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Objective. We review the neuroanatomical aspects of the temporal lobe related to the temporal lobe epilepsy. The neuronal, the ventricular, and the vascular structures are demonstrated. Methods. The previous articles published from the laboratory of the senior author are reviewed. Results. The temporal lobe has four surfaces. The medial surface has a complicated microanatomy showing close relation to the intraventricular structures, such as the amygdala or the hippocampus. There are many white matter bundles in the temporal lobe showing relation to the extra- and intraventricular structures. The surgical approaches commonly performed to treat temporal lobe epilepsy are discussed under the light of these data. Conclusion. A thorough knowledge of the microanatomy is necessary in cortical, subcortical, and intraventricular structures of the temporal lobe to achieve better results.

Object: The goal of this study was to delimit the external cranial projection of the transverse and sigmoid sinuses, and to establish initial strategic systematized burr hole sites for lateral infratentorial suboccipital approaches based on external cranial landmarks particularly related to the lambdoid, occipitomastoid, and parietomastoid sutures., Methods: The external cranial projection of the transverse and sigmoid sinuses was studied through their external outlining obtained with the aid of multiple small perforations made from inside to outside along the inner margins of the sinuses of 50 paired temporoparietooccipital regions in 25 dried adult human skulls. The burr hole placement was studied by evaluating the supratentorial, over-the-sinuses, and infratentorial components of 1-cm-diameter openings made at strategic sites identified in the initial part of the study, which was performed in another 50 paired temporoparietooccipital regions. The asterion and the midpoint of the inion-asterion line were found to be particularly related to the inferior half of the transverse sinus; the transverse and sigmoid sinuses' transition occurs 1 cm anteriorly to the asterion across the parietomastoid suture, and the most superior part of the sigmoid sinus is located anteriorly to the occipitomastoid suture, with its posterior margin crossing this suture posteriorly to the most superior aspect of the mastoid process, which is located at the most superior level of the mastoid notch. Burr holes made at the midpoint of the inion-asterion line, at the asterion, 1 cm anterior to the asterion, just inferiorly to the parietomastoid suture, and over the occipitomastoid suture at the most superior level of the mastoid notch are appropriate to expose the inferior half of the transverse sinus at its midpoint, the inferior half of the transverse sinus at its most lateral aspect, the transverse and sigmoid sinuses' transition, and the posterior margin of the basal aspect of the sigmoid sinus, respectively., Conclusions: These findings allow an estimation of the transverse and sigmoid sinuses' external cranial projection. The asterion and the most posterior part of the parietomastoid suture constitute a suitable initial burr hole site at which to perform an upper or asterional suboccipital craniectomy to expose the superior aspect of the cerebellopontine angle (CPA). The occipitomastoid suture at the most superior aspect of the mastoid notch constitutes an adequate initial burr hole site at which to perform a basal suboccipital craniectomy to expose the lower portion of the CPA. The sites can be used together as initial burr hole sites to perform wide suboccipital exposures, because they already constitute natural infratentorial lateral limits.

Objective: To study the microvascular anatomy of the perforating arteries on the third ventricular floor., Methods: The microanatomy of perforating arteries on the third ventricular floor in 25 cadaveric heads of adults was observed with 4 to 40-power surgical microscope., Results: The perforating arteries on the third ventricular floor arose from the internal carotid, posterior communicating, posterior cerebral and basilar arteries, and could be divided into three patterns: no ramification, proximal ramification, and distal ramification, according to their vascular origin and course. The perforating arteries of proximal ramification pattern had larger diameter and broader distribution These perforating arteries terminated at relative distant area, including a) anterior part: the optic chiasm and stalk and infundibulum; b) middle part: mamillary body and tuber cinereum; c) posterior part: posterior perforated substance and posterior fossa; and d) lateral part: paramedian perforated substance and anterior portion of optic tract. In middle part overlap and anastosis of perforating artery with posterior communicating artery from both sides were relatively few., Conclusion: The perforating arteries on the third ventricular floor can be divided into three patterns. The proximal ramification pattern possesses larger diameter of the vessel and broader blood supply area on the third ventricular floor. Identification and preservation of these perforating arteries are important when surgery is being planed.

A microanatomical study of the hypoglossal canal and its surrounding area was carried out using dry skulls and cadaveric heads to determine the course of the hypoglossal nerve in the hypoglossal canal, especially the significance for the transcondylar approach. The hypoglossal nerve enters the superomedial part of the hypoglossal canal as two bundles, which then change course abruptly to an anterosuperior direction, and unite as one trunk before exiting the canal. The hypoglossal nerve has an oblique course in the canal rather than being located in the center, and exits through the inferolateral part of the canal. A venous plexus surrounds the entire length of the nerve bundles in the canal. The present results suggest that during drilling the occipital condyle toward the hypoglossal canal from behind, the surgeon does not need to be overly concerned even if some bleeding occurs from the posterolateral edge of the hypoglossal canal.

Blood flow and patency rates obtained by lingual to basilar artery anastomosis were compared with those obtained by saphenous vein bypass graft from the carotid to the basilar artey in two groups of ten dogs. Flow was measured by an electromagnetic technique while blood pressure and blood gases were monitored. Graft patency also was determined by angiography and histological examination. The arterial and venous grafts carried more than enough blood to maintain a normal flow (9.5 ml per minute) through the basilar system of dogs. Immediately after anastomosis, average flow through the vein grafts was 15.5 ml per minute (range 10 to 24 ml per minute). Six weeks later, average flow through the vein graft was 11.5 ml per minute and through the arterial graft 13 ml per minute. With induced hypertension, flow increased in the arterial grafts to an average of 26.2 ml per minute and in the vein grafts 24 ml per minute. Hypercarbia increased arterial graft flow to an average of 27.8 ml per minute and vein graft flow to 23.5 ml per minute. By angiography, graft patency was shown in only 80% of the grafts at one week and in 60% at six weeks postoperatively, even though all grafts were patent by flow and histological determinations. This failure of angiography represents a limitation of the radiographical resolution in millimeter-sized vessels.