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04-08-2013 | Neurology | Article

Sleep deteriorates as Parkinson’s worsens


Free abstract

medwireNews: Sleep quality deteriorates as Parkinson’s disease (PD) advances, a study of Chinese patients without dementia shows.

The main problems experienced by the 487 patients in the study were poor sleep quality at night, difficulty in falling asleep, and difficulty in staying asleep, as measured on the PD Sleep Scale (PDSS).

The study researchers, led by Yingdong Zhang (Nanjing Medical University, Jiangsu, China), say that depression and anxiety may partly explain these sleep disturbances and call for better treatment of such conditions.

The study participants were classified, according to Hoehn and Yahr staging, as having mild (65.9%), moderate (29.3%), or severe (4.8%) PD.

While total PDSS scores did not differ significantly among the three groups, scores for the sleep quality sub-item deteriorated in line with increasing severity. The average scores were 25.4 for patients with mild PD, 24.6 for those with moderate PD, and 22.8 for those with severe PD.

Indeed, sleep quality was the only sub-item on the PDSS that was significantly associated with PD severity. Zhang et al suggest in The Journal of Biomedical Research that this may be because the patients had good nocturnal motor sign control, which Hoehn and Yahr staging is largely based on.

They therefore could not rule out the possibility that drugs used to achieve this control in turn led to increased sleep disturbance.

However, sleep disturbance was also significantly associated with anxiety and depression, both of which were common in the PD patients, although neither was strongly associated with the severity of PD.

The researchers hope that their findings will help increase the recognition of sleep disturbances in non-demented patients with PD and lead to “better treatment of depression and anxiety” to help reduce the effects of these disturbances.

medwireNews ( is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013

By Lucy Piper, Senior medwireNews Reporter

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