MR imaging and proton spectroscopy of the brain in posttraumatic cortical blindness.

Magnetic resonance (MR) imaging and localized proton MR spectroscopy of the occipital lobes were performed in a patient with cortical blindness following brain trauma. Computed tomography (CT) scans and MR images of the visual cortex were normal in the acute stage. Six weeks after the trauma, MR images showed cortical lesions in both occipital lobes, while the spectra showed elevated lactate and decreased N-acetyl aspartate levels relative to those of healthy volunteers. One year later, visual acuity had improved and follow-up studies revealed an increase in the ratios of N-acetyl aspartate to choline and creatine. These results demonstrate that parenchymal lesions may develop in brain regions that appear normal at CT and MR imaging during the acute stage after trauma. Metabolic changes can be observed in these areas by means of localized proton MR spectroscopy.

Isolated pontine lesion in algid cerebral malaria: clinical features, management, and magnetic resonance imaging findings.

Malaria, the most important of all tropical diseases, causes approximately one million deaths per year. In Plasmodium falciparum malaria, the organs most affected are the brain, kidneys, lungs, and liver. Cerebral involvement is the most important lethal complication with a mortality rate of up to 50%. We report a patient with malignant, tertian falciparum malaria with an initial parasitemia rate of 60% and severe cerebral, hepatorenal, and pulmonary involvement. In addition to the severe diffuse encephalopathy, an initial neurologic examination showed signs of a pontine lesion that was confirmed by cerebral magnetic resonance imaging. We therefore conclude that cerebral malaria may be responsible for focal neurologic lesions that can be demonstrated by this procedure.

Sneddon's syndrome: diagnosis by skin biopsy and MRI in 17 patients.

BACKGROUND AND PURPOSE: Sneddon's syndrome, characterized by generalized livedo racemosa and cerebrovascular lesions, is an underdiagnosed disease. We evaluated clinical, laboratory, histological, and neuroradiological findings in a series of 17 patients to improve diagnostic criteria for Sneddon's syndrome. METHODS: Patients with generalized livedo racemosa and cerebrovascular events were included in the study. All underwent neurological and dermatological examination, skin biopsy, computed tomographic scan, magnetic resonance imaging as well as magnetic resonance angiography, sonography of the extracranial arteries, and a comprehensive laboratory protocol. RESULTS: Completed stroke was present in eight patients, and 15 reported transient neurological deficits. Magnetic resonance imaging yielded cerebral abnormalities in 16 of 17, whereas computed tomographic scans were abnormal in only 12 of 16 patients. Magnetic resonance imaging revealed more lesions in individual patients than did computed tomography. Magnetic resonance angiography demonstrated patent intracranial vessels in 16 of 17 patients. Skin biopsy showed distinct histopathological findings in all patients. The involved vessels were small to medium-sized arteries at the border between dermis and subcutis. Early inflammatory reactions were followed by subendothelial proliferation and a late fibrotic stage. Laboratory examinations showed impaired creatinine clearance in eight patients, whereas all other laboratory tests, including antiphospholipid antibodies, were normal. CONCLUSIONS: In this series, magnetic resonance imaging and skin biopsy were useful for confirmation of the diagnosis of Sneddon's syndrome. Magnetic resonance findings were not specific, but the high sensitivity for detection of asymptomatic brain lesions helped to confirm the diagnosis in patients with transient symptoms. Histological features of skin biopsies were characteristic if appropriate techniques were employed.

Orbital involvement in Waldenström's macroglobulinemia: ultrasound, computed tomography and magnetic resonance findings.

A case of orbital involvement in Waldenström's macroglobulinemia is presented. Orbital echography, computed tomography (CT) and magnetic resonance imaging (MRI) were performed and revealed a retrobulbar mass of the right orbit. Ultrasonography suggested a lymphoid orbital tumor. A CT scan was nonspecific, but helpful in exactly locating the tumor and excluding bony lesions. Signal intensity patterns of MRI were characterized by a low intensity on T1- and T2-weighted images. A marked enhancement of the tumor was evident after intravenous injection of a paramagnetic contrast agent (gadolinium-DTPA). Although the definite diagnosis could only be established by means of an ultrasound-guided fine-needle aspiration biopsy, MRI in connection with the history of our patient strongly suggested a diagnosis of orbital lymphoma in Waldenström's disease.