Capsular and thalamic infarction caused by tentorial herniation subsequent to head trauma.

Five patients (4 male and 1 female) were observed to have capsular and thalamic infarction ascribed to descending transtentorial herniation (DTH) caused by head injury. A lucid interval immediately after the trauma and the presence of an epidural hematoma (EDH) characterized all five cases. At the time of hospitalization consciousness was seriously impaired and signs of cerebral herniation were apparent. Two to four days after the trauma, low attenuation in the computed tomography (CT) images pinpointed intracerebral damage in the anterolateral part of the thalamus and in the internal capsule on the same side as that of the EDH in three patients, and in the other two patients bilateral thalamic and capsular damage was noted. The low attenuation implicated the perforating arteries, that is the anterior thalamoperforating and anterior choroidal arteries, suggesting infarcted regions caused by occlusion of these arteries. Findings in the present study suggest that arterial occlusion in closed head injury may result from DTH. Moreover, infarction may be attributed to the delayed effects of injury.