fractures of the clivus are very rare , occurring in only 0.55% of head injury patients . longitudinal fractures are associated with a 67 - 80% mortality rate ( 1 , 2 ) , apparently due to vertebrobasilar artery occlusion ( 3 - 9 ) and direct brain stem trauma ( 10 , 11 ) . there are only 11 reported cases of vertebrobasilar artery entrapment or prolapse associated with longitudinal clivus fractures . eight of those cases were only identified at autopsy , while the other 3 cases ( 12 - 14 ) survived but had various neurological deficits . the present report describes a rare case of traumatic vertebrobasilar junction entrapment due to a longitudinal clival fracture . the patient was treated using surgical decompression of the left cerebellar infarction caused by the left vertebral artery occlusion . the patient was riding bicycle and landed face - down on a hard road surface . he presented with severe right facial and ocular swelling , and profuse cerebrospinal fluid ( csf ) rhinorrhea . neurological findings included a stuporous mental state ( gcs=8 ) and left hemiparesis ( grade 3 ) . brain and facial computed tomography ( ct ) revealed a comminuted fracture of the right frontal bone and anterior skull base extending to the clivus posteriorly , inferior and medial orbital wall fractures with extension to the maxillary sinus , diffuse but predominantly right - sided subdural hematoma , and a right - sided parenchymal frontotemporal hemorrhagic contusion with a 6.65 mm midline shift to the left side ( fig . after surgery , the patient showed decreased consciousness ( gcs=5 ) , aggravated left hemiparesis ( grade 2 ) , and worse right arm and leg response ( grade 3 ) under noxious stimuli . a brain ct scan on the second postoperative day demonstrated low - density lesions in the left cerebellum and lateral pons ( fig . 2 ) , indicating a left posterior inferior cerebellar artery ( pica ) territory infarction . a ct angiogram ( fig . 3a ) and its source images ( b ) revealed the right vertebral artery ( a , b ) , and the entrapped vertebrobasilar junction ( c , d ) and basilar artery ( e ) . a transfemoral conventional angiogram showed obstruction of the left vertebral artery in the cervical region ( fig . the patient underwent a suboccipital decompressive craniectomy and a c1 laminectomy in order to widen the foramen magnum ( fig . the patient remained dependent in terms of daily living activities , and required a wheelchair for movement . while longitudinal clivus fractures are associated with a 67 - 80% mortality , transverse or oblique fractures have a better prognosis but are still associated with cranial nerve deficits . identified nine cases involving clival fractures from the ct scans of 2,500 head injury patients . five of those patients had longitudinal fractures , and three of them died ( 15 ) . reported 17 cases of clival fracture from the ct scans of 3,000 head injury patients . there were four deaths among them , including a case involving a trapped vertebral artery according to the vertebral angiogram ( 2 ) . joslyn et al . identified 11 cases of clival fracture from another series of 2,000 head injury patients . five patients had longitudinal fractures , and four of those five died ( 1 ) . all of the three aforementioned reports suggested that vascular injury affecting the posterior circulation was a key reason for such a high mortality rate . to date , there have only been 11 confirmed cases ( including corradino 's case ) of longitudinal clival fractures associated with prolapse or entrapment of the vertebrobasilar arteries ( table 1 ) . autopsy results in several cases showed complete occlusion of the prolapsed artery within the fracture , or thrombosis of the proximal basilar artery ( 2 - 7 , 10 - 13 ) . in the present case , even though there was occlusion of the left vertebral artery and narrowing of the vertebrobasilar junction according to the ct angiogram , there was good distal basilar arterial flow . in addition , the decompressive suboccipital craniectomy was probably helpful in reducing brain stem compression caused by the infarction . in the current study , ct angiography was used to confirm the diagnosis of vascular entrapment . however , in most other cases , the patients died almost instantaneously as a result of the injury , and further imaging studies were not possible . magnetic resonance ( mr ) angiography may reveal vascular occlusion and other additional findings in some cases ( 13 , 14 ) . clival fractures are created as a result of three potential directional forces : frontal , occipital , or axial impact ( 14 ) . sights et al . suggested ( 3 ) that frontal impact contributes to multiple facial fractures , and temporary deformation and an increased coronal dimension create a longitudinal clival fracture , such as that seen in the present patient . occipital impact may have a similar mechanism in the formation of a longitudinal fracture ( 1 , 8 , 9 ) . a direct blunt injury to the vertex may cause enough axial force to form a fracture ( 3 , 6 , 9 ) . clivus fractures may be under - diagnosed due to the difficulty of demonstrating them on plain head radiographs . however , current bony window ct imaging has clearly shown the condition is not as infrequent as previously believed ( 9 ) . a ct angiogram is an essential diagnostic work - up in terms of associated vascular injury . in selected cases
vertebrobasilar junction entrapment due to a clivus fracture is a rare clinical observation . 
 the present case report describes a 54-yr - old man who sustained a major craniofacial injury . 
 the patient displayed a stuporous mental state ( glasgow coma scale [ gcs]=8 ) and left hemiparesis ( grade 3 ) . 
 the initial computed tomography ( ct ) scan revealed a right subdural hemorrhage in the frontotemporal region , with a midline shift and longitudinal clival fracture . 
 a decompressive craniectomy with removal of the hematoma was performed . 
 two days after surgery , a follow - up ct scan showed cerebellar and brain stem infarction , and a ct angiogram revealed occlusion of the left vertebral artery and entrapment of vertebrobasilar junction by the clival fracture . 
 a decompressive suboccipital craniectomy was performed and the patient gradually recovered . 
 this appears to be a rare case of traumatic vertebrobasilar junction entrapment due to a longitudinal clival fracture , including a cerebellar infarction caused by a left vertebral artery occlusion . 
 a literature review is provided .