Cerebellopontine angle and vascular supply of adjacent brainstem and cerebellum are susceptible to compression and eventual damage by tumors. Delicate and complicated neurosurgical operations in the cerebellopontine angles of the brainstem, where lateral recesses of fourth ventricle empty, are abundant especially operations in which foramina of Luschka are used as possible access to the floor of the fourth ventricle. So awareness and knowledge of the normal anatomical features of the region is valuable for neurosurgeons. Arteries of 40 human cerebella were injected with colored gelatin to investigate the microsurgical anatomy around the foramen of Luschka in the cerebellopontine angle. Two compartments of the foramen of Luschka were distinguished, choroidal part and the patent part. Seventy-four (92.5%) of foramina were open and only 6 (7.5%) foramina were closed. The mean distance between the foramen of Luschka and the anterior inferior cerebellar artery was 3.90 mm on the left side and 3.89 on the right side. The distance from the posterior inferior cerebellar artery was 7.08 and 5.81 mm to the left and right foramina of Luschka, respectively. In ten cases, tortuous vertebral artery was occupying the left cerebellopontine angle space and the foramen of Luschka.

The pterygoid hamulus (PH) is located in the infratemporal fossa and is part of the pterygoid process of the sphenoid bone. Its location on the cranial base and the multitude of anatomical structures whose attachments lie on the surface of the pterygoid hamulus make it of high functional and topographic significance. Due to insufficient literature on the PH morphometry, we decided to study this issue using modern and archaeological material. In total, 99 observations were subjected to quantitative and qualitative analysis (50 - from modern times and 49 - from medieval times). On the basis of the statistical analysis, statistically significant differences in the length of PH were found with respect to age and sex. Statistically significant differences in the PH width were also noticed with respect to sex and the period of origin. The results obtained may help better understand the development mechanism of the pterygoid hamulus bursitis.

Posterior inferior cerebellar artery (PICA) is one of the cerebellar arteries which originates from the vertebral artery and has the most complex and variable course. It usually originates from the vertebral artery intracranially and as a single trunk; however, absent, double trunk, extracranial, and extradural PICA may exists although very rare. In a collection of 50 cerebellar specimens (100 hemispheres) injected with colored gelatin, we have encountered unilateral double PICA in 2 specimens. In both the cases (both male, aged 45 and 65 years) double trunks of PICA were observed on the right side. Double-trunk PICA may signal an improved blood supply to the corresponding cerebellar hemisphere; however, the second trunk, which may also be called an accessory trunk, is usually smaller than the first (main) trunk of PICA.