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Background: Istanbul, home to numerous historical treasures, houses one of the oldest fully constructed hospitals., Methods: This 50-bed hospital was built in the early 12 th century during the Byzantine period by Empress Irene of Hungary and her husband Emperor John II Komnenos inside one of the largest monasteries of its time. The monastery housed one of the first hospitals and schools of medicine and included a nursing home, ophthalmologic health center, library, and cemetery. After the Empress died, her husband continued to enlarge the complex to its current state. Soon after the fall of Constantinople in 1453, the complex was renamed after Zeyrek Mehmet, who was ordered by Fatih Sultan Mehmet (Mehmet II or Mehmed the Conqueror) to convert the monastery into a mosque, constructing a Fatih Medrese for a short period of time. The hospital, however, remained untouched, and its rooms were used for Koran lessons. The building was fully restored from 2009 to 2017 and is still used as a mosque today. We would like to introduce the Pantokrator Monastery, maybe the only remaining hospital of the Byzantine era., Conclusion: Although it was built in the 12 th century, the monastery is still a modern facility meeting current standards., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: The dense and complex distribution of neural structures in the brainstem makes it challenging to understand their real configuration. We used the fiber microdissection technique to show the course of the medial and lateral lemnisci within the brainstem. Although these structures seem anatomically alike, they are functionally distinct., Methods: Fifteen human brainstems and 8 brain hemispheres (formalin-fixed and previously frozen) were dissected and studied under the operating microscope by applying the fiber microdissection technique., Results: We delineated and described the medial and lateral lemnisci, noting their gross elaborate arrangement. These structures are intimately compact and closely related to one another in their common trajectory through the tegmenta of the pons and midbrain. However, we were not able to identify the exact origin and termination of their fibers or the accurate delimitation between the medial lemniscus, spinothalamic tract, and lateral lemniscus along their course in the brainstem., Conclusions: Using the fiber microdissection technique, we were able to define a general perspective of the topography and architecture of the medial and lateral lemnisci in the brainstem. This perspective should be incorporated into interpretations of magnetic resonance imaging techniques, recognizing both their benefits and limitations. It should also be applied to surgical planning and strategies to achieve a safer and more precise microsurgical procedure., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: To describe the topographic anatomy of surgically accessible surfaces of the human thalamus as a guide to surgical exploration of this sensitive area., Methods: Using the operating microscope, we applied the fiber microdissection technique to study 10 brain specimens. Step-by-step dissections in superior-inferior, medial-lateral, and posterior-anterior directions were conducted to expose the surfaces and nuclei of the thalamus and to investigate the relevant anatomic relationships and visible connections., Results: There were 4 distinct free surfaces of the thalamus identified: lateral ventricle surface, velar surface, cisternal surface, and third ventricle surface. Each is described with reference to recognizable anatomic landmarks and to the underlying thalamic nuclei. The neural structures most commonly encountered during the surgical approach to each individual surface are highlighted and described., Conclusions: Observations from this study supplement current knowledge, advancing the capabilities to define the exact topographic location of thalamic lesions. This improved understanding of anatomy is valuable when designing the most appropriate and least traumatic surgical approach to thalamic lesions. These proposed surface divisions, based on recognizable anatomic landmarks, can provide more reliable surgical orientation., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: A challenging step of the paramedian supracerebellar-transtentorial approach is to expose the anterior portion of the mediobasal-temporal region (MTR), a step that seems most affected by the steepness of the tentorium. The objective of this study was to define magnetic resonance imaging measurements that can predict the level of challenge in exposing the anterior portion of the MTR., Methods: Cranial magnetic resonance imaging studies of 100 healthy individuals were examined. The tentorial and occipital angles were measured, and the amount of brain tissue that remained hidden on the microscopic view in front of the petrous apex was indirectly estimated. These measurements were statistically compared with the cephalic index of each person., Results: The mean values for the tentorial and occipital angles were 42° (range 25°-53°) and 98° (range 69°-122°), respectively. The results proved that the higher the tentorial angle, the higher the occipital angle and the greater the amount of hidden brain tissue. Of 100 persons, 3 (3%) were found to be dolichocephalic, 23 (23%) were mesocephalic, and 74 (74%) were brachycephalic. Statistical analysis proved that individuals with a dolichocephalic cranial shape have lower tentorial and occipital angles., Conclusions: The results provide strong evidence proving that the lesser the tentorial and occipital angles, the easier the exposure of the anterior portion of the MTR during the paramedian supracerebellar-transtentorial approach. The tendency of the cranial shape toward dolichocephaly seems to have the same practical value in choosing the approach. It is easier to expose the anterior portion of the MTR in these individuals., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objective: One significant drawback during a cranial reoperation is the presence of meningocerebral adhesions. The appearance of connective tissue bridges between the inner surface of the dura and the pia-arachnoid is mostly related to dural closure and the condition in which the surgical field was left in the previous surgery. This study was done to determine the benefit of placing a thin-layer gelatin sponge of polypeptides subdurally to prevent meningocerebral adhesions., Methods: From September 2005 through May 2012, 902 craniotomies were performed for various lesions by the senior author (U.T.). Beginning in February 2009, we began placing a gelatin sponge under the dural flap to isolate the dural healing process from the cortical surface. To compare the degree of meningocerebral adhesions statistically, reoperation cases between February 2009 and May 2012 were divided into 2 groups as group G (gelatin) and group C (Control) in which the dural closure was made with and without subdural application of the gelatin sponge, respectively., Results: In all patients of group G (n = 15), a neomembrane was found when the dura was opened. This layer was easily dissected and showed no or minimal attachment to the underlying cerebral cortex. However, in group C (n = 14), meningocerebral adhesions in various degrees were detected. Adhesion scores were significantly greater in group C than in group G (P < 0.001)., Conclusion: This study proves that, during the dural closure, placing a thin layer of gelatin sponge in the subdural space is a safe and effective method for preventing meningocerebral adhesions., (Copyright © 2015 Elsevier Inc. All rights reserved.)