A 55-year-old war veteran comes to the office due to new onset of bizarre behavior that has occurred during sleep at night over the past 3 months. His wife reports that he screams as if being attacked and swings his arms wildly while still asleep. The patient has knocked over lamps on the bedside table and has hit his wife several times, once leading to a black eye. He also hurt himself once by falling out of bed. He is able to describe his dreams vividly and says they normally involve fighting with animals; he is completely lucid on awakening. The patient snores loudly, but his wife has never seen him stop breathing during his sleep and he has not awakened gasping for breath. When he was in the military 20 years ago, he was involved in a firefight during which a close army friend was shot and killed next to him.
Other medical issues include recently diagnosed depression, hypertension, and hyperlipidemia. Current medications include hydrochlorothiazide, metoprolol, simvastatin, and venlafaxine.
Vital signs are normal. BMI is 32 kg/m². Physical examination is essentially normal except for a mild resting tremor.
Which of the following is the most likely diagnosis?

Question

A 55-year-old war veteran comes to the office due to new onset of bizarre behavior that has occurred during sleep at night over the past 3 months. His wife reports that he screams as if being attacked and swings his arms wildly while still asleep. The patient has knocked over lamps on the bedside table and has hit his wife several times, once leading to a black eye. He also hurt himself once by falling out of bed. He is able to describe his dreams vividly and says they normally involve fighting with animals; he is completely lucid on awakening. The patient snores loudly, but his wife has never seen him stop breathing during his sleep and he has not awakened gasping for breath. When he was in the military 20 years ago, he was involved in a firefight during which a close army friend was shot and killed next to him.
Other medical issues include recently diagnosed depression, hypertension, and hyperlipidemia. Current medications include hydrochlorothiazide, metoprolol, simvastatin, and venlafaxine.

Vital signs are normal. BMI is 32 kg/m². Physical examination is essentially normal except for a mild resting tremor.
Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

In normal rapid eye movement (REM) sleep, dreams cannot be enacted due to paralysis of skeletal musculature. This patient's repeated episodes of complex motor behaviors and vocalizations correlating with dream mentation are suggestive of REM behavior disorder (RBD), a parasomnia characterized by dream-enactment behaviors that occur during a loss of normal REM sleep atonia. Dream enactment behaviors may involve violent thrashing, punching, and kicking to avoid threats related to dream content. Patients typically come for medical attention due to the bed partner's concern for injury. Diagnosis is based on history and confirmed by polysomnography that captures dream enactment behaviors and REM sleep without atonia. Patients with spontaneous RBD are typically middle-aged or older males. Most cases represent a prodromal syndrome of neurodegeneration, with the vast majority eventually developing Parkinson disease (PD) or dementia with Lewy bodies (RBD to PD conversion rate is approximately 50% every decade). In younger patients (age <40), RBD is most often associated with narcolepsy or antidepressant medications including tricyclics, selective serotonin reuptake inhibitors, and venlafaxine. Treatment involves altering the sleep environment to minimize injury (eg, removing sharp and breakable objects, placing a cushion next to the bed) and pharmacotherapy. Melatonin is preferred as first-line treatment due to its favorable side-effect profile. Low-dose clonazepam is an effective augmentation or alternative therapy for refractory cases. (Choice A) Narcolepsy is unlikely as this patient has not reported severe, excessive daytime sleepiness. (Choice B) Although obstructive sleep apnea is possible in an obese, hypertensive, middle-aged male, it is less likely in this patient given the clear history of dream enactments, lack of witnessed apneas, absence of gasping awakenings, and lack of daytime sleepiness. (Choice C) Although post-traumatic stress disorder (PTSD) can present with nighttime awakenings from nightmares, it would not explain complex motor behaviors during asleep. This patient has no prior history of PTSD from his wartime experiences and exhibits no symptoms of hyperarousal or avoidance that are characteristic of PTSD. (Choice E) Sleepwalking is a non-REM parasomnia that typically presents in childhood. In contrast to RBD, sleepwalking is characterized by nonviolent activities, confusion if awakened, and no recall of the event or dream content. This patient is alert on awakening and describes vivid dream content. Educational objective: Rapid eye movement (REM) behavior disorder (RBD) is a sleep disorder characterized by loss of REM atonia, which precipitates the acting out of dreams during sleep. RBD is highly associated with the later development of neurodegenerative disease, particularly Parkinson disease and dementia with Lewy bodies. __________ References: REM sleep behaviour disorder: not just a bad dream. (http://www.ncbi.nlm.nih.gov/pubmed/28899330) REM sleep behavior disorder and REM sleep without atonia as an early manifestation of degenerative neurological disease. (http://www.ncbi.nlm.nih.gov/pubmed/22328094) REM sleep behavior disorder in Parkinson's Disease and other synucleinopathies. (http://www.ncbi.nlm.nih.gov/pubmed/28513079)

A 55-Year-Old War Veteran Comes to the Office Due to New