Diagnostic Patterns in the Evaluation of Patients Presenting with Syncope at the Emergency or Outpatient Department

강구현,김준수,오주헌,온영근,송형곤,조익준,김수진,배수진,신태건 연세대학교의과대학 2012 Yonsei medical journal Vol.53 No.3

Purpose: Patterns of syncope evaluation vary widely among physicians and hospitals. The aim of this study was to assess current diagnostic patterns and medical costs in the evaluation of patients presenting with syncope at the emergency department (ED) or the outpatient department (OPD) of a referral hospital. Materials and Methods: This study included 171 consecutive patients with syncope, who visited the ED or OPD between January 2009 and July 2009. Results: The ED group had fewer episodes of syncope [2 (1-2) vs. 2 (1-5), p=0.014] and fewer prodromal symptoms (81.5% vs. 93.3%, p=0.018) than the OPD group. Diagnostic tests were more frequently performed in the ED group than in the OPD group (6.2±1.7 vs. 5.3±2.0; p=0.012). In addition, tests with low diagnostic yields were more frequently used in the ED group than in the OPD group. The total cost of syncope evaluation per patient was higher in the ED group than in the OPD group [823000 (440000-1408000) won vs. 420000 (186000-766000) won, p<0.001]. Conclusion: There were some differences in the clinical characteristics of patients and diagnostic patterns in the evaluation of syncope between the ED and the OPD groups. Therefore, a selective diagnostic approach according to the presentation site is needed to improve diagnostic yields and to reduce the time and costs of evaluation of syncope. Purpose: Patterns of syncope evaluation vary widely among physicians and hospitals. The aim of this study was to assess current diagnostic patterns and medical costs in the evaluation of patients presenting with syncope at the emergency department (ED) or the outpatient department (OPD) of a referral hospital. Materials and Methods: This study included 171 consecutive patients with syncope, who visited the ED or OPD between January 2009 and July 2009. Results: The ED group had fewer episodes of syncope [2 (1-2) vs. 2 (1-5), p=0.014] and fewer prodromal symptoms (81.5% vs. 93.3%, p=0.018) than the OPD group. Diagnostic tests were more frequently performed in the ED group than in the OPD group (6.2±1.7 vs. 5.3±2.0; p=0.012). In addition, tests with low diagnostic yields were more frequently used in the ED group than in the OPD group. The total cost of syncope evaluation per patient was higher in the ED group than in the OPD group [823000 (440000-1408000) won vs. 420000 (186000-766000) won, p<0.001]. Conclusion: There were some differences in the clinical characteristics of patients and diagnostic patterns in the evaluation of syncope between the ED and the OPD groups. Therefore, a selective diagnostic approach according to the presentation site is needed to improve diagnostic yields and to reduce the time and costs of evaluation of syncope.

전,의경에서 발생한 실신의 원인과 임상적 특징

최규영 ( Kyu Young Choi ),안석진 ( Seok Jin Ahn ),김현근 ( Hyun Keun Kim ),이세한 ( Se Han Lee ),유창민 ( Chang Min Yu ),조재현 ( Jae Hyun Cho ),유지원 ( Ji Won Yoo ),서승오 ( Seong O Suh ),김은실 ( Eun Sil Kim ),정준오 ( Jun Oh J 대한내과학회 2010 대한내과학회지 Vol.78 No.2

