The human locus coeruleus 3-D stereotactic anatomy.

PURPOSE: The main goal of this work was to study the stereotactic anatomy of the human locus coeruleus (LC), important relay of adrenergic and dopaminergic human brainstem (HB) circuitry, to allow its easy localization on MRI and in microsurgical procedures. METHODS: Forty LC were studied from 20 adult HB of both sexes. The melanin pigmentation of its cells was used to identify and localize them and so to define the 2-D and 3-D LC contours. These HB were cut on a cryomicrotome with 3-D referenciation. The slices were coloured with haematoxyline-eosin. On the slices, digitized images of the cells were referenced to the midline, the fourth ventricle floor plane and the pontomedullary junction plane with an appropriate computer program. RESULTS: The LC revealed to be a symmetric, thin and elongated nucleus, divergent caudally except in its superior part, with a sub-ependymal location on the superior dorsal lateral pons. The main LC dimensions are: length 12.0-17.0 mm (m 14.5); width 2.5 mm; height 2.0 mm. The 3-D references of the LC center are: 3.2 ± 0.3 mm to the midline; 1.1 ± 0.2 mm to the IV ventricle floor and 18.5 ± 1.5 mm to the ponto-medullary junction. CONCLUSIONS: The human LC is a nucleus thinner and longer than previously described (in average 14.5 mm long and 2-2.5 mm thick), localized 1 mm under the IV ventricle, 3 mm apart from the midline and centered 14-21 mm above de ponto-medullary junction. No correlation was found between LC and pons dimensions, the gender or the age.

[The Institute of Anatomy in the centenary of the Medical Faculty of Lisbon University]. / O Instituto de Anatomia no centenário da Faculdade de Medicina da Universidade de Lisboa.

The authors join the celebrations of the Centenary of the establishment of the Faculdade de Medicina da Universidade de Lisboa, on the 22(nd) April 2011, through the historical account of one of its main pilasters, the Institute of Anatomy. It is discussed the scope of its creation at the time, the important work done, the presence and participation in major international evolutionary landmarks in Anatomy, current thinking and action, and the measures implemented to prepare the incoming medical generations. Finally it will be presented the challenges for the 21st century and the strategies to overcome them, which includes the development of the Institute of Anatomy at the Medical Faculty of Lisbon University, in order to create a major pedagogic-scientific study space, for teaching and research of human normal morphology, above all in vivo aspects more applied, the clinic and imaging pre- and post-graduate. There is a world of morphological investigations, basic and clinical, to be held, involving teachers, students, and even doctors and surgeons, with the privileged scientific and research support from the Institute of Anatomy of the Faculdade de Medicina da Universidade de Lisboa!

Stereotactic biopsies of focal brainstem lesions.

BACKGROUND: Stereotactic biopsies of the brainstem (SBB) are a selected group of stereotactic operations owing to the lower incidence of brainstem lesions requiring biopsy, the greater complexity, and the higher risks of these procedures. Usually, the lower the lesion in the brainstem, the greater the risks involved. The approach of the different target locations by distinct routes, transcerebral and transcerebellar, is still a matter of debate. Moreover, pure medullary lesions are seldom biopsied, whereas diffuse brainstem lesions, typical of children's brainstem gliomas and rather frequent in most published series, depend less and less on the histopathological confirmation for treatment. In this study, the authors present their own experience on SBB aiming to discuss mainly their indications, approach routes choice, and procedure techniques. METHODS: The authors reviewed a series of 30 SBB (27 adults and 3 children) out of 450 stereotactic biopsies of the central nervous system performed for the last 10 years. All cases but one presented as focal brainstem masses, 19 mainly in the pons and 10 in the midbrain. Eleven lesions (10 in the midbrain and one midbrain-pontine) were approached by a transfrontal route. All the others were approached by a suboccipital transcerebellar route. RESULTS: Twenty-six (87%) out of the 28 cases (93%) where a positive histopathological result was obtained had a specific diagnosis: 18 tumors (14 astrocytomas, 2 primary brain lymphomas, 1 oligodendroglioma, and 1 ganglioglioma), 2 toxoplasmosis, 2 sarcoidosis, 1 aspergillus abscess, 1 vasculitis, 1 acute inflammatory demyelinating disease, and 1 progressive multifocal leucoencephalopathy. Four nontumoral lesions arose in patients with AIDS. Morbidity was restricted to 2 cases consisting of transient cranial nerve deficits. CONCLUSIONS: Stereotactic biopsies are specially useful for the diagnosis of focal brainstem lesions. Midbrain and midline lesions should be approached through the cerebrum, whereas most of the pontine lesions through the cerebellum. Overall, this procedure should be performed with "functional-like" precision and require some technical refinements to reach maximal accuracy with minimal morbidity.

Corpus callosum: microsurgical anatomy and MRI.

The anatomy of the corpus callosum has received renewed interest during recent years due to the increasing number of callosotomies performed to treat intraventricular lesions, as well as some forms of generalized epilepsy. We have previously reported on the microsurgical anatomy of the corpus callosum and identified specific anatomical reference landmarks that can be used during surgery. In the present study we have continued the anatomical aspect of this earlier work in a larger number of cases, with in vitro observations (brain out of skull) being compared with the corresponding in vivo features seen in sagittal MRI slices. Fifty-three in vitro microsurgical callosotomies was performed and the data collected compared with a series of 57 in vivo normal MR callosal images. Callosal dimensions were measured on both the anatomical and MRI material, thus overcoming the problems associated with in vitro callosal deformation. Of the anatomical landmarks studied the distance from the genu of the corpus callosum to the bifurcation of the columns of the fornix was found to be useful for the intraoperative evaluation of the extent of rostral callosotomy, as it is not significantly changed in in vitro. The main microsurgical features of rostral callosotomy are presented.

Corpus callosotomy: some aspects of its microsurgical anatomy.

Corpus callosotomy was reported for the first time by Dandy in 1922 and developed by Van Wagenen and Herren in 1940, but only Wilson in 1975 started performing it with a microsurgical technique. Its indications have remained controversial for a long time, but during the last years new interest has been raised concerning callosotomy as a treatment for some kinds of generalized epilepsy or as route to the anterior ventricular system. The microsurgical anatomy of the corpus callosum has therefore regained interest. With this goal in mind, the authors studied some aspects of the microsurgical anatomy of the corpus callosum, namely its dimensions, variability and topography, as well as the transcallosal access to the deep interfrontal region and to the third ventricle. This study was carried out on 30 normal adult brains, obtained from routine autopsies, that were submitted to a special preparation procedure and dissected with microsurgical technique. The main aspects of the operating features, the measurements made and the variation in the different parameters are described. Some references are proposed respecting the extent of anterior partial and subtotal callosotomy.

[Arterial microangiographic aspects of the temporal lobe]. / Aspects microangiographiques artériels du lobe temporal.

Human brain microvascularisation, whose general patterns are well known, still raises unanswered questions, such as the ones concerning regional arterial angioarchitectonic variations. Following other papers already published about the Temporal Plan and the Prefrontal Cortex, this article presents new elements on the arterial microcirculation's morphology of the Temporal Lobe in its whole and in the different areas that constitute it. The microangiography is the first choice method for such research, allowing to observe and describe in detail multiple aspects that have not been pointed out before.