Adult skull fractures
Helen Whitwell, Christopher Milroy, Daniel du Plessis in Forensic Neuropathology, 2021
Externally, the scalp may show evidence of blunt force impact with combinations of laceration, bruising and abrasion. A variety of linear fractures may be produced in the occipital bone – vertical fractures extending into the occipital suture line or horizontal fractures curving towards the base of the brain (Figures 7.1 and 7.2). The fractures tend to avoid the strengthened buttresses of the internal occipital protuberance (Saukko and Knight 2016). The linear fracture may continue straight through the occipital suture and extend into the base of the skull into the posterior fossa, where it often follows a complex path to the anterior fossa across the occipital suture line with dissemination of the energy of the impact away from the primary impact site. When springing of the sutures is identified, further fracturing may be seen extending into the posterior fossa away from the primary impact site. Typically in such accelerated falls the brain shows a contre-coup pattern of contusion and laceration (see Chapter 10). Contre-coup orbital plate fractures are not infrequently seen in this scenario (see later).
Discussions (D)
Terence R. Anthoney in Neuroanatomy and the Neurologic Exam, 2017
There is no generally recognized “axis” of the cerebellum, nor did I find described in any recent textbook or atlas a means of ascertaining the orientation of the cerebellum when the head is in the standard anatomical position—i.e., when the plane of Frankfurt is horizontal. To investigate that orientation, I used two landmarks—the internal occipital protuberance of the skull and the apex of the roof of the fourth ventricle. A bilaterally symmetrical plane joining these two points divides the ovoid cerebellum into roughly equal superior and inferior halves. These landmarks can easily be seen on midsagittal MRI (magnetic resonance imaging) scans of the head as well as on radiologic studies with the fourth ventricle visualized in lateral view—e.g., some pneumoencephalograms.To estimate the angle of the line joining the internal occipital protuberance and the apex of the fourth ventricle (to be called the “mid-cerebellar axis”) to the plane of Frankfurt in lateral view, I used two midsagittal MRI scans (K&S, Fig. 22- 10 [p. 272]; Gademann, 1984, Fig. Sla [p. 22]). 1 had already determined the orientation of the plane of Frankfurt on each scan (see above for details). On both scans, the mid-cerebellar axis sloped upward from posterior to anterior, relative to the plane of Frankfurt. On the scan from Gademann, the axis made an angle of 13.5° (± 2°) to the plane of Frankfurt; whereas the analogous angle on the scan from Kandel and Schwartz was 3° (± 2°).
The Governor Vessel (GV)
Narda G. Robinson in Interactive Medical Acupuncture Anatomy, 2016
Superior sagittal sinus: Begins at the foramen cecum, located at the frontal crest of the frontal bone where it articulates with the ethmoid bone. The superior sagittal sinus drains from rostral to caudal along a groove running inside the frontal and parietal bones. Near the internal occipital protuberance, the superior sagittal sinus drains into the confluence of sinuses and continues with the transverse sinuses, often more closely affiliated with the right one than the left.
Skin flap thickness and magnet strength in Cochlear implants
Published in Cochlear Implants International, 2021
Tamara Searle, Evie Marshall, Louise Craddock, Peter Monksfield
Eighteen had imaging in the form of MRI, CT cone beam or both; these patients were excluded. Cone beam CT is different to the standard axial CT for skin measurements and so cannot be compared for this series. A further 54 patients were excluded due to poor quality of images or unavailability of the images on the PACS system. To standardise the skin thickness measurement taken in all patients, on axial CT scan, the slice was chosen at the top of the pinna on the side of implantation. A line was drawn from the top of the pinna to the internal occipital protuberance. At the midpoint of this line another line was drawn perpendicular to this. Skin thickness was measured from the outer cortex of the skull to the skin-air interface (Fig. 2).
Quantitative assessment of brainstem distortion in vestibular schwannoma and its implication in occurrence of hydrocephalus
Published in British Journal of Neurosurgery, 2022
Ashutosh Kumar, Sanjay Behari, Jayesh Sardhara, Prabhaker Mishra, Vivek Singh, Vandan Raiyani, Kamlesh Singh Bhaisora, Arun Kumar Srivastava
The midline of the posterior fossa was marked by drawing a straight line, from the midpoint of the clivus to the internal occipital protuberance and its continuation as the internal occipital crest. It was termed line 2. T2 weighted sequential axial images were taken for measurements. Further confirmation was done with constructive interference in steady state (CISS) sequence images when available.
Cranio-cervical junction malformation causing cord compression in infant with achondroplasia: a bigger picture
Published in British Journal of Neurosurgery, 2023
S. Caratella, M. Tarazi, F. T. Tomalieh, G. Spink, S. U. A. Bukhari, I. H. Ahmad, M. M. Hussain
CT of cervical spine (Figure 2) showed a significantly large keel shaped internal occipital protuberance extending to the foramen magnum. The opisthion extended backwards and below the basion level thus reducing the canal diameter at the cranio-cervical junction.
Related Knowledge Centers
- External Occipital Protuberance
- Occipital Bone
- Transverse Sinuses
- Cruciform Eminence
- Groove For Transverse Sinus