Background Stroke, the most devastating consequence of sickle cell anemia (SCA), is associated with endothelial damage and intracranial artery stenosis. We aimed to assess transcranial Doppler (TCD) ultrasound accuracy in detecting intracranial stenosis when compared to magnetic resonance angiography (MRA). Methods Children with SCA and at least one TCD and MRA within 1 month were identified from a retrospectively collected database. Sensitivity and specificity were obtained to assess the overall accuracy of TCD mean flow velocity (mFV) ≥200 cm/s in detecting vessel stenosis of ≥50%. Multivariate analysis identified independent factors associated with MRA stenosis. Results Among 157 patients in the database, 64 had a TCD and MRA within 1 month (age 11.8 ± 5.3 years, 56% female, 20% with cerebral infarcts on MRI, 8 or 13% had mFV ≥200 cm/s and 20% or 21%, had intracranial stenosis ≥50% on MRA). TCD mFV ≥200 cm/s had a high specificity (95%) but low sensitivity (29%) to detecting intracranial stenosis. As a continuous variable, TCD mFV of 137.5 cm/s had maximal specificity (77%) and sensitivity (72%). After adjustment for age, hemoglobin level, transfusion status, hydroxyurea treatment, and vessel, for every increase in cm/sec on TCD, there was a 2% increase in the odds of ≥50% stenosis on MRA (p < 0.001). Conclusion Our study reports TCD mFV is a positive predictor of MRA stenosis in SCA, independent of patient characteristics, including hemoglobin. A mFV ≥200 cm/s is highly specific but less sensitive in detecting stenosis ≥50%. Lower mFV cut points may be needed for the early detection of intracranial stenosis.

Background: Stroke is among the most devastating consequences of sickle cell disease (SCD). Most SCD strokes occur due to intracranial stenosis, that can be detected by increased flow velocities on Transcranial Doppler (TCD). However, increased velocities may also reflect anemia rather than arteriopathy and vessel stenosis. We aimed to assess the accuracy of TCD in detection of intracranial stenosis in SCD. Methods: Pediatric SCD patients with at least one TCD and MRA within one month apart were identified from a retrospectively collected database maintained at our institution from January 2000 to December 2016. Patient demographics, hemoglobin level, transfusion and hydroxyurea status were collected, along with mean flow velocities (mFV) and degree of stenosis from bilateral middle and anterior cerebral, and internal carotid arteries. A mFV of > 200 cm/s and vessel stenosis > 50% were considered abnormal. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were obtained to assess overall accuracy of TCD velocities in relation to vessel stenosis. Multivariate analysis was performed to identify independent factors associated with MRA stenosis. Results: A total of 164 patients were included in the database (median age 12 [IQR 8.9] years, 56% had ischemic strokes) and 64 of them had at least one TCD and MRA one month apart. Of these, 20% had ischemic strokes, 17% had MRA stenosis > 50% and 10% had TCD velocity > 200 cm/s. TCD mFV > 200 cm/s had a high specificity (95%) and NPV (87%) but low sensitivity (29%) and PPV (55%) when compared to MRA stenosis > 50%. As a continuous variable, TCD mFV 137.5 cm/s had the best balance between maximal specificity (77%) and sensitivity (72%). After adjustment for age, hemoglobin level, transfusion status, hydroxyurea, and vessel, for every increase in cm/sec on TCD, there was a 2% increase in the odds of > 50% stenosis on MRA (OR=1.02, 95% CI 1.01-1.03, p<0.001). Conclusion: Our study reports that TCD mFV is a positive predictor of MRA stenosis in SCD, independent of patient characteristics, including hemoglobin. A mFV > 200 cm/s is highly specific but less sensitive to detect stenosis > 50%. Lower mFV cut points may need to be considered for early detection of intracranial stenosis and risk of stroke.

No abstract

Background and Purpose: COVID-19 is associated with systemic thromboembolism including stroke. The study evaluated the 30-days stroke incidence in SARS-CoV-2 PCR positive patients and described the outcome of such patients. Methods: This is a retrospective study of consecutive patients with a positive SARS-CoV-2 PCR test between March 1st, 2020 and August 30th, 2020. The study included COVID-19 patients who were hospitalized and had a stroke within 30 days from the positive PCR test. Results: During the study period, there were 4301 patients with a positive SARS-CoV-2 PCR test. Of those, 1786 patients (41.5%) were hospitalized and 4 patients developed a stroke within 30 days. The 30-days stroke incidence was 0.09% and 0.2% of all and hospitalized patients, respectively. The mean age of stroke patients was 78 years and 2 died during the same hospitalization. The 4 patients had comorbidities, one had pre-existing atrial fibrillation and all had ischemic stroke. Conclusion: This study showed a low 30-day incidence of stroke among COVID-19 patients.