Parkinson's and Sleep Disorders

Sleep disorders or disturbances are one of the many symptoms reported by Parkinson's patients that do not tend to be as widely discussed. Several researchers have suggested that the sleep disturbances may pre-date the more obvious motor symptoms by several years.

The sleep disturbances in PD intrigue me because it is widely reported that any tremors stop while PD patients are sleeping. At the same time researchers note that PD patients seem to lose the normal function of "muscles freezing" while sleeping. Unlike "normal" people PD patients maintain more control over their muscles which can cause issues with "acting out" their dreams. This ability can cause PD patients to kick, hit, walk, talk, etc. regularly while asleep. To me the tremors stopping, but general movements increasing seems very odd, to say the least.

Because of this seemingly in congruent situation I decided to research more about sleep disorders in PD. What I found is that researchers believe the decrease in dopamine directly affects sleep. It has been shown in studies with mice that decreasing dopamine caused the mice to experience significant difficulties with sleeping. The mice also exhibited less brain activity associated with dreaming. Conversely if mice were given increased dopamine they were able to sleep and exhibited increased brain activity associated with dreaming during wakefulness. It is also reported that dopamine agonists tend to have excessive daytime sleepiness as a side effect. Given the studies in mice showing that increased dopamine can cause sleepiness this side effect makes sense.

Exactly how to treat the sleep disturbances does not have a clear cut answer. (At least not one that I have found.) The fact that depression and dementia can also be associated with PD complicates the issue of sleep disorders as both of these conditions can affect sleep on their own.

The most interesting aspect of what I learned about PD and sleep disturbances is still the idea that the motor symptoms are probably pre-dated by sleep disturbances. Wouldn't it be great to be able to diagnose sleep disturbances specific to PD early on so that the patient could start some of the medications that may delay onset of this disease?

Please let me know if you found this information useful or if there is something else you'd like to know about. I'll research any aspect of PD and blog about it to let you know what I find.