Background/Aims: The most common type of syncope in young adults is neurocardiogenic in origin, which is not related to organic problems and has a benign nature. Therefore, there have been few reports regarding syncope in young Korean adults. Here, we examined the causes of syncope and its clinical characteristics in young combat and auxiliary police in Korea. Methods: We performed a retrospective study of the medical records of 193 combat and auxiliary police in Korea admitted to the National Police Hospital for syncope or presyncope between January 2004 and December 2007. Results: The subjects` mean age was 21±1.2 years, and there were 2.8±2.9 episodes of syncope (mean±SEM). The first syncope occurred after enlistment in the police in 102 patients (52.8%). Basic diagnostic studies showed two cases of elevated creatine phosphokinase and one case of anemia to be related to syncope. Syncope-related traumatic injuries occurred in 38 patients (19.7%), and syncope was more prevalent in the summer. Head-up tilt test was performed in 175 of the 193 patients, and 123 showed a positive response. Other evaluations, including brain magnetic resonance imaging, electroencephalography, and echocardiography, were not helpful for diagnosis. Syncope was neurocardiogenic in origin in the majority of cases. Other causes of syncope were exhaustion (n=2), hyperventilation syndrome (n=2), Meniere`s disease (n=1), anemia (n=1), and psychiatric problems (n=5). The causes of syncope could not be identified in 59 patients (30.5%). Conclusions: Neurocardiogenic syncope was the most common type in our study population. More than half of our patients experienced their first episode after enlisting with the police. Further studies in these groups are necessary. (Korean J Med 78:198-206, 2010)

소아에서의 실신에 관한 임상적 고찰 및 안구압박검사의 진단적 유용성

김기성(Ki Sung Kim),이은별(Eun Byul Lee),정희정(Hee Jung Chung) 대한소아신경학회 2006 대한소아신경학회지 Vol.14 No.2

