Figure 12. Secondary traumatic brain injuries in patients with TBI.

Axial noncontrast CT images (A-C) from an 80-year-old female reveal left convexity holohemispheric and parafalcine subdural hematomas. Secondary complications resulting from mass effect from the hematomas include left to right midline shift (arrow shows position of the septum pelucidum) with subfalcine herniation (A), left uncal and downward transtentorial herniation (B,C), trapping of the temporal horn (asterisk) of the right lateral ventricle secondary to obstruction of the foramen of Monro (B,C), and a Duret hemorrhage in the midbrain (B) and pons (C). Images from a different patient show secondary complications in a 74-year-old female after TBI. The preoperative noncontrast CT (D) images demonstrate mass effect from a right holohemispheric subdural hematoma resulting in right uncal herniation and trapping of the temporal horn of the left lateral ventricle. The right temporal horn is nearly midline in location (asterisk. The post-operative noncontrast CT obtained later that evening (E) reveals a decompressive craniectomy, ventricular drain placement, and a new large hypodensity involving the territory of the right posterior cerebral artery (PCA) vascular territory, consistent with infarction. Diffusion weighted MRI (F) obtained 4 days after initial injury confirms the right PCA territory infarct, secondary to compression of the proximal PCA by the previously herniated right uncus.