Cumulative risk. (A) Cumulative risk of abnormal TCD (TAMMX velocities ≥ 200 cm/s). (B) Cumulative risk of abnormal MRA (stenosis). Of the 22 SS/Sβ0-patients with abnormal MRA, 16 had a history of abnormal TCD, 2 had conditional TCD, and 4 had normal TCD (1 had an extracranial cerebral vasculopathy, 1 had inadequate window on one side and normal velocities on the other side, and for the last 2, anomalies might have been related to flow artifact because the repeat MRA was normal). (C) Cumulative risk of silent strokes. Among the 35 SS/Sβ0 patients with silent strokes, 28 had silent strokes on the first MRI, and secondary occurrence of silent strokes was only observed in 7 boys: 1 had a history of abnormal TCD but parents had refused long-term TP, 1 with abnormal TCD still had abnormal velocities despite TP, and 5 nonintensified patients developed silent strokes. (D) Cumulative cerebral vasculopathy risk (strokes, abnormal TCD, stenosis, or silent strokes).