Purpose : Nevertheless that syncope of children is a relatively common disease which occurs during adolescence, diagnostic yield rate of syncope of children is far below than that of adults. Some reports indicate that the diagnostic rate could be increased up to 70% by using the head-up tilt test(HUT). However, HUT is relatively invasive and harmful to be used for children. The purpose of this study is to analyze the etiology of syncope in children and investigate whether the ocular compression test(OCT), which is not invasive and relatively safe, could substitute the HUT for vasovagal syncope. Methods : Children who visited NHIC Ilsan Hospital for syncope from January 2004 to July 2006 were retrospectively analyzed. We examined the medical records of the patients and performed the basic diagnostic tests including EEG as well as HUT. OCT was performed during EEG to find check out the presence and the duration of asystole. We classified the patients into 3 groups according to the etiology, such as neurally-mediated(vasovagal), cardiovascular and noncardiovascular syncopes and comparatively analyzed the clinical characteristics of each group. In addition, in case the asystole duration of OCT is prolonged, we performed cross-table analysis to know whether it matches the positive result of HUT in order to confirm the availability of OCT. Results : 55 patients were included in the study and the rate of males to female was 1: 2.4. The causes of syncope were identified in 43 cases(78.2%) and half of which was neurallymediated type. In detail, 24(43.6%) patients were neurally-mediated, 5(9.1%) were cardiovascular, 14(25.5%) non-cardiovascular and 12(21.8%) unidentified. There was no significant difference regarding the clinical characteristics among diagnostic groups. However, the neurallymediated syncope group showed statistically significant difference in the duration of asystole. Therefore, when we make a point over 3 seconds of asystole in OCT, it will produce the most similar result with the HUT in neurally-mediated(vasovagal) syncope(specificity 94.4%). Conclusion : Generally, syncope in children peaks during adolescence and it is more common among girls than boys. The etiologic diagnostic rate was 78.2% and the neurally-mediated syncope was the most common type. The cardiovascular syncope of children was much less in contrast to that of adults. There was no statistically significant difference in the clinical characteristics among the three diagnostic groups. It is concluded that OCT, a non-invasive and relatively safe test, could substitute the invasive, and harmful HUT for vasovagal syncope of children. 목 적 : 소아에서의 실신은 청소년기에 발생하는 비교적 흔한 질환임에도 불구하고 어른과는 달리 아직까지 우리나라에서는 임상양상에 대한 연구가 거의 없는 실태이며, 특히 소아에서는 전통적인 검사만으로는 원인 진단율이 어른에서보다 훨씬 낮다고 한다. 기립경사(head up tilt) 검사를 실시할 경우 진단율을 70%까지 높일 수 있다는 보고가 있으나 소아에서는 시행하기 힘든 침습적 검사이다. 이에 저자들은 실신을 주소로 내원한 환자들의 원인을 분석하고, 뇌파검사 시 시행하는 비침습적 검사인 안구압박(ocular compression) 검사가 혈관미주신경성 실신의 진단에 기립경사 검사를 대신할 수 있는지 여부를 알아보고자 본 연구를 실시하였다. 방 법: 2004년 1월부터 2006년 7월까지 일산병원 소아과에 실신을 주소로 내원한 환자 55례를 대상으로 혈액검사, 뇌파검사(안구압박검사 포함), 24시간 심전도검사, 기립경사 검사를 실시하여 발생 원인에 따라 신경인성, 심혈관계 및 비심혈관계의 세 군으로 크게 나누고 각 군의 임상적 특징을 비교 분석하였다. 또한 안구압박 검사에서 나타난 심정지(asystole) 시간에 따라 기립경사 검사 결과 중 혈관미주신경성 반응과 일치하는지를 교차 분석하여 알아봄으로써 비교적 쉽고 상대적으로 안전한 안구압박 검사의 유용성을 확인하여 보았다. 결 과: 실신을 주소로 내원한 총 환자 수는 55명이었으며 이중 남아 16명, 여아 39명으로 성비는 1:2.4이었고 평균 연령은 11.4세이었다. 실신의 원인은 신경인성 원인이 24명(43.6%), 심혈관계 원인 5명(9.1%), 비심혈관계 원인 14명(25.5%), 미상 12명(21.8%)이었다. 각 질환 군에서 전구증상, 증상이 나타날 때의 자세, 의식소실 시간, 실신이후 동 반되는 증상에는 세 군 간에 통계적인 차이가 없었다. 안구압박 검사 후의 심정지 시간은 신경인성환자 군에서 다른 군과 유의한 차이를 보였으며, 심정지 시간 3초 이상인 경우는 기립경사 검사 결과 혈관미주신경성 실신과 94.4% 특이도로 일치하는 것으로 보아 안구압박 검사의 유용성을 확인할 수 있었다. 결 론 : 소아에서 실신은 주로 청소년기에 발생하였으며 남아 보다 여아에서 더 흔하게 나타났다. 원인 발견률은 78.2%이었으며 이중 신경인성 원인이 약 1/2 정도로 가장 많았고, 어른에서와는 달리 심혈관계 원인이 훨씬 적었다. 실신의 임상양상은 세 군 간에 큰 차이가 없었다. 소아에서의 신경인성 실신 중 혈관미주신경성 실신의 진단에는 시행하기 쉽고 비교적 안전한 안구압박 검사가 상대적으로 위험하고 침습적인 기립경사 검사를 대신할 수 있을 것으로 사료된다.

실신을 주소로 방문한 소아 환자의 원인질환에 대한 임상적 고찰

류미선,이재희,김은영,노영일,양은석,문경래,박영봉 조선대학교 의학연구소 2013 The Medical Journal of Chosun University Vol.38 No.3

Syncope is a common symptom, with 15% to 25% of children and adolescents experiencing at least one syncopal episode by young adulthood. In most cases, syncope is a symptom of benign diseases however may be a symptom of severe cardiac disease that results in sudden death. The purpose of this study is to analyze the etiologies and clinical characteristics of syncope in children and adolescents. We retroprospectively analyzed 51 patients with syncope. A total of 51 patients were included in the study and the ratio of males to female was 1: 1.04. The mean patient age was 12.7±3.1 years. Abrupt standing was the most common state of patients with syncopal attack. The etiologies of syncope were noncardiac syncope (60.7%), cardiac syncope (2%), neuropsychiatric syncope (25.5%), and unknown (11.8%). Abnormality of the head-up tilt test was more common in noncardiac syncope than the others [38.7% (12/31) vs 5% (1/20) (p=0.007)]. Further, EEG is a useful diagnostic test for neuropychiatric syncope [41.6% (5/12) vs 2.7% (1/36) (p=0.002)]. Therefore, detailed history taking and physical examinations were useful tools to diagnose the etiology of sycope. The head-up tilt test is an effective diagnostic test in noncardiac syncope and EEG is a valuable test in neuropychiatric syncope, especially in seizure.

