Pregabalin improved sleep maintenance , demonstrated by reductions in WASO ( -@ min vs placebo -LSB- P < @ -RSB- ; -@ vs pramipexole ) and number of awakenings after sleep onset ( -@ vs placebo ; -@ vs pramipexole -LSB- P < @ -RSB- ) by polysomnography , and an increase in subjective total sleep time ( @ min vs placebo -LSB- P < @ -RSB- ; @ vs pramipexole ) .