Intramedullary spinal cord tumour (hemangioblastoma): Clinical case presentation

Hemangioblastomas represent cca. 1 - 2,5% of all the intracranial tumours and only 2 -3% at the level of the spinal cord. The symptomatology, usually insidious, is directly proportional with the size of the tumour. The native magnetic resonance imaging (MRI) scan and the use of a contrast agent is the investigation of choice for diagnosing intramedullary tumours. Authors report the case of a 51 years old man patient admitted in our institution for an intramedullary spinal cord tumor, developed insidious. The lesion was completely removed. Postoperatory outcome was excellent, and the histopathological result was: hemangioblastoma

-boundedness of Multilinear Pseudo-differential Operators on

The aim of this paper is to introduce and study multilinear pseudo-differential operators on Zn and Tn = (Rn/ 2πZn) the n-torus. More precisely, we give sufficient conditions and sometimes necessary conditions for Lp-boundedness of these classes of operators. L2-boundedness results for multilinear pseudo-differential operators on Zn and Tn with L2-symbols are stated. The proofs of these results are based on elementary estimates on the multilinear Rihaczek transforms for functions in L2(Zn) respectively L2(Tn) which are also introduced. We study the weak continuity of multilinear operators on the m-fold product of Lebesgue spaces Lpj(Zn), j = 1,...,m and the link with the continuity of multilinear pseudo-differential operators on Zn. Necessary and sufficient conditions for multilinear pseudo-differential operators on Zn or Tn to be a Hilbert-Schmidt operators are also given. We give a necessary condition for a multilinear pseudo-differential operators on Zn to be compact. A sufficient condition for compactness is also given