소아에서 발현한 배뇨 후 실신 1례

이선연,류수정,김덕수,김영휘,고태성,김재문,Lee, Sun Youn,Ryu, Su Jeong,Kim, Deok Soo,Kim, Young Hwue,Ko, Tae Sung,Kim, Jae Moon 대한소아청소년과학회 2003 Clinical and Experimental Pediatrics (CEP) Vol.46 No.12

배뇨 후 실신은 신경 매개성 반사에 의한 실신으로 사태실신의 한 종류이며 건강한 남성에서 아침에 기립 배뇨시에 잘 일어난다. 실신의 원인은 다양하기 때문에 배뇨후 실신의 진단을 위해 정확한 병력과 심전도, 운동부하검사, 심초음파, 기립경사검사, 뇌파, 뇌 자기공명영상, 요류 동태 검사 등이 사용된다. 배뇨후 실신의 기전은 부교감 신경계의 반사 자극으로 서맥과 말초혈관 확장이 일어나고 Valsalva 효과에 의해 심실로 정맥환류가 감소하게 되어서 대뇌 혈류감소가 일어나 실신하게 된다. 실신시 뇌파는 대뇌 혈류감소에 의해 고진폭의 서파와 평탄화 소견이 나타나게 되고 심한 허혈시에는 허혈성 경련을 일으킬 수도 있다. 저자들은 9세 남아로 기립배뇨시 실신을 보인 후 저혈압을 보이고 특징적인 뇌파소견을 보인 환아를 경험하였기에 보고하는 바이다. Syncope in children and adolescents have a common occurrence according for up to 15% before adulthood. Micturition syncope, a kind of situational syncope, can be considered a form of reflex syncope. It can typically occur in healthy young men after rising from bed in the early morning who experience sudden loss of consciousness during or immediately after urination. The mechanism of micturition syncope is not completely understood, but it has been suggested that vasovagal reflex mediated bradycardia and peripheral vasodilation and decreased venous return due to Valsalva effect and standing position lead to the decrease in cerebral blood flow resulting in syncope. The causes of syncope are variable. So complete history taking, physical examination, electrocardiography, exercise stress test, echocardiography, head-up tilt table test, electroencephalography(EEG), brain magnetic resonance image and urodynamic study should be required for the diagnosis of micturition syncope. There were several reports about micturition syncope. However, literature of micturition syncope at the pediatric age has rarely been reported in Korea so far. Therefore, we report a case of a 9-year-old boy with micturition syncope with typical EEG findings of high amplitude delta wave and flattening during syncope.

소아 신경-심인성 실신의 특징

이경연,이진영,김명현,이정은,김용대,이은주,임영수,김원섭 대한소아청소년과학회 2008 Clinical and Experimental Pediatrics (CEP) Vol.51 No.5

