Spontaneous Reperfusion of Cerebral Infarcts in Patients With Acute Stroke

OBJECTIVE: To determine the incidence, time course, and clinical importance of spontaneous reperfusion of cerebral infarcts in patients with acute stroke. DESIGN: Prospective, community based. SETTING: Department of Neurology, Bispebjerg Hospital, Copenhagen, Denmark. PATIENTS: Included in the incidence and time course study were 354 unselected patients with acute ischemic stroke. Clinical outcome was studied in a subgroup of 36 patients admitted on the day of stroke onset and in whom it was known whether spontaneous reperfusion occurred within the first week after stroke onset. MEASUREMENTS: Computed tomography and single photon emission computed tomography, with technetium Tc 99m exametazime used as a flow tracer. The Scandinavian Stroke Scale neurologic score was determined on admission, 1 and 2 weeks after stroke, and at discharge. RESULTS: The incidence of spontaneous reperfusion was 77% in patients with cortical infarcts. The frequency of reperfusion increased rapidly from zero at the time of onset to 60% on day 7 after stroke, reaching a maximum on day 14, at which time 77% showed reperfusion. Marked clinical improvement was observed in patients with spontaneous reperfusion (P = .001), while no improvement occurred in patients without reperfusion. Reperfusion was not observed in subcortical infarcts. CONCLUSIONS: The rate of spontaneous reperfusion increases gradually with time and occurs within the first 2 weeks after stroke onset in approximately four of five patients with cortical infarcts. Spontaneous reperfusion seemed to improve clinical outcome.