Early Diffusion-Weighted Imaging Reversal After Endovascular Reperfusion Is Typically Transient in Patients Imaged 3 to 6 Hours After Onset
Many studies have shown that early diffusion-weighted imaging (DWI) lesions in acute ischemic stroke can be reversible. The clinical significance of DWI reversibility is unknown. The current study by Inoue et al assessed the frequency and extent of early DWI reversal after endovascular therapy and determined whether early DWI reversal is sustained or transient and its association with clinical outcome. Sixty patients were eligible for this substudy of the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution (DEFUSE) 2 study. MRI with DWI and perfusion-weighted imaging was performed at baseline before endovascular treatment and within 12 hours after the procedure, and MRI with fluid attenuated inversion recovery imaging was performed at follow-up on day 5. Early DWI reversibility was seen in 32% (19/60) of the patients and was usually transient because only 17% (10/60) had sustained reversal. Only 2 patients (3%) had a final infarct volume on fluid attenuated inversion recovery that was smaller than their baseline DWI lesion. Among the patients with reperfusion after endovascular procedure, infarct growth into adjacent tissue was typically much greater than the volume of permanent reversal and final infarct size was at least as large as the baseline DWI volume. Early DWI reversal was not an independent predictor of favorable clinical response (P=0.569) or good functional outcome (P=0.311). In summary, early DWI reversibility after endovascular therapy is common but transient and not associated with clinical outcome. Additional studies will be needed to extend the early DWI reversal to permanent reversal in hopes of reducing final infarct size and potentially improving clinical outcome. See p 1024.
Time Course of Early Postadmission Hematoma Expansion in Spontaneous Intracerebral Hemorrhage
Early expansion of intracerebral hemorrhage is common and associated with worse clinical outcome. The spot sign has been shown to be an important predictor of hematoma expansion. Volumetric measurements using transcranial B-mode ultrasound of intracerebral hemorrhage have been shown to correlate well with computed tomographic (CT) scan measurements. Ovesen et al aimed to describe the temporal profile of early hemorrhage expansion in acute spontaneous intracerebral hemorrhage using serial transcranial B-mode ultrasound. Twenty-five patients with spontaneous intracerebral hemorrhage presenting within 4.5 hours were included in this study. All patients underwent a noncontrast CT and CT angiography at admission. Serial hematoma volume estimations by transcranial B-mode ultrasound were done through the contralateral transtemporal window and measured using the ABC/2 formula. Forty percent of patients had early hemorrhagic expansion. In patients with a final hematoma expansion of >12.5 mL, all early expansion happened within 6 hours after the admission scan and within 7 to 8 hours from symptom onset. In spot sign–positive patients, early hemorrhagic expansion continued during the first 5 hours after CT angiography. In spot sign–negative patients, no significant early expansion was seen. Neurological deterioration occurred in 5 (20%) patients and was well temporally correlated with hemorrhage expansion. Transcranial B-mode ultrasound demonstrated good volume estimation compared with the follow-up CT. In summary, early hemorrhagic expansion is common in the first several hours after symptom onset, and transcranial duplex ultrasound is a reliable tool to detect the expansion. Additional studies are needed and several are ongoing to act in this time period to reduce the possibility of hemorrhagic expansion and possibly improve outcomes. See p 994.
Endocarditis Is a Common Stroke Mechanism in Hemodialysis Patients
Patients with end-stage renal disease on hemodialysis (HD) are at increased risk of ischemic stroke. Cardiac embolism has been shown to be the most common mechanism of stroke in this population. The current study by Ishida et al was a retrospective review of HD patients admitted with ischemic stroke to the University of Pennsylvania Health System between 2003 and 2010 and classified stroke according to the modified Trial of Org 10 172 in Acute Stroke Treatment (TOAST) criteria. In their cohort, cardiac embolism followed by cryptogenic were the most common causes. Twelve percent of the cohort had infective endocarditis. Although a prior series showed that indwelling catheters pose increased risk for endocarditis, the current study found no association between HD access and endocarditis, likely attributable to limited power of the current study. Among patients with an echocardiogram performed, only 10% had a patent foramen ovale. In summary, cardioembolic causes seem to be the most common case of stroke in HD patients. Infective endocarditis was frequently seen in this HD cohort, and thus an increased suspicion for this diagnosis is needed when encountering this patient population. See p 1164.
- © 2014 American Heart Association, Inc.