Absceso recidivante por Nocardia asteroides en una paciente portadora de poliglobulia primaria Recurrent brain abscess caused by Nocardia asteroides in a patient with primary polycythaemia

La nocardiosis del sistema nervioso central (SNC) es una enfermedad poco común, cuya frecuencia ha aumentado con el crecimiento de los tratamientos inmunosupresores. El hombre se infecta por inhalación, inoculación traumática cutánea directa y tras una infección periodontal ingiriendo alimentos contaminados. La localización pulmonar es la más frecuente, siendo la fuente inicial de diseminación hemática, con predominio en piel, tejido celular subcutáneo y SNC. Es conocida la predilección de Nocardia por el SNC. Estos abscesos, asociados a altos índices de mortalidad, especialmente en pacientes inmunocomprometidos, siguen constituyendo un desafío diagnóstico y terapéutico, permaneciendo no aclarado su manejo terapéutico óptimo. A pesar de la controversia en cuanto al manejo quirúrgico de estas lesiones, el diagnóstico precoz, por aspiración esterotáxica, y la iniciación de una terapia antimicrobiana son esenciales para la buena evolución del paciente. Se presenta una paciente portadora de una poliglobulia primaria, con absceso cerebral recidivante por Nocardia asteroides de posible origen dentario.<br>Nocardiosis of the central nervous system (CNS) is an uncommon disease, but its frequency has increased due to the high number of immunosuppressive treatments. People become infected by inhalation, direct traumatic cutaneous inoculation and eating contaminated food after a periodontal abscess. Lung localization is the most frequent one, being the origin of haematic dissemination, with a high incidence in skin, subcutaneous tissue and the CNS. The preference of Nocardia for the CNS is well-known. These abscesses are a diagnostic and therapeutic challenge, since they are associated to high mortality rates, specially in immunocompromised patients; the best therapeutic management remains unclear. In spite of the existing controversy with regard to the surgical management of these lesions, an early diagnosis through stereotactic aspiration and the beginning of an antimicrobial therapy are essential to the patient’s good evolution. This paper presents a patient with a primary polycythaemia and a recurrent brain abscess by Nocardia asteroides, probably of dental origin

PET in Brain Arteriovenous Malformations and Cerebral Proliferative Angiopathy

A brain arteriovenous malformation (BAVM) is a neurovascular entity that consists of a localized dense network of abnormal blood vessels (a nidus) that holds arteries shunting directly into veins in the absence of a capillary bed. In their natural history, BAVMs carry a risk of hemorrhage or other neurological complications, for which reason they are frequently treated. Cerebral proliferative angiopathy (CPA) is a different type of neurovascular malformation with distinct angiographic and clinical features that can be used to differentiate it from a classical BAVM. The basic difference between CPA and a BAVM is that CPA has normal brain tissue intermingled in between its network of vessels. Treatment of CPA by surgery, radiosurgery, or embolization consequently harbors a high risk of neurological complications. As such, reliable diagnostic discrimination between CPA and BAVM is crucial to adequately treat patients. However, despite the fact that CPA has some characteristic imaging features, the differentiation between CPA and a brain AVM may be difficult. PET imaging as a technique that reveals functional brain tissue is therefore likely to be of additional diagnostic value.<br/