Increased REM sleep without atonia in Parkinson disease with freezing of gait
ABSTRACT The objective of this cross-sectional study was to test the hypothesis that patients with Parkinson disease (PD) and freezing of gait (PD+FOG) would demonstrate sleep disturbances comparable to those seen in patients with REM sleep behavior disorder (RBD) and these changes would be significantly different from those in PD patients without FOG (PD-FOG) and age-matched controls.
We conducted overnight polysomnography studies in 4 groups of subjects: RBD, PD-FOG, PD+FOG, and controls. Tonic and phasic muscle activity during REM sleep were quantified using EMG recordings from the chin, compared among study groups, and correlated with disease metrics.
There were no significant differences in measures of disease severity, duration, or dopaminergic medications between the PD+FOG and PD-FOG groups. Tonic muscle activity was increased significantly (p < 0.007) in the RBD and PD+FOG groups compared to the PD-FOG and control groups. There was no significant difference in tonic EMG between the PD+FOG and RBD group (p = 0.364), or in tonic or phasic EMG between the PD-FOG and control group (p = 0.107). Phasic muscle activity was significantly increased in the RBD group compared to all other groups (p = 0.029) and between the PD+FOG and control group (p = 0.001), but not between the PD+FOG and PD-FOG groups (p = 0.059).
These findings provide evidence that increased muscle activity during REM sleep is a comorbid feature of patients with PD who exhibit FOG as a motor manifestation of their disease.
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ABSTRACT: Freezing of gait (FOG) is a common, debilitating feature of Parkinson disease (PD), substantially affecting the patient's quality of life by limiting independence and causing falls. Although it occurs most frequently in the later stages of PD, it is also seen in 26% of early-stage patients not yet exposed to levodopa.(1) Since FOG lacks correlation with bradykinesia,(2) a nondopaminergic mechanism may explain this affliction. This concept is supported by the failure of dopaminergic therapies to relieve FOG, except for the category of "off" period FOG.(3) REM sleep behavior disorder (RBD), a condition characterized by potentially injurious disruptive behaviors during sleep, and REM sleep without atonia (RSWA), a condition defined by polysomnography, are both strongly associated with PD and may antedate the onset of motor symptoms.(4) Two previous studies have shown an increase in the frequency of FOG in PD patients with RBD,(5,6) suggesting a shared pathophysiologic link between these 2 conditions.Neurology 08/2013; 81(12). DOI:10.1212/WNL.0b013e3182a4a541 · 8.30 Impact Factor
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ABSTRACT: In his initial description of shaking palsy, James Parkinson first noted that sleep became disturbed with advancing paralysis agitans. More recent studies have confirmed that the majority of patients with Parkinson's disease (PD) suffer from some sleep disturbances. This can manifest as difficulty in falling or staying asleep, fractionated sleep, specific parasomnias, and daytime sleepiness. In this article, we will explore the pathophysiology of these varied sleep disorders. In most cases, however, the definitive etiology is debated, and phenotypes are often felt to be multifactorial. Some of these may be associated with dopaminergic dysfunction, some presumed to arise from varied non-dopaminergic PD pathology, and some from PD treatments.Journal of Neural Transmission 05/2014; 121. DOI:10.1007/s00702-014-1239-6 · 2.87 Impact Factor
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ABSTRACT: Objectives Over 40% of individuals with Parkinson’s disease (PD) have rapid eye movement sleep behavior disorder (RBD). This is associated with excessive sustained (tonic) or intermittent (phasic) muscle activity instead of the muscle atonia normally seen during REM sleep. We examined characteristics of manually-quantitated surface EMG activity in PD to ascertain whether the extent of muscle activity during REM sleep is associated with specific clinical features and measures of disease severity. Methods In a convenience sample of outpatients with idiopathic PD, REM sleep behavior disorder was diagnosed based on clinical history and polysomnogram, and severity was measured using the RBD sleep questionnaire. Surface EMG activity in the mentalis, extensor muscle group of the forearms, and anterior tibialis was manually quantitated. Percentage of REM time with excessive tonic or phasic muscle activity was calculated and compared across PD and RBD characteristics. Results Among 65 patients, 31 had confirmed RBD. In univariate analyses, higher amounts of surface EMG activity were associated with longer PD disease duration (srho=0.34; p=0.006) and greater disease severity (p<0.001). In a multivariate regression model, surface EMG activity was significantly associated with RBD severity (p<0.001) after adjustment for age, PD disease duration, PD severity and co-morbid sleep abnormalities. Conclusion Surface EMG activity during REM sleep was associated with severity of both PD and RBD. This measure may be useful as a PD biomarker and, if confirmed, may aid in determining which PD patients warrant treatment for their dream enactment to reduce risk of injury.Parkinsonism & Related Disorders 07/2014; 20(7). DOI:10.1016/j.parkreldis.2014.04.011 · 4.13 Impact Factor