Medical Image of the Week: REM without Atonia

Figure 1. Polysomnogram with thirty-second epoch showing leg movements and relative increase in chin tone during REM sleep.

Figure 2. Polysomnogram with thirty-second epoch demonstrating similar interval of REM without atonia with the addition of sleep-talking.

A 78 year-old man with a past medical history of Parkinson’s disease (PD) presented to the sleep medicine clinic for evaluation of obstructive sleep apnea (OSA). An overnight polysomnogram (PSG) study was consistent with sleep apnea and revealed frequent leg and arm movements and sleep-talking during rapid eye movement (REM) sleep.

REM sleep behavior disorder (RBD) is a parasomnia characterized by repeated episodes of abnormal behavior occurring during REM sleep (1,2). On PSG, REM sleep without atonia is seen while features of “normal REM” such as number of REM periods and REM cycling remain intact (2). RBD emerges most often in the context of alpha-synucleinopathies, and occurs in up to 60% of PD patients (3). The presence of RBD may be an important preclinical symptom prior to the onset of PD. Cases of PD with RBD are associated with a unique phenotype with an older age of onset, longer disease duration, more profound motor disability, and greater degrees of hallucinations and cognitive dysfunction (3). Establishing a safe sleep environment can be of primary importance in patients with RBD as REM without atonia is associated with injurious behavior. Melatonin is effective as a first-line agent in patients with dementia. In non-demented patients without OSA, low-dose clonazepam is the first line intervention and is rarely associated with withdrawal or need for dose escalation (1). Treating concomitant OSA is important adjunctive therapy.

Jared Bartell, Safal Shetty MD, and Kenneth S. Knox MD

University of Arizona Medical Center

Tucson, AZ

References

1. Aurora RN, Zak RS, Maganti RK, Auerbach SH, Casey KR, Chowdhuri S, Karippot A, Ramar K, Kristo DA, Morgenthaler TI; Standards of Practice Committee; American Academy of Sleep Medicine. Best practice guide for the treatment of REM sleep behavior disorder (RBD). J Clin Sleep Med. 2010;6(1):85-95. [PubMed]
2. Schenck CH, Mahowald MW. REM sleep behavior disorder: clinical, developmental, and neuroscience perspectives 16 years after its formal identification in SLEEP. Sleep. 2002;25(2):120-38. [PubMed]
3. Kim YE, Jeon BS. Clinical implication of REM sleep behavior disorder in Parkinson's disease. Parkinsons Dis. 2014;4(2):237-44. [CrossRef] [PubMed]

Reference as: Bartell J, Shetty S, Knox KS. Medical image of the week: REM without atonia. Southwest J Pulm Crit Care. 2015;10(3):147-8. doi: http://dx.doi.org/10.13175/swjpcc022-15 PDF

Medical Image of the Week: REM Sleep Behavior Disorder in Parkinson Disease

Figure 1. 120 second polysomnogram window showing phasic REM sleep without atonia. Arm and leg movements were seen (black up arrows) and patient was heard moaning and speaking out (black down arrows).

A 55 year old female with a past medical history significant for Parkinson disease status-post implantation of bilateral deep brain stimulators, depression, and restless legs syndrome, who initially presented to the sleep clinic on referral by neurology for evaluation of disordered sleep. Medications included carbidopa-levodopa, escitalopram, gabapentin, lorazepam, ambien, and pramipexole. Her subjective sleep complaints included snoring, restless sleep, difficulty in maintaining sleep, sleep related anxiety, dream enactment behavior, nightmares, and sleep talking. She was sent to the sleep laboratory for evaluation of suspected rapid eye movement behavior disorder (RBD). Overnight polysomnogram did not show evidence for sleep disordered breathing. The sleep study was notable for rapid eye movement (REM) sleep without atonia, visible arm and leg movements, and audible moaning, speaking, and crying out. These findings corroborated the subjective complaints expressed by the patient and her husband. Her medication regimen was altered. Zolpidem and lorazepam were discontinued and she was started on clonazepam. On follow up three months later she reported significant improvement in symptoms and quality of life. She reported near resolution of dream enactment behavior and reduction in restlessness as reported by her husband.

RBD is a sleep disorder characterized by vigorous motor activity that occurs during REM sleep. There is an abnormal loss of normal muscle atonia that usually occurs during REM sleep. REM behavior disorder is commonly seen in individuals with synucelopathies such as Parkinson disease. Lesions within pontomedullary structures are suggested to be the cause of dysfunction of motor control during sleep. REM sleep behavior disorder may actually precede symptoms of parkinsonism by decades, portending the development of overt Parkinson disease in the future (1).

Ryan Nahapetian, MD, MPH and Kenneth S. Knox, MD

Pulmonary, Allergy, Critical Care, & Sleep Medicine

University of Arizona, Tucson, AZ

Reference

1. Boeve BF. Idiopathic REM sleep behaviour disorder in the development of Parkinson's disease. Lancet Neurol. 2013 May;12(5):469-82. [CrossRef]  [PubMed]

Reference as: Nahapetian RR, Knox KS. Medical image of the week: REM sleep behavior disorder in Parkinson disease. Southwest J Pulm Crit Care. 2014;8(6):347-8. doi: http://dx.doi.org/10.13175/swjpcc062-14 PDF