Research in both humans and monkeys has shown that even simple hand movements require cortical control beyond primary sensorimotor areas. An extensive functional neuroimaging literature demonstrates ...the key role that cortical fronto-parietal regions play for movements such as reaching and reach-to-grasp. However, no study so far has examined the specific white matter connections linking the fronto-parietal regions, namely the 3 parallel pathways of the superior longitudinal fasciculus (SLF). The aim of the current study was to explore how selective fronto-parietal connections are for different kinds of hand movement in 30 right-handed subjects by correlating diffusion imaging tractography and kinematic data. We showed that a common network, consisting of bilateral SLF II and SLF III, was involved in both reaching and reach-to-grasp movements. Larger SLF II and SLF III in the right hemisphere were associated with faster speed of visuomotor processing, while the left SLF II and SLF III played a role in the initial movement trajectory control. Furthermore, the right SLF II was involved in the closing grip phase necessary for efficient grasping of the object. We demonstrated for the first time that individual differences in asymmetry and structure of the fronto-parietal networks were associated with visuomotor processing in humans.
Functional neuroimaging and brain lesion studies demonstrate that secondary motor areas of the frontal lobe play a crucial role in the cortical control of hand movements. However, no study so far has ...examined frontal white matter connections of the secondary motor network, namely the frontal aslant tract, connecting the supplementary motor complex and the posterior inferior frontal regions, and the U-shaped dorsal and ventral premotor fibers running through the middle frontal gyrus. The aim of the current study is to explore the involvement of the short frontal lobe connections in reaching and reach-to-grasp movements in 32 right-handed healthy subjects by correlating tractography data based on spherical deconvolution approach with kinematical data. We showed that individual differences in the microstructure of the bilateral frontal aslant tract, bilateral ventral and left dorsal premotor tracts were associated with kinematic features of hand actions. Furthermore, bilateral ventral premotor connections were also involved in the closing grip phase necessary for determining efficient and stable grasping of the target object. This work suggests for the first time that hand kinematics and visuomotor processing are associated with the anatomy of the short frontal lobe connections.
•Hand kinematics is associated with the anatomy of the short frontal lobe connections.•Frontal aslant and premotor tracts are related to variation in motor performance.•Ventral premotor tract is associated with closing grip phase of grasping.
Background
There is no established management algorithm for portal vein thrombosis (PVT) in cirrhotic patients. The aim of our study was to prospectively evaluate anticoagulation and transjugular ...intrahepatic portosystemic shunt (TIPS) to treat PVT.
Methods
Cirrhotics with non‐malignant PVT were included. Low weight molecular heparin anticoagulation was considered in all; TIPS was indicated if thrombosis progressed or anticoagulation was contraindicated. Patients who were not anticoagulated nor received TIPS served as controls.
Results
Fifty‐six patients (of whom 21 controls) were included. PVT was occlusive in 11/35, with extension to the superior mesenteric or splenic vein in 13/35. In the study group 33 patients were anticoagulated, with a recanalization rate of 36% (12/33) compared with 1/21 among controls. A time interval between appearance of thrombosis and anticoagulation < 6 months predicted chance of repermeation. Thrombus progression occurred in 15/21 non anticoagulated patients and in 5/33 anticoagulated patients (P < 0.001). TIPS was placed in six patients. There were five variceal bleedings and two intestinal venous ischaemia episodes in the control group, compared with one variceal bleeding episode in the study group.
Conclusions
In cirrhotics with PVT, a treatment algorithm using anticoagulation and TIPS achieves a good chance of complete repermeation, reduces portal hypertensive complications, and decreases the rate of thrombosis progression.
Current risk stratification for sudden cardiac death (SCD) in nonischemic dilated cardiomyopathy (NIDC) relies on left ventricular (LV) dysfunction, a poor marker of ventricular electrical ...instability. Contrast-enhanced cardiac magnetic resonance has the ability to accurately identify and quantify ventricular myocardial fibrosis (late gadolinium enhancement LGE).
To evaluate the impact of the presence and amount of myocardial fibrosis on arrhythmogenic risk prediction in NIDC.
One hundred thirty-seven consecutive patients with angiographically proven NIDC were enrolled for this study. All patients were followed up for a combined arrhythmic end point including sustained ventricular tachycardia (VT), appropriate implantable cardioverter-defibrillator (ICD) intervention, ventricular fibrillation (VF), and SCD.
LV-LGE was identified in 76 (55.5%) patients. During a median follow-up of 3 years, the combined arrhythmic end point occurred in 22 (16.1%) patients: 8 (5.8%) sustained VT, 9 (6.6%) appropriate ICD intervention, either against VF (n = 5; 3.6%) or VT (n = 4; 2.9%), 3 (2.2%) aborted SCD, and 2 (1.5%) died suddenly. Kaplan-Meier analysis revealed a significant correlation between the LV-LGE presence (not the amount and distribution) and malignant arrhythmic events (P < .001). In univariate Cox regression analysis, LV-LGE (hazard ratio HR 4.17; 95% confidence interval CI 1.56-11.2; P = .005) and left bundle branch block (HR 2.43; 95% CI 1.01-5.41; P = .048) were found to be associated with arrhythmias. In multivariable analysis, the presence of LGE was the only independent predictor of arrhythmias (HR 3.8; 95% CI 1.3-10.4; P = .01).
