Assessment of ascending aorta distensibility after successful coarctation repair by strain Doppler echocardiography

BACKGROUND: Increased arterial stiffness may participate in the genesis of hypertension and increase of left ventricular (LV) mass after surgical correction of coarctation of the aorta. The purpose of the current study was to assess the aortic elastic properties using Doppler tissue imaging and strain rate imaging in patients after coarctoplasty. METHODS: Echocardiography with Doppler tissue/strain rate imaging capabilities was performed in 26 adult normotensive patients who had successful repair of coarctation of the aorta in infancy and in 24 control subjects. Transesophageal aortic transverse sections were imaged at the level of the proximal and distal segments to the repair site. Doppler tissue imaging wall velocities during systole (S(w)), early relaxation (E(w)), and atrial systole (A(w)) and peak systolic strain (ps epsilon) were measured in both groups. Transthoracic ascending aorta (AAo) measurements were also obtained. RESULTS: In the patients with coarctoplasty, S(w) velocities and ps epsilon were significantly decreased in the proximal segments compared with control subjects. Both peak systolic blood pressure after exercise (P < .001) and pulse pressure after exercise (P < .001) were directly related to AAo wall strain. LV annular early diastolic velocity was significantly reduced compared with control subjects in patients with decreased AAo wall strain and exercise-induced hypertension (P < .001) and related to AAo wall velocity (P < .005) and strain (P < .001). In multiple linear regression analysis, only weight, study group, and AAo wall strain were correlated to LV mass index. CONCLUSIONS: Patients with coarctation of the aorta have reduced proximal aortic wall velocities and strain and increased stiffness even after successful repair. This amplifies stress-induced hypertension and increases LV burden

Event-related alpha suppression in response to facial motion

This article has been made available through the Brunel Open Access Publishing Fund.While biological motion refers to both face and body movements, little is known about the visual perception of facial motion. We therefore examined alpha wave suppression as a reduction in power is thought to reflect visual activity, in addition to attentional reorienting and memory processes. Nineteen neurologically healthy adults were tested on their ability to discriminate between successive facial motion captures. These animations exhibited both rigid and non-rigid facial motion, as well as speech expressions. The structural and surface appearance of these facial animations did not differ, thus participants decisions were based solely on differences in facial movements. Upright, orientation-inverted and luminance-inverted facial stimuli were compared. At occipital and parieto-occipital regions, upright facial motion evoked a transient increase in alpha which was then followed by a significant reduction. This finding is discussed in terms of neural efficiency, gating mechanisms and neural synchronization. Moreover, there was no difference in the amount of alpha suppression evoked by each facial stimulus at occipital regions, suggesting early visual processing remains unaffected by manipulation paradigms. However, upright facial motion evoked greater suppression at parieto-occipital sites, and did so in the shortest latency. Increased activity within this region may reflect higher attentional reorienting to natural facial motion but also involvement of areas associated with the visual control of body effectors. © 2014 Girges et al

Neural representations of the sense of self

The brain constructs representations of what is sensed and thought about in the form of nerve impulses that propagate in circuits and network assemblies (Circuit Impulse Patterns, CIPs). CIP representations of which humans are consciously aware occur in the context of a sense of self. Thus, research on mechanisms of consciousness might benefit from a focus on how a conscious sense of self is represented in brain. Like all senses, the sense of self must be contained in patterns of nerve impulses. Unlike the traditional senses that are registered by impulse flow in relatively simple, pauci-synaptic projection pathways, the sense of self is a system- level phenomenon that may be generated by impulse patterns in widely distributed complex and interacting circuits. The problem for researchers then is to identify the CIPs that are unique to conscious experience. Also likely to be of great relevance to constructing the representation of self are the coherence shifts in activity timing relations among the circuits. Consider that an embodied sense of self is generated and contained as unique combinatorial temporal patterns across multiple neurons in each circuit that contributes to constructing the sense of self. As with other kinds of CIPs, those representing the sense of self can be learned from experience, stored in memory, modified by subsequent experiences, and expressed in the form of decisions, choices, and commands. These CIPs are proposed here to be the actual physical basis for conscious thought and the sense of self. When active in wakefulness or dream states, the CIP representations of self act as an agent of the brain, metaphorically as an avatar. Because the selfhood CIP patterns may only have to represent the self and not directly represent the inner and outer worlds of embodied brain, the self representation should have more degrees of freedom than subconscious mind and may therefore have some capacity for a free-will mind of its own. S everal lines of evidence for this theory are reviewed. Suggested new research includes identifying distinct combinatorially coded impulse patterns and their temporal coherence shifts in defined circuitry, such as neocortical microcolumns. This task might be facilitated by identifying the micro-topography of field-potential oscillatory coherences among various regions and between different frequencies associated with specific conscious mentation. Other approaches can include identifying the changes in discrete conscious operations produced by focal trans-cranial magnetic stimulation

