Spontaneous middle cerebral artery reperfusion in ischemic stroke. A follow-up study with transcranial Doppler

The aim of this study was to investigate by means of transcranial Doppler (TCD) ultrasonography how many spontaneous reperfusions of the middle cerebral artery (MCA) occurred during the first week after onset of acute ischemic stroke in the carotid territory.

TCD examination, computed tomographic scan, and arterial digital angiography were performed in 56 patients with acute ischemic stroke within 6 hours of the onset of symptoms. The TCD examination was repeated within 24 hours, 48 hours, and 7 days after stroke; a further TCD examination was performed within 3 to 9 months in 27 patients.

At 6 hours, 33 patients presented abnormal TCD findings in the symptomatic MCA (16 "no flows" and 17 asymmetries). Of these, 4 patients (3 no flows and 1 asymmetry) died before the 7-day follow-up was completed, whereas of the 29 remaining patients undergoing all the TCD control examinations, only 14 presented permanently abnormal TCD findings (7 asymmetries and 7 no flows). These data are consistent with an MCA reperfusion occurring at any level of the MCA, although most frequently in the distal part, and in the majority of cases during the first 48 hours. One patient who showed MCA asymmetrical flow velocity at the day-7 TCD examination was normal at the TCD follow-up at 3 to 9 months.

TCD examination offers an easy and reliable way of monitoring MCA reopening and might be useful to identify subgroups of patients who may benefit most from pharmacological reperfusion.