Objective REM sleep characteristics of recurrent isolated sleep paralysis: a case-control study

Abstract Study Objectives Recurrent isolated sleep paralysis (RISP) is a rapid eye movement (REM) parasomnia characterized by a dissociative state with characteristics of REM sleep and wakefulness. Pathophysiology has not yet been clarified and very little research has been performed using objective polysomnographic measures with inconsistent results. The main aim of our study was to find whether higher REM sleep fragmentation is consistent with the theory of state dissociation or whether signs of dissociation can be detected by spectral analysis. Methods Nineteen participants in the RISP group and 19 age- and gender-matched participants in the control group underwent two consecutive full-night video-polysomnography recordings with 19-channel electroencephalography. Apart from sleep macrostructure, other REM sleep characteristics such as REM arousal index, percentage of wakefulness and stage shifts within REM sleep period were analyzed, as well as power spectral analysis during REM sleep. Results No difference was found in the macrostructural parameters of REM sleep (percentage of REM sleep and REM latency). Similarly, no significant difference was detected in REM sleep fragmentation (assessed by REM sleep arousal index, percentage of wakefulness and stage shifts within REM sleep). Power spectral analysis showed higher bifrontal beta activity in the RISP group during REM sleep. Conclusions The results showed an underlying persistent trait of higher cortical activity that may predispose patients with SP to be more likely to experience recurrent episodes, without any apparent macrostructural features including higher REM sleep fragmentation.

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Power Spectral Analysis of Heart Rate Variability in Patients with Charcot’s Neuroarthropathy

Journal of the American Podiatric Medical Association ◽

10.7547/0960001 ◽

2006 ◽

Vol 96 (1) ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

Alexandra Jirkovská ◽

Petr Boucek ◽

Stephanie Wu ◽

Jana Hosová ◽

Robert Bém ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Spectral Analysis ◽

Autonomic Neuropathy ◽

Power Spectral Analysis ◽

Short Term ◽

Cardiovascular Reflex ◽

Cardiovascular Reflex Tests ◽

Power Spectral ◽

Significant Difference

Charcot’s or neuropathic osteoarthropathy is one of the most debilitating orthopedic sequelae of diabetes mellitus. Distinguishing Charcot’s neuroarthropathy from clinically similar conditions may be challenging. The neurovascular theory postulates that Charcot’s neuroarthropathy may be secondary to sympathetic denervation of the lower-extremity vasculature. A convenient method for assessing autonomic neuropathy in patients with Charcot’s neuroarthropathy is needed. Short-term power spectral analysis (PSA) of heart rate variability (HRV), a noninvasive and quantitative method for assessing autonomic neuropathy, may be advantageous compared with the traditionally used Ewing’s cardiovascular reflex tests. However, there are limitations to the clinical use of PSA of HRV because of poor standardization. We standardized PSA of HRV and assessed autonomic neuropathy in 17 people with acute Charcot’s neuroarthropathy using PSA of HRV versus Ewing’s tests. More patients with Charcot’s neuroarthropathy were diagnosed as having autonomic neuropathy with PSA of HRV than with Ewing’s tests (94% versus 82%); however, no significant difference between the two methods was found. The results of this study suggest that PSA of HRV requires minimal patient collaboration and time expenditure compared with Ewing’s tests and may be useful in detecting autonomic neuropathy in patients with Charcot’s neuroarthropathy. (J Am Podiatr Med Assoc 96(1): 1–8, 2006)

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