Introduction Delayed post-hypoxic leukoencephalopathy (DPHL) is a rare condition that can occur after a lack of oxygen. There are few reports of DPHL following an acute ischemic stroke.

Case A 79-year-old female visited the hospital with left middle cerebral artery (MCA) occlusion. The patient showed residual stenosis in the left M1 following endovascular therapy, however, experienced clinical improvement. After 3 weeks of treatment, the patient experienced a decrease in verbal output, decreased cognitive ability, and progressed gradually.

After 3 months, a follow-up hospital visit was conducted due to suspected stroke recurrence. Brain MRI/A was performed, which revealed a change in the extended subcortical signal in the region of the left MCA with focal M1 stenosis. Digital subtraction angiography (DSA) was conducted as a result of the suspicion that the stenosis in the left MCA was greater than moderate and that there was a potential for borderline infarction.

However, DSA revealed only mild stenosis in the MCA, and the possibility of recurrent cerebral infarction was deemed low. Symptoms recovered after endovascular treatment, but neurological symptoms such as cognitive decline and aphasia deterioration occurred 3 weeks later, and these symptoms gradually progressed, and diffuse subcortical lesion occurred in brain imaging, and final diagnosis was determined to be DPHL.

Conclusion This case illustrates that the manifestation of clinical symptoms and morphological alterations observed on MRI, indicative of DPHL, may not exclusively result from global hypoxia. Rather, such changes can also manifest in patients with a large vessel occlusion within the corresponding vascular territories.

Disclosure of Interest Nothing to disclose