Adult vasovagal syncope with abdominal pain diagnosed by head-up tilt combined with transcranial doppler: a preliminary study.

BACKGROUND: Syncope is a common condition that increases the risk of injury and reduces the quality of life. Abdominal pain as a precursor to vasovagal syncope (VVS) in adults is rarely reported and is often misdiagnosed.​. METHODS: We present three adult patients with VVS and presyncopal abdominal pain diagnosed by synchronous multimodal detection (transcranial Doppler [TCD] with head-up tilt [HUT]) and discuss the relevant literature. RESULTS: Case 1: A 52-year-old man presented with recurrent decreased consciousness preceded by six months of abdominal pain. Physical examinations were unremarkable. Dynamic electrocardiography, echocardiography, head and neck computed tomography angiography, magnetic resonance imaging (MRI), and video electroencephalogram showed no abnormalities. Case 2: A 57-year-old woman presented with recurrent syncope for 30 + years, accompanied by abdominal pain. Physical examination, electroencephalography, and MRI showed no abnormalities. Echocardiography showed large right-to-left shunts. Case 3: A 30-year-old woman presented with recurrent syncope for 10 + years, with abdominal pain as a precursor. Physical examination, laboratory analysis, head computed tomography, electrocardiography, and echocardiography showed no abnormalities. Syncope secondary to abdominal pain was reproduced during HUT. Further, HUT revealed vasovagal syncope, and synchronous TCD showed decreased cerebral blood flow; the final diagnosis was VVS in all cases. CONCLUSIONS: Abdominal pain may be a precursor of VVS in adults, and our findings enrich the clinical phenotypic spectrum of VVS. Prompt recognition of syncopal precursors is important to prevent incidents and assist in treatment decision-making. Abdominal pain in VVS may be a sign of sympathetic overdrive. Synchronous multimodal detection can help in diagnosing VVS and understanding hemodynamic mechanisms.

Left atrial function evaluation by 2D speckle-tracking echocardiography in patients with vasovagal syncope.

OBJECTIVES: Evidence indicates left atrial (LA) involvement in vasovagal syncope (VVS). The LA regulates left ventricular filling during the cardiac cycle. We aimed to assess LA function in patients with VVS by 2D speckle-tracking echocardiography. METHODS: Sixty-nine consecutive patients with VVS were recruited. Based on the head-up tilt test (HUTT) results, the study population was divided into two groups: HUTT+ (n = 45) and HUTT- (n = 24). Fifty-one consecutive subjects were enrolled as the control group. LA myocardial deformation parameters were measured by 2D speckle-tracking echocardiography to evaluate LA function. RESULTS: Maximal, minimal, and pre-P LA volumes were lower in patients with VVS. Strain and strain rate during reservoir, conduit, and contraction phases in VVS patients with HUTT+ or HUTT- were not statistically significantly different from those in the control group. Additionally, the volumetric parameters of LA function showed no difference in statistical significance between the three study groups. CONCLUSIONS: While LA phasic function was not different between the two groups of VVS patients with HUTT+ or HUTT- and the control group, LA size during the three LA phases was smaller in patients with VVS.

Venous Pooling in Suspension Syndrome Assessed with Ultrasound.

INTRODUCTION: Suspension syndrome describes a potentially life-threatening event during passive suspension on a rope. The pathophysiological mechanism is not fully understood; however, the most widespread hypothesis assumes blood pools in the lower extremities, prompting a reduction in cardiac preload and cardiac output and leading to tissue hypoperfusion, loss of consciousness, and death. The aim of this study was to assess venous pooling by ultrasound in simulated suspension syndrome using human subjects. METHODS: In this trial, 20 healthy volunteers were suspended in a sit harness for a maximum of 60 min with and without preceding exercise. Venous pooling was assessed by measuring the diameter of the superficial femoral vein (SFV) with ultrasound at baseline in supine and standing positions as well as during and after suspension. RESULTS: SFV diameter increased and blood flow became progressively sluggish. In 30% of the tests, near syncope occurred. However, SFV diameter did not differ between subjects with and without near syncope. CONCLUSIONS: Free hanging in a harness leads to rapid venous pooling in the lower limbs. The most important measure to prevent suspension syndrome might be constant movement of the legs.