Purpose:Syncope is relatively common in children and adolescents. Among the etiologies of syncope, neurocardiogenical syncope is the most common, but it is often confounded with seizure. We investigated the clinical features of patients under the age of 15 with neurocardiogenical syncope, compared to patients with neurologic disorders including epilepsy. Methods:Among the children who visited the Department of Pediatrics at Cheongju St. Mary's Hospital and Chungbuk National University Hospital from March 2005 to February 2007, we retrospectively analyzed 69 patients whose chief complaint was syncope. We classified the patients by syncope etiology and made comparisons between the neurocardiogenical syncope (NCS) group and the neurological disorders (ND) group regarding to age; location; time and season in which syncope occurred; associated symptoms, including seizures, provocation factors; prodromes; duration of syncope; frequency of previous syncope; birth history; associated disease; past medical history; family history; neurological exam; physical exam; laboratory findings; electrocardiography; electroencephalography (EEG); head-up tilt test; brain CT; and MRI. Results:Among 69 syncope patients, 53 (76.8%) were in the NCS group and 11 (15.9%) were in the ND group. There were no statistically significant differences between the two study groups except for the presence of prodromes and EEG abnormalities. The presence of prodromes in the NCS group was more common than in the ND group [46.9% (23/49) vs. 9.1% (1/11), (P=0.038)]. The EEG abnormality in the ND group was more common than in the NCS group [90% (9/10) vs. 5.8% (3/52), (P<0.01)]. Conclusion:Our study suggests that detailed history-taking, including that concerning prodromes, is important for the accurate diagnosis of neurocardiogenical syncope, and EEG should be obtained if neurological disorders are suggested. (Korean J Pediatr 2008; 51:512-517) Purpose:Syncope is relatively common in children and adolescents. Among the etiologies of syncope, neurocardiogenical syncope is the most common, but it is often confounded with seizure. We investigated the clinical features of patients under the age of 15 with neurocardiogenical syncope, compared to patients with neurologic disorders including epilepsy. Methods:Among the children who visited the Department of Pediatrics at Cheongju St. Mary's Hospital and Chungbuk National University Hospital from March 2005 to February 2007, we retrospectively analyzed 69 patients whose chief complaint was syncope. We classified the patients by syncope etiology and made comparisons between the neurocardiogenical syncope (NCS) group and the neurological disorders (ND) group regarding to age; location; time and season in which syncope occurred; associated symptoms, including seizures, provocation factors; prodromes; duration of syncope; frequency of previous syncope; birth history; associated disease; past medical history; family history; neurological exam; physical exam; laboratory findings; electrocardiography; electroencephalography (EEG); head-up tilt test; brain CT; and MRI. Results:Among 69 syncope patients, 53 (76.8%) were in the NCS group and 11 (15.9%) were in the ND group. There were no statistically significant differences between the two study groups except for the presence of prodromes and EEG abnormalities. The presence of prodromes in the NCS group was more common than in the ND group [46.9% (23/49) vs. 9.1% (1/11), (P=0.038)]. The EEG abnormality in the ND group was more common than in the NCS group [90% (9/10) vs. 5.8% (3/52), (P<0.01)]. Conclusion:Our study suggests that detailed history-taking, including that concerning prodromes, is important for the accurate diagnosis of neurocardiogenical syncope, and EEG should be obtained if neurological disorders are suggested. (Korean J Pediatr 2008; 51:512-517)

