A revision of the dorsal origin of the frontal aslant tract (FAT) in the superior frontal gyrus: a DWI-tractographic study.

The frontal aslant tract (FAT) is a white matter tract connecting the superior frontal gyrus (SFG) to the inferior frontal gyrus (IFG). Its dorsal origin is identified in humans in the medial wall of the SFG, in the supplementary motor complex (SM-complex). However, empirical observation shows that many FAT fibres appear to originate from the dorsal, rather than medial, portion of the SFG. We quantitatively investigated the actual origin of FAT fibres in the SFG, specifically discriminating between terminations in the medial wall and in the convexity of the SFG. We analysed data from 105 subjects obtained from the Human Connectome Project (HCP) database. We parcelled the cortex of the IFG, dorsal SFG and medial SFG in several regions of interest (ROIs) ordered in a caudal-rostral direction, which served as seed locations for the generation of streamlines. Diffusion imaging data (DWI) was processed using a multi-shell multi-tissue CSD-based algorithm. Results showed that the number of streamlines originating from the dorsal wall of the SFG significantly exceeds those from the medial wall of the SFG. Connectivity patterns between ROIs indicated that FAT sub-bundles are segregated in parallel circuits ordered in a caudal-rostral direction. Such high degree of coherence in the streamline trajectory allows to establish pairs of homologous cortical parcels in the SFG and IFG. We conclude that the frontal origin of the FAT is found in both dorsal and medial surfaces of the superior frontal gyrus.

Comparison of ultrasound- versus fluoroscopy-guidEd femorAl access In tranS-catheter aortic valve replacement In the Era of contempoRary devices: The EASIER registry.

BACKGROUND: Vascular complications (VCs) still represent one of the principal concerns of trans-femoral trans-catheter aortic valve replacement (TF-TAVR). New-generation devices can minimize such complications but the arterial access management is left to the operator's choice. This study aims to describe the rate of VCs in a contemporary cohort of patients undergoing TAVR with new-generation devices and to determine whether an ultrasound-guided (USG) vs. a fluoroscopy-guided (FG) femoral access management has an impact on their prevention. METHODS: This is a prospective, observational, multicenter study. Consecutive patients undergoing TAVR with new-generation devices were analyzed from January 2022 to October 2022 in five tertiary care centers. Femoral accesses were managed according to the operator's preferences. All the patients underwent a pre-discharge peripheral ultrasound control. VCs and bleedings were the main endpoints of interest. RESULTS: A total of 458 consecutive patients were enrolled (274 in the USG group and 184 in the FG group). VCs occurred in 6.5 % of the patients (5.2 % minor and 1.3 % major). There was no difference between the USG and the FG groups in terms of any VCs (7.3 % vs. 5.4 %; p = 0.4), or any VARC-3 bleedings (6.9 % vs 6 %, p = 0.9). At logistic regression analysis, the two guidance strategies did not result as predictors of VCs (odds Ratio 0.8, 95 % Confidence Interval 0.46-1.4; P = 0.4). CONCLUSIONS: In a contemporary cohort of patients undergoing TAVR with new-generation devices, the occurrence of VCs is low and mostly represented by minor VCs. USG and FG modalities did not affect the rate of VCs.

Connectivity by the Frontal Aslant Tract (FAT) Explains Local Functional Specialization of the Superior and Inferior Frontal Gyri in Humans When Choosing Predictive over Reactive Strategies: A Tractography-Guided TMS Study.

Predictive and reactive behaviors represent two mutually exclusive strategies in a sensorimotor task. Predictive behavior consists in internally estimating timing and features of a target stimulus and relies on a cortical medial frontal system [superior frontal gyrus (SFG)]. Reactive behavior consists in waiting for actual perception of the target stimulus and relies on the lateral frontal cortex [inferior frontal gyrus (IFG)]. We investigated whether SFG-IFG connections by the frontal aslant tract (FAT) can mediate predictive/reactive interactions. In 19 healthy human volunteers, we applied online transcranial magnetic stimulation (TMS) to six spots along the medial and lateral terminations of the FAT, during the set period of a delayed reaction task. Such scenario can be solved using either predictive or reactive strategies. TMS increased the propensity toward reactive behavior if applied to a specific portion of the IFG and increased predictive behavior when applied to a specific SFG spot. The two active spots in the SFG and IFG were directly connected by a sub-bundle of FAT fibers as indicated by diffusion-weighted imaging (DWI) tractography. Since FAT connectivity identifies two distant cortical nodes with opposite functions, we propose that the FAT mediates mutually inhibitory interactions between SFG and IFG to implement a "winner takes all" decisional process. We hypothesize such role of the FAT to be domain-general, whenever competition occurs between internal predictive and external reactive behaviors. Finally, we also show that anatomic connectivity is a powerful factor to explain and predict the spatial distribution of brain stimulation effects.SIGNIFICANCE STATEMENT We interact with sensory cues adopting two main mutually-exclusive strategies: (1) trying to anticipate the occurrence of the cue or (2) waiting for the GO-signal to be manifest and react to it. Here, we showed, by using noninvasive brain stimulation [transcranial magnetic stimulation (TMS)], that two specific cortical regions in the superior frontal gyrus (SFG) and the inferior frontal gyrus (IFG) have opposite roles in facilitating a predictive or a reactive strategy. Importantly these two very distant regions but with highly interconnected functions are specifically connected by a small white matter bundle, which mediates the direct competition and exclusiveness between predictive and reactive strategies. More generally, implementing anatomic connectivity in TMS studies strongly reduces spatial noise.

Comparative treatments of a green tattoo ink with Ruby, Nd:YAG nano- and picosecond lasers in normal and array mode.

The tattoos removal has become an issue upon spread of the tattooing practice worldwide and hindsight regrets. Lasers are typically used for the purpose, though some colours such as green are considered "recalcitrant" to the treatment. In the current investigation, we aim at determining the efficacy of removal of a green ink water dispersion, using 5 laser treatments: Nd:YAG nano- and picosecond lasers in normal and array mode and Ruby nanosecond laser, keeping the total irradiated energy constant. The UV-Vis spectroscopy of the treated samples indicate that Nd:YAG picosecond laser is most effective, and the Ruby nanosecond laser is the least efficient. Fragment compounds generated from the pigment and siloxanes are common to all treatments, whereas hydrocarbon emerge by a larger amount upon Nd:YAG nanosecond treatment. Fibres are formed upon picosecond treatments and when operating in array mode, and lamellae are achieved by Ruby nanosecond laser treatment. Residual particles suspensions are very heterogeneous upon nanosecond treatments.

Hemodialysis shake-up on the front lines of the Covid-19 pandemic: the Treviglio Hospital experience.

The new coronavirus disease (Covid-19) pandemic in Italy formally started on 21st February 2020, when a 38-years old man was established as the first Italian citizen with Covid-19 in Codogno, Lombardy region. In a few days, the deadly coronavirus swept beyond expectations across the city of Bergamo and its province, claiming thousands of lives and putting the hospital in Treviglio under considerable strain. Since designated Covid-dialysis hospitals to centrally manage infected hemodialysis patients were not set up in the epidemic areas, we arranged to treat all our patients. We describe the multiple strategies we had to implement fast to prevent/control Covid-19 infection and spread resources in our Dialysis Unit during the first surge of the pandemic in one of the worst-hit areas in Italy. The recommendations provided by existing guidelines and colleagues with significant experience in dealing with Covid-19 were combined with the practical judgement of our dialysis clinicians, nurses and nurse's aides.