Restless legs syndrome (RLS) is one of the common nocturnal disturbance seen in
Parkinson's disease (PD) patients. The prevalence of RLS with PD is greater than that of general populations; however, etiology of RLS in patients with PD is still controversial. We report a 63-year-old man with PD, who was admitted to our hospital with uncontrollable unpleasant feeling in both legs leading to sleep disturbance. At age 59, he experienced
numbness and
nocturnal myoclonus in his right foot. One year later, he developed
resting tremor and
bradykinesia in his right hand, and was diagnosed as PD.
Levodopa was initiated with favorable response for his
resting tremor and
bradykinesia, however, his
dysesthesia of the legs spread to both side and associated with an urge to move which occurs at rest and was ameliorated by walking. On admission, his
parkinsonism was well controlled by 400 mg/ day of
levodopa/
benserazide. Polysomnography (PSG) revealed periodic limb movements in sleep (PLMS). Secondary RLS such as
drug-induced,
iron deficiency and uraemia, was excluded in this patient. Because
levodopa did not improve his RLS, additional symptomatic RLS treatment was initiated. Oral dosage with 150 microg
pergolide did not have any effect on his RLS symptoms. An increase up to 750 microg
pergolide led to a marked reduction of symptoms. Repeated PSG showed significant reduction of PLMS and improved sleep efficacy. Usually, low dose of
dopamine agonist is enough to treat RLS occurred in general populations. However, moderate to high dose of
dopamine agonists were needed for our patient with RLS, indicating that pharmacological responses might be different between RLS in general and that associated with PD. It is important to consider that PD-related RLS can be treated with high dose
dopamine agonist to obtain favorable management of nocturnal disturbances.