Early detection of delayed traumatic intracranial hematomas using near-infrared spectroscopy.

Delayed intracranial hematomas are an important treatable cause of secondary brain injury in patients with head trauma. Early identification and treatment of these lesions, which appear or enlarge after the initial computerized tomography (CT) scan, may improve neurological outcome. Serial examinations using near-infrared spectroscopy (NIRS) to detect the development of delayed hematomas were performed in 167 patients. The difference in absorbance of light (delta OD) at 760 nm between the normal and the hematoma side was measured serially during the first 3 days after injury. Twenty-seven (16%) of the patients developed a type of late hematoma: intracerebral hematoma in eight, extracerebral hematoma in six, and postoperative hematoma in 13 patients. Eighteen of the delayed hematomas caused significant mass effect and required surgical evacuation. The hematomas appeared between 2 and 72 hours after admission. In 24 of the 27 patients, a significant increase (> 0.3) in the delta OD occurred prior to an increase in intracranial pressure, a change in the neurological examination, or a change on CT scan. A favorable outcome occurred in 67% of the patients with delayed hematomas, which suggests that early diagnosis using NIRS may allow early treatment and reduce secondary injury caused by delayed hematomas.