Cardiovascular biomarkers and echocardiographic findings at rest and during graded hypovolemic stress in women with recurrent vasovagal syncope.

INTRODUCTION: Vasovagal reflex is the most common type of syncope but its etiology is not fully elucidated. Venous return and cardiac output are key in hemodynamic control. The aim of the study was to assess cardiovascular biomarkers and echocardiographic measures at rest and during hypovolemia in women with and without a history of vasovagal syncope. METHODS: Fourteen women (aged 18-30) suffering from recurrent vasovagal syncope and 15 age-matched healthy women were included. Graded lower body negative pressure (LBNP) was used to create central hypovolemic stress until signs of presyncope occurred. Echocardiography was applied at rest and throughout LBNP. Cardiovascular biomarkers: copeptin, mid-regional proadrenomedullin, mid-regional pro-ANP, C-terminal proendothelin-1, and plasma norepinephrine were measured both at rest and throughout graded hypovolemia to presyncope. RESULTS: Women prone to vasovagal syncope presented with a narrower right ventricle (RV) (29 ± 1 vs 32 ± 1 mm, P < .05), smaller left atrium (36 ± 2 vs 47 ± 3 cm3 , P < .01) and lower cardiac output at rest (3.1 ± 0.2 vs 3.7 ± 0.2 L/min, P < .05) and during graded hypovolemia (P < .05). Copeptin was elevated at rest (4.3 ± 0.8 vs 2.5 ± 0.2 pmol/L, P < .05) and increased more in women with vasovagal syncope during progression of LBNP (P < .01). At rest, lower C-terminal proendothelin-1 (35 ± 5 vs 46 ± 2 pmol/L, P < .05) and higher norepinephrine levels (1.1 ± 0.1 vs 0.8 ± 0.1 nmol/L, P < .01) were seen in women with vasovagal syncope. CONCLUSION: Women prone to vasovagal syncope demonstrate reduced cardiac preload, lower cardiac output, as well as increased release of vasopressin in rest and during hypovolemic challenge. The results emphasize the importance of venous return and cardiac output in the pathogenesis of vasovagal syncope.

Electroanatomic-mapping-guided cardioneuroablation versus combined approach for vasovagal syncope: a cross-sectional observational study.

PURPOSE: This study was designed to assess the efficacy of electroanatomic-mapping (EAM)-guided cardioneuroablation (CNA) vs combined approach for vasovagal syncope (VVS). METHODS: Twenty patients with VVS refractory to conventional treatments who underwent CNA in our institution were enrolled in the study. Twelve of these patients underwent recently introduced EAM-guided CNA using signal-based approach while 8 patients underwent combined CNA using a combination of high-frequency stimulation and spectral analysis. Both atria and coronary sinus were divided into seven segments to categorize distribution of ganglionated plexi in ablation sites. Clinical responses were evaluated and compared in terms of prodromal symptoms and syncope recurrence rates. Electrophysiological parameters and heart rate variability (HRV) analysis were used to evaluate procedural response. RESULTS: Procedural endpoints were achieved in all cases without any serious adverse events. Compared with the combined approach group, EAM-guided CNA was related to a shorter procedure and fluoroscopy times (p < 0.001). The mean number of ablation points in each anatomical segment was comparable between groups. The prodromal symptoms demonstrated a significant and comparable decrease after CNA. Median event-free survival was comparable between groups (χ2 = 0.03, p = 0.87). There was no new syncopal episode in any case at the end of 6-month follow-up. In the combined approach group, new syncope episodes occurred in two cases after 12-month follow-up. HRV parameters indicating parasympathetic activity were comparably decreased after ablation in both groups. CONCLUSION: This pilot study shows that EAM-guided CNA strategy is feasible and safe in VVS patients resistant to conventional therapies.

