Posture and Gender Differentially Affect Heart Rate Variability of Symptomatic Mitral Valve Prolapse and Normal Adults.

BACKGROUND: Heart rate variability (HRV) has been shown to be a useful measure of autonomic activity in healthy and mitral valve prolapsed (MVP) subjects. However, the effects of posture and gender on HRV in symptomatic MVP and normal adults had not been elucidated in Taiwan. METHODS: A total of 118 MVP patients (7 males, 39 ± 7 years old; and 111 females, 42 ± 13 years old) and 148 healthy control (54 males, 28 ± 4 years old; and 94 females, 26 ± 6 years old) were investigated. The diagnosis of MVP was confirmed by cross-sectional echocardiography. A locally developed Taiwanese machine was used to record the HRV parameters for MVP and control groups in three stationary positions. Thereafter, the HRV time-domain parameters, and the frequency-domain parameters derived from fast Fourier transform or autoregressive methods were analyzed. RESULTS: The MVP group showed a decrease in time domain parameters and obtunded postural effects on frequency domain parameters moreso than the control group. Though the parasympathetic tone was dominant in female (higher RMSSD, nHF and lower nLF vs. male), the sympathetic outflow was higher in MVP female (lower SDNN, NN50 and higher nLF vs. normal female). While the parasympathetic activity was lower in male, sympathetic outflow was dominant in MVP male (lower nHF and higher nLF vs. normal male). CONCLUSIONS: Both MVP female and male subjects had elevated levels of sympathetic outflow. The obtunded postural effects on frequency domain measures testified to the autonomic dysregulation of MVP subjects.

Movement-related cortical potentials in patients with Machado-Joseph disease.

OBJECTIVE: Movement-related cortical potentials (MRCP; nomenclature of MRCP components according to Shibasaki and Hallett (Shibasaki H, Hallett M. What is the Bereitschaftspotential? Clin Neurophysiol 2006;117:2341-56) were studied in patients with Machado-Joseph disease (MJD) to elucidate the pathophysiology of voluntary movement. METHODS: We studied nine genetically proven MJD patients and eight age-matched healthy subjects. Multi-channel electroencephalogram (EEG) recordings were obtained during self-paced fast extensions of the wrist. EEG epochs were time-locked to electromyography (EMG) onset or offset of the voluntary EMG burst and averaged. RESULTS: In the MJD patients, the early Bereitschaftspotential (early BP, -1500 to -500ms) was not affected but the late BP was reduced over the central midline area and contralaterally to the movement side. The amplitude of the fpMP, a post-movement MRCP component, was also reduced. In addition, the offset cortical potential in the first 500ms after EMG offset (Moff+500) was attenuated bilaterally over a wide cortical area. CONCLUSIONS: Findings suggest that cortical activations associated with the initiation and termination of a voluntary movement are impaired in MJD patients. SIGNIFICANCE: Abnormalities of pre- and post-movement MRCP components provide researchers with pathophysiological insight into voluntary motor dysfunction in MJD.

Interleukin-1beta mediates sleep alteration in rats with rotenone-induced parkinsonism.

STUDY OBJECTIVE: Recently, the pathogenesis of Parkinson disease (PD) has been focused on microglial activation, especially the subsequent increase of cytokines. A body of clinical evidence suggests that sleep is altered in patients with PD; however, there is a lack of understanding of the basic cellular mechanism. This study was designed to elucidate the influence of brain interleukin (IL)-1beta on sleep changes, in addition to the dopaminergic and gamma-aminobutyric acid (GABA)-ergic systems, in an animal PD model. DESIGN: We employed a long-term subcutaneous infusion of rotenone, a mitochondrial complex-I inhibitor, to induce a parkinsonism-like model in rats. Behavioral tests and tyrosine hydroxylase immunocytochemistry were used for confirmation of PD in this animal model. Pharmacologic agonist and antagonists were administered centrally to test the involvement of dopamine, GABA, and IL-1 in rotenone-induced sleep alteration. Protein expression of cytokines, ie, IL-1beta and tumor necrosis factor alpha (TNF-alpha), in 5 distinct brain regions was also determined by Western blot and enzyme-linked immunosorbent assay (ELISA). SETTING: Sleep-recording equipment in the National Taiwan University and China Medical University. PARTICIPANT AND INTERVENTIONS: Male Sprague-Dawley rats were implanted with electroencephalogram electrodes, a thermistor, and an intracerebroventricular guide cannula. Chronic infusion of rotenone was given by an Alzet minipump implanted subcutaneously on the back of each rat. MEASUREMENT AND RESULTS: We found that locomotion activity was reduced, slow-wave sleep (SWS) was increased during the dark (active) phase and decreased during the light (rest) period, and rapid eye movement sleep (REM) was enhanced in the dark period after rotenone treatment. This rotenone PD animal model successfully causes loss of tyrosine hydroxylase-immunopositive neurons in the substantia nigra; induces the events of sleep disturbance, such as excessive daytime sleepiness and insomnia during the nighttime, that are seen in patients with PD; and suppresses locomotion. Our results that intracerebroventricular administration of dopamine and blockade of GABA in the brain have less significant effect on rotenone-induced sleep alteration suggest that the sleep disturbance is not primarily mediated by the disruption of dopaminergic and GABAergic systems in the current PD rat model. The expression of TNF-alpha was not altered by rotenone. However, the results of enhanced expression of IL-1beta in the hypothalamus after rotenone and that of the blockade of sleep alteration, but not the locomotion activity, by intracerebroventricular administration of an IL-1 receptor antagonist implies that increased IL-1beta in the hypothalamus mediates sleep alteration, but not the locomotion, in rats with rotenone-induced parkinsonism. CONCLUSION: These observations suggest that rotenone-induced sleep-wake alteration is dominated by central increase of somnogenic IL-1.

Gamma-aminobutyric acid (GABA) receptor mediates suanzaorentang, a traditional Chinese herb remedy, -induced sleep alteration.

The sedative-hypnotic medications, including benzodiazepines and non-benzodiazepines, are the most common treatments for insomnia. However, concerns regarding patterns of inappropriate use, dependence and adverse effects have led to caution in prescribing those sedative-hypnotic medications. On the other hand, a traditional Chinese herb remedy, suanzaorentang, has been efficiently and widely used in clinic for insomnia relief without severe side effects in Asia. Although suanzaorentang has been reported to improve sleep disruption in insomniac patients, its mechanism is still unclear. The present study was designed to elucidate the effects of oral administration of suanzaorentang on physiological sleep-wake architectures and its underlying mechanism in rats. We found that oral administration of suanzaorentang at the beginning of the dark onset dose-dependently increased non-rapid eye movement sleep (NREMS) during the dark period, but had no significant effect on rapid eye movement sleep (REMS). Our results also indicated that intracerebroventricular (ICV) administration of gamma-aminobutyric acid (GABA) receptor type A antagonist, bicuculline, significantly blocked suanzaorentang-induced enhancement in NREMS during the dark period, but GABA(B) receptor antagonist, 2-hydroxysaclofen had no effect. These results implicated that this traditional Chinese herb remedy, suanzaorentang increases spontaneous sleep activity and its effects may be mediated through the GABA(A) receptors, but not GABA(B) receptors.