A: Distance from pharyngeal tubercle (PT) to the: foramen lacerum (FL); medial external margin of the carotid canal
(CC); anterior tip of the occipital condyle (OC); anterior margin of the foramen magnum (FM).
Nearly all cases are associated with lack of the bony carotid canal
on the affected side.
Also the frequency of insertion of the main and/or accessory sphenoid septa to the optic canal and the carotid canal
It extended inferiorly to the right infratemporal fossa, posteriorly to the petrous bone close to the right carotid canal
, inferomedially to the right parapharyngeal space, medially to the right lateral nasal wall, anterosuperiorly to the right orbit through the inferior orbital fissure, superoanteriorly compressing the right optic canal and superoposteriorly to the sphenoid bone.
Dolenc (21) has described the surgical approach to the lateral and cavernous sinus, including skeletonizing the internal carotid artery in the carotid canal
lateral to the fifth nerve.
Angiographic frequency of blunt cerebrovascular injury in patients with carotid canal
or vertebral foramen fractures on multidetector CT.
The Denver screening criteria for BCI Signs and symptoms * Arterial haemorrhage * Cervical bruit in patient <50 years of age * Expanding cervical haematoma * Focal neurological deficit * Neurological examination incongruous with head CT scan findings * Stroke on secondary CT scan Risk factors for BCI High-energy transfer mechanism with: * LeForte II or III fracture * Cervical spine fracture * Basilar skull fracture with carotid canal
involvement * Diffuse axonal injury with GCS < 6 * Near-hanging with anoxic brain injury CT = computed tomography; BCI = blunt carotid injury; GCS = Glasgow Coma Score.
Longitudinal fractures begin in the squamous part of the temporal bone, extend through the external auditory canal, across the middle ear, and terminate near the carotid canal
. Hearing loss in this type of fractures is usually conductive due to ossicular dislocation.
At the level of the skull base, the left internal carotid artery is absent (Figure 2A) and there is also absence of the left carotid canal
The rationale behind this is that the pneumatization of the petrous apex cells near the genu of the internal carotid canal
is a risk factor of CSF leaks through the ET [23-25].
Mechanisms in BCVI are thought to include cervical hyperextension or hyperflexion, internal carotid artery stretching over vertebral bodies one and two, direct cervical trauma, intraoral trauma, and basilar skull fracture involving the carotid canal
From an inferior view, there are ten skull base foramina conventionally described as constant: greater palatine, lesser palatine, lacerum, ovale, spinosum, external opening of the carotid canal
, stylomastoid, jugular, mastoid, and external opening of the hypoglossal canal (Drake et al.).