Novel functional advanced echocardiography for the assessment of myocardial mechanics in children with neurocardiogenic syncope - a blinded prospective speckle tracking head-up tilt-table challenge study.

BACKGROUND: Data on left ventricular (LV) function in patients with neurocardiogenic syncope (NS) is conflicting in adults and lacking in children. The aim of this study was to analyze LV myocardial performance in children with NS at rest and during head-up tilt-table (HUTT) testing. METHODS: This is the first study to combine HUTT and speckle-tracking echocardiography (STE) in children with NS. 43 consecutive normotensive pediatric patients with NS (mean age 13.9 ± 2.6 years, 51% female) and 41 sex- and age-matched healthy controls were included in the study. The study groups consisted of 21 patients with a positive HUTT reaction (HUTT+) and 22 with a negative HUTT reaction (HUTT-). STE was used to analyze peak systolic LV myocardial strain and strain rate. RESULTS: Conventional echocardiographic parameters were similar in all analyzed groups. When compared to healthy controls, children with NS had depressed levels of circumferential strain rate (p = 0.032) and significantly depressed longitudinal strain rate (p <  0.001) at rest. Interestingly, during HUTT testing LV global strain and strain rate were similar in both groups. LV strain rate was lowest in HUTT+ followed by HUTT- and control subjects both at rest and during HUTT. CONCLUSIONS: Resting LV longitudinal strain rate is attenuated in children with NS, especially in those with a positive HUTT response. This is further evidence that NS patients feature altered cardiac mechanics rendering them prone to vasovagal perturbations that can ultimately result in collapse. TRIAL REGISTRATION: Witten/Herdecke University ethics committee clinical study number: UWH-73-2014.

Left Ventricular Ejection Fraction and Fractional Shortening are Useful for the Prediction of the Therapeutic Response to Metoprolol in Children with Vasovagal Syncope.

The objective of this manuscript was to explore if left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) could predict the efficacy of metoprolol therapy on vasovagal syncope (VVS) in children. Forty-nine children, including 30 with VVS and 19 gender- and age-matched healthy controls, were included in the study. Metoprolol was prescribed to the VVS subjects. The clinical data were obtained during follow-up at 2 and 6 months. The results showed that LVEF and LVFS of responders were significantly higher than those of non-responders both at the 2-month follow-up (LVEF: 72.5 ± 3.2% vs. 64.6 ± 3.4%; LVFS: 40.9 ± 2.3% vs. 34.9 ± 2.9%), and at the 6-month follow-up (LVEF: 72.8 ± 2.8% vs. 65.5 ± 4.6%; LVFS: 41.1 ± 1.9% vs. 35.8 ± 3.6%). The receiver operating characteristic curve (ROC) analysis demonstrated that 70.5% as a cutoff value of baseline LVEF yielded a sensitivity of 80% and a specificity of 100% in predicting the therapeutic effectiveness of metoprolol at 2 months. For baseline LVFS, 38.5% as a cutoff value yielded a sensitivity of 90% and a specificity of 90%. At the 6-month follow-up, the ROC analysis demonstrated that 70.5% as a cutoff value of baseline LVEF yielded a sensitivity of 81.3% and a specificity of 88.9% in the prediction of metoprolol efficacy. For baseline LVFS, 37.5% as a cutoff value yielded a sensitivity of 93.8% and a specificity of 66.7%. In conclusion, baseline LVEF and LVFS might be useful predictors of the efficacy of ß-blocker therapy on VVS in children.

Vasovagal responses during cryoballoon pulmonary vein isolation in paroxysmal atrial fibrillation predict favorable mid-term outcomes.

