Characterized by rapid eye movements, REM sleep occurs in five to seven cycles each night. Those awakened during this phase often report vivid dreams. Comprising 20-25% of total sleep, REM sleep is essential for organizing the day’s mental activities. Unlike deep sleep, the brain remains active, exhibiting distinct brainwave patterns. This phase consolidates complex information, and inadequate REM sleep may lead to memory impairment, anxiety, or depression. Physically, REM sleep is marked by muscle atonia (temporary paralysis), irregular breathing, variable heart rates, and rapid eye movements.
REM sleep behavior disorder arises when muscle tone persists during REM sleep, resulting in excessive movements and abnormal behaviors tied to dream content. More prevalent in older adults, particularly men, RBD often involves acting out violent dreams—such as fighting, escaping, or confronting threats—which can lead to injuries. Patients may fall from bed, sustain bruises or abrasions, or, in rare cases, suffer fractures or brain hemorrhages. In some instances, they may unintentionally harm their bed partner. Commonly referred to as “senile sleep-talking” in older individuals, RBD stems from a brainstem dysfunction
that fails to regulate muscle atonia during REM sleep.
A 12-year study by McGill University in Canada found that approximately 50% of RBD patients later develop Parkinson’s disease or dementia, linking the disorder to neurodegenerative conditions. RBD serves as an early signal of brain degeneration, reflecting issues in neural pathways that govern movement and cognition.
Diagnosis typically involves polysomnography, a test that records brainwaves, eye movements, jaw muscle activity, snoring, and other physiological signals during sleep. Elevated muscle tone during REM sleep, coupled with abnormal behaviors, confirms the diagnosis of RBD.
Dr. Kim further notes, “RBD often indicates progressive brain degeneration, with many patients eventually developing Parkinson’s disease or dementia. Olfactory dysfunction is another early marker of these conditions. If RBD is accompanied by a diminished sense of smell, immediate medical evaluation, including polysomnography, is critical.”
Lim Hye Jung, HEALTH IN NEWS TEAM
press@hinews.co.kr
