The semiology of tilt-induced psychogenic pseudosyncope

Abstract

Objectives: To provide a detailed semiology to aid the clinical recognition of psychogenic pseudosyncope (PPS), which concerns episodes of apparent transient loss of consciousness (TLOC) that mimic syncope. Methods:We analyzed all consecutive tilt-table tests from 2006 to 2012 showing proven PPS, i.e., apparent TLOC had occurred without EEG changes or a decrease in heart rate (HR) or blood pressure (BP). We analyzed baseline characteristics, video data, EEG, ECG, and continuous BP measurements on a 1-second time scale. Data were compared with those of 69 cases of tilt-induced vasovagal syncope (VVS).Results: Of 800 tilt-table tests, 43 (5.4%) resulted in PPS. The majority (74%) were women. The median duration of apparent TLOC was longer in PPS (44 seconds) than in VVS (20 seconds, p , 0.05). During the event, the eyes were closed in 97% in PPS but in only 7% in VVS (p , 0.0001). A sudden head drop or moving down the tilt table was more common in PPS than in VVS (p , 0.01), but jerking movements occurred more frequently in VVS (p , 0.0001). In PPS, both HR and BP increased before and during apparent TLOC (p , 0.0001).Conclusions: PPS is clinically distinct from VVS and can be diagnosed accurately with tilt-table testing and simultaneous EEG monitoring. Compared with VVS, eye closure during the event, long periods of apparent TLOC, and high HR and BP are highly specific for PPS. Improved understanding of the semiology of PPS as a clinical entity is vital to ensure accurate diagnosis. Neurology â 2013;81:752-758 GLOSSARY BP 5 blood pressure; DBP 5 diastolic blood pressure; HR 5 heart rate; PNES 5 psychogenic nonepileptic seizure; PPS 5 psychogenic pseudosyncope; SBP 5 systolic blood pressure; sMAP 5 smoothed mean arterial pressure; TLOC 5 transient loss of consciousness; VVS 5 vasovagal syncope.Transient loss of consciousness (TLOC) is the reason for approximately 3% of all emergency department visits. 1 The most common major causes of apparent TLOC are syncope, epileptic seizures, and psychogenic events. [2][3][4] The pathophysiology of psychogenic and somatic apparent TLOC is different, but they can be difficult to distinguish clinically.Psychogenic apparent TLOC bears various labels. When episodes involve pronounced movements, they resemble epilepsy and are frequently labeled psychogenic nonepileptic seizures (PNES). 5 Episodes without pronounced movements resemble syncope and are generally labeled psychogenic pseudosyncope (PPS). 3 PNES and PPS are probably manifestations of the same underlying psychiatric disorder, but their different presentation has important consequences for diagnosis. PNES is relatively well known, with a reported prevalence of up to 30% in patients in epilepsy clinics. 5 In contrast, PPS is rarely mentioned in the literature on syncope, and the reported prevalence of PPS in those analyzed for presumed syncope is lower, ranging from 0% to 8%. [6][7][8]

Managing psychogenic pseudosyncope: Facts and experiences

“…In a longitudinal cohort of tilt-table induced PPS, 29% of patients showed a mixed pattern of PPS and VVS [18]. In this respect PPS also resembles PNES: the co-occurrence of epileptic seizures and PNES is well-known [20].…”

“…Finally, PPS can be distinguished from VVS using the duration of apparent TLOC, which is longer in PPS. When it lasts longer than 1 min, PPS is far more likely than VVS [18].…”

“…There is some evidence that altered preconscious threat processing causes a state of hypervigilance in patients who suffer from PNES [17]. During psychogenic apparent TLOC, heart rate (HR) and blood pressure (BP) are significantly increased [18]. This suggests that the episodes are accompanied by acute psychological stress [19].…”

“…This suggests that the episodes are accompanied by acute psychological stress [19]. PPS occurs in both sexes at all ages, although it appears to be more common in young women [18].…”

“…1, 2). Typically, PPS was characterized by a sudden loss of muscle tone (e.g., falling, dropping the head); this was less common in VVS [18]. In contrast, jerking movements were rarely seen in PPS, but occurred in approximately 60% of patients with VVS [26].…”