From the Guidelines
Yes, a Magnetic Resonance Imaging (MRI) should confirm a cerebrovascular accident (CVA) or stroke before a patient with Sickle Cell Disease (SCD) presenting with stroke-like symptoms receives an exchange transfusion, as it can change management and guide the decision to proceed with transfusion 1.
Key Considerations
- An MRI with diffusion-weighted imaging is particularly helpful in evaluating patients with stroke-like symptoms and can identify areas of restricted diffusion indicative of acute ischemic stroke 1.
- Confirming the diagnosis of acute ischemic stroke with brain imaging, such as MRI, may help with patient education and prognostication, which in turn may promote adherence to a prescribed prevention regimen 1.
- A significant proportion of acute stroke cases with an initially negative head CT will have an MRI with evidence of acute/subacute infarction, highlighting the importance of follow-up brain imaging with MRI within 1 to 2 days 1.
Recommendations
- A diffusion-weighted MRI sequence should be performed to identify areas of restricted diffusion indicative of acute ischemic stroke.
- If an MRI confirms a stroke, exchange transfusion with a goal of reducing hemoglobin S to less than 30% should be initiated promptly.
- The use of MRI for in-hospital stroke evaluation can provide valuable diagnostic information and inform treatment decisions, including the need for exchange transfusion in patients with SCD presenting with stroke-like symptoms 1.
From the Research
Importance of MRI Confirmation
- In patients with Sickle Cell Disease (SCD) presenting with stroke-like symptoms, it is crucial to confirm the diagnosis of a cerebrovascular accident (CVA) or stroke before proceeding with an exchange transfusion 2.
- A Magnetic Resonance Imaging (MRI) scan, particularly diffusion-weighted MRI (DWI), can help establish the presence and location of ischemic brain injury 3.
- However, normal DWI findings do not always rule out a cerebral ischemic event, and concomitant hemodynamically weighted MRI (HWI) can identify some patients with brain ischemia that is symptomatic but not yet causing DWI abnormality 3.
Stroke Mimics and Alternative Diagnoses
- Stroke-like symptoms can be caused by non-vascular conditions, known as stroke mimics, which can account for a significant percentage of acute stroke hospital admissions 4.
- Examples of stroke mimics include migraine, seizures, functional disorders, brain tumors, and infections 3, 4.
- In patients with SCD, other conditions such as tacrolimus-induced leukoencephalopathy can also present with stroke-like symptoms 5.
- Systemic lupus erythematosus (SLE) can also cause stroke-like symptoms due to small vessel vasculopathies localized in the unilateral hemisphere 6.
Diagnostic Approach
- A comprehensive diagnostic approach, including MRI and other imaging modalities, is essential to differentiate between a true CVA or stroke and stroke mimics or alternative diagnoses 3, 4.
- The diagnosis of a CVA or stroke should be confirmed before initiating exchange transfusion in patients with SCD presenting with stroke-like symptoms 2.