Dilatation of deep medullary veins in cortical venous occlusion due to focal tuberculous leptomeningitis.

We report a case of surgically proven, focal left parietal tuberculous leptomeningitis. Occlusion of superficial cerebral veins in the affected area led to dilatation of medullary veins to drain the left parietal lobe. Deep medullary veins were clearly demonstrated on MRI and angiography.

[Imaging of non-osseous malignant tumors of the anterior skull base. Preoperative evaluation]. / Imagerie des tumeurs malignes non osseuses de l'étage antérieur de la base du crâne.

Imaging is fundamental in pre-operative evaluation for cancers of anterior cranial base and ethmoido-sphenoidal region, particularly because clinical examination is poorly contributive and cannot evaluate the tumoral extension. Radiological data are based on CT-scan and MRI. The first goal of radiological evaluation is to recognize the presence of a tumor and to differentiate it from inflammatory lesions, which is not always very easy. The second aim is the evaluation of tumoral extension, particularly towards the intra-cranial cavity and the orbit. It leads to an extension grading which is essential for the choice of a therapeutic strategy (inductive chemotherapy, surgical approach, radiotherapy). The third goal of imaging examination is the evaluation of tumoral response to pre-operative inductive chemotherapy.

[MRI of degenerative extrapyramidal syndromes. Parkinson disease, progressive supranuclear palsy and multiple system atrophy]. / L'IRM dans les syndromes extrapyramidaux d'origine dégénérative. La maladie de Parkinson, la paralysie supranucléaire progressive et l'atrophie systématisée multiple.

MR imaging of the brain, particularly with high field MR imagers, may demonstrate signal abnormalities consistent with deposits of iron or other paramagnetic substances in extrapyramidal disorders. The diagnosis of Parkinson's disease and progressive supranuclear palsy can be made on clinical grounds in most of the cases and MR signs are of little help in the diagnosis of these diseases. In patients with parkinsonian disorders poorly responding to therapy, MR imaging may be useful in demonstrating signal abnormalities in the putamen that may help to establish the diagnosis of striatonigral degeneration (component of multiple system atrophy) with a poorer prognosis than Parkinson's disease. Finally, MR imaging may be useful in the exclusion of other disease processes.