Flemming, Kelly D.

Symptomatic brainstem cavernous malformations carry a high risk of permanent neurological deficit related to recurrent hemorrhage, which justifies aggressive management. Detailed knowledge of the microscopic and surface anatomy is important for understanding the clinical presentation, predicting possible surgical complications, and formulating an adequate surgical plan. In this article the authors review and illustrate the surgical and microscopic anatomy of the brainstem, provide anatomoclinical correlations, and illustrate a few clinical cases of cavernous malformations in the most common brainstem areas.

Background and Purpose— Internal carotid artery (ICA) occlusion is an important cause of transient ischemic attack (TIA) and cerebral infarction. There are no previous population-based natural history studies evaluating outcome after symptomatic ICA occlusion (SICAO). Methods— We performed a retrospective, population-based study of SICAO. All Olmsted County (Minnesota) residents with possible SICAO from 1986 to 2000 were identified by cross-referencing appropriate clinical and imaging codes. Inclusion criteria were cerebral infarction or TIA in a carotid distribution and imaging documentation of ipsilateral ICA occlusion <3 months after the index event. Kaplan–Meier estimates were used to calculate the risk of cerebral infarction, myocardial infarction, and death after SICAO. Results— Seventy-five patients qualified. Annual SICAO incidence was 6 per 100 000 persons (age and gender adjusted to the 2000 US white population). Risk of cerebral infarction during follow-up was 8% at 30 days, 10% at 1 year, and 14% at 5 years. Five of 11 cerebral infarctions occurred within the first week after diagnosis of occlusion. Risk of myocardial infarction was 0% at 30 days, 8% at 1 year, and 24% at 5 years. Risk of death was 7%, 13%, and 29%, respectively. Conclusions— There may be 15 000 to 20 000 incident cases of SICAO in the United States annually. Risk of cerebral infarction after SICAO is initially high and then stabilizes, whereas risk of myocardial infarction is initially low but gradually increases. Better strategies are needed to reduce early stroke recurrence in this setting.

Background and Purpose— There is little information to provide an estimate for stroke risk in patients with established stenosis or occlusion in the basilar or intracranial vertebral arteries undergoing surgical procedures. The objective of this study was to determine the ischemic stroke risk in this specific patient population. Methods— A medical records linkage system retrospectively identified patients with a diagnosis of symptomatic vertebrobasilar stenosis or occlusion matched with surgical procedures. Patients were selected if they had stenosis or occlusion of the basilar or intracranial vertebral arteries identified on vascular imaging before undergoing surgical procedures under general anesthesia. Clinical and radiographic features were reviewed, along with the nature of the surgeries and details of the perioperative management. Records were reviewed for the diagnosis of stroke occurring within 1 month of surgery. Results— Thirty-eight patients with a history of symptomatic vertebrobasilar ischemia underwent 50 operations under general anesthesia, and 3 had ischemic strokes in the vertebrobasilar territory immediately after surgery, a per-procedure rate of 6.0% (95% confidence interval, 1.2 to 16.6) All 3 had episodes of prolonged hypotension (systolic blood pressure <100 mm Hg for >10 minutes) during surgery. Conclusions— The risk of perioperative stroke in patients with vertebrobasilar stenosis undergoing surgery under general anesthesia is 6.0%, which is notably higher than the risk for patients with other patterns of cerebrovascular disease.