Characterizing the discriminability of visual categorical information in strongly connected voxels.

Functional brain responses are strongly influenced by connectivity. Recently, we demonstrated a major example of this: category discriminability within occipitotemporal cortex (OTC) is enhanced for voxel sets that share strong functional connectivity to distal brain areas, relative to those that share lesser connectivity. That is, within OTC regions, sets of 'most-connected' voxels show improved multivoxel pattern discriminability for tool-, face-, and place stimuli relative to voxels with weaker connectivity to the wider brain. However, understanding whether these effects generalize to other domains (e.g. body perception network), and across different levels of the visual processing streams (e.g. dorsal as well as ventral stream areas) is an important extension of this work. Here, we show that this so-called connectivity-guided decoding (CGD) effect broadly generalizes across a wide range of categories (tools, faces, bodies, hands, places). This effect is robust across dorsal stream areas, but less consistent in earlier ventral stream areas. In the latter regions, category discriminability is generally very high, suggesting that extraction of category-relevant visual properties is less reliant on connectivity to downstream areas. Further, CGD effects are primarily expressed in a category-specific manner: For example, within the network of tool regions, discriminability of tool information is greater than non-tool information. The connectivity-guided decoding approach shown here provides a novel demonstration of the crucial relationship between wider brain connectivity and complex local-level functional responses at different levels of the visual processing streams. Further, this approach generates testable new hypotheses about the relationships between connectivity and local selectivity.

Inherited myopathies in patients from Sub-Saharan Africa: Results from a retrospective cohort.

The clinical epidemiology of inherited myopathies in sub-Saharan Africa (SSA) is unknown but likely underdiagnosed due to problems of scientific research and social issues. We report a case series of patients born in SSA, evacuated to Portugal through an international health protocol and seen at a single neuromuscular disorders centre, between January/2004 and August/2021. We identified 9 patients (5 males), 35.6 ± 19.3 years-old (10-64), from Cape Verde (n = 4), Angola (n = 2), Sao Tome and Principe (n = 2) and Guinea-Bissau (n = 1), with a delay in diagnosis of 19.7 ± 14.3 years. Seven patients (77.8 %) had positive family history. Most patients had significant morbidity, requiring wheelchair (55.6 %), and nocturnal non-invasive ventilation (55.6 %). The diagnosis included Bethlem myopathy (n = 2), Duchenne muscular dystrophy (n = 2), Emery-Dreifuss muscular dystrophy (n = 1), LGMDR1 (n = 2), LGMDR2 (n = 1), and type-1 myotonic dystrophy (n = 1). Genetic testing was remarkable for 3 mutations previously not described. Despite the small sample, the spectrum of hereditary myopathies in our cohort is like western studies. Further studies are needed to better understand the epidemiology of muscle diseases in SSA.

Neurological Complications of Infective Endocarditis.

PURPOSE OF REVIEW: The purpose of this narrative review and update is to summarize the current knowledge and provide recent advances on the neurologic complications of infective endocarditis. RECENT FINDINGS: Neurological complications occur in about one-fourth of patients with infective endocarditis. Brain MRI represents a major tool for the identification of asymptomatic lesions, which occur in most of the patients with infective endocarditis. The usefulness of systematic brain imaging and the preferred treatment of patients with infective endocarditis and silent brain lesions remains uncertain. The basis of treatment of infective endocarditis is early antimicrobial therapy. In stroke due to infective endocarditis, anticoagulation and thrombolysis should be avoided. Endovascular treatment can be useful for both acute septic emboli and mycotic aneurysms, but evidence is still limited. In patients with neurological complications, cardiac surgery can be safely performed early, if indicated. The optimal management of a patients with neurological complications of infective endocarditis needs an individualized case discussion and the participation of a multidisciplinary team including neurologists, cardiologists, cardiothoracic surgeons, neuroradiologists, neurosurgeons, and infectious disease specialists.

Neurological Complications of Cardiac Tumors.

PURPOSE OF REVIEW: This article reviews recent literature regarding the neurological manifestations of cardiac tumors, including diagnosis, pathophysiology, and treatment. RECENT FINDINGS: Clinical cases of patients with acute ischemic stroke due to cardiac tumors who were treated with intravenous alteplase show a favorable safety profile. Mechanical thrombectomy seems to be a reasonable treatment alternative for these patients, when there is a large vessel occlusion. Histopathology analysis of mechanical thrombectomy specimens may allow the diagnosis of a cardiac tumor. Prolonged time interval between stroke and tumor excision surgery is significantly associated with stroke recurrence. Myxomatous aneurysms are a late complication of cardiac myxomas, which commonly demand imaging follow-up after excision of the primary tumor. Aneurysms are more frequent in patients who present with other embolic complications. Conservative treatment of myxomatous aneurysms is a reasonable strategy, as the majority of aneurysms remain stable over many years. Spontaneous regression of these formations has been documented after excision of the primary tumor. Other complications recently described include acute psychosis and mononeuropathy multiplex. Cardiac tumors are rare. There are mainly case reports and retrospective case series describing the neurological manifestations of cardiac tumors. Hyperacute stroke treatment seems to be safe, and mechanical thrombectomy is a reasonable treatment. A conservative approach towards myxomatous aneurysms should be considered.