• Annals of Clinical Neurophysiology
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• v.21 no.1
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• pp.30-35
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• 2019

Background: Postural tachycardia syndrome (POTS) refers to the presence of orthostatic intolerance symptoms associated with a heart rate increment of greater than 30 beats/min, usually up to 120 beats/min, on head-up tilt test. Symptoms related to POTS are usually light-headedness, palpitations and tremor, but syncope can also occur. The pathophysiology of POTS is heterogeneous and its prognosis is uncertain. Methods: We prospectively evaluated patients who met the criteria for POTS, at baseline and follow-up, using composite autonomic symptom scores and autonomic tests to assess the autonomic function. We compared the clinical and autonomic test results between baseline and follow-up. Results: Sixty-eight patients met the inclusion criteria for POTS and forty-five patients were ultimately followed up for at least 1 year after baseline. The patients were predominantly young females (84%), with a mean age of 21 years. Most patients showed improved orthostatic symptoms and more than a quarter of patients had no longer met the criteria for POTS at follow-up. Conclusions: Most patients had a benign outcome in that they could resume their daily activities without great limitations. Our results demonstrated a relatively favorable prognosis in most patients with POTS.

• Journal of the Korean neurological association
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• v.35 no.1
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• pp.8-15
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• 2017

Near-infrared spectroscopy (NIRS), a noninvasive optical method, utilizes the characteristic absorption spectra of hemoglobin in the near-infrared range to provide information on cerebral hemodynamic changes in various clinical situations. NIRS monitoring have been used mainly to detect reduced perfusion of the brain during orthostatic stress for three common forms of orthostatic intolerance (OI); orthostatic hypotension, neurally mediated syncope, and postural orthostatic tachycardia syndrome. Autonomic function testing is an important diagnostic test to assess their autonomic nervous systems for patients with symptom of OI. However, these techniques cannot measure dynamic changes in cerebral blood flow. There are many experimentations about study of NIRS to reveal the pathophysiology of patients with OI. Research using NIRS in other neurologic diseases (stroke, epilepsy and migraine) are ongoing. NIRS have been experimentally used in all stages of stroke and may complement the established diagnostic and monitoring tools. NIRS also provide pathophysiological approach during rehabilitation and secondary prevention of stroke. The hemodynamic response to seizure has long been a topic for discussion in association with the neuronal damage resulting from convulsion. One critical issue when unpredictable events are to be detected is how continuous NIRS data are analyzed. Besides, NIRS studies targeting pathophysiological aspects of migraine may contribute to a deeper understanding of mechanisms relating to aura of migraine. NIRS monitoring may play an important role to trend regional hemodynamic distribution of flow in real time and also highlights the pathophysiology and management of not only patients with OI symptoms but also those with various neurologic diseases.

• The Korean Journal of Pain
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• v.26 no.3
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• pp.303-306
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• 2013

Postural orthostatic tachycardia syndrome (POTS) refers to the presence of orthostatic intolerance with a heart rate (HR) increment of 30 beats per minute (bpm) or an absolute HR of 120 bpm or more. There are sporadic reports of the autonomic nervous system dysfunction in migraine and fibromyalgia. We report a case of POTS associated with migraine and fibromyalgia. The patient was managed with multidisciplinary therapies involving medication, education, and exercise which resulted in symptomatic improvement. We also review the literature on the association between POTS, migraine, and fibromyalgia.

• 한국전산유체공학회:학술대회논문집
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• 2000.10a
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• pp.123-128
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• 2000

Orthostatic stress in human cardiovascular system following spaceflight remains a critical problem in the current lifercience space program. The study presented in this paper is part of an ongoing effort to use mathematical models to investigate the effects of gravitational stresses on the cardiovascular system of normals and microgravity adapted individuals. We employ a twelve compartment lumped parameter representation of the hemodynamic system coupled to set-point models of the arterial baroreflex and the cardiopulmonary reflex to investigate the transient response of heart rate to orthostatic stress. We simulate current hypotheses concerning the mechanisms underlying postspaceflight orthostatic intolerance over a range of physiologically reasonable values and compare the simulations to astronaut stand-test data pre-and postflight.

• The Korean Journal of Physiology
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• v.30 no.2
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• pp.237-247
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• 1996

This study was carried out to determine the effect of $-6^{\circ}$ head-down bedrest on the cardiovascular and hormonal responses to orthostasis and to evaluate the mechanism of orthostatic intolerance. Ten healthy young men were changed the body position from $-6^{\circ}$ head-down or supine bedrest for 2 hr to $70^{\circ}$ head-up tilt for 20 min. During the bedrest, there were no differences in hemodynamic and hormonal changes between the head-down and the supine positions. However, the tendency of decreased end-diastolic volume and increased cardiac contractility during the later period of 2 hr showed that the cardiovascular adaptation could be accelerated within a relatively short period in the head-down bedrest. During the head-up tilt, presyncopal signs were developed in five subjects of the supine bedrest, and one of the same subjects of the head-down bedrest. In the tolerant subjects, the increase in cardiac contractility and plasma epinephrine level during the bend-up tilt was greater following the head-down bedrest than that following the supine bedrest to compensate for reduced venous return. The intolerant subjects showed the greater decrease in end-diastolic and stroke volume, and the greater increase in heart rate during the head-up tilt than the tolerant subjects. Cardiac contractility and plasma epinephrine level were remarkably increased. However, arterial pressure was not maintained at the level for the appropriate compensation of the reduced venous return. It seems that the tolerance to orthostasis is more effective after the short-term head-down bedrest than after the supine bedrest, and the secretion of epinephrine induces the higher cardiac performance as a compensatory mechanism fur the reduced venous return during the orthostasis following the head-down bedrest than the supine bedrest.

