Background: Neuroimaging strategies are essential to locate, to elucidate the etiology, and to the follow up of brain disease patients. Magnetic resonance imaging (MRI) provides good cerebral soft-tissue contrast detection and diagnostic sensitivity. Inflammatory lesions and tumors are common brain diseases that may present a similar pattern of a cerebral ring enhancing lesion on MRI, and non-enhancing core (which may reflect cystic components or necrosis) leading to misdiagnosis. Texture analysis (TA) and machine learning approaches are computer-aided diagnostic tools that can be used to assist radiologists in such decisions. Methods: In this study, we combined texture features with machine learning (ML) methods aiming to differentiate brain tumors from inflammatory lesions in magnetic resonance imaging. Retrospective examination of 67 patients, with a pattern of a cerebral ring enhancing lesion, 30 with inflammatory, and 37 with tumoral lesions were selected. Three different MRI sequences and textural features were extracted using gray level co-occurrence matrix and gray level run length. All diagnoses were confirmed by histopathology, laboratorial analysis or MRI. Results: The features extracted were processed for the application of ML methods that performed the classification. T1-weighted images proved to be the best sequence for classification, in which the differentiation between inflammatory and tumoral lesions presented high accuracy (0.827), area under ROC curve (0.906), precision (0.837), and recall (0.912). Conclusion: The algorithm obtained textures capable of differentiating brain tumors from inflammatory lesions, on T1-weghted images without contrast medium using the Random Forest machine learning classifier.

Background and purpose Thrombotic microangiopathy (TMA) is a group of microvascular occlusive disorders that presents with neurological involvement in up to 87% of the cases. Although the central nervous system (CNS) is an important target organ in TMA, the role of neurological manifestations in the disease clinical course is not well established. In this study, we described the neurological manifestations and CNS radiological aspects in patients with a first, acute TMA event. We also examined the association between severe neurological involvement and adverse clinical outcomes in TMA. Methods A cohort of patients diagnosed with a first TMA event between 1995 and 2016 was included, their medical charts and imaging tests were retrospectively evaluated. Results A total of 49 patients were included, 85.7% were women and the mean age was 36.5 years-old (SD 13.0). Neurological manifestations were described in 85.7% of the patients, most of them (88%) were considered severe and consisted of confusion, compromised sensorimotor function, stupor, seizures, and personality change. Imaging tests were performed in 62% of the patients with neurological manifestations and detected acute CNS lesions, such as posterior reversible encephalopathy syndrome, hemorrhagic and ischemic stroke were observed, in 7 (27%) of them. While the need for intensive care unit admission was greater and longer among patients with severe neurological manifestations, the number of plasma exchange sessions, the total duration of hospitalization and in-hospital death were similar between groups. Conclusions Severe neurological manifestations are common in first TMA events and are responsible for a worse disease presentation at admission. While the effect of neurological manifestations on acute TMA clinical course seems to be modest, these manifestations may have an important impact on the development of chronic cognitive impairment, which highlights the need for proper diagnosis and treatment.

Idiopathic intracranial hypertension is characterized by increased intracranial pressure, headache, and visual perturbations. Although the pathophysiology of idiopathic intracranial hypertension is obscure, several mechanisms have been proposed, such as increased cerebral blood volume, excessive cerebrospinal fluid volume (due to high production or impaired resorption), and inflammatory mechanisms as a likely cause of or contributor to impaired cerebrospinal fluid circulation. It predominantly affects women of reproductive age who are overweight or obese. The most common symptoms are daily headache, synchronous pulsatile tinnitus, transient visual perturbations, and papilledema with visual loss. The main neuroimaging findings are a partially empty sella turcica; flattening of the posterior sclera; transverse sinus stenosis (bilateral or in the dominant sinus); a prominent perioptic subarachnoid space, with or without optic nerve tortuosity; and intraocular protrusion of the optic nerve head. The main complication of idiopathic intracranial hypertension is visual loss. Within this context, neuroimaging is a crucial diagnostic tool, because the pathology can be reversed if properly recognized and treated early.

