What does a battle sign indicate?

From the Guidelines

Battle sign is a clinical indicator of a basilar skull fracture, appearing as bruising or discoloration behind the ear over the mastoid process, and its presence requires immediate medical attention and evaluation with CT imaging to confirm the fracture and assess for intracranial injuries. This sign develops when blood from the fracture tracks along tissue planes and becomes visible at the skin surface, typically 24-48 hours after injury 1. Battle sign is often accompanied by other symptoms of basilar skull fracture, such as cerebrospinal fluid leakage from the ears or nose, hearing loss, facial paralysis, or cranial nerve deficits. The Canadian CT Head Rule, which includes signs of basal skull fracture as one of its high-risk factors, can be used to guide the decision to perform CT imaging in patients with mild traumatic brain injury 1.

Key Points

• Battle sign is a specific indicator of basilar skull fracture
• It requires immediate medical attention and evaluation with CT imaging
• The Canadian CT Head Rule can be used to guide the decision to perform CT imaging in patients with mild traumatic brain injury
• Battle sign should not be confused with simple bruising from direct trauma to the mastoid area; true Battle sign results from blood that has tracked from a skull base fracture

Clinical Implications

The presence of Battle sign indicates a serious head injury that may have complications including meningitis, brain injury, or vascular damage. Therefore, it is essential to prioritize the evaluation and management of patients with this sign to prevent morbidity and mortality. The use of clinical decision rules, such as the Canadian CT Head Rule, can help guide the decision to perform CT imaging and ensure that patients receive appropriate care 1.

From the Research

Battle Sign Indication

• A battle sign, also known as mastoid ecchymosis, is a clinical indication of a basilar skull fracture 2.
• It is characterized by bruising behind the ear, in the mastoid area, and is often associated with other signs of basilar skull fracture, such as raccoon eyes, otorrhea, and rhinorrhea 3.
• The presence of a battle sign can indicate a potential basilar skull fracture, but its accuracy and specificity are relatively low, with a positive predictive value of 25.7% to 27.1% 3.
• The sign is not exclusive to basilar skull fractures and can be present in other conditions, such as hepatic encephalopathy 2.

Clinical Significance

• The presence of a battle sign, along with other clinical signs, can be correlated with head injury severity, as indicated by the Glasgow Coma Scale and Maximum Abbreviated Injury Scale-Head region 3.
• However, the low accuracy and specificity of the battle sign and other clinical signs of basilar skull fracture contraindicate their use in making decisions about initial trauma care, such as the introduction of catheters and tubes via the nasal route 3.
• In patients with periorbital ecchymosis, which is often associated with basal skull fractures, the presence of a battle sign can be an important indicator of potential cranial nerve injury and other complications 4.