RESUMO
Our everyday life summons numerous novel sensorimotor experiences, to which our brain needs to adapt in order to function properly. However, tracking plasticity of naturalistic behavior and associated brain modulations is challenging. Here, we tackled this question implementing a prism adaptation-like training in virtual reality (VRPA) in combination with functional neuroimaging. Three groups of healthy participants (N = 45) underwent VRPA (with a shift either to the left/right side, or with no shift), and performed functional magnetic resonance imaging (fMRI) sessions before and after training. To capture modulations in free-flowing, task-free brain activity, the fMRI sessions included resting-state and free-viewing of naturalistic videos. We found significant decreases in spontaneous functional connectivity between attentional and default mode (DMN)/fronto-parietal networks, only for the adaptation groups, more pronouncedly in the hemisphere contralateral to the induced shift. In addition, VRPA was found to bias visual responses to naturalistic videos: Following rightward adaptation, we found upregulation of visual response in an area in the parieto-occipital sulcus (POS) only in the right hemisphere. Notably, the extent of POS upregulation correlated with the size of the VRPA-induced after-effect measured in behavioral tests. This study demonstrates that a brief VRPA exposure can change large-scale cortical connectivity and correspondingly bias visual responses to naturalistic sensory inputs.
Assuntos
Encéfalo , Córtex Cerebral , Humanos , Encéfalo/fisiologia , Córtex Cerebral/fisiologia , Mapeamento Encefálico , Imageamento por Ressonância Magnética/métodos , Adaptação Fisiológica/fisiologiaRESUMO
BACKGROUND: Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiomyopathy characterized by fibrofatty myocardial replacement, and accurate diagnosis can be challenging. The clinical course of patients expressing a severe phenotype of the disease needing heart transplantation (HTx) is not well described in the literature. Therefore, this study aims to describe the clinical and echocardiographic evolution of patients with ACM necessitating HTx. METHODS: We retrospectively studied all patients who underwent HTx in our institution between 1998 and 2019 with a definite diagnosis of ACM according to the explanted heart examination. RESULTS: Ten patients with confirmed ACM underwent HTx. Only four of them had a diagnosis of ACM before HTx. These patients were 28 ± 15 years old at the time of their first symptoms. Patients received a diagnosis of heart failure (HF) after 5.9 ± 8.7 years of symptom evolution. The mean age at transplantation was 40 ± 17 years old. All the patients experienced ventricular tachycardia (VT) at least once before their HTx and 50% were resuscitated after sudden death. The mean left ventricular ejection at diagnosis and before transplantation was similar (32% ± 21% vs. 35.0% ± 19.3%, p = NS). Right ventricular dysfunction was present in all patients at the time of transplantation. CONCLUSION: Patients with ACM necessitating HTx show a high burden of ventricular arrhythmias and frequently present a biventricular involvement phenotype, making early diagnosis challenging. HF symptoms are the most frequent reason leading to the decision to transplant.
Assuntos
Displasia Arritmogênica Ventricular Direita , Transplante de Coração , Humanos , Estudos Retrospectivos , Displasia Arritmogênica Ventricular Direita/diagnóstico por imagem , Displasia Arritmogênica Ventricular Direita/etiologia , Arritmias Cardíacas/etiologia , Ecocardiografia , Transplante de Coração/efeitos adversosRESUMO
BACKGROUND: Patients with liver cirrhosis are generally considered ineligible for isolated cardiac transplantation or left ventricular assist device (LVAD) implantation. The aim of this retrospective study is to explore the diagnostic value of abdominal ultrasound, computed tomography scan (CT scan) and liver-spleen scintigraphy to detect the presence of cirrhosis in patients with advanced heart failure. METHODS: Among 567 consecutive patients who underwent pre-transplantation or LVAD evaluation, 54 had a liver biopsy to rule out cardiac cirrhosis; we compared the biopsy results with the imaging investigations. RESULTS: In about 26% (n = 14) of patients undergoing liver biopsy, histopathological evaluation identified cirrhosis. The respective sensitivity of abdominal ultrasound, CT scan and liver-spleen scintigraphy to detect cirrhosis was 57% [29-82], 50% [16-84], and 25% [3-65]. The specificity was 80% [64-91], 89% [72-98], and 44% [20-70], respectively. CONCLUSION: Ultrasonography has the best-combined sensitivity and specificity for the diagnosis of cirrhosis. However, more than a third of patients with cirrhosis will go undiagnosed by conventional imaging. As liver biopsy is associated with a low rate of complication, it should be considered in patients with a high-risk of cirrhosis or with evidence of portal hypertension to assess their eligibility for heart transplantation or LVAD implantation.