Transcranial Doppler ultrasound criteria for recanalization after thrombolysis for middle cerebral artery stroke

Background and Purpose-Transcranial Doppler (TCD) can demonstrate arterial occlusion and subsequent recanalization in acute ischemic stroke patients t reated with intravenous tissue plasminogen activator (tPA). Limited data ex ist to assess the accuracy of recanalization by TCD criteria. Methods-In patients with acute middle cerebral artery (MCA) occlusion treat ed with intravenous tPA, we compared posttreatment TCD with angiography (di gital subtraction or magnetic resonance). On TCD, complete occlusion was de fined by absent or minimal signals, partial occlusion by blunted or dampene d signals, and recanalization by normal or stenotic signals. Angiography wa s evaluated with the Thrombolysis In Myocardial Ischemia (TIMI) grading sca le. Results-Twenty-five patients were studied (age 61+/-18 years, 16 men and 9 women). TCD was performed at 12+/-16 hours and angiography at 41+/-57 hems after stroke onset, with 52% of studies performed within 3 hours of each ot her. Recanalization on TCD had the following accuracy parameters compared w ith angiography: sensitivity 91%, specificity 93%, positive predictive valu e (PPV) 91%, and negative predictive value (NPV) 93%. To predict partial oc clusion (TIMI grade II), TCD had sensitivity of 100%, specificity of 76%, P PV of 44%, and NPV of 100%. TCD predicted the presence of complete occlusio n on angiography (TIMI grade 0 or I) with sensitivity of 50%, specificity o f 100%, PPV of 100%, and NPV of 75%. TCD flow signals correlated with angio graphic patency (chi(2)=24.2, P<0.001). Conclusions-Complete MCA recanalization on TCD accurately predicts angiogra phic findings. Although a return to normal flow dynamics on TCD was associa ted with complete angiographic resumption of now, partial signal improvemen t on TCD corresponded with persistent occlusion on angiography.