Definition, epidemiology, classification, and pathophysiology

Reflex Syncope ◽

Cardiac Syncope ◽

Syncope can closely resemble other disorders with which it shares an apparent short-lived transient loss of consciousness. Together, these disorders are labelled as ‘transient loss of consciousness (T-LOC)’. Syncope is the form of T-LOC caused by cerebral hypoperfusion; the other main T-LOC forms are several types of epileptic seizures and the psychogenic conditions that resemble either syncope or epileptic seizures. The main forms of syncope are reflex syncope, syncope due to orthostatic hypotension, and cardiac syncope, also comprising cardiopulmonary causes and disorders of the great vessels. All forms of syncope share cerebral hypoperfusion and arterial hypotension as a final common pathway. They differ in the mechanism of hypotension: cardiac syncope is largely due to a low cardiac output, but in orthostatic hypotension and reflex syncope both low peripheral resistance and low cardiac output contribute to syncope. The clinical expression of the main forms is tightly linked to their pathophysiology, which is therefore important for differential diagnosis.

Definition, epidemiology, classification, and pathophysiology

ESC CardioMed ◽

10.1093/med/9780198784906.003.0468 ◽

2018 ◽

pp. 2017-2021

Author(s):

J. Gert van Dijk ◽

Roland D. Thijs

Keyword(s):

Cardiac Output ◽

Orthostatic Hypotension ◽

Epileptic Seizures ◽

Cerebral Hypoperfusion ◽

Loss Of Consciousness ◽

Low Cardiac Output ◽

Reflex Syncope ◽

Cardiac Syncope ◽

Syncope can closely resemble other disorders with which it shares an apparent short-lived transient loss of consciousness. Together, these disorders are labelled as ‘transient loss of consciousness (T-LOC)’. Syncope is the form of T-LOC caused by cerebral hypoperfusion; the other main T-LOC forms are several types of epileptic seizures and the psychogenic conditions that resemble either syncope or epileptic seizures. The main forms of syncope are reflex syncope, syncope due to orthostatic hypotension, and cardiac syncope, also comprising cardiopulmonary causes and disorders of the great vessels. All forms of syncope share cerebral hypoperfusion and arterial hypotension as a final common pathway. They differ in the mechanism of hypotension: cardiac syncope is largely due to a low cardiac output, but both low peripheral resistance and low cardiac output contribute to syncope due to orthostatic hypotension and reflex syncope. The clinical expression of the main forms is tightly linked to their pathophysiology, which is therefore important for differential diagnosis.

Transient loss of consciousness

10.1093/med/9780199568741.003.0039 ◽

2018 ◽

Author(s):

Jonathan Timperley ◽

Sandeep Hothi

Keyword(s):

Cardiovascular Disease ◽

Orthostatic Hypotension ◽

Short Duration ◽

Complete Recovery ◽

Complete Loss ◽

Cerebral Hypoperfusion ◽

Clinical Approach ◽

Loss Of Consciousness ◽

Transient loss of consciousness (TLoC) is characterized by a rapid, transient, and complete loss of consciousness of short duration with spontaneous, complete recovery. Syncope is a specific type of TLoC caused by transient, global, cerebral hypoperfusion. TLoC may be traumatic or non-traumatic. Causes of non-traumatic TLoC include syncope, epilepsy, psychogenic causes, and other, rarer causes. Syncope may be reflex (neurally mediated), due to orthostatic hypotension or to cardiovascular disease. This chapter describes the clinical approach to the patient with transient loss of consciousness.

Syncope

Oxford Textbook of Medicine ◽

10.1093/med/9780198746690.003.0578 ◽

2020 ◽

pp. 5896-5901

Author(s):

Andrew J. Larner

Keyword(s):

Cardiac Output ◽

Heart Disease ◽

Physical Examination ◽

Specific Treatment ◽

Cerebral Hypoperfusion ◽

Loss Of Consciousness ◽

Body Parts ◽

History Of ◽

Syncope is the most common identified cause of transient loss of consciousness, being ten times more frequent than epilepsy. It is a consequence of cerebral hypoperfusion due to reduced cardiac output, often related to reduced venous return due to decreased peripheral vascular resistance with pooling of blood volume in dependent body parts. Diagnosis is clinical, based on history of the circumstances of the event obtained from the patient and reliable eyewitness(es). In most patients, particularly under 45 years of age, the condition is benign and self-limiting, with an excellent prognosis, requiring little investigation beyond physical examination and electrocardiogram to exclude heart disease. Cardiac causes of syncope may require specific treatment.

