14 Exploring the relation of certain sleep disorders on brain lesions and Parkinson’s disease patients

There are many factors that influence our dreaming, and some of these factors may influence the stages of dreaming differently. REM sleep behavior disorder and sleepwalking are two sleep disorders that occur during sleep to a fraction of individuals globally. REM sleep behavior disorder (RBD) occurs in REM sleep, while sleep walking (SW) occurs in slow-wave sleep (NREM3) stage of sleep. Throughout this section, these two disorders will be discussed more in depth while focusing on lesion studies and the study of Parkinson’s Disease (PD) related to RBD and SW along with possible treatments for RBD and SW. As well, various terms related to this topic such as a disorder called parasomnia overlap disorder will be described later in greater detail.

REM sleep behaviour disorder vs. sleepwalking

RBD is characterized by a loss in muscle atonia leading to the individual to act out the dreams they are experiencing. As previously mentioned, RBD happens in REM sleep, in the later parts of the night. The body will move by making jerky and repetitive movements (Di Fabio et al., 2013). Some may shout, scream, kick, and punch (Jung & St. Louis, 2016). On the contrary, SW happens in slow wave sleep, or NREM3 (non-REM) stage sleep. This stage typically occurs early at night. Sleepwalking typically occurs more in children, with a prevalence of 10% whereas only 2-3% of adults experience sleepwalking. Sleepwalking is not related to dreaming and doesn’t necessarily happen based on a dream someone is having. This is one way in which sleepwalking differs from REM sleep behavior disorder because RBD is where much of our dreaming occurs (Di Fabio et al., 2013).

Potential causes for sleep disorders

Brain lesions

Why does REM sleep behavior disorder or sleepwalking occur and, what are the causes? There are several potential causes for RBD and SW. Sometimes there is no root cause. However, cognitive impairments such as brain lesions, or effects of Parkinson’s disease can induce RBD or SW. Based on lesion study research, there is evidence that lesions may cause RBD and SW. More specifically, parasomnia overlap disorder which is a combination of the two disorders (Limousin et al., 2009). There are also cases where RBD and parasomnia overlap disorder are associated with neurogenerative diseases. Parkinson’s disease is a neurodegenerative disease which will be discussed later relating to these sleep disorders. Some other cases of RBD and SW have been observed in some patients with focal lesions of the brainstem. A reported case of someone suffering from an inflammatory disease of the central nervous system had a pontine and medulla lesion. This caused the patient to develop parasomnia overlap disorder (Limousin et al., 2009). Some lesions in certain brain regions focused on visual perception of color and motion are linked to corresponding deficits in dreaming (Nir & Tononi, 2010).

Parkinson’s disease

Parkinson’s disease is associated with sleepwalking. Three patients involved in research around RBD, SW, and parasomnia overlap disorder also suffered from PD (Di Fabio et al., 2013). There has also been evidence of SW found in 6 of 165 patients with PD in a questionnaire (Di Fabio et al, 2013). It was also found that patients with any history of sleepwalking and Parkinson’s disease had a higher outcome on depression and anxiety questionnaires in comparison to PD patients without history of sleepwalking and REM sleep behaviour disorder. Furthermore, Parkinson’s patients with a history of depression and anxiety paired with RBD and SW tended to have more advanced disease and higher impairment such as hallucinations (Di Fabio et al., 2013).

Treatment approaches

Medications

Given that RBD and SW are uncontrollable, there are treatments available to help lessen the chances of an episode. Melatonin and clonazepam are the most commonly used types of medications that happen to be the most effective. Patients suffering with RBD, or SW are usually prescribed melatonin first, and if it is ineffective, they are then prescribed clonazepam. Even if this treatment is used, this does not mean it will be effective in terminating dream enactment behavior. Melatonin has fewer adverse effects compared to patients who take clonazepam. Common side effects of clonazepam are drowsiness, unsteadiness, dizziness, and cognitive impairment. Melatonin has been proven to re-establish normal REM muscle atonia (Jung & St. Louis, 2016).

Non-medicated treatments

There are also some assistive devices like pressure sensitive bed alarms that have an audio message attached to eliminate possible violent dream enactment behaviors while in REM sleep. This helps with avoiding sleep-related injury. This is a good treatment for those who do not respond well to medications. Some other non-invasive treatments to consider might be safety measures as simple as moving big/sharp objects out of the way to prevent possible injury like moving nightstands, tables, and firearms (Jung & St. Louis, 2016). Lastly, a treatment that has not been used enough as there is limited successful treatment is hypnosis. This treatment has been effective in reducing parasomnia behaviors and is used in patients with non-REM parasomnias and nightmare disorders. If further research is done, hypnosis could be a promising treatment.

Conclusion

Overall, REM sleep behavior disorder and sleepwalking differ in many ways but are often grouped together in terms of impairment and treatment. The possible causes of RBD and SW can vary especially with lesion studies and the location of the lesion on the brain. For example, having a lesion on the visual cortex will affect visual pathways of the brain and impact how we see, even in dreaming. The research on dreaming will be ongoing, but the evidence found as of now is promising.