Abstract
Pneumocephalus is defined as an abnormal presence of intracranial air or gas. Traumatic pneumocephalus (TP) typically occurs on the injured side and is in communication with the external environment. This report presented an extremely rare case of TP that occurred on the opposite side of the injured site, even with the absence of any traumatic injury. The patient sustained injuries, including linear skull fracture, acute epidural hematoma, fractures in the clavicle and scapula, and subcutaneous emphysema, on the left side of the body. However, TP occurred on the right side. Although the exact underlying pathogenic mechanism remains unclear, the condition might be attributed to the migration of air bubbles or negative pressure on the opposite side caused by side-to-side closed head injury.