LV-LGE is a powerful and independent predictor of malignant arrhythmic prognosis, while its amount and distribution do not provide additional prognostic value. Contrast-enhanced cardiac magnetic resonance may contribute to identify candidates for ICD therapy not fulfilling the current criteria based on left ventricular ejection fraction.
BACKGROUNDAdrenal vein sampling is crucial for identifying the primary aldosteronism subtypes, but the cutoff values for ascertaining selectivity of catheterization and lateralization of aldosterone ...secretion remain controversial.
OBJECTIVESTo investigate the safety of adrenal vein sampling, the cutoff values for the selectivity and lateralization indexes, and the effect of adrenocorticotropic hormone stimulation on selectivity index and lateralization index performance.
DESIGNWe assessed the proportion of selective adrenal vein sampling at different selectivity index cutoff values in 151 consecutive patients with primary aldosteronism undergoing bilaterally simultaneous adrenal vein sampling. Aldosterone-producing adenoma was diagnosed on the basis of the evidence of primary aldosteronism and lateralized aldosterone secretion, adenoma at pathological examination, and normokalemia, and correction of primary aldosteronism and cure or improvement of hypertension at follow-up. In 44 patients with bilaterally selective adrenal vein sampling and unequivocal diagnosis of aldosterone-producing adenoma on the basis of all these criteria, we examined the cutoff values of the lateralization index for assessing the lateralization of aldosterone excess and the effect of adrenocorticotropic hormone stimulation on selectivity index and lateralization index.
RESULTSAdrenal vein rupture occurred in one case (0.7%). Bilaterally selective adrenal vein sampling decreased steadily (from 79.9 to 40.2%) with increase in the selectivity index cutoffs from 1.1 to 5.0. Likewise, the proportion of correctly identified aldosterone-producing adenomas decreased (from 95.5 to 43.2%) with increase in lateralization index cutoffs from 1.125 to 5.0. Adrenocorticotropic hormone improved the assessment of selectivity but exerted a confounding effect on lateralization index.
CONCLUSIONAdrenal vein sampling is safe; increasing the selectivity index cutoffs lowers the number of usable adrenal vein samplings; higher lateralization index cutoff values lead to missing a proportion of aldosterone-producing adenomas. The improved selectivity rate provided by adrenocorticotropic hormone stimulation should be weighed against the loss of correct lateralization.
Stopping an action at the very last moment is an important feature of human behavioural flexibility. Intentional inhibition has been defined as the ability to inhibit an action on the basis of an ...internal decision process. Without this ability, actions would be impulsive and would leave little space to correct misguided decisions. Previous research suggests that making a choice between action alternatives activates a specific “choice network” that includes the rostral cingulate zone (RCZ), the anterior insula (AI), the dorsolateral prefrontal cortex (DLPFC) and the inferior parietal lobe (IPL). The activity of this network has shown to be influenced by non-conscious (subliminal) stimuli. In this study, we tested whether the same regions are recruited by free-choices to inhibit and modulated by unconscious information as reported in the case of free-choices to act. Using functional magnetic resonance imaging (fMRI) we manipulated the degree of ‘freedom’ of the choice between acting and inhibiting an action by introducing explicit cues or leaving the participants free to choose between action alternatives. We included subliminal masked primes to test whether responses to targets were facilitated and/or obstructed by conditions of congruency and incongruency between primes and targets. Our findings confirmed higher activation of the “choice network” in free-choice trials when compared to cued choices. However subliminal priming failed to significantly influence participants’ responses, in free-choice conditions.
•Masked primes were used to bias free and cued choices.•Free-choices modulated activity within the RCZ, the AI, the DLPFC and the IPL.•Masked priming was unable to significantly bias free-choices.•Masked primes might not be ideal to determine the neural substrates of intentional inhibition.
OBJECTIVE:As metoclopramide stimulates aldosterone secretion, we tested its usefulness in the assessment of lateralization of primary aldosteronism by adrenal vein sampling (AVS).
DESIGN:Prospective ...within-patient study in consecutive patients undergoing AVS for primary aldosteronism subtyping.
METHODS:We compared the diagnostic accuracy of baseline and postmetoclopramide lateralization index and relative (to cortisol) aldosterone secretion indices (RASI) for each adrenal gland with aldosterone-producing adenoma (APA) determined by the four corners criteria as the reference diagnosis.
RESULTS:We recruited 93 consecutive patients (mean age52 years; women 31%). Metoclopramide increased plasma aldosterone in the inferior vena cava and in both adrenal veins. The postmetoclopramide lateralization index was accurate in identifying APA, but did not increase diagnostic accuracy over baseline lateralization index, because the RASI increased similarly in both sides. Conversely, metoclopramide raised RASI to values more than 0.90 bilaterally in non-APA patients allowing accurate identification of factitious aldosterone suppression. In contrast, RASI was 0.90 or less in 48% contralateral to the tumor in APA patients. Regression analysis showed the APA patients with persistent suppression of RASI contralaterally showed a more florid primary aldosteronism phenotype.
CONCLUSION:Metoclopramide does not enhance lateralization of aldosterone excess in APA, but consistently increased the value of RASI in non-APA cases, thus unmasking potentially misleading suppression of aldosterone. Postmetoclopramide RASI may therefore allow a more precise diagnosis when AVS can be achieved only unilaterally.
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