Follow the sound of my violin: Granger causality reflects information flow in sound.

Recent research into how musicians coordinate their expressive timing, phrasing, articulation, dynamics, and other stylistic characteristics during performances has highlighted the role of predictive processes, as musicians must anticipate how their partners will play in order to be together. Several studies have used information flow techniques such as Granger causality to show that upcoming movements of a musician can be predicted from immediate past movements of fellow musicians. Although musicians must move to play their instruments, a major goal of music making is to create a joint interpretation through the sounds they produce. Yet, information flow techniques have not been applied previously to examine the role that fellow musicians' sound output plays in these predictive processes and whether this changes as they learn to play together. In the present experiment, we asked professional violinists to play along with recordings of two folk pieces, each eight times in succession, and compared the amplitude envelopes of their performances with those of the recordings using Granger causality to measure information flow and cross-correlation to measure similarity and synchronization. In line with our hypotheses, our measure of information flow was higher from the recordings to the performances than vice versa, and decreased as the violinists became more familiar with the recordings over trials. This decline in information flow is consistent with a gradual shift from relying on auditory cues to predict the recording to relying on an internally-based (learned) model built through repetition. There was also evidence that violinists became more synchronized with the recordings over trials. These results shed light on the planning and learning processes involved in the aligning of expressive intentions in group music performance and lay the groundwork for the application of Granger causality to investigate information flow through sound in more complex musical interactions.

Creating a shared musical interpretation: Changes in coordination dynamics while learning unfamiliar music together.

The ability to coordinate with others is fundamental for humans to achieve shared goals. Often, harmonious interpersonal coordination requires learning, such as ensemble musicians rehearing together to synchronize their low-level timing and high-level aesthetic musical expressions. We investigated how the coordination dynamics of a professional string quartet changed as they learned unfamiliar pieces together across eight trials. During all trials, we recorded each musician's body sway motion data, and quantified the group's body sway similarity (cross-correlation) and information flow (Granger causality) on each trial. In line with our hypothesis, group similarity increased, while group information flow decreased significantly across trials. In addition, there was a trend such that group similarity, but not information flow, was related to the quality of the performances. As the ensemble converged on a joint interpretation through rehearsing, their body sways reflected the change from interpersonal information flow for coordinative mutual adaptations and corrections, to synchronous musical coordination made possible by the musicians learning a common internally based expressive interpretation.

Vocal-motor interference eliminates the memory advantage for vocal melodies.

Spontaneous motor cortical activity during passive perception of action has been interpreted as a sensorimotor simulation of the observed action. There is currently interest in how sensorimotor simulation can support higher-up cognitive functions, such as memory, but this is relatively unexplored in the auditory domain. In the present study, we examined whether the established memory advantage for vocal melodies over non-vocal melodies is attributable to stronger sensorimotor simulation during perception of vocal relative to non-vocal action. Participants listened to 24 unfamiliar folk melodies presented in vocal or piano timbres. These were encoded during three interference conditions: whispering (vocal-motor interference), tapping (non-vocal motor interference), and no-interference. Afterwards, participants heard the original 24 melodies presented among 24 foils and judged whether melodies were old or new. A vocal-memory advantage was found in the no-interference and tapping conditions; however, the advantage was eliminated in the whispering condition. This suggests that sensorimotor simulationduring the perception of vocal melodies is responsible for the observed vocal-memory advantage.

Short-Term Choir Singing Supports Speech-in-Noise Perception and Neural Pitch Strength in Older Adults With Age-Related Hearing Loss.

Prior studies have demonstrated musicianship enhancements of various aspects of auditory and cognitive processing in older adults, but musical training has rarely been examined as an intervention for mitigating age-related declines in these abilities. The current study investigates whether 10 weeks of choir participation can improve aspects of auditory processing in older adults, particularly speech-in-noise (SIN) perception. A choir-singing group and an age- and audiometrically-matched do-nothing control group underwent pre- and post-testing over a 10-week period. Linear mixed effects modeling in a regression analysis showed that choir participants demonstrated improvements in speech-in-noise perception, pitch discrimination ability, and the strength of the neural representation of speech fundamental frequency. Choir participants' gains in SIN perception were mediated by improvements in pitch discrimination, which was in turn predicted by the strength of the neural representation of speech stimuli (FFR), suggesting improvements in pitch processing as a possible mechanism for this SIN perceptual improvement. These findings support the hypothesis that short-term choir participation is an effective intervention for mitigating age-related hearing losses.

Management of Aortic Aneurysms: Is Surgery of Historic Interest Only?

