An adult male was found to have a variation of the left basal vein of Rosenthal after presenting with complaints of headache and balance issues. In this case, the vein drained directly into the left superior petrosal sinus (SPS) instead of the great vein of Galen. Anatomical variation of the basal vein is likely due to embryonic development of the deep cerebral venous system as primitive structures either differentiate regress or further with age. These changes may result in the uncommon presentation seen in this case. To our knowledge, this is the first case that shows the basal vein drains into the SPS. The normal and variant anatomy of this vessel are discussed.

Anatomical variations identified at the skull base can result in challenges to the clinician. For example, the anatomy of the foramen ovale and its neighboring structures is critical knowledge for the surgeon who performs transcutaneous approaches to the foramen ovale for treating patients with trigeminal neuralgia. One nearby structure that can compound invasive procedures and potentially result in complications is the foramen of Vesalius. Although usually small, we report a giant foramen of Vesalius found in an adult female skull. The anatomy and clinical aspects of such a finding are discussed and related to other reports in the literature.

Trabeculae or septations in the transverse sinus can have potentially life-threatening clinical significance. The current study demonstrates trabecula/septum patterning within the transverse sinus with measurements and distribution data supplemented by imaging, and describes the possible etiology of idiopathic intracranial hypertension and turbulent blood flow in the transverse sinus. Twenty-four sides from 12 cadaveric heads, all fresh-frozen, were used (five males, seven females; age at death 65–91 years, mean 79.1 years). The length and diameter of the transverse sinus were measured along with the number and locations of septations/trabeculae and their tensile strength. The mean length of the transverse sinus was 68.43 mm on the right side and 74.31 mm on the left. A total of 42 septations were found in the 24 transverse sinuses.The number of septations per side ranged from zero to four with a mean of 1.75. The septations were located in the proximal 1/3 in 54.8% (23/42), the middle 1/3 in 21.4% (9/42), and the distal 1/3 in 23.8% (10/42). The work presented here furthers our understanding of transverse sinus anatomy, including its detailed internal architecture. The measurements can provide a technical guide for neurosurgeons and influence instrument selection when a large thrombus forms or anchors in one of these trabeculae or septa and necessitates treatment.

The external carotid plexus is a combination of postganglionic sympathetic fibers derived from the superior cervical ganglion. This plexus travels along the external carotid artery and continues onto the artery’s branches. The external carotid plexus plays an important role in innervating the mid and lower face. Therefore, implications to the plexus may result in facial abnormalities. Herein, we review the anatomy, function, and review its clinical applications.

The pathogenesis of Chiari 1 malformations has been explained in several different ways, but extensive evidence suggests a relationship between loss of volume within the posterior cranial fossa and Chiari 1 presentations. It is important to be able to differentiate Chiari 1.5 from Chiari 1 malformations as they have similar clinical presentations, but the latter have progressed further and are characterized by caudal herniations of the brain stem through the foramen magnum. Despite the similarities of presentation, Chiari 1.5 malformations have greater rates of complications following posterior decompression surgeries, which are typically performed to relieve ventral compression. An improved understanding of the odontoid synchondroses could lead to better understanding of Chiari malformations and lead to improved treatment of patients with these presentations. Here we present a rare case of an accessory odontoid synchondrosis in a patient with a Chiari 1.5 malformation and ventral compression.

We present a rare case of external carotid artery-vertebral artery anastomosis via the ascending pharyngeal artery, diagnosed upon cadaveric dissection. The ascending pharyngeal artery gave rise to a branch to the hypoglossal canal, which is a variation of a true persistent fetal hypoglossal artery. Knowledge of persistent carotid-vertebrobasilar anastomoses is important as these fetal vessels can contribute significantly to the posterior cerebral circulation. Only 10 cases of external carotid artery-vertebrobasilar artery anastomoses have been reported to our knowledge, and our case presents the first cadaveric dissection of this rare variation.

Knowledge of the variant anatomy of the intradural venous sinuses is important to anatomists and clinicians alike. Herein, we report a cadaveric case of the rare venous sinus of Kelch, which some have believed is a remnant of the cranioorbital sinuses. To our knowledge, only one other cadaveric case has been reported in the extant medical literature. Clinically, knowledge of such a variant venous sinus can minimize misdiagnoses such as when anatomical variations are noted on imaging. Surgically, such an understanding can avoid intraoperative complications such as iatrogenic hemorrhage.

Variations of the ovarian veins can impact imaging diagnosis, surgical procedures of the region, and can be related to clinical findings such as compression of the ureter. Therefore, a good working knowledge of such variants is important to the clinician who interprets imaging of the posterior abdominopelvic region of women and surgeons who operate in this region. Herein, we present a comprehensive review of duplicated ovarian veins and provide a case illustration.

Variations of the skull base can affect surgical approaches and must be considered when viewing and interpreting radiological imaging. Here, we report a unique collection of bony anatomical variations found on a single adult skull. Three bony excrescences from the occipital bone were identified in the paracondylar region. The smallest of these processes was 7 mm long and was just medial to the mastoid process of the temporal bone and posterior to the styloid process. One bony process was attached to the occipital condyle and was 12 mm in length. The longest of these processes was 17 mm long and arose from the jugular process of the occipital bone. Paracondylar processes can be symptomatic. Knowledge of the bony variations at the skull base is important to those who operate in this region or review and interpret radiological imaging.

The vasculature of the pituitary gland is discussed briefly and the details of an anatomical discovery of the vessels supplying the pituitary gland provided. Twenty latex injected cadaveric heads were dissected. Any vessels that were found to penetrate the sella turcica and travel to the pituitary gland were documented and measured. Additionally, 25 adult skulls were evaluated for the presence, size, and sites of bony foramina in the floor of sella turcica. Trans-sellar vessels were identified in 65% of specimens. There was a mean of 1.5 vessels per specimen consisting usually of a mixture of veins and arteries. The mean diameter of these vessels was 0.3 mm and the mean length from the sella turcica to the pituitary gland was 2.3 mm. These vessels were concentrated in the most concave part of the sella turcica. In bony specimens, the mean number of transsellar foramina was four. The diameter of these foramina ranged from 0.3 to 0.6 mm in size. The trans-sellar foramina were concentrated near the center part of the sella turcica and had no regular pattern. The pituitary gland receives at least some blood supply and drainage via vessels traveling along the septum of the sphenoidal sinuses and through the sella turcica.Knowledge of such vessels might lead to a better understanding of the vascular supply and drainage of the pituitary gland and would be useful during skull base approaches such as trans-nasal approaches to the pituitary gland.