REM-related Parasomnias and Management of Parasomnias

00:00 Now, let's talk about some of the REM sleep behavior disorders. Again, these are occurring during REM sleep. The predominance of REM sleep is later in the night and so we tend to see these occurring late in the night. These events are occurring during REM sleep and patients are often able to be awakened during these episodes. As we recall in normal REM sleep, patients are atonic, they're unable to move as a result of muscle atonia that occurs during REM sleep. We want patients dreaming. This is helpful and important in terms of the processes that are occurring in the brain during REM sleep and the body doesn't want to act out those dreams and so muscle atonia is a protective mechanism for the body. In REM behavior disorder, we see the loss of muscle atonia. So now patients are able to act out those dreams that are occurring. What's the typical description and presentation of REM behavior disorder? Well, typically these episodes start with dream-enacting behaviors.

01:05 Patients may sleep talk or yell. There may be limb jerking. They may walk, or turn often, though not leaving the bed. And we frequently hear punching or other violent behaviors that may occur during these episodes. This is a REM parasomnia.

01:21 So patients are able to be awoken during the episode. They can easily awaken.

01:27 Upon awakening, patients are often alert but maybe briefly disoriented as they wake up from this REM sleep. And in terms of the next morning, patients may often recall their dream content but are usually not aware of the dream and acting behavior or assault on a bed partner or other secondary consequences of these episodes. So how do patients present with REM behavior disorder? Well, typically, the presenting complaint is often made by the patients bed partner or family member reporting violent behaviors during sleep or injury to a partner. We can see this in elderly patients. We can see this occurring in patients taking certain medications, serotonergic antidepressants or occasionally beta-blockers. And then importantly, there is a strong association between early onset REM sleep behavior disorder and neurodegenerative conditions like idiopathic Parkinson's disease, multiple system atrophy, and Lewy body disorder or Lewy body dementia. Those alpha synucleinopathies. Now, let's talk about nightmare disorder. This is a REM sleep parasomnia characterized by vivid nightmares. Typically, these events start with vivid dreaming, scary, negative themes associated with the dreams and this is not associated with motor activity or sleep injury. Patients are in normal REM sleep. There is muscle atonia so we see and hear those vivid dreams without motor activity. At the end of the event, patients may awaken from an unpleasant dream and be fully alert. There is typically no confusion or disorientation.

03:06 Wakefulness during REM sleep is not uncommon or abnormal and we see that present in this condition. And after this in the morning, typically there is complete recollection of the unpleasant dream. So what makes nightmare disorder different from just a nightmare? Well, typically, we see that this causes significant distress or impaired functioning in these patients and is not associated with medication or substance use which can precipitate nightmares or particularly vivid dreams.

03:36 So how do we manage the non-REM and REM parasomnias? Let's start with some of the interventions for non-REM parasomnias. Behavioral therapy is often our first step. Thinking about sleep hygiene and education as well as reassurance of both patients, bed partners, family members, and others around the patient.

03:54 Risk factor modification is also important. Discontinuing medications that may precipitate non-REM parasomnias. Environmental safety is critically important particularly for those with sleep walking or sleep-related eating disorders or others. We want to secure locks, remove dangerous objects, and keep the patient safe during this event. And we treat co-existing sleep disorders, obstructive sleep apnea or others that may precipitate these events or worsen the underlying condition. In terms of pharmacotherapy, we have a number of options that can be available. Short course benzodiazepines are primarily used for refractory cases for a short period of time. Selective serotonin reuptake inhibitors can be helpful particularly for sleep-related sexual behavior and eating disorder. And sometimes we will consider topiramate for sleep-related eating disorder owing to its ability to result in weight loss in some patients. How about the REM sleep behavior disorder? How do we treat that? The first step is risk factor modification. Second is ensuring environmental safety, removing dangerous objects or bed partners from that situation where they may experience injury. And then medications that can be used for this disorder include clonazepam, melatonin, and others. For nightmare disorder, reassurance is often enough but desensitization, rehearsal therapy can be beneficial and in some cases medications.