Therapeutic interventions for daytime somnolence in Parkinson's disease

Primary objective
* To evaluate the efficacy and safety of pharmacological interventions for the treatment of daytime somnolence in PD.
Secondary objectives:
* To address the spectrum of pharmacological strategies proposed for the treatment of daytime somnolence in PD.
* To address the methodological quality of trials on the treatment of daytime somnolence in PD.

This is a protocol.