[Show abstract][Hide abstract] ABSTRACT: This paper aimed at studying presentations of the central nervous system (CNS) lymphoma using structural images obtained by magnetic resonance imaging (MRI).
The MRI features at presentation of 15 patients diagnosed with CNS lymphoma in a university hospital, between January 1999 and March 2011, were analyzed by frequency and cross tabulation.
All patients had supratentorial lesions; and four had infra- and supratentorial lesions. The signal intensity on T1 and T2 weighted images was predominantly hypo- or isointense. In the T2 weighted images, single lesions were associated with a hypointense signal component. Six patients presented necrosis, all of them showed perilesional abnormal white matter, nine had meningeal involvement, and five had subependymal spread. Subependymal spread and meningeal involvement tended to occur in younger patients.
Presentations of lymphoma are very pleomorphic, but some of them should point to this diagnostic possibility.
Full-text · Article · Feb 2012 · Arquivos de neuro-psiquiatria
[Show abstract][Hide abstract] ABSTRACT: Meningiomas are common central nervous system tumors with a wide range of morphological variants, assigned World Health Organization (WHO) Grades I - III. We report an extremely rare rhabdoid, papillary and clear cell meningioma (WHO Grade III) in a 29-year-old female, who presented with diplopia and headache over a few days, 2 years ago. Magnetic resonance imaging showed a well-circumscribed, lobulated, predominantly solid and contrast-enhancing lesion in the right temporal, parietal and occipital lobes. On routine staining, the tumor did not display classical meningioma features. A wide immunohistochemical panel ruled out metastasis and endorsed the meningothelial nature of the lesion (positivity for epithelial membrane antigen and vimentin). Electron microscopy did not show usual hallmarks of meningioma but was helpful in excluding other tumors. Even though the three variants are associated with aggressive behavior, the patient is currently asymptomatic. The concurrent use of different techniques was essential for diagnosis.
Preview · Article · Nov 2011 · Clinical neuropathology
[Show abstract][Hide abstract] ABSTRACT: To report the outcome of a patient who developed compartment syndrome after Bothrops jararaca snakebite.
A 39-year-old male was admitted 5 h after being bitten on the lower right leg. Physical examination revealed tense swelling, ecchymosis, hypoesthesia, and intense local pain that worsened after passive stretching, limited right foot dorsiflexion, and gingival bleeding. The case was classified as moderate/severe and eight vials of bothropic antivenom (AV) were infused 1 h postadmission. The main laboratory findings upon admission were incoagulable blood (incoagulable PT, aPTT, and INR), thrombocytopenia, serum creatine kinase (CK) of 580 U/L (reference value < 170 U/L), and a serum venom level of 33.7 ng/mL (ELISA; cutoff = 2.3 ng/mL). High anterior compartment pressure (60 mmHg) was identified 8 h post bite, with progressively lower pressures after AV administration and limb elevation (36 mmHg; 19 h post bite). However, moderate pain and limited foot dorsiflexion persisted. In addition, there was a progressive increase in serum CK (6,729 U/L; 45 h post bite), as well as marked edema and hemorrhage of the anterior compartment detected by magnetic resonance imaging (MRI) at 48 h post bite. A fasciotomy done after a further increase in intracompartmental pressure (66 mmHg, 57 h post bite) revealed hemorrhage/necrosis of the anterior tibial muscle that subsequently required partial resection. The patient developed a local infection (day 15 post bite) and a permanent fibular palsy.
Compartment syndrome is an unusual but severe complication of snakebites. MRI, in conjunction with subfascial pressure measurements, may be useful in the diagnosis of compartment syndrome after snakebites.
No preview · Article · Jan 2010 · Clinical Toxicology
[Show abstract][Hide abstract] ABSTRACT: Rasmussen's 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 Rasmussen's 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 Rasmussen's encephalitis.
Full-text · Article · Sep 2009 · Arquivos de neuro-psiquiatria
[Show abstract][Hide abstract] ABSTRACT: Sensory neuronopathies (SN) are peripheral nervous system disorders associated with degeneration of dorsal root ganglion neurons. Magnetic resonance imaging (MRI) studies have shown abnormalities limited to T2-weighted high signal intensity in the posterior columns.
A 65-year-old woman with Sjögren syndrome had slowly progressive unsteadiness of gait and limb paresthesias. A blink reflex examination suggested a paramedian brainstem lesion, confirmed by MRI.
Sjögren's syndrome-related SN may be associated with a more diffuse immune-mediated aggression, involving also the brainstem, and leading to some of the blink reflex abnormalities observed in nonparaneoplastic SN.
No preview · Article · Jul 2009 · Journal of neuroimaging: official journal of the American Society of Neuroimaging
[Show abstract][Hide abstract] ABSTRACT: Artifacts caused by metallic objects, such as dental crowns, dental implants and metallic orthodontic appliances, are a common problem in head and neck MRI. The aim of this retrospective study was to identify the main metal dental objects that produce artifacts on brain MRIs.
Imaged metallic artifacts and their sources were identified. Artifact image plane was rated on a score of 0 or 1 (0--distinguishable for diagnosis and 1--not distinguishable for diagnosis).
