Sleep disorders are very common in Parkinson’s, occurring in 80-90% of patients. There are several reasons for these sleep disorders such as Parkinson’s itself, side effects of Parkinson’s medications and co-existing psychiatric disorders (especially depression). The various types of sleep disorders in Parkinson’s are listed below (Friedman JH, 2008).
|Sleep disorders in Parkinson’s
· Sleep fragmentation
· Excessive daytime sleepiness
· Restless leg syndrome
· Obstructive sleep apnoea
· Vivid dreams
· REM-related behavioural disorder.
Insomnia (difficulty falling asleep) is a common problem among Parkinson’s patients. Insomnia can be due to poorly controlled motor symptoms of Parkinson’s such as
|Causes of insomnia||Treatment|
|Body stiffness and tremor||A dose of long acting levodopa (Sinemet CR or Madopar HBS) before sleep|
|Dyskinesia||Reduce the dose of Madopar or Sinemet before sleep|
|Selegiline||Take the second dose of Selegiline during lunch|
|Depression / anxiety||Anti-depressant and anti-anxiety medications|
dyskinesia and body stiffness (as part of “wearing off” phenomenon). The former tend to occur in the evening in some Parkinson’s patients due to the accumulation of Parkinson’s medications in the body throughout the whole day (dyskinesia is commonly worsened by increasing dose of Parkinson’s medications – the peak-dose dyskinesia). The latter causes Parkinson’s patients to have difficulty turning their body when lying flat. Obviously, this results in insomnia as patients are unable to find the most comfortable sleeping position (many of us sleep better on our sides).
Selegiline, which causes increased level of alertness, can contribute to insomnia.
Treatment of insomnia: as outlined above. In addition, the following steps are helpful;
This refers to frequent night-time awakening. Typically, patients start sleeping at the usual time. After about 2-3 hours, they wake up, feeling refreshed. Consequently, they have difficulty falling asleep again.
|Causes of sleep fragmentation||Treatment|
|Body stiffness as part of “wearing off” phenomenon||A dose of long acting levodopa (Sinemet CR or Madopar HBS) before sleep|
|Depression and anxiety||Anti-depressant and anti-anxiety medications|
|Restless leg syndrome||Dopamine agonist at bedtime|
|Nocturia (due to bladder overactivity)||Reduce evening fluid intake, Detrusitol|
Excessive daytime sleepiness (EDS)
This is the result of many factors such as poor sleep quality (due to other types of sleep disorders in Parkinson’s such as insomnia, sleep fragmentation, vivid dreams or nightmares, Restless leg syndrome and Obstructive sleep apnea), Parkinson’s medications, coexisting depression and Parkinson’s itself.
EDS occurs in 15-50% of Parkinson’s patients. It is important to recognize and treat EDS because it can affect the quality of life in Parkinson’s. A major concern is the development of sleep attacks, which have been reported in 4-8% of Parkinson’s patients (the true prevalence is unknown).
Sleep attacks can occur without any warning or be preceded by excessive sleepiness. It typically strikes during inappropriate circumstances (when we usually do not expect it to happen) such as driving, talking and eating. Motor vehicle accidents due to falling asleep while driving have been known to occur (Frucht SJ, 1999). The risk factors for sleep attacks are both dopamine agonists and levodopa. The association between sleep attacks with dopamine agonists is not confined to any specific medications in this group of medications – Ropinirole, Pramipexole, Bromocriptine, Pergolide and Piribedil have been implicated. The issue of driving in Parkinson’s is further discussed in Chapter 19.
Treatment of EDS: treat the underlying cause. In cases of sleep attacks, reducing the dose or discontinuing the implicated medication is beneficial.
Restless leg syndrome (RLS)
RLS refers to a condition in which patients experience unpleasant sensations (burning, “insects crawling inside”, creeping) in the legs, especially when they are resting (sitting, lying in bed). There is also an uncontrollable urge to move in order to relieve these unpleasant sensations. As moving the legs relieves the discomfort, patients are constantly “shaking” their legs when sitting, pacing and “toss and turn” when in bed – thus explaining the term “restless leg”.
