Abstract 1122‐000190: Persistent DWI Signal for 18 Months in Ischemic Stroke Patient with Carotid Web

Abstract

Introduction: Diagnostic tools for acute ischemic infarcts include the use of DWI sequence on MRI to identify acute infarcts is especially useful since lesions can become hyperintense on this sequence very rapidly (Albers 1998). Over the next 15 days, DWI hyperintensity slowly decreases back to isointense. In some patients, however, there is persistent DWI hyperintensity past 1 month. There are theories that these persistent areas exhibit delayed onset infarct, prolonged ischemia, or perhaps different repair processes (Rivers, et al 2006). To this day, all DWI signals have been known to resolve within a few months even for persistent hyperintensities (Rivers, et al 2006). Carotid webs are a rare form of fibromuscular dysplasia that protrudes from the intimal tissues of carotid arteries. They are shelf‐like projections that grow into the lumen and disrupt normal blood flow (Zhang, et al 2018). These outgrowths are theorized to lead to ischemic strokes due to flow stasis and subsequent embolization of clots that form (Zhang, et al 2018). There is no consensus on the best management of carotid webs, and secondary prevention of recurrent strokes range from medical management to carotid stenting. Methods: This is a case report, and information for the patient was gathered through review of medical records on the EMR. Results: We present a case of ischemic stroke in the right basal ganglia/corona radiata, who presented with left sided weakness. The patient was found to have prediabetes, HTN, and HLD. However, she had recurrence of her symptoms over the next 18 months (figure 1). Repeat MRIs showed persistent DWI hyperintensity that slowly decreased in size and signal intensity over this period but in the same area as the initial infarct. The rest of the work up was only significant for a carotid web in the right internal carotid artery identified on conventional angiography. Ultimately she was managed with medical therapy including aspirin, statin, and antihypertensives. Conclusions: It is unclear whether the carotid web is associated with persistent DWI for such an extended time frame. There is very little research that explores the pathophysiology of ischemic strokes from carotid webs. In addition, there is even less information about the physiology of an evolving infarct that shows persistent DWI signals for such an extended time frame. Further studies that look into carotid webs may help us understand the best long term management in such patients. Future studies that explore the physiology of ischemic strokes that show such persistent DWI signals may elucidate and perhaps expand upon current management options and possibly identify new areas for intervention.

Keywords

• Stroke
• Imaging