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We present a vascular anatomical study of the arteries and veins of the sylvian fissure and insula.A good knowledge of the sylvian fissure, the insula, and their vascular relationship would seem mandatory before performing surgery in this area, whatever the type of surgery (aneurysms, arteriovenous malformations, insular tumors).We start with the sylvian fissure and insula morphology, followed by the MCA description and its perforators, with special attention paid to the insular perforators. We demonstrate that the long insular perforators penetrating in the superior part of the posterior short gyrus and long gyri vascularize, respectively, the corticonuclear and corticospinal fasciculi. We particularly insist too on three anatomical constants regarding the vascularization of the insula, already described in the literature: The superior periinsular sulcus is the only sulcus on the lateral surface of the brain without an artery along its axis; the superior branch of the MCA supplies the anterior insular pole and both the anterior and middle short gyri in 100 % of cases; in at least 90 % of cases, the artery that supplied the central insular sulcus continued on to become the central artery.We end with the anatomical study of the veins and cisterns.

One hundred brains (first injected in cerebral arteries and veins with latex neoprene or India ink and studied under optic magnification) illustrate this anatomic chapter concerning the microsurgical anatomy of the cisternal segment, the neurovascular relationships, and the blood supply of the IIIrd to the XIIth cranial nerves.

This study of 25 brains at the pontomedullary junction defined the different possible origins of the perforating arteries and lateral spinal arteries in relation to the posterior inferior cerebellar arteries (PICAs). - If the PICA emerges from the common trunk of the AICA-PICA coming from the basilar artery, it never gives perforating arteries or a lateral spinal artery on the lateral surface of the brain stem but supplies blood to a part of the ipsilateral cerebellar hemisphere. - If the PICA arises extradurally at C1, it never gives perforating arteries for the lateral surface of the brain stem, but it gives pial branches for the posterior surface of the medulla oblongata and is always the origin of the lateral spinal artery. - If the PICA emerges in the intradural vertebral artery, it is the source of the perforating arteries for the lateral surface of the brain stem and of the blood supply of the ipsilateral cerebellum.

The anatomy of the radial tunnel was studied on twenty-five elbow preparations. We noted five different elements that could affect the deep branch of the radial nerve in the radial tunnel and cause an entrapment syndrome : a capsule-tendon-aponeurotic complex on the anterior aspect of both the humeroradial joint and the radial head, the vascular arcade formed by the radial recurrent a. and its branches, the arcade formed by the medial edge of extensor carpi radialis brevis muscle, and the superior and inferior arcades of the superficial layer of the supinator muscle. These results are compared with recent anatomical and clinical data, and the relevance of a surgical approach between the extensor carpi radialis brevis and longus muscles is discussed.

In this study, the authors present the results of 50 dissections of the anterior choroidal a. in man. Fifty cerebral hemispheres were prepared with the classic techniques of preservation and vascular injection. An ectopic origin was observed in 4% of cases. The intracisternal segment of the anterior choroidal a. forms a neurovascular bundle with the optic tract and basal v. Most of its intraparenchymatous branches arise from the cisternal segment, while branches supplying the optic tract, lateral geniculate body and thalamus arise from the intraplexual segment. Constant anastomoses exist with the vertebrobasilar system, specially the postero-lateral choroidal and posterior cerebral aa. We discuss the importance of an adequate knowledge of the anatomy of the anterior choroidal a. and its relations in the surgical approach to arterial aneurysms and arteriovenous malformations of the region.

Olfactory ensheathing cell tumour (OECT) and olfactory groove schwannoma (OGS) are among the rarest intracranial tumour types that develop within anterior cranial fossa. These tumours share several similarities, including radiological and histological aspects, and only immunohistochemical staining can differentiate between them. We report a case of OECT occurring in a 28-year-old woman with a history of complex partial seizures, emotional lability and anosmia. Radiological features showed a predominantly left subfrontal extra-axial mass. Total excision of the tumour, connected to the cribriform plate and contiguous to the left olfactory bulb, was performed. Histological examination suggested an atypical schwannoma; however, immunohistochemical staining was strongly positive for S-100 protein but negative for both epithelial membrane antigen (EMA) and CD 57 (Leu-7). The final diagnosis was olfactory ensheathing cell tumour. We describe the third case of OECT and emphasize the important role of immunohistochemical staining in diagnosis: awareness of this entity, and use of immunohistochemistry help to distinguish it from OGS.

