It is now well recognized that poor quality of sleep, with fragmentation as the main characteristic, is a common problem in patients with Parkinson's disease. The effect of a sustained-release levodopa compound (Prolopa HBS) was assessed in a long-term (12 months) study of 15 patients presenting with distressing night time symptoms prolopa HBS was administered only ante noctem, without changing the usual daytime treatment. It appeared that alleviation of nighttime akinesia, reflected by the ability to turn around in bed, was perceived as the most worthwhile improvement.