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]
Rationale: Assessing the relative contributions of cardioinhibition and vasodepression to the blood pressure (BP) decrease in tilt-induced vasovagal syncope (T-VVS) requires methods that reflect BP physiology accurately. Objective: To assess the relative contributions of cardioinhibition and vasodepression to T-VVS using novel methods. Methods and Results: We studied the parameters determining BP, i.e. stroke volume (SV), heart rate (HR) and total peripheral resistance (TPR), in 163 patients with T-VVS documented by continuous ECG and video EEG monitoring. We defined the beginning of cardioinhibition as the start of a heart rate decrease (HR) before syncope, and used logarithms of SV-, HR- and TPR-ratios to quantify the multiplicative relation BP=SV·HR·TPR. We defined three stages before syncope and two after it based on direction changes of these parameters. The earliest BP decrease occurred nine minutes before syncope. Cardioinhibition was observed in 91% of patients at a median time of 58 s. before syncope. At that time SV had a strong negative effect on BP, TPR a lesser negative effect, while HR had increased (all p<0.001). At the onset of cardioinhibition, median HR was at 98 bpm higher than baseline. Cardioinhibition thus initially only represented a reduction of the corrective HR increase, but was nonetheless accompanied by an immediate acceleration of the ongoing BP decrease. At syncope, SV and HR contributed similarly to the BP decrease (p<0.001), while TPR did not affect BP. Conclusions: The novel methods allowed the relative effects of SV, HR and TPR on BP to be assessed separately, even though all act together. The two major factors lowering BP in T-VVS were reduced SV and cardioinhibition. We suggest that the term 'vasodepression' in reflex syncope should not be limited to reduced arterial vasoconstriction, reflected in TPR, but should also encompass venous pooling, reflected in SV.
This exploratory follow-up study investigated whether EEG parameters can predict future cognitive performance. Forty elderly subjects, ranging from cognitively unimpaired to those with Alzheimer disease underwent EEG registration at baseline and neuropsychological examination at both baseline and follow-up. We assessed relations between EEG measures and future cognitive performance (i.e., global cognition, memory, language, and executive functioning) controlling for age, follow-up time, and baseline cognitive performance. Regression models were constructed to predict performance on the Cambridge Cognitive Examination, a widely used tool within dementia screenings. Baseline EEG measures, i.e., increased theta activity (4-8 Hz) during eyes closed and less alpha reactivity (8-13 Hz) during eyes open and memory activation, indicated lower global cognitive, language (trend significant), and executive performance at follow-up. A regression model combining baseline cognitive and EEG measures provided the best prediction of future Cambridge Cognitive Examination performance (93%). EEG and cognitive measures alone predicted, respectively, 43% and 92% of variance. EEG and cognitive measures combined provided the best prediction of future cognitive performance. Although the "cognition only" model showed similar predictive power, the EEG provided significant additional value. The added value of EEG registration in the diagnostic work-up of dementia should be further assessed in larger samples.
Scientific inveStigAtionSStudy objectives: We investigated autonomic balance and resting metabolic rate to explore their possible involvement in obesity in hypocretin/orexin-deficient narcoleptic subjects. Methods: Resting metabolic rate (using indirect calorimetry) and variability in heart rate and blood pressure were determined in the fasted resting state. Subjects included 15 untreated, hypocretin-deficient male narcoleptics and 15 male controls matched for age and body mass index. Results: Spectral power analysis revealed greater heart rate and blood pressure variability in hypocretin-deficient male narcoleptic patients (heart rate: p = 0.01; systolic blood pressure: p = 0.02; diastolic: p < 0.01). The low to high frequency ratio of heart rate power did not differ between groups (p = 0.48), nor did resting metabolic rate (controls: 1767 ± 226 kcal/24 h; patients: 1766 ± 227 kcal/24h; p = 0.99). conclusions: Resting metabolic rate was not reduced in hypocretindeficient narcoleptic men and therefore does not explain obesity in this group. Whether the increased heart rate and blood pressure variability-suggesting reduced sympathetic tone-is involved in this regard remains to be elucidated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.