Andréia V. Faria

Cerebral venous thrombosis: influence of risk factors and imaging findings on prognosis.

PURPOSE To investigate imaging findings, risk factors and outcome in patients with cerebral venous thrombosis (CVT). METHODS Records of all patients with diagnosis of CVT between 1992 and 2002 were reviewed. Patients with CNS infection and with CVT secondary to invasive procedures were excluded. Inherited and acquired thrombophilia were searched in all patients. RESULTS Twenty-four patients (18 women, 6 men) with mean age of 29.5 years (range 3-48 years) were identified. Mean follow-up was 44 months (range 11-145 months). The most common symptoms were headache (75%), vomiting (33%) and impairment of consciousness (21%). Probable causes of CVT could be determined in 21 (88%) patients: pregnancy or puerperium in six (25%), oral contraceptive use in four (17%), head trauma in two (8%), mastoiditis in one (4%), nephrotic syndrome in one (4%), systemic disease in three (13%), and inherited thrombotic risk factors in four (17%) patients. CVT associated with pregnancy, puerperium and use of oral contraceptives had a significant better outcome than CVT caused by inherited thrombophilia or systemic disease (OR=14.4; p=0.02). CT scans were abnormal in 15 (62.5%) patients and MRI with gadolinium was abnormal in all. Those with parenchymal involvement had neurological sequelae during follow-up. All were treated with heparin followed by oral anticoagulants, and none had new or worsening of pre-existing intracerebral hemorrhage. CONCLUSION MRI is superior to conventional CT for diagnosing CVT. Patients with parenchymal lesions, thrombophilia and antiphospholipid syndrome had greater risk to be left with neurological sequelae. Anticoagulant therapy did not predispose to further intracerebral hemorrhage.

Neuroimaging in Pineal Tumors

Background and Purpose. The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. Methods. Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. Results. CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2‐weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. Conclusions. Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread.

Dissemination patterns of pilocytic astrocytoma

Two patients with multifocal pilocytic astrocytoma diagnosed by magnetic resonance imaging (MRI) and confirmed by histopathological examination are reported. They presented distinct sites and mechanisms of metastasis: to distant ventricles through the cerebral spinal fluid (CSF) in patient 1 and to contralateral parenchyma, possibly through white matter tracts, in patient 2, a pathway not so far reported in pilocytic astrocytoma. Early detection of multifocal pilocytic astrocytoma by MRI may change treatment strategies and improve prognosis.

MRI shows dorsal lesions and spinal cord atrophy in chronic sensory neuronopathies

Sensory neuronopathies (SN) represent a specific subgroup of peripheral nervous system diseases, characterized by degeneration of dorsal root ganglia (DRG) and its projections. We tried to estimate the frequency and extent of spinal cord MRI abnormalities in a group of patients with SN and correlate these with clinical and neurophysiological features.

Larva migrans: a case report and review

A case of massive Ancylostoma sp. larval infestation is presented in a patient who had received systemic corticosteroid therapy. What attracts attention in this case is the exuberance and rarity of clinical manifestation. Based on the pertinent literature, we discuss the mechanisms of parasital infection, the natural history of the disease and its treatment.

MRI findings in the diagnosis and monitoring of Rasmussen's encephalitis.

Rasmussens encephalitis is a devastating syndrome of multifocal brain dysfunction and focal seizures. Magnetic resonance (MR) findings, associated with clinical data and electroencephalogram (EEG), may indicate the diagnosis and could be an indicative of prognosis. We studied 5 patients with Rasmussens encephalitis, assessing clinical history and MR images. All patients had refractory focal seizures with a predominant motor component associated with hemispheric atrophy, that was proportional to severity of disease and neurological deficits in these patients. Gray and white matter abnormal signal on T2 MR images were found in patients who had hemiparesis. It was not related to the duration of the disease but to aggressiveness. MR proton spectroscopy in severe disease showed lactate and choline increase and decreased NAA, reflecting neuronal and axonal loss, gliosis and elevated membrane turnover and recent - crisis (not controlled). MR studies, in addition to help in diagnosis, may be useful for monitoring metabolic changes and progression of disease in Rasmussens encephalitis.

