Rationale for the study
Although the role of cholinergic dysfunction in RBD has been described, and linked with
cognitive impairment, this association has not been adequately explored in PD-RBD.
Ascertaining the exact extent of cholinergic deficit in PD-RBD using SAI will provide a
quantitative metric for this deficit. This metric when correlated with cognitive scores obtained
from detailed neuropsychological evaluation will enable a better understanding of the complex
interplay between cholinergic dysfunction and cognitive impairment in PD-RBD. Furthermore,
these neurophysiological parameters such as SAI may be utilized to develop markers for
cognitive impairment and dementia.