J Neuroradiology
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In nerve root infiltration (NRI) consisting of neural blockage and radiculography, response to the nerve root block has usually been thought to be diagnostically significant. However radiculography has not been statistically evaluated. The purpose of this paper is to assess the value of selective radiculography of patients with group 1 response (typical pain reproduced by needle placement and then relieved by nerve root block) according to Dooley's criteria. ⋯ The accuracy of radiculography was 84% in the canal zone and 100% in the intra and extraforaminal zones. If the L5 nerve root angle was more than 60(o), an intra or extraforaminal lesion was strongly suggested (P<0.01). Radiculography of patients with group 1 response is useful for detecting compressed sites in the symptomatic nerve root, particularly for detecting lesions in the intra and extraforaminal zones.
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Clinical studies report a rate of 5% and autopsy results a rate of 25% of brain involvement in sarcoidosis. The aim of this study was to evaluate the role of magnetic resonance imaging (MRI) in the diagnosis of patients with neurosarcoidosis. The MRI brain scans of 22 patients with sarcoidosis were retrospectively reviewed, along with the clinical information that was provided in the request form. ⋯ A wide spectrum of MR findings was noted: Periventricular and white matter lesions on T2W spin echo images, mimicking multiple sclerosis (46%); multiple supratentorial and infratentorial brain lesions, mimicking metastases (36%); solitary intraaxial mass, mimicking high grade astrocytoma (9%); solitary extraaxial mass, mimicking meningioma (5%); leptomeningeal enhancement (36%). These findings are not specific for sarcoidosis and one must consider appropriate clinical circumstances in arriving at the correct diagnosis. In selected cases with isolated brain involvement, meningeal or cerebral biopsy may be required.
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Comparative Study
Rathke's cleft cysts: surgical-MRI correlation in 16 symptomatic cases.
Rathke's cleft cysts (RCCs) are non neoplastic epithelial lesions of the sellar region that have been rarely reported as a clinical entity. We retrospectively reviewed the magnetic resonance imaging (MRI), intraoperative, and pathological findings of a series of 16 cases of RCCs operated at our institution since 1992. Concurrently, we discussed the different hypotheses about their embryological origin. ⋯ Except in few cases, there were no correlation between MRI and intraoperative findings. Therefore, even with MRI studies, differential diagnoses with others cystic lesions of the sellar region remains extremely difficult. The most interesting findings on MRI studies of RCCs were to locate the pituitary gland to help the surgeon to preserve pituitary tissue during surgery.
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Increase in transcranial Doppler ultrasound flow velocities in the major basal arteries correlates with symptomatic vasospasm. Transcranial Doppler examinations are performed using a pulsed Doppler Probe via the trans temporal approach. Transcranial colour-coded real time sonography can be useful and help to identify the cerebral arteries. ⋯ Flow velocity is directly related to cerebral blood flow. Intracranial pressure, blood pressure and volume, hematocrite and subarachnoid hemorrhage affect Doppler flow velocities. False-negative examinations of vasospasm using TCD are associated with distal vasospasm, severe spasm of the carotid siphon, chronic high blood pressure and increased intracranial pressure.
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Dural arteriovenous fistulas (dAVFs) can cause cerebral venous hypertension (VHT). The most common mechanism is due to the fact that some dAVFs can drain retrogradelly in cortical (better defined as leptomeningeal) veins (directly or after drainage in a dural sinus) causing venous engorgement and consequently an impairment of the cerebral venous drainage. However, more rarely, dAVFs without a cortical venous drainage can also be responsible for VHT probably due to dAVF shunts causing insufficient antegrade cerebral venous drainage. ⋯ After the endovascular treatment, in 12 patients with complete occlusion of the dAVF, the disappearance of angiographic signs of VHT and clinical cure were observed. In 8 patients with partial occlusion of the dAVF, the disappearance of angiographic signs of VHT and clinical cure were observed in 4 cases (almost complete dAVF occlusion in 2 cases); in the other 4 cases, only reduction the angiographic signs of VHT and clinical improvement were obtained. In all 16 patients who were clinically cured angiographic signs of VHT disappeared despite the persistence of dAVF shunts as observed in 4 cases. (ABSTRACT TRUNCATED)