Journal of Sleep Disorders & Therapy
Open Access

REM Sleep Behavior Disorder as a Prodromal Marker for Neurodegenerative Disease

Kimani Ali^{* *}Correspondence: Kimani Ali, Department of Integrative Health and Sleep Sciences, Mount Kenya University, Thika, Kenya, Email:

Author info »

Description

Parasomnia represents one of the most intriguing and complex categories of sleep disorders, defined by unusual behaviors, perceptions, or experiences that occur during the transitions into sleep, within sleep itself, or upon awakening. Unlike simple insomnia, where difficulty falling or staying asleep is the central complaint, parasomnia intrudes upon the very architecture of sleep, blending consciousness with unconscious states in ways that can be both fascinating and disturbing. It challenges the traditional dichotomy between wakefulness and sleep by creating experiences where elements of each state coexist, leaving patients and families bewildered. From sleepwalking and night terrors to REM sleep behavior disorder and confusional arousals, parasomnias span a wide spectrum, reflecting disruptions in the delicate neurological processes that govern sleep regulation.

The societal perception of parasomnia has often been colored by folklore, mystery, and sometimes fear. Sleepwalking, for instance, has been woven into literature, theater, and mythology as a symbol of unconscious forces at play. People who act out dreams may be viewed with a mix of fascination and anxiety, as their behaviors defy conventional understanding of what it means to be asleep. In some legal cases, parasomnia has even been used as a defense, with claims of criminal acts performed during sleepwalking episodes. These scenarios highlight the blurred ethical and legal boundaries that parasomnia raises, where questions of responsibility, awareness, and intent are far from straightforward. From a cultural perspective, parasomnia resonates deeply because it disrupts the assumed security of sleep, a state most people regard as safe, restorative and private.

From a physiological standpoint, parasomnias can be broadly divided into non-REM and REM-related disorders, each with distinct features. Non-REM parasomnias, such as sleepwalking and night terrors, usually occur in the first third of the night during slow-wave sleep. The brain is partly asleep yet partly awake, producing bizarre states of arousal where individuals may sit up in bed, talk incoherently, scream in terror, or wander about with no recollection the following morning. These episodes are more common in children, reflecting the immaturity of sleep-wake regulation in developing brains, but when they persist into adulthood, they may carry heightened risk of injury or signal underlying pathology. REM sleep behavior disorder, on the other hand, occurs during dream sleep, when the normal paralysis of muscles that prevents us from acting out dreams is lost. The result can be vivid enactments of dream content, sometimes involving violent thrashing, shouting, or fighting, which can endanger both the sleeper and their bed partner. Unlike childhood parasomnias, REM sleep behavior disorder is strongly linked with neurodegenerative disease, making it a particularly important condition in adult sleep medicine.

The implications of parasomnia extend beyond the nighttime episodes themselves. Patients and families often endure significant distress, not only from disrupted sleep but from the unpredictability of the events. The fear of injury, embarrassment, or even social stigma may lead individuals to avoid sleeping in shared environments, to withdraw from relationships, or to experience heightened anxiety around bedtime. Daytime consequences such as fatigue, irritability, and impaired concentration compound the burden, making parasomnia a disorder with ripple effects far beyond the bedroom. For children, recurrent night terrors or sleepwalking can distress parents who feel powerless to intervene, while for adults, the danger of accidents or the association with neurological disease can create a lingering sense of unease.