A recent study published in JAMA Network Open investigated the question of a possible causal relationship between Parkinson’s disease and restless legs syndrome. It turned out that the coexistence of RLS may lead to the development of Parkinson’s disease. Nevertheless, based on this research, it is also indicated that adequate RLS therapy can alleviate the risk and be vital for health in the future.
What Exactly Is Restless Legs Syndrome?
Restless legs syndrome is a neurological sleep disorder that makes people feel a strong need to move their legs. Many describe the feeling as crawling, creeping, or itching sensations that get worse in the evening or at night. Because of this, people with RLS often struggle to fall asleep or stay asleep. The discomfort usually improves for a short time when they move their legs, stretch, or walk around.
A recent study published in JAMA Network Open explored the possibility of a link between restless legs syndrome (RLS) and the risk of developing Parkinson’s disease (PD). The researchers concluded that those who had RLS may be more likely to get Parkinson’s disease. The research also indicates that treating RLS effectively might lower the risk and be instrumental in maintaining overall health in the long run.
The reasons for RLS can be different for each individual. Iron deficiency may be the cause, and diabetes, kidney problems, pregnancy, or even some drugs may also be the cause.
Besides that, RLS can be a result of the brain area that controls movement not functioning properly. This region releases a chemical called dopamine that is responsible for smooth muscle movement. When the dopamine level is disturbed, the person can suffer from involuntary movements.
Medical professionals rely on symptoms presented by the patients in order to diagnose RLS. However, there are no blood tests, scans, or sleep studies that can confirm this condition.
If the symptoms are severely affecting the quality of life of the patients, they can take some prescribed drugs to help ease their condition. Most of these medications are designed to influence the brain’s dopamine system, and in this group fall the drugs such as pramipexole, ropinirole, rotigotine, and levodopa. These drugs were the main methods of treatment until now when the new guidelines of the American Academy of Sleep Medicine recommend using them occasionally if at all due to the possibility of side effects or long-term issues. Besides these medicines, there are other prescription drugs that can affect dopamine, GABA, or opioid receptors and be of assistance with RLS.
Parkinson’s Disease: What Dopamine Has to Do With It
A recently published study in JAMA Network Open analyzed whether individuals with restless legs syndrome (RLS) have a higher risk of developing Parkinson’s disease (PD). The scientists concluded that RLS might double one’s risk of developing Parkinson’s. Nonetheless, the research also implies that taking good care of RLS may not only lessen that risk but also be instrumental in one’s overall well-being in the future.
The reasons for RLS are different in each case. It can be etiologically linked to iron deficiency, diabetes, chronic renal failure, pregnancy, or even specific drug intake.
Besides, RLS could result from a malfunction of the brain region responsible for the control of the movements. This part normally uses dopamine, a neurotransmitter that makes the movement of the muscles easy and precise. However, if the levels of dopamine get disrupted, the patient might experience some twitching or involuntary movements without even realizing it.
The medical staff relies solely on symptomatology when diagnosing RLS, hence no laboratory tests, scans, or sleep studies are required for confirmation.
As a major cause of tremors and walking difficulties, Parkinson’s gradually deteriorates the central nervous system. It is due to the death of neuronal cells in certain parts of the brain which results in both motor and non-motor symptoms like tremors, rigidity, bradykinesia, and postural instability. Eventually, it can lead to the worsening of the functions of the brain like memory, speech, and other activities of daily living.
One of the characteristics of Parkinson’s is the gradually decreased production of dopamine, a chemical in the brain that regulates movement. As both Parkinson’s and RLS are related to dopamine changes, this is one of the reasons why the two diseases can have similar movement impairments and partly benefit from the same medications.
Key Findings from the Study
First, researchers in South Korea compared the health data of nearly 20,000 people, of which about 50% had restless legs syndrome (RLS) and the other 50% did not. The average age in both the RLS and non-RLS groups was 50, and about 63% of the participants were women.
As a matter of fact, over time, Parkinson’s disease was recorded in 1% of individuals without RLS, while in 1.6% of people with RLS. In other words, those with RLS had a higher chance of developing Parkinson’s than those without the disorder.
Moreover, the research considered medication effects. The individuals with RLS who were not on dopamine-related treatments had a higher risk of developing Parkinson’s and were diagnosed at a younger age. Conversely, those who took dopamine agonists were less likely to develop the disease and were diagnosed at a later stage, thus implying that the treatment may be helpful in reducing the risk.
Sleep Disorders and Their Role in Parkinson’s Disease
Besides restless legs syndrome, Parkinson’s has been associated with other sleep problems as well. One of them is REM sleep behavior disorder (RBD), a disorder in which an individual physically expresses his dream during sleep. This disorder has been linked to a higher chance of Parkinson’s development in the future. To be precise, RBD is even referred to as a “prodromal symptom” of Parkinson’s and other neurodegenerative diseases in some cases.
Conclusion
Although restless legs syndrome (RLS) and Parkinson’s disease (PD) are different types of neurological disorders, they exhibit similarities such as abnormal muscle movements and changes in brain activity related to movement. Both conditions are also associated with low levels of dopamine.
One of the pieces of evidence is that RLS is significantly more frequent in patients with PD — a study reported that the prevalence of RLS in people with Parkinson’s was around 16%, while the prevalence in the general population was only 5% to 10%. There is new research indicating that having RLS may increase the risk of developing Parkinson’s in the future, but these studies have shown contradictory results, partly due to the fact that methods of diagnosis have changed over time.
Researchers are still investigating the link between the two disorders and whether early diagnosis and treatment can lead to better results. Since both RLS and Parkinson’s may cause sleep disruption, consulting a sleep specialist or visiting a certified sleep center is highly recommended if you have sleep problems that persist.
