Pediatric Head Trauma Workup

Updated: Dec 17, 2017
  • Author: Michael J Verive, MD, FAAP; Chief Editor: Muhammad Waseem, MBBS, MS, FAAP, FACEP, FAHA  more...
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Workup

Laboratory Studies

A complete blood cell (CBC) count should be monitored serially, especially when bleeding is suspected in patients with head trauma. Blood chemistry studies, including amylase and lipase levels, provide information regarding other organ injuries.

A coagulation profile; a prothrombin time (PT), with international normalized ratio (INR); activated partial thromboplastin time (aPTT); and a fibrinogen level should be obtained in patients with head trauma because these patients may have an underlying or trauma-triggered coagulopathy.

An admission INR measurement of 1.3 or higher appears to be a strong independent prognostic factor for death in children who have suffered abusive head trauma. [29] A retrospective study (2005-2014) of 101 level 1 pediatric (age, 0-17 years) trauma patients with abusive head trauma noted an overall mortality of 24.8%, of which 60% were in children with an INR of 1.3 or greater. Elevated INR was also associated with more early packed RBC transfusions and neurosurgical intervention. [29]

Typing and cross-matching of blood is useful in anticipation of a possible need for transfusion, especially in patients with multiple trauma.

Arterial blood gas values provide information regarding oxygenation, ventilation, and acid-base status and can be used to help direct further treatment.

A blood or urine toxicology screen should be obtained in addition to the routine panel, especially in patients who have altered mental status, seizures, and an unclear history.

S100β and Glial fibrillary acidic protein

Serum levels of S100β (S100B) protein appear to be a useful adjunct diagnostic tool for detecting intracranial injury in children with mild head trauma, having a high degree of sensitivity (all children, 95%; those aged >2 years, 100%) but poor specificity (all children, 34%; those aged >2 years, 37%). [30]

Glial fibrillary acidic protein (GFAP) appears to outperform S100β as a marker for detecting intracranial lesions on computed tomography (CT) scanning not only in adults but also in children and youth with mild traumatic brain injury. [31]  In one study, the area under the receiver operating characteristic curve (AUC) for distinguishing head trauma from no head trauma for GFAP was 0.84 but 0.64 for S100β, and the AUC for predicting intracranial lesions on CT scanning for GFAP was 0.85 versus 0.67 for S100β. In children 10 years or younger, the AUC for predicting intracranial lesions was 0.96 for GFAP and 0.72 for S100β, whereas in those younger than 5 years, the AUC was 1.00 for GFAP and 0.62 for S100β. [31]

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Computed Tomography

Computed tomography (CT) scanning of the head remains the most useful imaging study for patients with severe head trauma or unstable multiple organ injury. [1]

Indications for CT scanning in a patient with a head injury include anisocoria, Glasgow Coma Scale (GCS) score less than 12 (some studies suggest CT scanning in any pediatric patient with a GCS score of < 15), posttraumatic seizures, amnesia, progressive headache, an unreliable history or examination because of possible alcohol or drug ingestion, loss of consciousness for longer than 5 minutes, physical signs of basilar skull fracture, repeated vomiting or vomiting for more than 8 hours after injury, and instability after multiple trauma. Various studies and prediction algorithms (eg, National Emergency X-Radiography Utilization Study II [NEXUS II], Canadian Assessment of Tomography for Childhood Head Injury [CATCH], among others) have attempted to assess the ability of clinical characteristics to predict the utility of neuroimaging for patients with mild head injury, but there remains considerable variation in clinical practice.

One study noted that CT scanning may be unnecessary for children who are at very low risk for clinically important traumatic brain injury (TBI) after closed head trauma. In this study, the prediction rules for children younger than 2 years were normal mental status, no scalp hematoma except frontal, no loss of consciousness or loss of consciousness for less than 5 seconds, nonsevere injury mechanism, no palpable skull fracture, and normal behavior as deemed by the parents. The prediction rules for children older than 2 years were normal mental status, no loss of consciousness, no vomiting, nonsevere injury mechanism, no signs of basilar skull fracture, and no severe headache. [32]

A retrospective study (2014-2016) indicated that a subset of pediatric patients up to age 24 months whose presentation to an emergency department was delayed (>24 hours) after minor head trauma and who had scalp swelling with otherwise nonfocal neurologic findings did not need surgical intervention nor experienced any neurologic decline. [33] Neurosurgical management in these patients was not affected with findings from further radiographic studies.The investigators noted that CT scan findings might have influenced workup for child abuse and social care and suggested further work needs to be done to determine how to safely avoid CT scanning in the setting of delayed presentation after minor head trauma with scalp swelling. [33]

A noncontrast study is useful in the immediate posttrauma period for rapid diagnosis of intracranial pathology that calls for prompt surgical intervention.