Seventy-eight percent of the artifacts appearing in images were caused by orthodontic appliances, followed by dental titanium implants (18%) and metallic crowns (4%). Orthodontic appliances obtained the highest scores in all planes.
We concluded that is difficult to avoid the effect of metallic artifacts in the maxillofacial regions on brain scan. Removing metallic parts of the orthodontic appliance should ensure diagnostically useful quality scans.
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to review magnetic resonance imaging (MRI) findings in patients with vascular involvement of the central nervous system (CNS) associated with systemic diseases. We reviewed the MRI findings in clinically suspected cases of vascular involvement of the CNS associated with systemic diseases. Vascular CNS involvement was considered in the presence of characteristic clinical, MRI and/or MR angiography findings. In order to be included in the study, patients needed to have a complete clinical and laboratory investigation and a follow-up of a minimum of 6 months. Twenty-four patients (17 women and 7 men), with mean age of 29.5 years had diagnosis of CNS vasculitis and were included. The clinical presentation was variable, but the most common complaints were headache in 18, focal deficits in 9, disturbances of consciousness in 9, and seizures in 8 patients. Underlying causes for CNS vasculitis were identified in all patients and included systemic lupus erythematosus in eight, tuberculosis in three, bacterial meningitis in three, Takayasu arteritis in two, polyarteritis nodosa in two, syphilis in two, drug abuse in two, yellow fever in one and varicella in one patient. Nonspecific high intensity T2WI/FLAIR lesions in white matter were the most common finding, present in ten patients. Eight patients had infarctions in large cerebral arteries territory, associated or not with high intensity T2WI/FLAIR small foci. Vascular involvement of the CNS can be found in a great variety of systemic diseases, including rheumatologic, infectious and drug abuse. Clinical findings are unspecific and MRI/MRA may help to establish the correct diagnosis.
No preview · Article · Oct 2008 · Rheumatology International
[Show abstract][Hide abstract] ABSTRACT: 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.
We performed spinal cord MRI scans in 16 chronic SN patients. Images were analyzed for the presence of posterior hyperintense lesions on T2WI and cord areas at C3 level were obtained using a previously validated method. A group of 14 healthy controls with similar age and gender distribution was used for comparison. ANOVA was employed for statistical analysis.
Posterior T2WI lesions were found in 13 out of 16 patients. Cord areas were significantly smaller in SN patients than controls (84.3 x 97.2 mm(2), P < .05). Atrophy correlated with severity of sensory ataxia and neurophysiologic abnormalities but not with duration of disease.
These findings support volumetric spinal cord MRI as a useful tool in the assessment of chronic SN.
No preview · Article · May 2008 · Journal of Neuroimaging
[Show abstract][Hide abstract] ABSTRACT: 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.
Full-text · Article · Jan 2008 · Arquivos de Neuro-Psiquiatria
[Show abstract][Hide abstract] ABSTRACT: The craniocervical junction (CCJ) comprehends the brainstem, proximal cervical spinal cord and cerebelar structures and is subjected to several congenital anomalies and anatomic variations. Although the morphological abnormalities are present at birth, many patients develop symptoms after third and fourth decades. Magnetic Ressonance Imaging (MRI) analyses were performed for 61 patients with these malformations towards discriminating the degree of compression, elevated signal in fluid sensitive sequences and presence of syringomyelia. The severity of skeletical disturbances correlated with the degree of neural tissue damage, with shorter base skull (represented by basilar hypoplasia) and greater basilar invagination (elevation of odontoid tip) correlating with compression and signals of tissue injury. The small posterior fossa correlated to a higher frequence of tonsilar invagination, and with higher incidence of syringomyelia. Eight patients had brainstem auditory evoked potentials (BAEP) tests. 2 patients did not presented compression of neuro-axis; 2 showed compression and magnetic signal alteration, and 4 presented syringomyelia. One patient with compression and hyperintense signal in fluid sensitive sequences presented the greater delay in intervals I-III and I-V of auditory pathway. All patients with syringomyelia presented longer I-V interval, even after decompressive surgery. All patients with significant compromise to neural tissue showed assynchronic waves on binaural acquisition, with phase shift of wave V. MRI is an important tool to assess the morphological abnormalities of craniocervical junction. The discrepance between the duration of compressive injury and appearence of symptoms do not allow understand whether functional impairment is secondary to compressive state or to unknown neural tissue incipient malformations. BAEP analyses of these patients are not routinelly done, and these previous data demonstrated that the image and functional correlation can lead to unrevealing features of morphophysiology of the craniocervical juntion malformations.
No preview · Article · Jan 2008 · IFMBE proceedings
[Show abstract][Hide abstract] ABSTRACT: First described by James Ewing in 1921, Ewing's sarcoma (ES) or Ewing's tumor is one of the most aggressive bone tumors known. ES is an uncommon intra-osseous malignant tumor of questionable pathogenesis that occurs in children and young adults. Reports indicate that only 2 to 7% of cases involve the maxillofacial region, usually the mandible ramus, and few reported cases have involved the maxilla. In the present report of a case of ES of the mandible, we describe the results of imaging and evaluation after therapeutic treatment. This report provides a rare opportunity to observe radiologic features of ES in the mandible.