Approach

Key risk factors for skull fractures include a fall, a motor vehicle accident (MVA), assault resulting in head trauma, gunshot injury to the head, and male sex.[2][4][5][7][8][11]​ However, skull fractures can be found even in patients with minor head trauma, and may feature in 2% to 20% of all pediatric head trauma presenting to emergency rooms, and in 5.8% of minor adult head trauma.[2][7]​ Therefore, in the presence of even minor head injury, a high level of suspicion must be maintained. With the exception of basilar skull fractures, isolated skull fractures rarely manifest any clinical signs. In one study, only 2.1% of patients with fractures had clinical signs of injury; and signs, when present, were nonspecific.[7]

It is very important to identify patients with associated intracranial injury early in order to institute emergency management. The patient's neurologic status should both be assessed at initial presentation and be subsequently monitored to help guide management decisions. A computed tomography (CT) scan of the head and brain should be considered in high-risk patients or those with deteriorating neurologic status.[28]​​[29][30]

History

Patients may report a history of trauma. This may include a fall (especially from a height), MVA, or assault.[2][4][5][8][11] The trauma may be relatively minor.[7]

Presenting complaints may be due either to the skull fracture itself or to associated injury.

Basilar fractures can also affect cranial nerves resulting in hearing deficit, facial paralysis (VII) or numbness (V), and nystagmus.[1]​ Facial (VII) nerve injury may cause sensorineural hearing loss. Conductive hearing loss may also present early (<3 weeks) due to hemotympanum with temporal bone fractures, or later (>6 weeks) with longitudinal temporal bone fracture with disruption of the ossicular chain.

Less-specific features include cranial pain and swelling, and patients may complain of headache and/or nausea. They may report loss of consciousness, which may be related to associated intracranial pathology rather than to the fracture itself.

In children, any history of previous hospital attendance for nonaccidental injury should be considered. This and any clinical signs and symptoms inconsistent with the history (e.g., unexplained bruising, faltering growth for age) should prompt the physicians to consider child abuse as an underlying etiology. See Child abuse.

Cranial exam

The skull should be manually examined for bony deformity. A laceration (or wound) to the skin/soft tissue with visible exposed fractured bone or bone fragments is suggestive of a skull fracture. However, palpable changes in the bony cortex contour (step-offs) or palpable fracture fragments are rare.

The majority of patients present either with no evidence of injury or with nonspecific evidence of trauma, such as soft-tissue swelling, hematomas, crepitus, lacerations, and tenderness. Altered mental status and loss of consciousness are related to underlying associated intracranial injury, and are rare in isolated skull fractures. The presence of cranial hematomas is more suggestive of a skull fracture in children than in adults.[31] Unexplained dental injury and/or the presence of torn lingual or labial frenae should prompt consideration of child abuse.[32]​ See Child abuse.

Basilar skull fractures often have specific clinical features. Blood pooling from these fractures can result in ecchymosis over the mastoid area (e.g., Battle sign); periorbital ecchymosis (raccoon eyes), particularly if unilateral; and bloody otorrhea. Cerebrospinal fluid (CSF) leakage can result in CSF rhinorrhea or otorrhea. The positive predictive value in detecting a basilar skull fracture is 85% for a unilateral raccoon eye, 66% for the Battle sign, and 46% for bloody otorrhea.[1] Furthermore, these signs may assist in localization of the basilar fracture; Battle sign and otorrhea are most often associated with fractures of the petrous portion of the temporal bone, while periorbital ecchymosis and CSF rhinorrhea are more often associated with fractures of the anterior cranial fossa.[1] There are no data to support the use of the "halo" sign, where CSF may be distinguished from blood/mucus by the formation of a "halo" when fluid is deposited on filter paper, as a specific or sensitive marker for CSF leakage.[33]

Neurologic exam

The patient's neurologic status should both be assessed at initial presentation and be subsequently monitored to help guide management decisions. The Glasgow Coma Scale (GCS) is commonly used to assess any associated traumatic brain injury.[34] It also acts as a guide in assessing the need for CT imaging.[29][30]

Pupils should be examined for size, symmetry, direct/consensual light reflexes, and duration of dilation/fixation. Abnormal pupillary reflexes can suggest herniation or brainstem injury.