Clinical relevance of syncope in patients with pulmonary embolism

Lee, Yong-Hoon,Cha, Seung-Ick,Shin, Kyung-Min,Lim, Jae-Kwang,Yoo, Seung-Soo,Lee, Shin-Yup,Lee, Jaehee,Kim, Chang-Ho,Park, Jae-Yong,Lee, Won Kee Elsevier 2018 Thrombosis research Vol.164 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Syncope is an unusual clinical manifestation of pulmonary embolism (PE), and the clinical significance of syncope in PE patients remains controversial. We investigated the incidence of syncope, examined the clinical factors associated with syncope, and assessed the association between syncope and the short-term outcomes of PE.</P> <P><B>Methods</B></P> <P>We retrospectively classified patients presenting with PE into 2 groups: patients with syncope and those without syncope. We compared the clinical and computed tomography parameters between the groups.</P> <P><B>Results</B></P> <P>Among 1084 patients diagnosed with PE, 45 (4.2%) presented with syncope. Four patients which presented with cardiac arrest were excluded from the study. The syncope group showed significantly higher blood biomarker levels and higher rates of central PE and right ventricular dilation than the control group. Unprovoked PE (odds ratio [OR] 8.046, 95% confidence interval [CI] 3.073–21.069, p < 0.001), female sex (OR 3.419, 95% CI 1.348–8.675, p = 0.010), central PE (OR 2.854, 95% CI 1.298–6.278, p = 0.009), and troponin I level (OR 2.812, 95% CI 1.765–4.480, p < 0.001) were observed to be independent factors associated with syncope in PE patients. However, multivariate analysis showed that the presence of syncope was not a significant predictor of adverse outcomes and recurrent venous thromboembolism in PE patients.</P> <P><B>Conclusions</B></P> <P>Although syncope is associated with a more severe form of PE, it does not influence the short-term prognosis of PE. Central PE, blood troponin I level, unprovoked PE, and female sex were observed to be clinical factors related with syncope in patients with PE.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The clinical implications of syncope in patients with pulmonary embolism are suggested. </LI> <LI> Syncope was associated with a more severe form of pulmonary embolism. </LI> <LI> Syncope did not influence the short-term prognosis of pulmonary embolism. </LI> <LI> Central emboli and blood troponin I level were independent factors of syncope. </LI> <LI> Unprovoked pulmonary embolism and female sex were also associated with syncope. </LI> </UL> </P>

원인 불명의 실신 환자의 진단에 있어서 Head - up tilt Test 의 유용성과 혈관미주신경성 실신 환자의 임상적 특징

윤호중(Ho Joong Youn),정욱성(Wook Sung Chung),백상홍(Sang Hong Baek),김철민(Chul Min Kim),박인수(In Soo Park),김재형(Jae Hyung Kim),최규보(Kyu Bo Choi),홍순조(Soon Jo Hong) 대한내과학회 1994 대한내과학회지 Vol.47 No.2

N/A Background: Syncope, defined as a transient loss of consciousness, is a frequently encountered symptom, but despite thorough clinical and invasive diagnostic investigation, the cause of syncope remains unexplained. In recent years, head-up tilt test has been of increasing interest as a diagnostic aids in patients with unexplained syncope. We studied to define the usefulness of various diagnostic test in the evaluation of patients with recurrent syncope, to assess the usefulness of head-up tilt test in the working of syncope of unknown origin and to evaluate the clinical characteristics of subgroups of patients with syncope induced by head-up tilt test. Methods: Between June, 1991 and November, 1992 at St. Mary`s hospital, 21 patients with history of syncope and 24 control subjects without history of syncope underwent 60° head-up tild test for 60 min. Results: 1) The definite cause for recurrent syncope were diagnosed in 10 of patients (47,6%) after clinical and invasive tests. 2) During head-up tilt test, vasovagal responses were provoked in 5 of 21 patients (23.8%) with recurrent syncope and 1 of 24 patients (4.2%) without syncope (p<0,05). 3) The head-up tilt test induced symptomatic bradycardia or hypotension in 3 of 10 patients (30%.) with negative electrophysiologic results. 4) During tilt induced vasovagal response, a) mean heart rate decreased to 42±24 beat/min from supine control of 70±12 beat/min (p<0. 05), b) mean systolic blood pressure decreased to 95±12 mmHg from supine control of 120±S mmHg (p<0,05), c) mean diastolic blood pressure decreased to 60±21mmHg from supine control of 72±13 mmHg (p<0.05), d) the time interval to onset of vasovagal response was 22±12 min. Conclusions: 1) In a large proportion of patients with recurrent syncope, the diagnosis remains unexplained despite a neurologic and cardiologic investigation including an electrophysiologic study. 2) Vasovagal responses are frequent cause in patients with recurrent unexplained syncope. 3) The head-up tilt test may be a simple, safe and highly yielding provocative test in the investigation of syncope of unknown origin.