BACKGROUND: Vasovagal responses (VR) encountered during radiofrequency pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (PAF) suggest ablation of the atrial tissue subjacent to the ganglionic plexi (GP) and confer durability of PVI. OBJECTIVE: We hypothesized that VR during cryoballoon PVI (CB-PVI) in PAF can predict mid-term AF recurrence. METHODS: We enrolled 39 patients who underwent PVI using 2nd generation cryoballoon for PAF from November 2014 to July 2016. We evaluated the long term outcomes for those who had VR during index procedure. RESULTS: A total of 39 patients (76% male, mean age 57 ±â€¯9 years) underwent CB-PVI for PAF and 66.67% (26/39) had VR. VR was frequently observed in the LSPV (100%), followed by RSPV (64%), LIPV (60%), and less frequently, RIPV (28%). Overall, the mean difference in the HR and SBP, and the relative differences in the HR and SBP were observed during CB-PVI in the LSPV (mean difference in HR, p < 0.001; mean difference in SBP, p < 0.001; relative difference in HR, p < 0.001); relative difference in SBP, p < 0.001). After PVI, 22/26 (84.62%) and 5/13 (38.46%) of patients in the VR and NVR group, respectively, maintained SR at 14 ±â€¯6 months follow-up. The Kaplan-Meier analysis showed statistical difference in favor of patients with VR during CB-PVI (log rank p < 0.01) with a better mid-term outcome. CONCLUSION: In a small cohort of patients, VR during CB-PVI in PAF is a surrogate marker for ablation of atrial tissue subjacent to the GP and predicts a favorable mid-term outcome for AF recurrence.

Deceleration capacity-a novel measure for autonomic nervous system in patients with vasovagal syncope on tilt-table testing.

This study was to investigate the changes of autonomic nerve function and hemodynamics in patients with vasovagal syncope (VVS) during head-up tilt-table testing (HUT). HUT was performed in 68 patients with unexplained syncope and 18 healthy subjects served as control group. According to whether bradycardia, hypotension or both took place during the onset of syncope, the patients were divided during the test into three subgroups: vasodepressor syncope (VD), cardioinhibitory syncope (CI) and mixed syncope (MX) subgroups. Heart rate, blood pressure, heart rate variability (HRV), and deceleration capacity (DC) were continuously analyzed during HUT. For all the subjects with positive responses, the normalized low frequency (LFn) and the LF/HF ratio markedly decreased whereas normalized high frequency (HFn) increased when syncope occurred. Syncopal period also caused more significant increase in the power of the DC in positive groups. These changes were more exaggerated compared to controls. All the patients were indicative of a sympathetic surge in the presence of withdrawal vagal activity before syncope and a sympathetic inhibition with a vagal predominance at the syncopal stage by the frequency-domain analysis of HRV. With the measurements of DC, a decreased vagal tone before syncope stage and a vagal activation at the syncopal stage were observed. The vagal tone was higher in subjects showing cardioinhibitory responses at the syncopal stage. DC may provide an alternative method to understand the autonomic profile of VVS patients.

Increased (18)F-fluorodeoxyglucose accumulation in bilateral adrenal glands of the patients suffering from vasovagal reaction due to blood vessel puncture.

OBJECTIVE: The purpose of the study was to evaluate the hypothesis that patients having a vasovagal reaction (VVR) after blood vessel puncture show increased FDG accumulation in bilateral adrenal glands. METHODS: Over the past 8 years, 26 patients experienced a VVR after blood vessel puncture following intra-venous injection of FDG at our institution. Of the 26 patients, 16 underwent multiple-occasion FDG-PET/CT scans while suffering a VVR at only one examination. All 16 patients had no morphological abnormality in the adrenal glands on FDG-PET/CT and follow-up examination. For the 16, we retrospectively reviewed the FDG-PET/CT scan with respect to the adrenal glands and compared the result to that for the FDG-PET/CT scan of the same patient when there was no VVR event. We used both visual analysis and semi-quantitative analysis employing either maximum standardized uptake value (SUVmax) or adrenal-to-liver (A/L) SUVmax ratio. RESULTS: On visual analysis of the FDG-PET/CT with VVR, accumulations in both of the adrenal glands was judged positive, defined as higher than the hepatic accumulation, in 84 % of the cases. The SUVmax in the right adrenal gland was 2.79 ± 0.69 with VVR and 1.92 ± 0.33 without VVR; this value in the left adrenal gland was 3.07 ± 0.71 with VVR and 2.05 ± 0.39 without. Mean SUVmax of both adrenal glands was 2.93 ± 0.66 with VVR and 1.98 ± 0.35 without. The A/L SUVmax ratio in the right adrenal gland was 1.02 ± 0.26 with VVR and 0.69 ± 0.11 without; this value in the left was 1.11 ± 0.23 with VVR and 0.74 ± 0.15 without. The mean A/L SUVmax ratio of both adrenal glands was 1.06 ± 0.24 with VVR and 0.72 ± 0.13 without. Each parameter with VVR was significantly higher than that without. For the two adrenal glands, the mean SUVmax with VVR was 48 % higher than that without VVR. CONCLUSIONS: We confirmed the hypothesis that patients having a VVR after blood vessel puncture show increased FDG accumulation in their bilateral adrenal glands. This may reflect hyper-metabolism of the adrenal glands in synthesizing and secreting catecholamine.

