A case of cerebral hyperperfusion following spontaneous recanalization of occluded middle cerebral artery: Reperfusion injury or true cerebral hyperperfusion syndrome?

Abstract

Background: Cerebral hyperperfusion syndrome (CHS) and reperfusion injury are distinct pathological phenomena.

Case summary: We present the case of a young ischemic stroke patient with middle cerebral artery (MCA) occlusion and spontaneous recanalization. Follow-up transcranial Doppler ultrasound showed high velocity flow in the left MCA, and neuroimaging revealed infarction, brain edema, artery dilatation, and hyperperfusion, consistent with both CHS and reperfusion injury.

Conclusion: In cases with signs of both CHS and reperfusion injury, we speculate that CHS may be both a contributor to and a manifestation of reperfusion injury.

Figure 1

Emergency cranial multiple mode CT and diffusion-weighted images on hospital presentation (day 1). (A, B) Cranial CT showing left middle cerebral artery (MCA) hyperdensity sign with low brain tissue density at admission. (C, D, G, H) CT perfusion showing low perfusion throughout the whole left MCA distribution. (D) Cranial CT angiography (CTA) showing left MCA occlusion. (F) Diffusion-weighted imaging (DWI) showing high signal throughout the MCA distribution, indicating acute cerebral infarction. CT = computed tomography, CTA = CT angiography, DWI = diffusion-weighted imaging, MCA = middle cerebral artery.

Figure 2

Follow-up cranial CT, CT angiography (CTA), and digital subtraction angiography (DSA). (A, F) Repeated cranial CT showing large infarction lesion with brain edema and HT; (G) repeated CT angiography showing spontaneous recanalization of the occluded left MCA complicated by MCA dilatation (but normal cervical artery structure). (H, I) Digital subtraction angiography (DSA) showing spontaneous recanalization of the left MCA with artery dilatation. CT = computed tomography, CTA = CT angiography, DSA = digital subtraction angiography, DWI = diffusion-weighted imaging, HT = hemorrhagic transformation, MCA = middle cerebral artery.

Figure 3

Follow-up MR angiography (MRA), arterial spin labeling (ASL), and susceptibility weighted imaging (SWI) results. (A) Time of flow MRA (TOF-MRA) showing marked left MCA dilatation at 9 days after disease onset; (B) TOF-MRA source image also indicated left MCA dilatation; (C, D) ASL perfusion image showed left MCA distribution hyperperfusion; (E, F) repeated MR image at about 2 weeks post-onset (C: SWI, F: T1-weighted image) showing large infarction of the left MCA distribution with HT and brain edema. Results show left infarction lesion with reduced HT and brain edema; (G,F) Repeated MRA and source image showing that the dilated left MCA recovered to normal but artery branch number was lower than the right MCA.ASL = arterial spin labeling, HT = hemorrhagic transformation, MCA = middle cerebral artery, MRA = MR angiography, TOF-MRA = time of flow MRA.