How is levodopa affecting the sleep of patients with Parkinson’s disease?

This study investigated if there is an association between treatment with levodopa and sleep in patients with Parkinson’s disease (PD). Researchers suggested that there is a strong association between sleep abnormalities and patients treated with levodopa.  

PD is a chronic disease that affects brain cells. This can result in a variety of movement symptoms, such as tremors, muscle rigidity, and impaired balance. The standard treatment of PD patients is levodopa. This drug is very effective in treating PD symptoms. However, long-term use causes negative side effects. These effects can be abnormal involuntary movements, called dyskinesia.

Prior studies in animals showed that dyskinesia is associated with abnormal brain function while sleeping. During sleep is when the daytime learning process sets in. Therefore, an abnormal brain activity during sleep might affect PD outcomes. It is not clear how levodopa treatment may be related to sleep abnormalities and how these reflect in PD outcomes.

This study included 36 patients, at different stages of PD. Patients underwent 1 week of actigraphy (a non-invasive method of studying human sleep/wake patterns). After this, patients proceeded with a whole night of video-polysomnography (or a sleep study, used to study brain activity while sleeping). Patients were divided into 3 different groups. Patients with mild, newly diagnosed PD were in group 1 (9). Patients with advanced PD were in group 2 (13) and those with severe PD, with dyskinesia, in group 3 (14). 

Patients with a longer duration of PD had shorter sleep durations and were more tired. In group 3 there was a strong association between sleep duration and abnormal movements in PD. This suggested that these patients do not have an adequate brain activity during sleep.

This study suggests a strong association between PD symptoms and sleep abnormalities in patients treated with levodopa.

This study had a limited number of participants. Larger studies are necessary.