GCS has 3 components: best eye response (E), best verbal response (V), and best motor response (M).

  • Eye opening: spontaneous (4 points); on verbal stimulation (3 points); on painful stimulation (2 points); none (1 point)

  • Verbal response: oriented, fluent, coherent (5 points); disorientated, confused (4 points); incoherent (3 points); incomprehensible (2 points); none (1 point)

  • Motor response: obeys commands (6 points); localizes to stimulus (5 points); withdraws to stimulus (4 points); decorticate or flexor posturing (3 points); decerebrate or extensor posturing (2 points); none (1 point).

The total GCS score is the sum of points from eye opening, verbal response, and motor response scores (ranging from 3 to 15 points):

  • GCS of 13 to 15 is associated with mild brain injury

  • GCS of 9 to 12 is associated with moderate brain injury

  • GCS of <8 is associated with severe brain injury.

CT scan head and brain

CT remains the imaging modality of choice and is superior to magnetic resonance imaging (MRI) for detecting skull fracture in both pediatric and adult patients.[35][36][37]​ All patients with features suggestive of a skull fracture (e.g., Battle sign, periorbital ecchymoses, rhinorrhea, or otorrhea) should have cranial CT. Basilar skull fractures are the most difficult to detect; CT scans should be performed with thin cuts and should include 3D reconstruction of some type.[38][39][40][41]​ A retrospective comparison of 3 different reconstructive techniques revealed the best sensitivity with high-resolution multiplanar reformation (HRMPR), which is currently the standard of care, in combination with maximum intensity projection (MIP) reconstructions.[40] MIP reconstructions increase detection rate by 18% and can detect different types of fractures compared with HRMPR.[41] Yield of fracture detection is increased if more than one radiologist reviews the images.[40]

Other adjuncts to conventional CT include the use of intrathecal contrast to localize the source of CSF leak and CT angiography if there is any suspicion for vascular injury, such as when the fracture involves the carotid canal or overlies a vessel (e.g., middle meningeal artery, sagittal sinus).[37]

However, as skull fractures often present with no clinical symptoms or signs on physical exam but are significant risk factors for intracranial pathology, the question of whom to scan is very important. Prospective evaluation of several head trauma imaging guidelines found that increased sensitivity for detecting pathology was associated with a significant number of unnecessary CT scans.[7] Evaluation criteria to guide imaging include the New Orleans Criteria, the Canadian CT head rule, and the American College of Radiology Appropriateness Criteria®, and UK National Institute for Health and Care Excellence (NICE) criteria.[28][29][30][37]​​​

New Orleans criteria:[29]

  • CT is required for patients with minor head trauma (minor head injury was defined as a loss of consciousness in patients with normal findings on a brief neurologic exam and a GCS score of 15, as determined by a physician on arrival at the emergency room), with any one of the following:

    • Headache

    • Vomiting

    • Age >60 years

    • Drug or alcohol intoxication

    • Persistent anterograde amnesia (deficits in short-term memory)

    • Evidence of traumatic soft-tissue or bone injury above clavicles

    • Seizure (suspected or witnessed).

Canadian CT head rule:[30]

  • CT head required for patients with minor head injuries, defined as witnessed loss of consciousness, definite amnesia, or witnessed disorientation in a patient with a GCS score of 13 to 15, with any one of the following:

  • High risk (for neurologic intervention):

    • GCS <15 at 2 hours after injury

    • Suspected open or depressed skull fracture

    • Any sign of basal skull fracture: hemotympanum, raccoon eyes (periorbital ecchymosis), CSF otorrhea/rhinorrhea, Battle sign (ecchymosis of the mastoids)

    • 2 or more episodes of vomiting

    • Age 65 years or above.

