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News In Brief
A new study of the use of donepezil (Aricept®) in people with Parkinson’s disease (PD) who have problems with balance shows that the drug reduced the number of falls experienced by one-half. The study, which appears in the October 2010 issue of Neurology, also suggests that the drug, widely used for the cognitive symptoms of Alzheimer’s disease, may ease cognitive symptoms in PD.
Among the movement symptoms of Parkinson’s, balance and gait difficulties are among the most common, with as many as two-thirds of people with PD suffering a fall each year. But they are also among the most difficult to treat.
Donepezil works by boosting the level of acetylcholine, a neurotransmitter that is depleted in the Parkinson’s brain. Because earlier studies have linked low brain levels of acetylcholine to falls, the author of the new study, Kathryn A. Chung, M.D., of the Oregon Health & Science University, reasoned that donepezil might improve balance and reduce falls in people with PD. The problem is that the drug has also been shown to increase PD tremors.
In the new study, Dr. Chung examined 23 people with PD who reported falling or nearly falling more than twice a week. Participants took donepezil for six weeks and a placebo for six weeks, with a three-week break in between. The average participant age was 68; 15 were male; and six had undergone deep brain stimulation.
- Study participants who were taking donepezil were found to fall about one-half as often as those taking a placebo.
- Participants who reported experiencing the most falls before the start of the study showed the greatest improvement after six weeks on donepezil.
- The number of near falls among people in both groups was the same.
What Does it Mean?
Falls are a serious complication of PD. People with PD may be at risk for falling for a variety of reasons including slower reflexes, postural instability, inattentiveness, light-headedness and dyskinesia. Carbidopa/levodopa (Sinemet®) can help in only some of these areas, and additional treatment is needed. Although these results are encouraging, follow-up studies will be needed to confirm them and to understand how donepezil may help to prevent falls.
Among people with Parkinson’s disease (PD), sleep problems such as vivid dreams are not associated with increased risk of developing hallucinations, according to a study in the October 20, 2010 online issue of Neurology. Although people with PD who experience hallucinations often do have sleep difficulties, the two issues may not be related and they progress differently.
Sleep difficulties are common among people with Parkinson’s. The most common sleep difficulties include sleep fragmentation (that is, the tendency to wake up multiple times at night); acting out dreams (REM sleep behavior disorder); and vivid dreams. Traditionally, vivid dreams were considered an early manifestation of hallucinations — a common problem in mid- or late-stage PD, which can actually be exacerbated by some PD medications — and were treated similarly.
To understand hallucinations and sleep disorders, researchers at Rush University Medical Center, led by Christopher G. Goetz, M.D., followed 89 people with PD for 10 years. At the time of enrollment, 60 participants had never hallucinated but reported a range of sleep disturbances, and 29 had experienced hallucinations.
The average age of the participants was 68, and the average time since PD diagnosis was about 10 years. All were taking levodopa, and about half also took other PD medications, including those for sleep.
The researchers used standard assessments to rate the quality of participants’ sleep and the presence and frequency of hallucinations at six months, 18 months, four years, six years and 10 years.
- During the 10-year study, the percentage of participants who experienced hallucinations nearly doubled, and among those who experienced them, the hallucinations were more frequent and more severe.
- Acting out dreams was the only sleep disturbance that was found to progress over time, reported by just 12 percent of participants at the beginning of the study and by 33 percent by the end. Other common disturbances — such as frequent waking during the night, vivid dreams and daytime sleepiness — did not worsen over the course of the study.
- People who reported sleep disturbances at the start of the study did not have an increased risk of hallucinations.
- No association was found between dosages of levodopa and hallucinations.
What Does it Mean?
This study disproves the common notion that vivid dreams are a simply mild form of hallucinations. The authors also point out that no hallucinations should be considered “benign,” as this symptom most often becomes chronic and progresses over time. In addition, the finding that four study participants never developed hallucinations suggests that there may be factors that protect against hallucinations. Further study is needed.
A consensus on the use of deep brain stimulation (DBS) for Parkinson’s disease (PD) made by 50 international experts was published in the October 2010 issue of Archives of Neurology. In 1997, DBS was approved by the US Food and Drug Administration for Parkinson’s. Since then, this procedure has become a standard treatment for some people with PD who experience disabling tremors, wearing-off fluctuations and dyskinesias.
Yet DBS is a complicated procedure, and many questions remain. This panel met in New York in 2009 to address them.
Some of the panel’s most important recommendations included:
- People with PD who are most likely to benefit from DBS are those whose motor symptoms are not well-controlled by medication or who cannot tolerate side effects of medication.
- Those most likely to benefit are people who do not do not have significant active cognitive or psychiatric problems.
- DBS surgery is best performed by an experienced team and neurosurgeon who have expertise in surgery deep within the brain that uses three-dimensional imaging to guide the procedure.
- Complication rates vary widely, with infection being the most commonly reported.
- The benefits of DBS for improving motor symptoms such as dyskinesia and tremor seem to be long-lasting.
- DBS, when used in the two most commonly treated areas of the brain — the subthalamic nuclei or the globus pallidus pars interna — is effective in addressing the motor symptoms of PD.
- Treatment in the subthalamic nuclei may cause increased depression in some people with Parkinson’s disease.
- Surgical electrical removal of a part of the brain affected by PD is an effective alternative to DBS that should be considered in appropriate candidates.
What Does it Mean?
The new report can help people with PD and their doctors make informed decisions when considering DBS. It confirms that people with certain PD symptoms such as tremor and dyskinesia can benefit from DBS. As with any surgery, there are risks, and it can take three to six months of adjustment to tune the implanted apparatus so that it works effectively.
In addition, Parkinson’s disease continues to progress after DBS and the surgery does not address all facets of the disease. Over time, people may still develop problems, such as gait impairment, balance difficulties, and nonmotor symptoms, such as cognitive impairment, that the surgery does not benefit.
PDF recommends that people with PD and their families considering DBS seek out a center that has long-standing experience with DBS and resources dedicated to the surgical treatment of PD.
The choice of whether to have surgery depends on many factors. To learn more, order the PDF booklet, Deep Brain Stimulation for Parkinson’s Disease by calling (800) 457-6676, emailing email@example.com or visiting www.pdf.org.
The medication entacapone/carbidopa/levodopa, (Stalevo®) is under review by the US Food and Drug Administration (FDA) for possible increased risk of prostate cancer and increased risk of certain cardiac events in some individuals. No new conclusions or recommendations about the use of this drug have been made. People living with Parkinson’s should not stop taking their medication unless directed to do so by their doctor. For updated information, visit www.pdf.org/en/meds_treatments.