Late recurrence of a completely occluded large intracranial aneurysm treated with a Tubridge flow diverter.

We report a rare case of recurrence of a large intracavernous aneurysm after angiography proved complete occlusion. The aneurysm was treated by a combination of a Tubridge flow diverter and coils, and balloon angioplasty, after flow diverter devices deployment for parent vessel stenosis. Six month angiographic follow-up demonstrated complete occlusion. Unfortunately, obvious aneurysm recurrence was confirmed on 2 year angiographic follow-up. The probable mechanism of recurrence was analyzed.

Importance of arterial distensibility in patients with vasovagal syncope.

OBJECTIVE: Vasovagal syncope (VS) has a significant place in the etiology of syncope; tilt table (TT) test is used for identification of patients with vasovagal syncope (VS); however, the repeatability of the TT test is low. Upon repeated administration of TT test to patients with a positive result, the test may reveal a negative result. This feature of the test renders it inadequate particularly in evaluating therapeutical efficacy in patients receiving treatment. The left ventricular (LV) volume changes are important in the pathology of VS; in addition, LV volume changes are directly affected by the changes in the arterial system and therefore, the present study investigated arterial distensibility (AD) in this patient population. PATIENTS AND METHODS: A total of 142 VS patients with a positive TT test result (A group) and 93 healthy individuals (B group) were enrolled in the study. The patients received tilt training treatment for 6 months. VS patients were further classified into two: syncope (+) or syncope (-) subgroup according to having at least one or more syncope episode during the 6 months of training program. All patients and controls underwent Doppler echocardiography and AD measurement which were repeated at the end of 6th month in syncope (+) and (-) subgroups. RESULTS: The mean AD value of patients in group A was significantly lower than that of participants in group B (0.39 ± 0.1 vs. 0.42 ± 0.1, p = 0.025). In Group A, AD was significantly correlated with left ventricular diastolic filling time (DFT), isovolumetric relaxation time and right ventricular DFT (r = 0.38, p < 0.05; r = -0.42, p < 0.05; r = 0.35, p < 0.05, respectively). Syncope (+) subgroup had lower mean AD value compared to syncope (-) subgroup (0.38 ± 0.1 vs. 0.44 ± 0.1, p < 0.001). CONCLUSIONS: AD may have valuable contribution to understanding the pathophysiology underlying VS and AD may be used in evaluating therapeutical efficacy for vasovagal syncope.

Cerebral blood flow of children with vasovagal syncope.

INTRODUCTION: We aimed to evaluate changes in the cerebral blood supply in children during vasovagal syncope and to clarify the diagnostic value of transcranial Doppler for vasovagal syncope. MATERIALS AND METHODS: Patients were divided into three groups. Group 1 consisted of 31 patients who were symptomatic and whose head-up tilt test was positive. Group 2 comprised 21 patients who were symptomatic but whose tilt test was negative. Group 3 included 22 healthy children. For the diagnosis of vasovagal syncope, the tilt test was applied. For the subjects of the patient and control groups, the tilt test was repeated. The flow rates of bilateral middle cerebral arteries were continuously and simultaneously recorded with temporal window transcranial Doppler. RESULTS: There were no statistically significant differences between the three groups with respect to age and gender distribution (p>0.05). When the bed was at an upright position, the maximum blood flow rate of the right middle cerebral artery was lower in Group 1 than in Group 2, although the decrease was more significant in comparison to the healthy control group (p<0.05). The minimum blood flow rate of the right middle cerebral artery was lower in Group 1 than the Group 2, although the decrease was more significant in comparison with the healthy control group (p<0.05). The maximum blood flow rate of the left middle cerebral artery was significantly lower in Group 1 than in the control group (p<0.05). CONCLUSION: Minimum and maximum blood flow rates are significantly decreased in patients tilt test (+) patients with vasovagal syncope during orthostatic stress.