• Journal of the Korean neurological association
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• v.36 no.4
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• pp.280-288
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• 2018

Vertigo/dizziness is a common complaint in patients who are seeking a primary health clinic. Vertigo is traditionally attributed to damage of the vestibular system. Many peripheral and central vestibular disorders are usually presented with vertigo. However, patients with benign paroxysmal positional vertigo (BPPV), a leading cause of vertigo, may present with postural lightheadedness, near faint, imbalance rather than true vertigo. On the contrary, patients with orthostatic hypotension may present with true spinning vertigo, not dizziness. Persistent postural perceptual dizziness, a second most common cause of dizziness (after BPPV), is mainly occurred after organic vestibular disorders such as BPPV or vestibular neuritis, and classified as a chronic functional vestibular disorder. This article describes non-vestibular disorders presenting dizziness and/or vertigos, which conditions may be misdiagnosed as structural vestibular disorders.

• The Journal of Korean Medicine
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• v.40 no.4
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• pp.84-90
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• 2019

Objectives: Chronic fatigue syndrome (CFS) is a debilitating illness impairing seriously quality of life, while CFS would be an optimized target disorder of Korean medicine. This study aims to present the recent information especially in aspect of medical policy and new diagnosis criteria for CFS. Methods: The literature survey was conducted using the terms of "chronic fatigue syndrome", "myalgic encephalomyelitis" and "fibromyalgia" in PubMed database and Google database in its entirety from January 2011 to February 2019. The in-depth review was made focusing on the changes in policy and medical perspective for CFS. Results: Recently large medical attentions and researches for CFS have been existed worldwide. By supporting of USA government, IOM made a report which leaded to a turning point in clinical practices and research in 2015. This report recommended a new name of CFS to systemic exertion intolerance disease (SEID), and new diagnostic criteria focusing on post-exertional malaise, unrefreshing sleep, cognitive impairment and orthostatic intolerance. The medical perspective also was changed into "a serious, chronic, complex, systemic disease" from a psychological-like disorder, and then UAS and EU governments sharply increased the research grants. Conclusions: This study provided practitioners in Korean medicine (KM) a core information about the recent changes in CFS-related perspectives. This review would be helpful for KM-derived researches or therapeutics development for CFS.

• Annals of Clinical Neurophysiology
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• v.12 no.2
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• pp.61-65
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• 2010

Background: Orthostatic hypotension (OH) refers to a fall in systolic blood pressure (BP) of 20 mmHg or more, or in diastolic BP of 10 mm Hg or more within 3 minutes of standing up. The head-up tilt test (HUT) is the most useful, but potentially invasive test for the diagnosis of OH. The purpose of this study was to identify the usefulness of spontaneous baroreflex sensitivity (sBRS). Methods: Ninety one patients with orthostatic intolerance, in whom the HUT data were available, were included in the study. Patients were classified into HUT-positive (group I) and HUT-negative (group II) group. Twenty five healthy volunteers served as normal controls, and were designated as group III. In all subjects, beat-to-beat BP and heart rate were recorded using BeatScope 1.1a. We collected the 50 sBRS data in each patient in a supine position. The average value of one to ten of 50 sBRS data was defined as sBRS10, one to twenty as sBRS20, one to thirty as sBRS 30, one to forty as sBRS 40, and one to fifty as sBRS 50. Differences in sBRS10 and sBRS50 levels were statistically analyzed and compared between groups I, II, and III. Results: No significant difference in the sBRS50 level was found between Groups II and III. sBRS50 was significantly lower in Group I than in Groups II and III (p<0.05), and the same pattern of differences was observed for sBRS40, sBRS30, sBRS20, and sBRS10. Conclusions: Patients with OH showed significantly lower sBRS levels than HUT-negative patients or normal controls. Our study implies that a supine-position sBRS would provide additional diagnostic information for OH.

• Journal of Medicine and Life Science
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• v.16 no.3
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• pp.96-100
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• 2019

Postural tachycardia syndrome (POTS) is common, although not so well-known variant of cardiovascular autonomic disorder characterized by an excessive heart rate increase on standing. POTS is probably underdiagnosed due to the heterogeneity in both presentation and etiology. This study aimed to evaluate the clinical and autonomic features in patients with POTS. We reviewed the medical records of patients with POTS. Medical records include onset age, sex, presenting symptoms, body mass index (BMI) and prognosis. All patients had an autonomic function and laboratory tests. Ninety-nine patients met the inclusion criteria for POTS (51.5% male; mean±SD age, 20.0±9.7 years; mean±SD, BMI 21.9±3.9). Common presenting symptoms were a brief loss of consciousness, dizziness, blurred vision and headache. Autonomic function tests showed abnormal quantitative sudomotor axon reflex testing in 20 patients of 99 POTS patients. The abnormal post-ganglionic sympathetic sudomotor function is generally considered to reflect a neuropathic form of POTS. In treatments, 83 patients were treated by non-pharmacological management including lifestyle changes and 16 patients required the initiation of pharmacological therapies. Most patients with POTS showed a relatively favorable prognosis. POTS is a chronic disease with a substantial subset of patients recovering within a few years after the initial presentation. Future efforts should focus on better understanding of POTS pathophysiology and designing randomized controlled trials for the selection of more effective therapy.