Magnetic resonance spectroscopy in the diagnosis and etiological definition of brain bacterial abscesses

We report two patients with bacterial brain abscesses whose etiological diagnosis was correctly proposed by association of diffusion weighted images (DWI) and magnetic resonance spectroscopy (MRS) with conventional MRI. Both patients presented ring enhancing lesions with evidences of restricted diffusion. On MRS, the abscess caused by aerobic bacteria presented lactate and aminoacids peaks and the abscess caused by anaerobic facultative bacteria showed also acetate and succinate peaks. These results are in agreement with an unique previous study that related MRS pattern with bacterial etiology. Conventional MRI, associated with DWI and MRS is effective in diagnosing bacterial abscess and promising in exploring its etiology.

Myositis with sensory neuronopathy

Inflammatory myopathies (IM) are a heterogeneous group of diseases characterized by immune‐mediated damage to skeletal muscle. Sensory abnormalities are rare in patients with IM. We report two patients, one with dermatomyositis and the other with inclusion‐body myositis, who presented with unexpected sensory abnormalities due to probable immune‐mediated damage to dorsal root ganglia. We emphasize the importance of combined neuroimaging and neurophysiological assessment for proper diagnosis. Muscle Nerve, 2007

The pattern of proton magnetic resonance spectroscopy in non-neoplastic encephalic lesions.

The purpose of this article is show the role of proton magnetic resonance spectroscopy (MRS), associated with magnetic resonance images, in the study of non-neoplastic disorders, helping in diagnosis and better characterization of the nature of the lesion. Herein, we analyzed single voxel proton spectroscopy in eight different non-neoplastic lesions, displayed in six categories (infectious, ischaemic, demyelinating, inflammatory, malformation of development and phacomatosis). The presence or the ratios of signal intensities brain tissue metabolites observed with this technique (N-acetyl aspartate, choline, creatine, lactate and lipids) helped in their differentiation with neoplastic lesions and helped in correct diagnosis. In infectious diseases, signals of acetate, succinate and amino acids were also important. In conclusion, proton MRS is a noninvasive method, very useful as an additional technique to define the nature of non-neoplastic encephalic lesions.

Manual and semi-automatic quantification of in vivo ¹H-MRS data for the classification of human primary brain tumors

In vivo proton magnetic resonance spectroscopy (¹H-MRS) is a technique capable of assessing biochemical content and pathways in normal and pathological tissue. In the brain, ¹H-MRS complements the information given by magnetic resonance images. The main goal of the present study was to assess the accuracy of ¹H-MRS for the classification of brain tumors in a pilot study comparing results obtained by manual and semi-automatic quantification of metabolites. In vivo single-voxel ¹H-MRS was performed in 24 control subjects and 26 patients with brain neoplasms that included meningiomas, high-grade neuroglial tumors and pilocytic astrocytomas. Seven metabolite groups (lactate, lipids, N-acetyl-aspartate, glutamate and glutamine group, total creatine, total choline, myo-inositol) were evaluated in all spectra by two methods: a manual one consisting of integration of manually defined peak areas, and the advanced method for accurate, robust and efficient spectral fitting (AMARES), a semi-automatic quantification method implemented in the jMRUI software. Statistical methods included discriminant analysis and the leave-one-out cross-validation method. Both manual and semi-automatic analyses detected differences in metabolite content between tumor groups and controls (P < 0.005). The classification accuracy obtained with the manual method was 75% for high-grade neuroglial tumors, 55% for meningiomas and 56% for pilocytic astrocytomas, while for the semi-automatic method it was 78, 70, and 98%, respectively. Both methods classified all control subjects correctly. The study demonstrated that ¹H-MRS accurately differentiated normal from tumoral brain tissue and confirmed the superiority of the semi-automatic quantification method.