[Signification of NT-proBNP in the differential diagnosis of syncope in adults]. / Znaczenie NT-proBNP w diagnostyce róznicowej omdlen u osób doroslych.

Syncope is a transient loss of consciousness, which is the result of global brain hypoperfusion, characterized by rapid onset, short duration, and spontaneous complete resolution. Syncope is a common clinical problem due to its complex, multi-causal etiology, not completely understood pathogenesis and potential complications. Diagnosis of syncope is often associated with the implementation of many medical tests. In the recent years, the role of determining the concentration of NT-proBNP in the differential diagnosis of syncope has been highlighted. Aims of the study was analysis of NT-proBNP concentrations in patients with cardiogenic syncope in comparison to patients with neurogenic syncope and determination of the threshold value of NT-proBNP to differentiate cardiac and neurogenic syncope and to determine its sensitivity and specificity. The study included 160 pts (64 man, 96 women), aged 18 - 77 yrs (mean age 50,6) with a reflex syncope (group I) or cardiac syncope (group II). To determine the etiology of syncope, collected were: medical history for symptoms and circumstances of the syncope, measurements of blood pressure, resting ECG recording, cardiac echocardiography, and the concentration of NT-proBNP levels. Results: the group I included 80 pts (29 men, 51 women), aged 18 - 72 yrs (mean age 41.2). Group II included 80 pts (35 man, 45 women), aged 38 - 77 yrs (mean age 62.1). The assessment of concentrations of NT-proBNP showed significantly higher levels in group II than group I (467.6 +/- 227.4 vs 64.1 +/- 59.1; p <0.0001). In patients with arrhythmias and conduction abnormalities, the levels of NT-proBNP were higher in comparison to those without such disorders (364 +/- 249 vs. 171 +/- 209 pg/ml, p < 0.001). It was found that the concentration of NT-proBNP at 230.6 pg/ml might be a cut-off point that allows the prediction of cardiogenic cause of syncope with 96% specificity, 92% sensitivity and 93% negative predictive value. Conclusions: 1. The concentration of peptide NT-proBNP patients with reflex syncope. 2. It was shown that the cut off concentration of the NT-proBNP equal 230.6 pg/ml is characterized by the high sensitivity, specificity, and negative predictive value in determining the etiology of syncope.

Anomalous chord of the left atrium without involvement of the mitral valve.

An anomalous chord from the left side of the atrial septum to the left atrial free wall was incidentally noted on transthoracic echocardiography in a 14-year-old boy with vasovagal syncope. Previously reported cases of anomalous chords in the left atrium were associated with the mitral valve leaflets in all but two cases. This is the first reported case of an echocardiographic diagnosis of anomalous left atrial chord without insertion of the chord into the mitral valve.

Cardiac autonomic disturbances in patients with vasovagal syndrome: comparison between iodine-123-metaiodobenzylguanidine myocardial scintigraphy and heart rate variability.