발작과 실신에서 일시적 혈중 암모니아 상승의 차이

최윤호,김지화,고원,김혜인,김원주 대한신경과학회 2012 대한신경과학회지 Vol.30 No.4

Background: Differential diagnosis between a generalized tonic-clonic seizure and syncope may be difficult due to similar clinical features. The need for a biological marker to distinguish a seizure from syncope has been emphasized from past studies. Transient hyperammonemia could be an indicator of recent convulsive seizure. The purpose of this study is to review the use of plasma ammonia level in the differential diagnosis of seizure and syncope. Methods: Adult patients who were admitted to the Department of Neurology at Gangnam Severance Hospital with final diagnosis of a generalized tonic-clonic seizure or syncope were eligible for this study. Plasma ammonia levels were checked within 8 hr after an insult. Results: Among the patients with a loss of consciousness who underwent analysis of plasma ammonia level, diagnoses were made with a seizure (n=65) and syncope (n=38). The seizure group had 70.29±70.86 μmol/L and the syncope group had 28.37±10.27 μmol/L of ammonia level, respectively. The seizure group presented with a significantly increased plasma ammonia (p<0.05) compared to the syncope group. The cut-off value with the reliable diagnostic level was defined as 36 μmol/L (=61.308 μg/dL) with a sensitivity of 0.65 and specificity of 0.80 by receiver operating characteristic (ROC) curve analysis. Conclusions: Plasma ammonia measurement during acute post-ictal period may be a useful test for the identification and the differential diagnosis of seizures and syncope. Background: Differential diagnosis between a generalized tonic-clonic seizure and syncope may be difficult due to similar clinical features. The need for a biological marker to distinguish a seizure from syncope has been emphasized from past studies. Transient hyperammonemia could be an indicator of recent convulsive seizure. The purpose of this study is to review the use of plasma ammonia level in the differential diagnosis of seizure and syncope. Methods: Adult patients who were admitted to the Department of Neurology at Gangnam Severance Hospital with final diagnosis of a generalized tonic-clonic seizure or syncope were eligible for this study. Plasma ammonia levels were checked within 8 hr after an insult. Results: Among the patients with a loss of consciousness who underwent analysis of plasma ammonia level, diagnoses were made with a seizure (n=65) and syncope (n=38). The seizure group had 70.29±70.86 μmol/L and the syncope group had 28.37±10.27 μmol/L of ammonia level, respectively. The seizure group presented with a significantly increased plasma ammonia (p<0.05) compared to the syncope group. The cut-off value with the reliable diagnostic level was defined as 36 μmol/L (=61.308 μg/dL) with a sensitivity of 0.65 and specificity of 0.80 by receiver operating characteristic (ROC) curve analysis. Conclusions: Plasma ammonia measurement during acute post-ictal period may be a useful test for the identification and the differential diagnosis of seizures and syncope.

An Alternative Analysis of Syncope in English

Chung, Chin-Wan 한국중앙영어영문학회 2022 영어영문학연구 Vol.64 No.2

This study provides an alternative analysis of English syncope occurring in post-stressed positions to improve syllable parsing and foot structure in English. In post-tonic syllables, two types of syncope occur: one is general syncope, where only a vowel in an unstressed vowel deletes, and the other is a variant syncope in which two unstressed vowels delete. Analyses on syncope so far have focused on syncope environments and the clusters to be formed after syncope. It has been argued that syncope occurs when consonant clusters formed after syncope show a rising sonority. This common factor has been the major argument in syncope. However, such a concept might be problematic in multiple-syllabled inputs where two variant syncope outputs are possible. To avoid such a problem in syncope, we need to limit the domain of syncope to a foot. Thus, if there are two feet and syncope occurs in the first trisyllabic left-headed foot, the vowels in the first and second syllables become the target of syncope. To distinguish a preferred syncope output from a secondarily favored output, we employ constraint reranking of Parse-σ/NoCoda and *Comp-Ons/Contig-Rt, which are not highly ranked in the analysis to explain the most common type of syncope and variant syncope outputs by using two combined constraint rankings in English.