstract

Objective The objectives of this study are (1) to describe the non-motor profile, the motor disability progression, and survival analysis of atypical parkinsonism in a tertiary care hospital of eastern India and (2) to elucidate the neurocircuitry and the putative substrates responsible for non-motor manifestations. Methods In this prospective observational study, patients were diagnosed based on Consensus Criteria for Progressive Supranuclear Palsy (PSP), The Fourth Consensus Report of the Dementia with Lewy Body (DLBD) Consortium 2017, The Autonomic Neuroscience 2018 Criteria for Multiple System Atrophy (MSA), and Armstrong 2013 Criteria for Corticobasal Degeneration (CBD). Disease severity was assessed at baseline and 6 months of follow-up using the Unified Parkinson's Disease Rating Scales (UPDRS). For PSP and MSA, the PSP-Clinical Deficits Scale (PSP-CDS) and the Unified MSA Rating Scale (UMSARS), respectively, were used. Cox regression analysis and the hazard ratio were calculated. Results Out of 27 patients, the diagnosis was probable PSP in 12, probable MSA in 7, probable CBD in 5, and probable DLBD in 3. Non-motor symptoms were highly prevalent across all subtypes. Motor disability progression as assessed by UPDRS parts 2 and 3 showed significant deterioration over 6-month follow-up across all groups ( p < 0.05). Disease progression assessed by PSP-CDS and UMSARS over 6 months was significant ( p < 0.05). One PSP and two MSA patients died during a 6-month follow-up period. The hazard ratio in MSA was 3.5 (95% confidence interval: 0.31-0.38) with p = 0.306. Conclusion Atypical parkinsonian disorders are rare, and usually more severe than idiopathic parkinsonism. As no definitive treatment is available, symptomatic management involving a multidisciplinary team approach must be prioritized.