battle sign

Battle sign

Battle’s sign or Battle sign is defined as mastoid ecchymosis (bruising of the scalp overlying the mastoid process) and is strongly suggestive of a base of skull fracture, most commonly a petrous temporal bone fracture 1). Another common bruising sign of a skull injury is raccoon eyes, the purplish discoloration around the eyes following fracture of the frontal portion of the skull base.

Basilar fractures of the skull also known as base of skull fractures, are a common form of skull fracture, particularly in the setting of severe traumatic head injury, and involve the base of the skull. They may occur in isolation or often in continuity with skull vault fractures or facial fractures.

One of the most important issues associated with Battle sign is that it takes 1 to -2 days for the sign to appear and is thus not helpful in the initial management of head trauma 2).

Battle sign may be confused with a spreading hematoma from a fracture of the mandibular condyle, which is a less serious injury 3).

Another issue surrounding Battle sign is that there was a recent case report that showed mastoid ecchymosis associated with hepatic encephalopathy in the absence of trauma. This case means that Battle sign may not be as specific for head trauma as initially thought. However, more research is necessary regarding the association between hepatic encephalopathy and mastoid ecchymosis 4).

Battle sign derives its name from Dr. William Henry Battle who initially described the sign in the late 1800s 5). He was an English surgeon who initially described the ecchymosis in 17 patients who had head injuries with fractures to the posterior aspect of the skull base. His description noted that to develop the sign, there was significant head trauma and may indicate significant internal injury to the brain and not just the posterior cranial vault or mastoid 6).

The naming of Battle sign has caused much confusion over the years. Many believe that the sign gets its name from fighting or battling as a mechanism for obtaining the injury instead of the credit going to Dr. Battle. Additionally, although Dr. Battle is credited with the sign and has his name on the sign, he was not the first to note the sign. Sir Prescott G. Hewett, an English surgeon, had actually written about the association before Dr. Battle 7).

Figure 1. Battle’s sign and raccoon eyes

battle sign

Battle’s sign causes

Battle sign is prominent when there is a fracture of the petrous temporal bone. Battle sign may also be associated with rhinorrhea and bruising over the eyes (raccoon eyes). Depending on the severity of the head trauma, the patient may also present with loss of consciousness and a depressed Glasgow Coma Scale (GCS).

Basilar skull fractures are present in only 4% of patients with severe head injury 8). There is no reported increased predilection amongst either sex or any race. Battle sign typically correlates with blunt head trauma; this is most commonly a result of motor vehicle accidents, with sports injuries, falls and assault, but may also be present in non-accidental head trauma, including in child abuse 9). Clearly, the relative incidence and demographics affected will vary widely depending on regional differences and mechanism.

Fractures may either occur at the site of direct impact or remotely due to forces passing through the skull 10). As a general rule most base of skull fractures result from impact to the skull around its base (e.g. occiput, temporal region, frontal region – the so-called “hat band” distribution. Less commonly, base of skull fractures are extensions of fractures that have occurred due to impact at the vertex 11).

The specific pattern of fracture and the associated complications (e.g. CSF leak, sensorineural hearing loss, cranial nerve palsies etc.) will depend on the location of the fracture. Generally, the direction of a fracture will be in line with the direction of impact (i.e. a transverse fracture will result from an impact on the side of the head) 12).

As is the case elsewhere, fractures may be linear, comminuted, depressed or compound. Overall the majority of skull-based fractures are linear and tend to be more common in children. The temporal bone is involved in the majority of skull fractures (45%), followed by basilar skull fractures (20%). When a depressed skull fracture occurs, it is usually an open fracture, which generally necessitates surgery as soon as possible.

Battle’s sign symptoms

Battle sign presents as ecchymosis over the mastoid process, located behind the ear. It is typically associated with tenderness of the area as well. Other findings that may be seen that indicate basilar skull fracture include raccoon eyes (periorbital ecchymosis), hemotympanum (which is the presence of blood in the tympanic cavity of the middle ear), facial nerve injury and laceration of the external auditory canal 13).

Battle sign is often present with a basilar skull fracture. Skull base fractures are often encountered in the setting of severe head injury and thus the damage to the underlying brain and/or intracranial hemorrhage dominate the clinical presentation. The presence of Battle sign correlates with a positive predictive value of greater than 75% for the presence of an associated basilar skull fracture. In multiple studies, Battle sign associated with a positive predictive value of 66% for intracranial lesions and 100% for skull base fractures 14).

It is also rare to not obtain a CT of the brain in all such cases, however, historically a number of signs were described as being helpful in suggesting the presence of a base of skull fracture:

  • Anterior cranial fossa fracture
    • CSF rhinorrhea
    • raccoon eyes sign
  • Petrous temporal bone fracture
    • Battle sign
    • CSF otorrhea
    • otorrhagia

Battle sign complications

When patients present with Battle sign, it is vital to rule out associated cervical spine injury. Data reveal that at 15% of patients with a basilar skull fracture have an associated cervical spine injury.

Battle’s sign diagnosis

Battle sign is a clinical sign. No further evaluation is needed to diagnose Battle sign 15). However, given that Battle sign correlates with an underlying skull fracture, imaging is typically warranted when Battle sign is observed. The initial evaluation is with a non-contrast CT scan, although linear or non-displaced fractures may not be detectable, necessitating further imaging 16). If the presentation gets delayed and infection is suspected, a contrast-enhanced CT or MRI may prove useful.

It is vital that one check for bleeding from the nose to rule out a CSF leak; this may be done by analyzing the presence of tau transferrin or glucose level.

Battle’s sign treatment

In general, the treatment following skull fracture depends on the type of injury. Patients with linear fractures who have no neurological deficits and have a Glasgow Coma Scale (GCS) of 14 or higher can be discharged home safely after a period of observation in the emergency room. However, the patient must be available for follow up if he or she becomes symptomatic. Children with linear fractures need to be admitted overnight irrespective of the absence/presence of neurological deficits.

Surgery is usually required when patients have depressed skull fractures. The current consensus is that is the depressed segment is more than 5 mm below the inner table of adjacent bone, that the patient should undergo surgery to elevate that bone segment. Other indications for surgery include underlying hematoma, gross infection/contamination and dural tear with pneumocephalus.

Patients should be treated with tetanus toxoid and broad-spectrum antibiotics if they have an open wound or if the presentation has been delayed.

Basilar skull fractures are secondary to trauma, and thus management requires a thorough trauma evaluation. Admission for observation is usually necessary with further management determined based on the fracture 17). Battle sign itself will fade and heal with time, although it may take several weeks for the ecchymosis to disappear. When the battle sign is present, the patient is more likely to have a slower than expected recovery from head injury 18).

Rehabilitation care

Following surgery, patients will require monitoring for intracranial hematoma, venous sinus thrombosis, and mental status. Those dicharged without surgery need to be seen in the clinic within 24 to 48 hours to assess the GCS and mental status.

All patients who undergo surgery need to have a repeat CT scan within 6 to 8 weeks to rule out the presence/absence of an abscess. Other reasons to follow up include the presence of seizures and neurological deficits.

References   [ + ]