Orthostatic Hypotension As Cause of Syncope in Patients Older Than 65 Years Admitted to Emergency Departments for Transient Loss of Consciousness

The Journals of Gerontology Series A ◽

10.1093/gerona/glp028 ◽

2009 ◽

Vol 64A (7) ◽

pp. 801-806 ◽

Cited By ~ 37

Author(s):

C. Mussi ◽

A. Ungar ◽

G. Salvioli ◽

C. Menozzi ◽

A. Bartoletti ◽

...

Keyword(s):

Orthostatic Hypotension ◽

Emergency Departments ◽

Loss Of Consciousness ◽

Synkope, epileptischer oder psychogener Anfall? Der Weg zur richtigen Diagnose

DMW - Deutsche Medizinische Wochenschrift ◽

10.1055/a-0629-0362 ◽

2019 ◽

Vol 144 (12) ◽

pp. 835-841

Author(s):

Tobias Baumgartner ◽

Rainer Surges

Keyword(s):

Emergency Room ◽

Daily Life ◽

Epileptic Seizures ◽

Loss Of Consciousness ◽

Daily Life Activities ◽

Transient Loss ◽

Impact On Treatment ◽

Key Features ◽

The Impact

AbstractTransient loss of consciousness (TLOC) is a frequent cause of referral to an emergency room. In view of the impact on treatment and the patients’ daily life activities (e. g. profession, driving license), an accurate and timely diagnosis is of uttermost importance. This article provides key features and suggests a practical step-by-step approach of how to differentiate syncope, epileptic and psychogenic non-epileptic seizures as the commonest causes of nontraumatic TLOC.

#3079 Investigating the feasibility of automating the differential diagnosis of transient loss of consciousness

Journal of Neurology Neurosurgery & Psychiatry ◽

10.1136/jnnp-2021-bnpa.18 ◽

2021 ◽

Vol 92 (8) ◽

pp. A7.1-A7

Author(s):

Nathan Pevy ◽

Heidi Christensen ◽

Traci Walker ◽

Markus Reuber

Keyword(s):

Differential Diagnosis ◽

Random Forest ◽

Epileptic Seizures ◽

The Other ◽

Future Research ◽

Loss Of Consciousness ◽

Audio Recordings ◽

Transient Loss ◽

Nonepileptic Seizures

BackgroundThere are three common causes of Transient Loss of Consciousness (TLOC), syncope, epileptic and psychogenic nonepileptic seizures (PNES). Many individuals who have experienced TLOC initially receive an incorrect diagnosis and inappropriate treatment. Whereas syncope can be distinguished from the other two causes relatively easily with a small number of yes/no questions, the differentiation of the other two causes of TLOC is more challenging. Previous qualitative research based on the methodology of Conversation Analysis has demonstrated that epileptic and nonepileptic seizures are described differently when patients talk to clinicians about their TLOC experiences. One particularly prominent difference is that epileptic seizure descriptions are characterised by more formulation effort than accounts of nonepileptic seizures.AimThis research investigates whether features likely to reflect the level of formulation effort can be automatically elicited from audio recordings and transcripts of speech and used to differentiate between epileptic and nonepileptic seizures.MethodVerbatim transcripts of conversations between patients and neurologists were manually produced from video and audio recordings of interactions with 45 patients (21 epilepsy and24 PNES). The subsection of each transcript containing the patients account of their first seizure was manually extracted for the analysis. Seven automatically detectable features were designed as markers of formulation effort. These features were used to train a Random Forest machine learning classifier.ResultsThere were significantly more hesitations and repetitions in descriptions of first epileptic than nonepileptic seizures. Using a nested leave-one-out cross validation approach, 71% of seizures were correctly classified by the Random Forest classifier.ConclusionsThis pilot study provides proof of principle that linguistic features that have been automatically extracted from audio recordings and transcripts could be used to distinguish between epileptic seizures and PNES and thereby contribute to the differential diagnosis of TLOC. Future research should explore whether additional observations can be incorporated into a diagnostic stratification tool. Moreover, future research should explore the performance of these features when they have been extracted from transcripts produced by automatic speech recognition and when they are combined with additional information provided by patients and witnesses about seizure manifestations and medical history.

