Male Androgens and Sleep Rem Sleep Behavior Disorder (rbd) Is a Parasom- Nia Characterized by Vigorous Dream-enact- Ing Behaviors Related to Lack of Muscle Atonia

REM SLEEP BEHAVIOR DISORDER (RBD) IS A PARASOMNIA CHARACTERIZED BY VIGOROUS DREAM-ENACTING BEHAVIORS RELATED TO LACK OF MUSCLE ATONIA during REM sleep.1,2 Patients recall dreams with violent content, such as being attacked and threatened by people or animals, and display aggressive dream-enacting behaviors including punching, kicking, and shouting.1,2 RBD may be idiopathic or associated with neurological diseases.1-7 For unknown reasons, more than 85% of the subjects presenting to sleep centers with idiopathic RBD are men.4-6 It has been hypothesized that sex hormone abnormalities might account for this male predominance and the violent nature of the RBD-associated behaviors.2 This is based on the following observations. First, testosterone exerts neuroprotective effects,8 and testosterone deficiency occurs in Parkinson disease,9 a neurodegenerative condition in which RBD is common.3,5,6 Second, androgen receptors are distributed in the brain structures that modulate both REM sleep and aggressiveness, such as the subceruleus nucleus, periaqueductal gray, amygdala, and frontal lobe.10,11 Third, data from both humans and animals indicate that high testosterone levels are related to increased physical aggressiveness.12 The aim of our study was to determine the serum sex hormone levels in consecutive idiopathic RBD male patients who presented to our sleep center. PATIENTS AND METHODS