What symptoms suggest dream enactment is associated with a neurodegenerative disorder, such as REM (Rapid Eye Movement) sleep behavior disorder?

From the Guidelines

Dream enactment behaviors that suggest a neurodegenerative disorder include violent or aggressive movements during sleep, acting out complex behaviors that match dream content, onset later in life (typically after age 50), and movements that occur during REM sleep rather than at sleep onset. These symptoms are particularly associated with REM sleep behavior disorder (RBD), which can precede Parkinson's disease, Lewy body dementia, or multiple system atrophy by years or even decades, as noted in the 2023 American Academy of Sleep Medicine clinical practice guideline 1. Additional concerning features include the presence of other neurological symptoms such as tremor, cognitive decline, balance problems, or autonomic dysfunction, which are commonly seen in patients with secondary RBD due to an underlying neurodegenerative disorder 1. The persistence and worsening of these behaviors over time, especially when they occur multiple times per night or week, also raises concern.

Some key points to consider when evaluating dream enactment behaviors for potential neurodegenerative disorders include:

• Onset later in life, typically after age 50, which is more commonly seen in secondary RBD due to neurodegenerative disorders such as DLB/PD 1
• Presence of other neurological symptoms such as tremor, cognitive decline, balance problems, or autonomic dysfunction, which are frequently observed in patients with neurodegenerative disorders 1
• Movements that occur during REM sleep rather than at sleep onset, which is a characteristic feature of RBD 1
• Acting out complex behaviors that match dream content, which is a hallmark of RBD and can be associated with neurodegenerative disorders 1

It is essential to note that the treatment of secondary RBD due to neurodegenerative disorders often involves managing the underlying condition, and medications such as clonazepam, immediate-release melatonin, and rivastigmine may be used to address dream enactment behaviors, as recommended in the 2023 American Academy of Sleep Medicine clinical practice guideline 1. However, the choice of medication should be individualized based on the patient's underlying disease and attendant symptoms, as well as potential side effects and interactions 1.

From the Research

Symptoms Suggesting Dream Enactment Association with Neurodegenerative Disorder

• Dream enactment behavior during REM sleep, characterized by loss of muscle atonia, is a key symptom of REM sleep behavior disorder (RBD) 2, 3, 4, 5
• Presence of subtle prodromal neurodegenerative abnormalities, such as:
  • Hyposmia (loss of smell) 4
  • Constipation 4
  • Orthostatic hypotension (low blood pressure upon standing) 4
• Abnormalities on various neuroimaging, neurophysiological, and autonomic tests 4
• History of RBD may begin several years to decades before onset of any clear daytime symptoms of motor, cognitive, or autonomic impairments 4
• Severity of REM atonia loss, which can be measured by polysomnography, is a predictor of neurodegenerative disease development 3

Neurodegenerative Diseases Associated with RBD

• Parkinson's disease 2, 3, 4, 5
• Lewy Body dementia 3, 4, 5
• Multiple system atrophy 3, 4, 5
• Synucleinopathies (a group of neurodegenerative diseases characterized by abnormal accumulation of alpha-synuclein protein) 3, 4, 5