AIMS: The aim of this study was to examine autonomic disorders in patients with different types of vasovagal syndrome by performing both a cardiac sympathetic innervation evaluation and a head-up tilt-test with heart rate variability (HRV) analysis. METHODS AND RESULTS: We enrolled 60 patients with vasovagal syncope (32 women, mean age 40 ± 16 years), and 20 age-matched controls. We assessed the integrity and function of the myocardial pre-synaptic nerve endings and in the sympathovagal activity, using (123)I-metaiodobenzylguanidine (MIBG) scintigraphy and time-domain indexes of HRV. A significantly lower heart/mediastinum ratio was found in the syncopal patients compared with the control group, both at 10 min (1.9 ± 0.25 vs. 3.6 ± 1.7, P = 0.02) and at 4 h (1.79 ± 0.12 vs. 2.07 ± 0.19, P = 0.04), whereas washout rate was significantly greater in syncopal patients (5.5 ± 3.7 vs. 2 ± 0.19, P = 0.04). There were no significant differences in any of the above parameters between patients with different types of syncope. In addition, the majority of the patients showed multiple adrenergic innervation defects in the left ventricular myocardium. No significant difference was found in any of the HRV time-domain indexes. However, a correlation was found between root-mean-square of the difference between successive RRs and washout rate in syncopal patients (r = -0.256, P = 0.48). CONCLUSION: Patients with vasovagal syncope induced by tilt testing reveal a high degree of disturbance of myocardial adrenergic innervation and multiple adrenergic innervation defects. This suggests a possible predominance of cardiac adrenergic activity in those with abnormal cardiac MIBG scintigraphy.

Stretch syncope: reflex vasodepressor faints easily mistaken for epilepsy.

The pathophysiology of stretch syncope is demonstrated through the clinical, electrophysiological, and hemodynamic findings in three patients. Fifty-seven attacks were captured by video/EEG monitoring. Simultaneous EEG, transcranial (middle cerebral artery) doppler, and continuous arterial pressure measurements were obtained for at least one typical attack of each patient. They all experienced a compulsion to precipitate their attacks. Episodes started with a stereotyped phase of stretching associated with neck torsion and breath holding, followed by a variable degree of loss of consciousness and asymmetric, recurrent facial and upper limb jerks in the more prolonged episodes. Significant sinus tachycardia coincided with the phase of stretching and was followed within 9-16 seconds by rhythmic generalized slow wave abnormalities on the EEG in attacks with impairment of consciousness. Transcranial doppler studies showed a dramatic drop in cerebral perfusion in the middle cerebral arteries during the episodes. The combination of the stereotyped semiology of the attacks, the pseudofocal myoclonic jerking, and the rhythmic generalized slow wave EEG abnormalities with the tachycardia make differential diagnosis from epilepsy challenging.

Cerebral blood flow abnormalities in patients with neurally mediated syncope.

The aim of this study is to investigate regional cerebral blood flow (rCBF) in patients with syncope. We compared brain single photon emission computed tomography (SPECT) images of neurally mediated syncope patients with those of age/sex matched healthy volunteers. (99m)Tc-ethylcysteinate dimer (ECD) brain SPECT was performed in 35 patients (M/F = 17/18, mean 36.6 years) with syncope during the asymptomatic period, and in 35 healthy volunteers. For statistical parametric mapping (SPM) analysis, all SPECT images were spatially normalized to the standard SPECT template and then smoothed using a 14-mm full width at half maximum Gaussian kernel. The mean duration of syncope history was 4.9 years and the mean number of syncope episodes was 6.3. In all patients, syncope or presyncope episodes occurred during head-up tilt tests, and all were the vasodepressive type. SPM analysis of brain SPECT images showed significantly decreased rCBF in the right anterior insular cortex, left parahippocampal gyrus, bilateral fusiform gyri, bilateral middle and inferior temporal gyri, left lingual gyrus, bilateral precuneus and bilateral posterior lobes of the cerebellum in syncope patients at a false discovery rate corrected p < 0.05. There were no brain regions that showed increased rCBF in syncope patients. Furthermore, we found a negative correlation between the total number of syncopal episodes and the rCBF of the right prefrontal cortex, and between the duration of syncope history and the rCBF of the right cingulate gyrus at uncorrected p < 0.001. Decreases of rCBF in multiple brain regions may be responsible for autonomic dysregulation and improper processing of emotional stress in neurally mediated syncope patients, and frequent syncope episodes may lead to frontal dysfunction.