Basal brain injury in aneurysm surgery

OBJECTIVE: The goal of this study was to determine the frequency of lesions in the basal frontotemporal area that were related to surgical damage to t he brain tissue. METHODS: A prospective series of 101 patients with ruptured intracranial an eurysms were examined with high-field magnetic resonance imaging, 2 to 6 ye ars (mean, 3.3 yr) after early surgery. RESULTS: Lesions in the basal frontotemporal region, on the side of the pte rional approach, were observed for 36 patients. These lesions were not visi ble in computed tomographic scans obtained pre- or postoperatively or 3 mon ths after subarachnoid hemorrhage. Patients with ruptured aneurysms in the anterior communicating artery exhibited fewer of these lesions than did pat ients with aneurysms in the internal carotid artery or middle cerebral arte ry; this difference was not statistically significant. The age of the patie nt, the duration and depth of hypotension, the amount of blood or ventricul ar enlargement in pre- and postoperative computed tomographic scans, and th e incidence and severity of angiographic vasospasm in pre- and postoperativ e angiograms did not predict the existence of these lesions. The clinical c onditions of the patients, as assessed using the Glasgow Outcome Scale, at 3 months after surgery and at the time of magnetic resonance imaging did no t predict the existence of these lesions. Nine of the 10 patients who under went surgical treatment of unruptured aneurysms on the contralateral side e xhibited no signs of tissue damage. CONCLUSION: Surgical treatment of ruptured intracranial aneurysms seems to cause damage in the basal frontotemporal region in one-third of patients. T he significance of these lesions remains unclear.