The PLASMIC score was recently developed for rapid diagnosis of thrombotic thrombocytopenic purpura (TTP) and therapeutic decision, as ADAMTS13 is frequently unavailable. The score consists of a scale from 1 to 7 that considers clinical and laboratory factors. PLASMIC score 6 - 7, 4 - 5 and below 4 are associated with high, intermediate and low probability of ADAMTS13 deficiency, respectively. Although the PLASMIC score is validated to predict ADAMTS13 values, its role as a predictor of adverse clinical outcomes in TTP is not established. The primary aim of this study was to evaluate whether the PLASMIC score is associated with neurological complications during TTP episodes. We also evaluated the association of the score with treatment outcomes, such as number of plasma exchange procedures, need for a second line immunosuppression therapy, days in hospital and death. In the present study, we retrospectively applied the PLASMIC score at the time of diagnosis of TTP episodes treated at the UNICAMP Clinical Hospital (University of Campinas - Brazil) between 1995 and 2016. All clinical data were retrieved from medical charts. We grouped the episodes according to the PLASMIC score, calculated at diagnosis, and compared the occurrence of neurological symptoms and other clinical manifestation between the PLASMIC score groups. The association between the PLASMIC score and neurological symptoms was evaluated by regression analysis. A total of 50 episodes of TTP were identified, of these 47 episodes, and 34 patients, were included in the study. Three episodes were excluded due to lack of clinical data. Twenty-seven (79.4%) patients were women, and the mean age was 35.7 years (SD 12.7). At the diagnosis, the mean PLASMIC score was 6, no PLASMIC score below 4 was detected, and the most common clinical features were thrombocytopenia (mean platelet count = 21,029 x 109 / L [SD 18,371 x 109]) and reticulocytosis (mean count = 7.83% [SD 5.29]). Plasma exchange was the main treatment in 98% of the episodes and an immunosuppression therapy was used in 94% of the cases. In 74.5% of the episodes, the patients presented with neurological symptoms at diagnosis or during hospitalization. Clinical features at diagnosis and during hospitalization of all TTP episodes, and of TTP episodes grouped according to the initial PLASMIC score, are presented in Table 1. The incidence of neurological symptoms was higher in PLASMIC score 7 (n= 14 [87, 5%]) and 6 (18 [81, 8%]) when compared with scores 5 (n=1, [16.7%) and 4 (n= 2 (66.7%]). The neurological complications tended to be more severe in PLASMIC scores 6 and 7. Personality change was reported in 2 (9%) TTP episodes in which the PLASMIC score was 6, in 4 (25%) episodes in which the PLASMIC score was 7 and was not reported in PLASMIC scores 4 and 5. Sensitivity loss was reported in 1 (16%) TTP episode in which the PLASMIC score was 5, in 11 (50%) episodes in which the PLASMIC score 6, and in 10 (62%) episodes in which the PLASMIC score was 7 . Seizures were reported in 3 (13.6%) TTP episodes in which the PLASMIC score was 6, in 5 (31.2%) episodes in PLASMIC score 7 and was not reported in PLASMIC scores 4 and 5. Stupor or coma were reported only in PLASMIC scores 6 [n=7 (31%]) and 7 (n= 9 [56%]). The mean number of plasma exchange procedures was 10.67 (SD=4.93) in PLASMIC score 4, 5 (SD=4.94) in PLASMIC score 5, 18.38 (10.61) in PLASMIC score 6 and 7.94 (SD=5.27) in PLASMIC score 7. The length of hospitalization and the days in intensive care unit were similar between groups. Deaths during hospitalization occurred only in cases with PLASMIC score 6 or 7. In the regression analysis, the risk of neurological complications was 9.0-fold increased (95%CI 1.6 - 52.3) in PLASMIC score 6 and was 14-fold increased (95%CI 1.8 - 106.5) in PLASMIC score 7, when compared with PLASMIC score 4 and 5. The risk of severe neurological complications was also higher in PLASMIC score 6 (odds ratio 12.0, 95% CI 1.7 - 83.5) and 7 (odds ratio 18.0, 95% CI 2.0 - 161.0) as compared to PLASMIC score 4 and 5. In conclusion, the frequency and severity of neurological injuries increased with higher PLASMIC scores. These observations suggest that further attention to neurological complications are needed when PLASMIC score is 6 or 7. Awareness of the risk of neurological complications may also improve treatment. Therefore, the PLASMIC score may be an important tool not only to predict ADAMTS13 values but also to provide information on prognosis from a neurological point of view. Disclosures No relevant conflicts of interest to declare.

Resumo A hipertensão intracraniana idiopática é caracterizada por aumento da pressão intracraniana, cefaleia e manifestações visuais. Apresenta fisiopatologia incerta, porém, alguns mecanismos já foram propostos, como o aumento do volume sanguíneo cerebral, o excesso de líquor por aumento da produção ou a redução da reabsorção, e mecanismos inflamatórios como fator causal ou mesmo determinando limitação na circulação do líquor. Predomina em mulheres obesas em idade reprodutiva. Os sintomas e sinais mais comuns são cefaleia diária, zumbido síncrono ao pulso, obscurecimentos visuais transitórios e papiledema com perda visual. Os principais achados em neuroimagem são: sela turca vazia, achatamento posterior do globo ocular/esclera, estenose do seio transverso bilateral ou do seio dominante, distensão do espaço liquórico perióptico com ou sem tortuosidade do nervo óptico e protrusão intraocular da cabeça do nervo óptico. A principal complicação da hipertensão intracraniana idiopática é a perda visual. Nesse contexto, o papel da neuroimagem no diagnóstico é fundamental, pois a doença pode ser revertida se devidamente reconhecida e precocemente tratada.