Updated on 15/04/2024
Normally, our sleep consists of different stages: wakefulness, stage 1, stage 2, stage 3, and REM (rapid eye movement) sleep. REM sleep is characterized by the presence of dreaming and atonic, or paralyzed, state in all muscles except the diaphragm and eye muscles.
Photo: Dilek Necioğlu Örken
Isolated/idiopathic REM sleep behavior disorder (iRBD) is a parasomnia characterized by increased muscle tone during REM sleep, contrary to the atonic or paralyzed state normally associated with this sleep stage. This condition involves excessive motor activity during REM sleep, resulting in behaviors such as acting out dreams, self-injury, or harm to the bed partner. For instance, if you dream of being in a fight, you may punch or kick while in bed. These episodes typically last less than a minute. Additionally, you may talk or shout during your sleep. Severe episodes may awaken you, but milder ones may allow you to continue sleeping. Upon waking after an episode, the patient typically remembers and recounts the nightmare consistent with their movements. Attacks tend to occur more frequently in the early hours of the morning when REM sleep is most intense. The dreams individuals act out tend to be nightmares. Acting out dreams may lead to injuries such as falling out of bed or hitting something. Aggressive or violent movements may also pose a danger to your bed partner.
iRBD is often seen in males over 50 years of age. The disorder typically begins gradually and worsens over time. It may be idiopathic or associated with neurodegenerative diseases such as Parkinson's disease (PD), multiple system atrophy (MSA), or dementia with Lewy bodies (DLB). Additionally, it can be linked to alcohol and antidepressant medication use.
The diagnosis is made through polysomnography examination.
If you experience frequent, disruptive, or dangerous attacks during sleep, your doctor may recommend medication. Additionally, if it is suspected to be related to a medication you are currently taking, discontinuing or changing the medication may resolve the issue. If you experience frequent violent episodes, sleeping separately from your partner may be safer. Measures such as placing a mattress on the floor or installing bed rails can be taken if you frequently fall out of bed or jump out.
It is known that iRBD is the most specific precursor of α-synucleinopathies, including Parkinson's disease and dementia with Lewy bodies. Individuals with iRBD have a 45% risk of developing one of these diseases within 5 years, a 76% risk within 10 years, and a 90% risk within 14 years. Therefore, individuals diagnosed with iRBD should be informed and monitored for the development of these diseases.
Additionally, iRBD has been included in the diagnostic criteria for DLB. The core clinical features of DLB are iRBD, progressive dementia, parkinsonism, fluctuations in cognition and attention, and spontaneous recurrent visual hallucinations. DLB is the second most common cause of cognitive decline seen in memory clinics and typically affects verbal learning, attention/executive functions, and visual-spatial skills in the early stages of the disease course, in contrast to typical Alzheimer's disease, which presents with prominent episodic memory deficits.
