Spontaneous reperfusion of cerebral infarcts in patients with acute stroke. Incidence, time course, and clinical outcome in the Copenhagen Stroke Study.

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.