A basilar skull fracture is a fracture occurring in the bones that constitute the base (bottom part) of the skull. It is usually a result from strong blunt force applied to the head, such as falling from the high. The temporal region of skull is the most common location. Fracture causes intracranial hemorrhage is a possible life-threatening complication, requiring immediate surgical management.
Presentation varies with the fractures location and extent.
Temporal fractures may manifest with a CSF leakage from ear canal (otorrhea) and bruises on the mastoid processes (Battle sign), whereas anterior variants may show characteristic hematomas around the eyes (raccoon eyes) and CSF rhinorrhea. Occipital condylar fracture has a much more severe course , usually resulting in coma. Condylar fractures are also associated with co-occurring cervical spine injuries potentially causing hemiplegia or quadriplegia. The injury of IX, X, XI, and XII cranial nerves with occipital condylar fracture is referred to as Collet-Sicard syndrome   .
A variety of symptoms may develop depending on the involvement of cranial nerves and related structures. Longitudinal temporal fractures are frequently resulting in the hearing apparatus damage and conducting deafness usually lasting longer than 6 weeks. However, hearing loss may be also caused just by the collection of blood (hemotympanum) and associated mucosal edema. In that case, deafness usually goes away in 3 weeks or less. Transverse temporal fractures tend to injure cranial nerve VIII causing permanent sensorineural hearing loss as well as nystagmus and ataxia.
The co-occurring damage to the VII, VI, and V cranial nerves may manifest as facial paralysis and numbness as well as nystagmus. The Vernet syndrome is an injury of the IX, X, and XI cranial nerves in the jugular foramen and presents as vocal cord and palate paralysis on the ipsilateral side resulting in difficulties with speech.
CT scan is an ultimate diagnostic modality for the skull fractures , having sensitivity of 85.4% and specificity of 100% . Sagittal reconstruction with thin slices of 1-1.5 mm thickness is the optimal mode of CT scanning. Helical scan may be useful for evaluating occipital condylar fractures.
CT scan is superior to other imaging studies. Some studies report CT scans missing up to 11.9% of skull fractures with a plain x-ray missing approximately 19.1% of them. However, plain x-ray may be useful for diagnosis of the fracture at the vertex, which tend to be missed more by CT.
To ascertain the content of leakage from nose or ear as CSF, a “halo” sign may be tested. When dabbing the tested liquid on a tissue paper it will form a clear ring beyond the blood area. Laboratory testing of the liquid could also be performed as CSF contains certain amounts of glucose and tau-transferrin, which may differentiate it from other liquids.
A complete physical examination must be performed on all patients with the particular focus on neurologic functions.
All patients with basilar skull fractures need to be immediate hospitalization as serious life-threatening complication could arise and require immediate management. Intracranial hemorrhages is an example of such surgical emergency.
The CFS leaks, although usually resolve spontaneously in a time of one week, may pose a risk for development of meningitis. The risk for meningitis is reported to be approximately 3% during the first week of admission. Studies suggest that antibiotic prophylaxis is not sufficiently effective in prevention of meningitis in patients with basilar skull fractures in the first seven days, however, may provide a benefit if the leakage continues past the first week .
Cranial nerve deficits due to compression or contusion usually have delayed presentation and may resolve with glucocorticoids treatment, however, the research data supporting such management is not sufficient at the time. The treatment strategies of the nontraumatic neurological deficits such as Bell's palsy may be applied in the cases of basilar skull fracture. Facial nerve deficits caused by nerve transection are not recoverable and will not respond to corticosteroids.
Stable fractures without displacement may heal spontaneously. However, a couple of complications may arise following the course of the disease. Patients are particularly prone to meningitis with antibiotic prophylaxis showing questionable efficacy. Temporal fractures may affect the internal carotid artery through damage of carotid canal , which certainly makes the prognosis less positive.
The causative event of the fracture is applied force. Amongst the most common causes are assault (30%), motor vehicle accidents (20-25%) , and most frequently, the fall from high (25-35%). The cause also differs with age. Physical abuse and falls are the most common etiology in infants. In adults and adolescents the most common causes in decreasing order are falls, motor vehicle accidents and assaults .
The type of occurring fracture depends on the vector of the applied external force and the surface it is applied to. Linear fractures are usually occurring from falls, when mild force is utilized over a broad surface. Comminuted and depressed types are possible from assault performed with blunt or sharp object. In these types of fractures the resulted injury is from severe force applied over a smaller localized area. Comminuted and depressed types also happen from penetrating and gunshot wounds.
Basilar skull fracture in children should rise a concern for physical abuse as a possible cause if the parents explanation of occurred events is not consistent with the injury. Thorough examination for other possible signs such as retinal hemorrhages, bruises and burns and long-bone fractures should be performed if abuse is suspected. However, the prevalence of basilar skull fracture is reported to be higher in non-abused rather than abused children under the age of 2.
Of all the head trauma, skull fractures account for 2% to 20% of the cases. The annual incidence in general population is 35 to 45/100,000 . Basilar skull fracture accounts for approximately 20% of all skull fractures.
Basilar skull fractures tend to more likely affect younger and most active part of population in the ages of 20 to 50 years. Most of the patients are male as the male gender has been associated with consistently higher risks for trauma, probably due to the fact that men are more prone to risky behavior, crime and violence in general.
