OBJECTIVE The authors report a novel surgical route from a superior anatomical aspect-the contralateral anterior interhemispheric-transcallosal-transrostral approach-to a lesion located in the subcallosal region. The neurosurgical approach to the subcallosal region is challenging due to its deep location and close relationship with important vascular structures. Anterior and inferior routes to the subcallosal region have been described but risk damaging the branches of the anterior cerebral artery. METHODS Three formalin-fixed and silicone-injected adult cadaveric heads were studied to demonstrate the relationships between the transventricular surgical approach and the subcallosal region. The surgical, clinical, and radiological history of a 39-year-old man with a subcallosal cavernous malformation was retrospectively used to document the neurological examination and radiographic parameters of such a case. RESULTS The contralateral anterior interhemispheric-transcallosal-transrostral approach provides access to the subcallosal area that also includes the inferior portion of the pericallosal cistern, lamina terminalis cistern, the paraterminal and paraolfactory gyri, and the anterior surface of the optic chiasm. The approach avoids the neurocritical perforating branches of the anterior communicating artery. CONCLUSIONS The contralateral anterior interhemispheric-transcallosal-transrostral approach may be an alternative route to subcallosal area lesions, with less risk to the branches of the anterior cerebral artery, particularly the anterior communicating artery perforators.

The cerebral cortex folding in humans allow that an extensive area of cerebral cortex fit into the limited space of the skull. The factors that guide this folding are complex and its final result leads to sulci and gyrus patterns in adult brain. These patterns, depending on the region of cerebral cortex analyzed, can have or not a high degree of variability 1 . There are some evidence that factors guiding the cerebral cortex folding starts in the beginning of cerebral morphogenesis. First, in a coronal brain slice, we can see that sulcus in the inferior and lateral surface of the brain are oriented toward the ventricular cavity and sulcus in the medial surface are oriented parallel to corpus callosum fibers. (In cases of total corpus callosum agenesis, the sulcus in the medial surface seems to be ventricular-guided too). Second, neurons sends axons across the corpus callosum even before the neuron migration process end 2 , and this neuronal projection affect the final brain morphology 3 . Based on these observations, we can suppose that the final brain morphology depends on neuronal migration, axonal connection and probably others factors.The frontal lobe has four surfaces: a lateral, a medial, a basal and a sylvian surface 4 . The basal surface is in contact with the orbital roof, compounded of the frontal, ethmoid and sphenoid bones being, for this reason, called orbitofrontal surface.In the last ten years, many studies have showed the relationship between altered orbitofrontal cortical pattern and ABSTRACTThe anatomical characterization of the orbitofrontal cortex in human is limited in literature instead of many functional and clinical studies involving it. Objective: Anatomically define the orbitofrontal region aiming to possible neurosurgical treatments and unify the scientific nomenclature as well. Method: We analyze eighty four human hemispheres using a surgical microscope. Then we chose four hemispheres and dissect them according to Klinger' technique. Results: We found five main sulcus: olfatory sulcus, orbital medial sulcus, orbital lateral sulcus, orbital transverse sulcus and orbital intermediate sulcus. These sulcus, excluding the intermediate sulcus, delimit five gyrus: rectus gurys, orbital medial gyrus, orbital anterior gyrus, orbital lateral gyrus and orbital posterior gyrus. The main sulcal configuration can be divided on four more frequently patterns. Conclusion: Orbitofrontal cortex is associated with many psychiatric disorders. Better anatomical and functional characterization of the orbitofrontal cortex and its connections will improve our knowledge about these diseases.

Chemical fractionation of Brickellia paniculata methanolic extract by monitoring its inhibitory effect on K(+)-induced contraction in guinea-pig ileum in vitro led to the isolation of 5,4'-dihydroxy-6,7,8-trimethoxyflavone (xanthomicrol) and the labdane-diterpene 3 alpha-angeloyloxy-2 alpha-hydroxy-13,14 Z-dehydrocativic acid (AAHDD). Both compounds inhibited the tonic contraction the effect being highly potent when a mixture in a proportion of 3 : 1 (xanthomicrol/AAHDD) was assayed. The phasic component of the contractile response with K(+) was also reduced by the compounds. Xanthomicrol depressed the spasms induced with ACh, Hist, and BaCl(2) and its effect on Ca (2+) concentration-response curve showed a type of non-surmountable calcium blocking action; unlike the flavonoid, AAHDD produced a parallel rightward shift of the concentration-response curve to calcium, suggesting a competitive antagonism with an estimated pA(2) of 4.66. Obtained results support, in part, the popular use of B. paniculata as a spasmolytic remedy.

At least 1 variation in ACP anatomy was found in 38.7% of cases with this simple method. Thus, a preoperative computed tomography scan could improve surgical procedures that involve removal of the anterior clinoid process.