CT scanning provides information regarding the following:

  • The integrity of soft tissue and bone, the size of the fontanel and suture lines, and the presence of foreign bodies

  • The appearance of the normal structures, the presence or absence of hemorrhage, and signs of edema, infarct, or contusion

  • Mass effect as indicated by midline shift

  • The appearance of the ventricles and cisterns - Compression of the ventricles is suggestive of mass effect; ventricular enlargement may suggest development of hydrocephalus from intraventricular hemorrhage or blockage by mass effect

  • The presence of cerebral edema as indicated by loss of gray-white matter demarcation

In the absence of neurologic deterioration or increasing intracranial pressure (ICP), obtaining a repeat CT scan more than 24 hours after the admission and initial follow-up study may not be indicated for decisions about neurosurgical intervention.

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Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is a more sensitive imaging study than computed tomography (CT) scanning in the setting of traumatic brain injury, providing more detailed information regarding the anatomic and vascular structures and the myelination process as well as allowing the detection of small hemorrhages in areas that might escape CT scanning.

MRI is useful for estimating the initial mechanism and extent of injury and predicting its outcome in the neurologically stable patient. It is not practical in emergency situations, because the magnetic field precludes the use of the monitors and life-support equipment needed by unstable patients. In addition, the time required for obtaining the appropriate MRI studies can cause unacceptable delays in the management of patients with severe traumatic brain injury.

Although MRI sensitivity is understood to be superior to CT scanning for intracranial evaluation, it is not as easily obtained acutely after injury and has not been as widely validated in large studies, particularly regarding influence on management decisions. In current practice, little evidence supports the use of MRI in influencing management of patients with severe traumatic brain injury. [34]

Ultrafast MRI appears to have limited use in pediatric patients for the evaluation of abusive head trauma. In a prospective study that compared nonsedated ultrafast MRI, noncontrast head CT scanning, and standard MRI for identifying intracranial trauma in 24 children with potential abusive head trauma (AHT), interreader agreement between two pediatric neuroradiologists were almost perfect for standard MRI and substantial for noncontrast CT scanning but only moderate for ultrafast MRI. [35] There was a high discrepancy rate between standard MRI and ultrast MRI (42% of patients). The specificity and positive predictive values were 100% each for noncontrast CT scanning, ultrast MRI, and a combination of the two; however, noncontrast CT scanning had a 25% sensitivity and 21% negative predictive value versus 50% and 31%, respectively, for ultrafast MRI. Sensitivity for detecting intraparenchymal hemorrhage was greater for ultrafast MRI than noncontrast CT scanning, and the combination of both was more sensitive for intracranial trauma than noncontrast CT scanning alone. [35]

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Ultrasonography

Ultrasonography can be performed in neonates and small infants with open fontanel and may provide information regarding intracranial bleeding or obstruction of the ventricular system.

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ICP Monitoring and CSF Drainage

Intracranial pressure (ICP) should be monitored in all salvageable patients with severe traumatic brain injury (TBI) (GCS score of 3-8 after resuscitation) and an abnormal computed tomography (CT) scan. An abnormal CT scan of the head is one that reveals hematomas, contusions, swelling, herniation, or compressed basal cisterns.

ICP monitoring is also indicated in patients with severe TBI with a normal CT scan in the presence of unilateral or bilateral motor posturing or a systolic blood pressure less than the fifth percentile for age.

In certain conscious patients with CT findings suggesting risk of neurologic deterioration (hematomas, contusions, swelling, herniation, or compressed basal cisterns), however, monitoring may be considered based on the opinion of the treating physician. Inability to perform serial neurologic examinations, because of pharmacologic sedation or anesthesia, may also influence a clinician’s decision to monitor ICP in an individual patient.

External ventricular drains are often used as a therapeutic modality, especially when the removal of cerebrospinal fluid (CSF) during episodes of increased ICP or drainage of hemorrhage-induced hydrocephalus may be required.

Lumbar drains may also used for patients with refractory increased ICP, allowing further CSF removal. An external ventricular drain should be placed initially; basilar cisterns must be open on CT scan before placement of a lumbar drain.

ICP can also be monitored by transducers placed via small burr holes, especially when an intraventricular catheter cannot be placed. The theoretical advantages (eg, ease of placement, reduced risk of infection, and decreased risk of hemorrhage) should be weighed against the inability to remove CSF. The recent introduction of tissue partial pressure of oxygen monitoring allows direct measurement of brain tissue oxygenation. If brain oxygenation monitoring is used, maintenance of partial pressure of brain tissue oxygen greater than 15 mm Hg may be considered. [34]

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