The exact pathophysiology of basilar skull fracture depends on the specific location of the fracture on the skull base. In general, basilar skull fractures are a form of linear fracture and usually are accompanied by the tear in dura.
Temporal bone is the most common location of basilar skull fracture and represents 75% of all skull base fractures. Several classifications of the temporal fracture exist.
Temporal fractures can be either longitudinal, transverse or mixed. Longitudinal type is the most common (70-90%) and constitutes for the fracture of temporoparietal zone. It affects such structures as the superior wall of the external auditory canal, squamous portion of the temporal bone and the tegmen tympani. The fracture may extend further into the cochlea and labyrinth and even reach the foramen spinosum of middle cranial fossa or the mastoid air cells. Transverse type is less common (5-30%) and originates at the foramen magnum. Transverse fracture may also reach middle cranial fossa, cochlea and labyrinth. Mixed type has features of both types.
Temporal fractures can also be classified as petrous and nonpetrous. Nonpetrous type is characterized by mastoid cell involvement and is not associated with cranial nerve injury .
Occipital condylar fracture
Occipital condylar fracture occur from damage to the alar ligament. The possible ways of such injury are axial compression, bending or rotation from blunt force. Three types of the occipital condylar fracture have been described. An additional specification may be made as to involvement of ligaments with differentiation of stable and displaced subtypes .
Clivus fracture occurs from a forced blow in the events of motor vehicle collisions. Several types have been described, such as longitudinal, transverse and oblique. Longitudinal type accounts for the worst outcomes, as it can affect the vertebrobasilar system and cranial nerves VI and VII .
Skull fractures can be prevented by basic safety measures. Protective gear (helmets) should be worn during such high-risk activities as motorcycle and bicycle riding and active sports.
A basilar skull fracture is a fracture occurring in the bones that constitute the base (bottom part) of the skull. The skull has several “weak” anatomical points which are prone to fracture when the extensive force is applied. Amongst these sites are the cribriform plate, roof of the orbits, temporal and parietal bones, sphenoid sinus, foramen magnum and the skull base . In the base of the skull, the middle cranial fossa consists of rather weak structures of thin bones and multiple orifices. Anterior and posterior fossa also have certain soft spots at the upper walls of the orbits and mastoids, respectively.
A sufficient force need to be applied to the skull in order to cause a basilar fracture. Most commonly it happens as the result of a falls, motor vehicle accidents or violent assault. The most common cause varies in different age groups. The active population is more affected and the majority of the patients are male.
The characteristics and the applicable area of the force are influencing the type of fractures that occur. The basilar skull fracture can develop at the temporal, occipital and clivus locations. Temporal fractures are the most common and are classified as longitudinal, transversal or mixed as well as petrous and non-petrous in regards to the fracture location. Occipital fractures are classified as three types and stable versus dislocated. Clivus fracture is also a possible subtype.
The presentation varies according to the location. All types can present with cerebrospinal fluid (CSF) leakage from nose and ears, which usually resolves spontaneously, however, also makes patients vulnerable to meningitis. The anterior fossa fractures may classically present with dark bruises around the eyes (raccoon eyes) and the posterior fossa fractures manifest as bruising on the mastoids (Battle sign). The occipital condylar fracture is usually severe and results in coma. A diverse variety of symptoms may arise from the cranial nerves involvement. Some of the most common are hearing loss and facial palsy.
The computed tomography (CT) scan is the main diagnostic modality. Other imaging studies are not as effective. Laboratory testing of leakage from the nose or ear may be performed to determine if the liquid is CSF.
All patients have to be hospitalized due to possible life-threatening emergencies like intracranial hemorrhage. Antibiotic prophylaxis for meningitis has not been proven to be effective. Cranial nerves involvement may respond to corticosteroid therapy if it is caused by compression, however, transection injuries are permanent.
A basilar skull fracture is a fracture of the bones located at the bottom of the skull, which is called the base of the skull. Those bones are the temporal bone, occipital bone, sphenoid bone and ethmoid bone.
It is a rather rare type of fracture and requires a blow of significant force to be applied to the head. This is most commonly happening from the falls from high places, during the motor vehicle collisions and violent assaults.
Symptoms of the basilar skull fractures may be depends on the exact location of the fracture and the surrounding blood vessels, nerves and brain structures. Some of the possible symptoms: clear or mixed with blood liquid oozing from the ear or nose (the liquid is called cerebrospinal fluid and normally covers the brain and spinal cord), hearing loss, blurred or decreased vision, trouble with maintaining posture, headache, nausea, vomiting, weakness and numbness of the face and body, bruises around the eyes and behind the ear. In severe cases people with basilar skull fractures may appear in coma.
The doctors will need to take images of the patient’s brain in order to make the diagnosis and determine the treatment plan. This is usually done with computed tomography (CT) scan. If a leakage from the nose or ear is present, a sample may be taken to the laboratory to determine the origin of the fluid.
All patients with basilar skull fractures need to admit in hospital immediately and closely monitored for some time. In some cases, surgical intervention is necessary. The medication to reduce the inflammation of compressed nerves may be given to reduce symptoms.