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The authors consider some clinical and radiological aspects of spontaneous intracranial hypotension syndrome, based on the knowledge obtained from three clinical situations. Postural headache was a constant complaint. In all cases, magnetic resonance imaging data obtained was diffuse dural enhancement and, in two cases, bilateral subdural fluid collections. The increasing recognition of this syndrome led to its distinction from meningeal inflammatory or neoplasic conditions, sparing the patient from unnecessary investigation.

Hypertrophic Olivary Degeneration is a type of transneuronal degeneration caused by lesions in the dento-rubro-olivary pathway. It involves the inferior olivary nucleus and is a unique type of degeneration because it is associated with hypertrophy of this nucleus. The authors report MRI findings in 10 patients with Hypertrophic Olivary Degeneration, whose exams were reviewed.

The authors describe their experience with three-dimensional (3D) MRI reconstructions of the cerebral cortex in neurosurgical planning of cortical and subcortical lesions. The majority of the lesions were located on the cerebral hemispheres; there were also few cases of posterior fossa lesions. The authors selected three clinical cases to demonstrate the interest of 3D MRI. The authors describe another image processing method based on the three dimensional models obtained by using Curvilinear Multiplanar Reformatting (CMR) for the identification of subtle focal dysplastic lesions in patients with epilepsy. The advantages and disadvantages of those 3D MRI reconstructions methods are discussed and a comparison with conventional cross-sectional images is mentioned. The main disadvantages are the raw data relative to long acquisition time and the difficulty in sometimes establishing the cleavage plane between the cortex and extra-axial structures (e.g. young patients; lesions with great mass effect; lesions ventrally located in the cerebral lobes). In conclusion, the 3D MRI reconstructions of the cerebral cortex reveal additional information to conventional cross-sectional images and permit a precise location of the lesions. This is essential in some circumstances for neurosurgical planning and strategy, improving neurosurgical performance and patient outcome.

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 main clinical applications of FMRI cortical mapping regarding the sensorimotor cortex of the hand and of language are mentioned. The experiment involves 29 patients, 16 with gliomas (G), 7 with mesial temporal sclerosis (MT S) and 6 with arteriovenous malformations (AVM) The most frequent clinical applications were the determination of the topographic relationship of the cerebral lesions with these eloquent cortices as well as the presurgical lateralization of language in medically intractable epileptic patients. 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.