RLS occurs in at least 20% of Parkinson’s patients. The symptoms of RLS are annoying and disabling because they cause insomnia and frequent awakening. As a result, many patients are exhausted and sleepy during daytime.
Treatment of RLS: Dopamine agonists such as Ropinirole and Pramipexole (Oertel WH, 2007).
Obstructive sleep apnoea (OSA)
OSA is characterized obstruction to the airway during sleep which results in snoring and frequent night-time awakening (due to intermittent reduction of oxygen supply to the brain). The term “apnoea” refers to episodes of temporary cessation of breathing, which is another feature of this sleep disorder. The poor quality of sleep leads to excessive daytime sleepiness. It is uncertain whether OSA occurs more often in Parkinson’s patients than the general population. The long-term complications of OSA include hypertension, stroke and heart attack.
OSA is confirmed by a sleep study, during which patients sleep for a night in a laboratory, while the brain wave activities and breathing pattern are monitored.
Treatment of OSA: Oxygen supply via facial mask during sleep.
Vivid dreams or nightmares
About 30% of Parkinson’s patients experience vivid dreams or nightmares, which can be associated with Parkinson’s itself, the Parkinson’s medications (levodopa, dopamine agonists) and dementia. As mentioned previously, vivid dreams are different from hallucination (which occurs during wakefulness).
A 67-year-old Parkinson’s patient reported having nightmares. She dreamed about getting trapped in a building in which the lifts were “jammed”. Having a strong feeling that a “bomb” would be detonated soon in the building, she panicked as she frantically tried to get out of the building.
At other times, she dreamed about struggling to prevent a very fierce dog from biting someone. As she maintained a tight grip on the jaws of the ferocious dog using her right hand, she had to keep herself steady by holding on to the wall using the left hand.
These nightmares often woke her up in the early morning, with her sleeping gowns drenched in sweat. She just could not calm herself down. Feeling terrified, she lay awake in bed till the daybreak, not knowing what to do.
In contrast to RMBD (please refer to the following section), there is no “acting out” of dreams in Parkinson’s patients who have vivid dreams or nightmares. Furthermore, vivid dreams or nightmares are usually reported by the Parkinson’s patients, while RMBD is usually reported by the bed partners. If frequent enough, vivid dreams or nightmares can disrupt sleep pattern and result in excessive daytime sleepiness.
Treatment of vivid dreams or nightmares: reduce the nighttime dose of Parkinson’s medications. If this is not possible (due to poorly controlled motor symptoms of Parkinson’s at night or in the early morning), anti-psychotic such as Quetiapine can be helpful.
REM-related behavioural disorder (RMBD)
RMBD occurs in one-third of Parkinson’s patients, being more common in men. In 20% of Parkinson’s patients, RMBD precedes the motor symptoms. In contrast to vivid dreams, patients with RMBD physically “act out“ their dreams, in the form of verbalization (shouting, threatening) and abnormal body movement (jerking of legs or arms, violent assaults). Typically, the patients dream of “defending themselves from robbers or assailants” or “being chased”, and in the process of doing so, they unknowingly (and really) punch or kick their bed partners. Obviously, the spouses who are not aware of this disorder will chose to sleep separately from the Parkinson’s patients.
Treatment of RMBD: Clonazepam (Rivotril).
Role of the DBS surgery in sleep disorders
By improving the motor symptoms of Parkinson’s, the DBS surgery can improve the quality of sleep. However, this surgery has little or no effect on RMBD and RLS.
· Sleep disorders are common among Parkinson’s patients
· The origin of sleep disorders in Parkinson’s is complex it could be due to Parkinson’s itself, the Parkinson’s medications or coexisting psychiatric disorders
· The sleep disorders are disabling and affect the quality of life
· A thorough investigation should be carried out as the treatment is tailored to each type of sleep disorder.
Frucht SJ, Rogers JD, Greene PE, et al. Falling asleep at the wheel: motor vehicle mishaps in people taking pramipexole and ropinirole. Neurology 1999; 52: 1908-1910.
Friedman JH, Millman RP. Sleep disturbances and Parkinson’s disease. CNS Spectr 2008; 13: 3 (Suppl 4): 12-17.