Since its advent in 1991, endovascular aortic aneurysm repair (EVAR) has become a mainstay of treatment for abdominal aortic aneurysms (AAA). Studies such as the comparison of endovascular aneurysm repair with open repair in patients with abdominal aortic aneurysm (EVAR 1) trial, have demonstrated the effectiveness of EVAR in reducing perioperative mortality. Technological improvements in graft design and delivery account for an increasing utilization of endovascular repair. Newer branch and fenestrated graft designs have allowed for treatment of patients with complex aortic anatomy that previously could not be treated with EVAR. Endovascular repair, while dominant, is unlikely to eliminate the need for open repair or to relegate open surgery for AAA to historical interest only. The unprecedented adoption of EVAR has led to complications and modes of failure that were not seen with open repair. The rate of failure is markedly increased when endografts are used outside of the instructions for use (IFU). The long-term durability of fenestrated and investigational branch devices remains to be established. The demand for an endovascular approach by patients and the willingness of physicians to place endografts outside the anatomic IFU criteria may have resulted in the pendulum swinging too far away from open surgical management. The consequence of reduced open aortic surgeries is a concern for both patient care as well as training for vascular surgery fellows. Vascular surgery training programs will require innovative changes in training to assure that vascular surgery trainees will have the requisite skill and experience required to competently perform open surgical repair on what will undoubtedly be some of the most complex aortic pathology.

Reporting the impact of inferior vena cava perforation by filters.

BACKGROUND: Perforation of the inferior vena cava by filters struts is a known complication. The goal of our review is to assess the impact of inferior vena cava perforation by filters based on an open, voluntary national database. METHODS: We reviewed 3311 adverse events of inferior vena cava filters reported in Manufacturer and User Facility Device Experience database from January 2000 to June 2011. Outcomes of interest were incidence of inferior vena cava perforation, type of filter, clinical presentation, and management of the perforation, including retrievability rates. RESULTS: Three hundred ninety-one (12%) cases of inferior vena cava perforation were reported. The annual distribution of inferior vena cava perforation was 35 cases (9%), varying from seven (2%) to 70 (18%). A three-fold increment in the number of adverse events related to inferior vena cava filters has been noted since 2004. Wall perforation as an incidental finding was the most common presentation (N = 268, 69%). Surrounding organ involvement was found in 117 cases (30%), with the aorta being the most common in 43 cases (37%), followed by small bowel in 36 (31%). Filters were retrieved in 97 patients (83%) regardless of wall perforation. Twenty-five (26%) cases required an open procedure to remove the filter. Neither major bleeding requiring further intervention nor mortality was reported. CONCLUSIONS: Inferior vena cava perforation by filters remains stable over the studied years despite increasing numbers of adverse events reported. The majority of filters involved in a perforation were retrievable. Filter retrieval, regardless of inferior vena cava wall perforation, is feasible and must be attempted whenever possible in order to avoid complications.

Endovascular strategy for recanalization of long-segment central vein occlusion with concomitant arteriovenous fistula creation.

Recanalization of long-segment central vein flush occlusion in hemodialysis patients has been advocated in lieu of central vein bypass and thoracotomy to restore arteriovenous access availability. We report a challenging case of complex central venous flush occlusion in a 50-year-old woman on hemodialysis who presented with right arm and facial swelling. A concise step-by-step description of endovascular strategy with retrograde and antegrade balloon angioplasty techniques for central vein recanalization with concomitant arteriovenous fistula creation is provided.

Stratifying risk: asymptomatic carotid disease / Estratificação do risco na doença carotídea assintomática

Stroke generates significant healthcare expenses and it is also a social and economic burden. The carotid artery atherosclerotic plaque instability is responsible for a third of all embolic strokes. The degree of stenosis has been deliberately used to justify carotid artery interventions in thousands of patients worldwide. However, the annual risk of stroke in asymptomatic carotid artery disease is low. Plaque morphology and its kinetics have gained ground to explain cerebrovascular and retinal embolic events. This review provides the readers with an insightful and critical analysis of the risk stratification of asymptomatic carotid artery disease in order to assist in selecting potential candidates for a carotid intervention.

O acidente vascular encefálico gera custos significativos na área da saúde e representa um problema social e econômico. A instabilidade da placa carotídea aterosclerótica é responsável por um terço dos acidentes vasculares encefálicos embólicos. O grau de estenose tem sido usado para justificar, deliberadamente, intervenções carotídeas em milhares de pacientes no mundo todo. No entanto, o risco anual de acidente vascular encefálico em doença carotídea assintomática é baixo. A morfologia da placa e sua mobilidade têm ganhado importância na elucidação dos eventos embólicos cerebrovasculares e retinais. Esta revisão proporciona aos leitores uma análise crítica e inteligente da estratificação de risco da doença carotídea assintomática com o intuito de auxiliar na seleção de potenciais candidatos à intervenção carotídea.

Diagnosing common carotid artery agenesis using duplex ultrasound.

The complete absence of a common carotid artery, also known as common carotid artery (CCA) agenesis, is a well-described yet extremely rare congenital anomaly. Most carotid system anomalies are related to origins of the external or internal carotid arteries. All such anomalies are typically asymptomatic unless associated with a concomitant arterial lesion that results in a workup for symptomatic intracerebral pathology or a focal neurological deficit. The literature is scant on the topic, being limited to singular case reports. We report 3 cases of CCA agenesis and provide the readers with insightful data on the available literature.