L'echec du traitement medical d'un syndrome douloureux evoquant un syndrome du tunnel radial justifie l'exploration chirurgicale du tunnel radial a la recherche de structures de compression avec la BPNR, en gardant a l'esprit tous les sites possibles de conflit. L'abord entre les mm. court et long extenseur radiaux du carpe permet alors une approche directe et rapide aux deux structures les plus frequemment en cause : l'arcade du CERC et l'arcade superieure du chef superficiel du m. supinateur. Cet abord est aussi approprie pour l'exploration de l'ensemble du tunnel radial en restant a distance des multiples branches nerveuses collaterales pour les mm. brachioradial et LERC. La difficulte reside alors dans le reperage de la branche collaterale unique pour le CERC, particulierement lorsqu'elle nait de la BPNR a proximite de la zone exploree.

Any variations in the origin of the ophthalmic a. are uncommon and well-explained by the comparative anatomy and human embryology. A unique case is reported of an ophthalmic a. arising from the middle meningeal a. associated with an occlusion of the central retinal a. Embryologic variations which can give such an unusual origin are discussed. Although this association may be fortuitous, we consider that an unusual origin of the ophthalmic a. could be a further factor for an occlusion of the central retinal a.

Capillary haemangioma of the central nervous system is extremely rare. Histologically proven cases developed in the dura mater and choroid plexus, or were typically intracranial extensions of an extra-cranial lesion.This report details a case that developed in the anterior choroidal artery of a newborn infant and manifested as a lethal intra-cerebral haemorrhage. Pathological criteria for the diagnosis of vascular malformations should be carefully investigated and the differential diagnoses of the present case are discussed.Intracranial haemangioma presents a diagnostic challenge and the treatment of deep lesions remains problematic.

The anatomic study (under a surgical microscope) of 25 brains that had previously been injected with colored latex confirmed the fact that in the majority of cases, the anterior spinal artery results from the merging of two arterioles which both derive from two vertebral arteries. This bilateral nature is determined by the symmetric origin of the posterior inferior cerebellar arteries. When the conformation is asymmetrical, a single anterior spinal artery branches off from the vertebral artery that supplies the closest posterior inferior cerebellar artery.

Advances in microsurgery for pathologies of the cerebellopontine angle require excellent knowledge of the anatomy of neural and vascular structures and of neurovascular relationships in this area. This chapter summarizes the authors’ personal works as well as those presently found in the literature.

The microanatomic study of the pineal region was made from 18 cadaver brains. The purpose of this paper is to describe the surgical anatomy needed to approach this area, which is deeply located and in the midline, by analysing the different methods of approach.

We studied the perforating arteries of the interpeduncular fossa in 100 human brains which had previously been embalmed and injected with coloured intravascular neoprene latex. Three groups of perforating arteries were observed: the short interpeduncular arteries, a group of very fine arteries which can originate on every artery in the interpeduncular fossa and are destined to the cerebral peduncles and the oculomotor nerves (III); the diencephalic arteries, larger in diameter, most of which supply the mamillary bodies; only a few of them (one or two) penetrate the diencephalic floor and reach the posterior limb of the internal capsule and the anterior and medial thalamus; the diencephalic arteries are either individual branches of the P1 segment of the posterior cerebral arteries (PCA) or stem from the same segment of the PCA via a trunk common to the mesencephalic arteries; the latter supply the mesencephalic area medial to the pars reticularis of the black substance. Our study focusses on where the diencephalic and mesencephalic arteries originate, based on how both anterior longitudinal neural arteries merged into a basilar artery in the embryo. When merging was symmetrical, whether in the early stages or later, the origins are more or less equally distributed; however, when merging was asymmetrical, the great majority of the perforating diencephalic and mesencephalic arteries stem from the P1 segment on the side that merged earliest (cranially).