Diagnostic evaluation

ESC CardioMed ◽

10.1093/med/9780198784906.003.0469 ◽

2018 ◽

pp. 2021-2023

Author(s):

Frederik J. de Lange ◽

J. Gert van Dijk

Keyword(s):

Cardiovascular Events ◽

Epileptic Seizures ◽

Loss Of Consciousness ◽

Pressure Measurements ◽

History Taking ◽

Ambulance Personnel ◽

Major Cardiovascular Events ◽

Cardiac Syncope ◽

Transient Loss ◽

Standing Blood Pressure

When a patient presents with transient loss of consciousness (T-LOC), the history, usually initially derived from a general practitioner or ambulance personnel, is most important to determine whether it is indeed T-LOC. If so, more history taking is of paramount importance to differentiate between the different forms of T-LOC: syncope, epileptic seizures, or psychogenic attacks. When T-LOC is syncope and epileptic seizures and psychogenic attacks are less likely, the initial syncope evaluation should address the different forms of syncope: reflex syncope, orthostatic hypotension, or cardiac syncope. The initial syncope evaluation consists of (1) more detailed and careful history taking, (2) a physical examination, including supine and standing blood pressure measurements, and (3) an electrocardiogram. When the initial syncope evaluation does not yield either a certain or a highly likely diagnosis, the next step is to perform risk stratification of major cardiovascular events including sudden death. The subsequent evaluation will be determined by the causal risk.

Syncope and palpitation

Oxford Textbook of Medicine ◽

10.1093/med/9780198746690.003.0341 ◽

2020 ◽

pp. 3284-3293

Author(s):

K. Rajappan ◽

A.C. Rankin ◽

A.D. McGavigan ◽

S.M. Cobbe

Keyword(s):

Orthostatic Hypotension ◽

Cardiac Rhythm ◽

Cerebral Hypoperfusion ◽

Loss Of Consciousness ◽

Neurocardiogenic Syncope ◽

Cardiac Syncope ◽

Appropriate Treatment ◽

Heart Beating ◽

Transient Episode ◽

Premature Beats

Syncope is a transient episode of loss of consciousness due to cerebral hypoperfusion. Its causes can be subdivided on the basis of pathophysiology, including neurally mediated—or reflex—syncope; orthostatic hypotension; cardiac causes; and cerebrovascular or psychogenic causes. Neurocardiogenic syncope, or simple faint, is the commonest cause and is benign, but it is always important to exclude or establish the diagnosis of cardiac syncope, because this has an adverse prognosis that may be improved with appropriate treatment. Meanwhile, palpitation is the awareness of one’s heart beating—it may be due to an awareness of an abnormal cardiac rhythm, or an abnormal awareness of normal rhythm. It is most commonly due to premature beats (ectopics) and is benign. Correlation between symptoms and cardiac rhythm is the initial aim of investigations in patients presenting with palpitations.

Syncope in the older person: a review

Reviews in Clinical Gerontology ◽

10.1017/s0959259806001808 ◽

2005 ◽

Vol 15 (3-4) ◽

pp. 219-235 ◽

Cited By ~ 1

Author(s):

Samiran Nath ◽

Rose Anne Kenny

Keyword(s):

Cerebral Hypoperfusion ◽

Loss Of Consciousness ◽

Older Person ◽

Systemic Hypotension ◽

‘Syncope’ is derived from the Greek words ‘syn’ (meaning ‘together’) and ‘koptein’ (meaning ‘cut’). It is a syndrome characterized by transient loss of consciousness resulting from temporary and self-limited cerebral hypoperfusion, most often the result of systemic hypotension.

Approach to Loss of Consciousness: Distinguishing Epileptic Seizures, Psychogenic Nonepileptic Seizures, and Syncope

Seminars in Neurology ◽

10.1055/s-0041-1726359 ◽

2021 ◽

Vol 41 (06) ◽

pp. 667-672

Author(s):

Ima Ebong ◽

Zahra Haghighat ◽

Meriem Bensalem-Owen

Keyword(s):

Physical Examination ◽

Diagnostic Tests ◽

Epileptic Seizures ◽

Loss Of Consciousness ◽

Psychogenic Nonepileptic Seizures ◽

Transient Loss ◽

Nonepileptic Seizures

AbstractTransient loss of consciousness (TLOC) is a common emergent neurological issue, which can be attributed to syncope, epileptic seizures, and psychogenic nonepileptic seizures. The purpose of this article is to outline an approach to diagnosing the most common etiologies of TLOC by focusing on the importance of the history and physical examination, as well as targeted diagnostic tests.