[Two cases of delayed posttraumatic vasospasm followed by brain SPECT]

This is a report of two cases of delayed posttraumatic vasospasm. In case 1, a 68-year-old male was injured by falling. He did not show any neurological deficits on admission. CT scan revealed a diffuse subarachnoid hemorrhage (SAH) without brain contusion. Aneurysm was not disclosed by angiography. On the 7th day after admission, he presented disorientation. Reviewed angiography revealed diffuse delayed vasospasm. 123I-IMP brain SPECT showed an extensive low perfusion area in the bilateral parietal portion. In case 2, a 71-year-old female experienced immediate development of a deep comatose state after head injury. CT scan on admission disclosed a massive acute left subdural hematoma and the severe compression of the left cerebral hemisphere by the hematoma. But traumatic SAH was not diffuse and was restricted to the left basal cistern. After emergency operation, her consciousness level improved and the mass effect of the subdural hematoma was diminished. On the 7th day after the operation, her neurological condition worsened. CT scan showed some infarction lesions in the left cerebral hemisphere and mild left cerebral swelling. Angiography on the same day revealed vasospasm in M2-M3 portion of left middle cerebral artery. HM-PAO brain SPECT disclosed low perfusion in the left parietal region, but a state of high perfusion in the other region. In case 1, vasospasm might have been derived from diffuse clots of traumatic SAH caused by the same process as postruptured aneurysmal vasospasm. In case 2, the region of vasospasm was not associated with traumatic SAH. It corresponded to the site of the brain contusion. It was suggested that the cause of vasospasm might have been the direct mechanical injury to the arterial wall and chemical substances deriving from the contused brain tissues. We conclude that SPECT or transcranial Doppler monitoring should be used for the early detection of posttraumatic vasospasm.