  • Medium risk (for brain injury on CT):

    • Amnesia for >30 minutes before impact (retrograde amnesia)

    • Dangerous mechanism (pedestrian struck by motor vehicle, occupant ejected from motor vehicle, fall from height of >3 feet or 5 stairs).

American College of Radiology Appropriateness Criteria®[37]

  • Patients identified as having moderate or high risk for intracranial injury should undergo early post-injury noncontrast CT for evidence of intracerebral hematoma, midline shift, or increased intracranial pressure.

Additional imaging

X-ray skull

  • Plain films were previously used to help screen patients who would benefit from CT scanning. However, they offer no additional information and are associated with poor sensitivity and failure to detect any associated intracranial pathology.[36] With the widespread availability of CT scans to help detect intracranial pathology, plain skull x-rays are no longer recommended as a first-line investigation in either children or adults. However, they may be used as an interim aid if CT scanning is not available.

MRI brain

  • While CT is considered the first-line imaging modality for suspected intracranial injury, magnetic resonance imaging (MRI) is useful when there are persistent neurologic deficits that remain unexplained after CT, especially in the subacute or chronic phase or in the absence of trauma history.[37] The main benefit of MRI is increased detection of associated intracranial pathology. MRI can detect diffuse axonal injury not seen on the CT scan, and can increase detection of intracranial hemorrhage (extradural/subdural) by up to 30%.[4][35][39][42]​ MRI may therefore be considered if there is continuing concern of intracranial pathology in the absence of CT findings.

  • MRI and MR angiography may also be useful if the fracture involves major vascular structures (e.g., the carotid canal or superior sagittal sinus), to assess underlying vascular injury/pathology.[37]​[39][43][44][45]

Cervical spine imaging

  • Historically, skull fractures (in particular, occipital condylar fractures) were associated with a high risk of cervical spine injury. However, several studies have found no such association.[46][47] Cervical spinal imaging should be at the discretion of the attending physician, based on clinical exam, level of suspicion, age of the patient, and mechanism of injury.

Cranial ultrasound

  • May be a useful adjunct to a CT head following confirmation of a fracture in the pediatric population, to detect dural tears, brain herniation, or a growing skull fracture.[37] There may also be a role for ultrasound to screen for skull fractures in pediatric patients with minor head trauma.[48][49][50]

Skeletal survey

  • Should be considered if child abuse is a suspected underlying etiology.[51][52]​​ The skeletal survey should be composed of frontal and lateral views of the skull, lateral views of the cervical spine and thoracolumbosacral spine, and single frontal views of the long bones, hands, feet, chest, and abdomen. Oblique views of the ribs should be obtained to increase the accuracy of diagnosing rib fractures which may be the only skeletal manifestation of abuse.[51] A repeat limited skeletal survey after 2 weeks can detect additional fractures and can provide fracture dating information.[51] Repeat skeletal survey should be performed when abnormal or equivocal findings are found on the initial study and when abuse is suspected on clinical grounds.[51][53]​ To limit radiation exposure, pelvis, spine, and skull radiographs can be omitted if no injury was initially seen in these regions.[51]

CT angiogram

  • Should be considered if there is any suspicion for vascular injury, such as when the fracture involves the carotid canal or overlies a vessel (e.g., middle meningeal artery, sagittal sinus).[37]

CT venogram

  • From an imaging standpoint, the most important risk factor for traumatic venous injury is a skull fracture (or less commonly a penetrating foreign body) that involves a dural venous sinus or jugular bulb or foramen).[37] In the acute setting, CT venogram is the most useful study in the imaging evaluation of suspected intracranial venous injury.[37][54]

Laboratory investigations

For any patient with head trauma and otorrhea/rhinorrhea, an immunoassay (beta-2 transferrin assay) of the suspect fluid can stain positive in the presence of the protein.

The test should be performed if clear or blood-tinged drainage is present from the nose or ears.

If positive, it indicates CSF leakage and is reliable even in the presence of blood or mucus. It has a sensitivity of nearly 100% and a specificity of 95%.[55]

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