Prevalence of Sleep Disturbances Varies According to Parkinson's Disease Subtype: Presented at ENS

By Norra MacReady

LAUSANNE, SWITZERLAND -- June 1, 2006 -- People with the akinetic-rigid subtype Parkinson's disease (PD) have an especially high risk of sleep disturbances, according to preliminary findings from a study presented here at the 16th Annual Meeting of the European Neurological Society (ENS).

Sleep disorders are commonly associated with PD, said Natasa Klepac, MD, professor of neurology, University of Zagreb Medical School, Zagreb, Croatia. In these patients, sleep disorders have several causes, including neurodegenerative changes that affect sleep centers in the brain, and the persistence of PD symptoms at night that make sleeping difficult, she said during a poster session on May 31st.

Dr. Klepac and her colleague, Maja Relaj, MD, professor of neurology, University of Zagreb Medical School, conducted a study to determine whether there is a difference in the incidence and type of sleep problems according to PD subtype.

They studied a consecutive series of 44 women and 39 men with idiopathic PD. The cohort's mean age was 61 years, they had a mean PD duration of 5 years, and a mean Hoehn & Yahr disease stage of 2, which is indicative of bilateral symptoms and affected gait and posture, but minimal disability.

Patients' motor performance was evaluated using the motor section of the Unified Parkinson's Disease Rating Scale, which gives a score according to tremor to bradykinesia ratio (TBR). This score was then used to classify patients as akinetic-rigid or tremor-dominant. Tremor-dominant patients were defined as those with TBR of 0.5 or more, while the akinetic-rigid types had a TBR less than 0.5.

Insomnia severity over a 1-month was assessed using patient self-reports on the Pittsburgh Sleep Quality Index (PSQI), which uses a higher score to denote poorer quality of sleep. Daytime sleepiness was measured with the Epworth Sleepiness Scale (ESS). An ESS score a score of 10 or more suggests that the person may not be getting enough sleep, and a score of 18 or more is considered very sleepy.

Results showed that 54 (65%) of the patients had the akinetic-rigid subtype and 29 (35%) had tremor-dominant PD. The mean PSQI score among the akinetic-rigid patients was 14, and among the tremor-dominant patients it was 9 (P <.05). The akinetic-rigid patients had worse scores in the quality, duration, and latency of sleep, as well as sleep disturbances. There was no significant difference between the groups on the ESS scores.

Nocturnal immobility among patients with the akinetic-rigid subtype of PD may interfere with normal sleep patterns, Dr. Klepac said. She suggested that clinicians maintain a particularly high index of suspicion for sleep disturbances among patients with this form of Parkinson's disease.


[Presentation title: Sleep and Parkinson's Disease: Preliminary Results. Poster 557]

Source
http://www.docguide.com/news/content...257180006BCF6D