Extensive hemispheric cerebral infarction.

BACKGROUND AND PURPOSE: Patients with extensive hemispheric cerebral infarction have a high incidence of mortality and serious morbidity. Because of their poor prognosis, they warrant attention; however, in acute stroke therapy trials they do not appear to benefit from treatment. We sought to determine the clinical features, pathophysiological mechanisms, and outcome in a series of cases with radiologically defined extensive hemispheric infarction.

METHODS

Cases of extensive hemispheric infarction were ascretained retrospectively from stroke admissions during a 5-year period. Extensive hemispheric infarction was defined radiologically as infarction involving greater than 75% of the middle cerebral artery territory, with or without involvement of the adjacent anterior or posterior cerebral artery territories. Clinical, risk factor, and stroke mechanism data were compared with that of a control group of ischemic stroke patients admitted during the same period.

RESULTS

Extensive hemispheric infarction occurred in 53 of 1,440 cases of ischemic stroke (3.7%). Infarction involved the middle cerebral artery territory alone in 79% of cases, and the adjacent anterior or posterior cerebral artery territories as well as 21% of cases. A cardioembolic mechanism was likely in 58% of cases; 42% had atrial fibrillation. When compared with the control group, a cardioembolic mechanism was the only feature more frequently associated with extensive hemispheric infarction. The overall in-hospital mortality rate was 52%; 84% of those discharged from hospital required nursing home care because of severe disability.

CONCLUSION

Although uncommon, extensive hemispheric infarction is an important stroke subtype with dramatic and easily recognizable presenting clinical features, frequent cardio-embolic mechanism, an extremely poor outcome, and failure to benefit from most experimental acute stroke therapies.