New approaches to the study of human brain networks underlying spatial attention and related processes

Cognitive processes, such as spatial attention, are thought to rely on extended networks in the human brain. Both clinical data from lesioned patients and fMRI data acquired when healthy subjects perform particular cognitive tasks typically implicate a wide expanse of potentially contributing areas, rather than just a single brain area. Conversely, evidence from more targeted interventions, such as transcranial magnetic stimulation (TMS) or invasive microstimulation of the brain, or selective study of patients with highly focal brain damage, can sometimes indicate that a single brain area may make a key contribution to a particular cognitive process. But this in turn raises questions about how such a brain area may interface with other interconnected areas within a more extended network to support cognitive processes. Here, we provide a brief overview of new approaches that seek to characterise the causal role of particular brain areas within networks of several interacting areas, by measuring the effects of manipulations for a targeted area on function in remote interconnected areas. In human participants, these approaches include concurrent TMS-fMRI and TMS-EEG, as well as combination of the focal lesion method in selected patients with fMRI and/or EEG measures of the functional impact from the lesion on interconnected intact brain areas. Such approaches shed new light on how frontal cortex and parietal cortex modulate sensory areas in the service of attention and cognition, for the normal and damaged human brain

Terapie non farmacologiche nel trattamento dei disturbi del comportamento in anziani con demenza: massaggio della mano e conversazionalismo a confronto

Le terapie non farmacologiche hanno mostrato effetti significativi nella riduzione dei disturbi del comportamento in anziani con demenza (Cohen-Mansfield, 2001). Obiettivo del presente lavoro è comparare l’efficacia di due approcci non farmacologici nel trattamento dei disturbi comportamentali in anziani con demenza di Alzheimer moderatamente compromessi. 22 persone, con diagnosi di demenza di Alzheimer di grado moderato, frequentanti il centro diurno, sono state casualmente assegnate a due gruppi di trattamento: massaggio alla mano e tecniche conversazionali. Ciascun gruppo ha preso parte a due sessioni settimanali di intervento per una durata complessiva di 4 settimane. L’efficacia dei due trattamenti è stata valutata in termini di riduzione della sintomatologia comportamentale mediante l’utilizzo di appositi strumenti di misura (Neuropsychiatric Inventory-NPI- e Agitated Behavior Scale-ABS). Entrambi i gruppi mostrano, in generale, una significativa riduzione dei disturbi del comportamento. Tuttavia si rilevano alcune differenze in termini di efficacia in alcuni degli aspetti comportamentali indagati

Efficacia a breve e lungo termine del protocollo Spector, presso la residenza protetta

Aimee Spector dal 2001, attraverso una serie di studi randomizzati controllati, sviluppa e dimostra l’efficacia di un protocollo di stimolazione cognitiva per persone affette da demenza di grado lieve-moderato (Spector et al., 2006). Il presente studio, i cui dati preliminari sono stati presentati lo scorso anno, si è proposto di verificare in un campione di 39 grandi vecchi con demenza l’efficacia del protocollo Spector e confermare quanto già riportato in letteratura (Woods et al., 2012). Si è però inteso ovviare ai limiti metodologici degli studi precedenti comparando l’efficacia del protocollo con un gruppo di controllo attivo impiegato in attività alternative ma comparabili, per numero di sessioni, a quelle svolte dal gruppo sperimentale. Sono state poi introdotte prove volte ad indagare l’eventuale miglioramento in aree quasi o completamente nuove nell’ambito della stimolazione cognitiva in anziani con demenza come il linguaggio. Nello specifico, quindi, è stata valutata l’efficacia a breve e lungo termine (follow-up a 3 mesi) in prove volte ad indagare il funzionamento cognitivo globale, il tono dell’umore, aspetti comportamentali, qualità di vita e abilità di produzione linguistica. Si riportano i risultati ormai definitivi dello studio e vengono discussi ex novo i risultati relativi al mantenimento nel tempo (follow-up a tre mesi) dei benefici ottenuti

INFLUENZA DELLA CHIMICA DELL’ACQUA DI POROSITA’ SULLE CARATTERISTICHE FISICHE DEI TERRENI TRATTATI A CALCE

Nella presente nota si riportano i risultati di un’indagine sperimentale finalizzata alla valutazione dell’influenza della chimica dell’acqua di porosità sulle caratteristiche fisiche dei terreni trattati a calce. Lo studio si inserisce in una più ampia attività di ricerca mirata all’approfondimento dei meccanismi di interazione di natura chimico-fisica che si sviluppano a livello particellare al fine di indagare gli effetti indotti sullo stato di aggregazione (microstruttura) e sulle caratteristiche fisiche dei terreni trattati