Sleep episodes and daytime somnolence as result of individual susceptibility to different dopaminergic drugs in a PD patient: a polysomnographic study

We describe the case of a 61-year-old patient affected by PD who experienced sleep episodes (SE) occurring during pramipexole plus l-Dopa therapy. Polysomnographic sleep studies and subjective evaluations of daytime sleepiness (Epworth Sleepiness Scale) were carried out under administration of pramipexole plus l-Dopa, l-Dopa monotherapy and cabergoline plus l-Dopa. The polysomnography revealed two sleep events during pramipexole plus l-Dopa. Moreover, the polysomnographic data showed an increase of both diurnal and nocturnal sleep under pramipexole plus l-Dopa compared with cabergoline plus l-Dopa and l-Dopa as monotherapy. In addition, while Epworth Sleepiness Scale (ESS) Score showed a mild sleepiness under pramipexole (ESS score=11), ESS scores were normal under both l-Dopa and cabergoline plus l-Dopa. Sleep episodes also disappeared under both l-Dopa and cabergoline plus l-Dopa (2- and 12-month follow-up). We hypothesize that an individual susceptibility to specific antiparkinsonian drug may play a significant role in the genesis of sleepiness in our PD patient.