Acta médica portuguesa
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Acta médica portuguesa · Jan 2001
Review[Vascularization of the skull base--review of the literature and illustrative cases].
The dural vascularization of the skull base and proximal nervous structures, depends on the external carotid artery, internal carotid artery and vertebral artery branches. The authors describe these branches, emphasizing possible anastomoses between them, and present images from their own experience. Such arterio-arterial anastomosis represent incomplete regressions of embryologic arterial connections and are always present, but functionally inactive. It is usually in the presence of pathologic situations (stroke, tumours, dural fistulas) that they become active and, therefore, special care is necessary if endovascular procedures with embolic material are to be performed.
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Acta médica portuguesa · Jan 2001
Comparative Study[Subarachnoid hemorrhage and computerized tomography cerebral angiography].
We present a review of 57 cases of nontraumatic subarachnoid hemorrhagesubmitted to CT angiography of the cerebral vessels. The purpose of our study was to estimate the value of CT angiography in the detection of intracranial aneurysms. These findings were compared with those from selective angiography. The results showed that CT angiography is a rapid, low-risk technique with a low level of invasiveness and high specificity and sensitivity in the detection of cerebral aneurysms, allowing the planning of endovascular intervention and surgical approach.
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Acta médica portuguesa · Jan 2001
[Preoperative applications of cortical mapping with functional magnetic resonance].
The authors describe a clinical experience in cortical brain mapping by Functional Magnetic Resonance Imaging (FMRI) with a 1.0 T MR scanner with BOLD technique and echo-planar imaging (EPI). A brief review is made of the theoretical basis of the BOLD technique and of the different functional tasks used. ⋯ The results are discussed in order to assess the FMRI cortical mapping role as a noninvasive method for presurgical planning, regarding the evaluation of the potential neurosurgical risks and the identification of viable cortex regions displaced or reorganized as a consequence of disease. Additionally, FMRI cortical mapping can also assess the atypical speech representations and the language lateralization of the patients.