• DOI:10.1136/eb-2013-101479
• Corpus ID: 2218369

Family history of REM sleep behaviour disorder more common in individuals affected by the disorder than among unaffected individuals

@article{Schenck2013FamilyHO,
  title={Family history of REM sleep behaviour disorder more common in individuals affected by the disorder than among unaffected individuals},
  author={Carlos H. Schenck},
  journal={Evidence-Based Mental Health},
  year={2013},
  volume={16},
  pages={114 - 114}
}

• C. Schenck
• Published 22 August 2013
• Psychology, Medicine
• Evidence-Based Mental Health

ED FROM Dauvilliers Y, Postuma RB, Ferini-Strambi L, et al. Family history of idiopathic REM behavior disorder: a multicenter case-control study. Neurology 2013;80:2233–5. Correspondence to: [e-mail] Sources of funding: Canadian Institutes of Health Research and the Fonds de la Recherche en Santé Quebec. ▸ Additional material and references are published online only. To view please visit the journal online (http://dx.doi.org/10.1136/eb-2013-101479). CO M M EN TA RY Rapid eye movement (REM) sleep behaviour disorder (RBD) is a parasomnia, that is, a sleep behaviour-experiential disorder identified in 1986. RBD typically presents with dream-enacting behaviours in older men. Documentation of RBD with video-polysomnography (vPSG) reveals that the generalised skeletal muscle paralysis of REM sleep (‘REM-atonia’) is intermittently or continually lost. The resulting motor dyscontrol in REM sleep demonstrates increased muscle tone, excessive muscle twitching and release of complex, vigorous and violent behaviours. Injury to self and bed partner is common. The dream content of RBD involves aggression with unfamiliar people and animals. RBD is usually controlled with bedtime clonazepam or melatonin. Despite the bizarre and violent nocturnal behaviours, RBD rarely reflects a psychiatric disorder. RBD is, however, associated with: (1) neurological disorders, especially narcolepsy and parkinsonism and (2) antidepressant pharmacotherapy. There is a brainstem-lesion animal model of RBD, and the neural circuitry subserving REM-atonia is known. Psychiatrists need to be aware of RBD as a non-psychiatric parasomnia that manifests with abnormal nocturnal (dream-enacting) behaviours, and a parasomnia side effect from the use of antidepressants. The study by Dauvilliers and colleagues is one of three publications by the International RBD Study Group. The study reports on a familial basis to RBD; significantly elevated odds for a positive family history of dream-enacting behaviours (presumptive RBD) were found in a cohort of 316 patients with vPSG-confirmed idiopathic RBD compared to 316 controls: 13.8% vs 3.9%. This suggests a genetic contribution to RBD. An immediate clinical implication is that clinicians managing patients with RBD should search for a family history of RBD, since (1) RBD carries an increased risk for major injury; (2) RBD is treatable; (3) RBD is a major risk factor for parkinsonism. The Minnesota and Barcelona groups reported in 2013 that 81% and 82%, respectively, of older patients with idiopathic RBD eventually developed a parkinsonian disorder, with the mean interval from the onset of RBD to the onset of parkinsonism of about 14 years. Finally, clinicians managing older patients should routinely question them and their spouses and any caregivers about RBD.