The stroke mechanism, clinical presentation, and radiological feature of bilateral medial medullary infarction

Bilateral medial medullary infarct causing stepwise tetraparesis: delayed appearance of the ‘heart-shaped’ sign

“…Bilateral medial medullary infarction is rare and frequently has a poor clinical outcome 3. In this case, the patient presented with stepwise right then left hemiparesis; the underlying mechanism was probably ischaemia that progressed from occlusion of a perforator branch supplying the bilateral medulla that arose from the dominant right vertebral artery 3. In case series of bilateral medulla infarction, 53% of patients had severe stenosis or occlusion in a unilateral vertebral artery 3.…”

“…It probably results from occlusion of branches off the anterior spinal artery, which arises from the vertebral arteries. Bilateral medial medullary infarction is rare and frequently has a poor clinical outcome 3. In this case, the patient presented with stepwise right then left hemiparesis; the underlying mechanism was probably ischaemia that progressed from occlusion of a perforator branch supplying the bilateral medulla that arose from the dominant right vertebral artery 3.…”

Bilateral Medial Medullary Stroke: A Single Center Case Series

“…The stroke mechanisms in our series showed severe stenosis of either vertebral artery the occlusion extending into the proximal basilar artery and a probable small vessel etiology in the last case. Larger studies also showed large vessel atherosclerosis as the most common mechanism and that an atheromatous branch occlusion is more common in a bilateral lesion (Kim & Han, 2019;Hu et al, 2022;Pongmoragot et al, 2013).…”

“…Case reports and recent studies generally agree that it carries a worse prognosis. The study of Hu et al, (2022) reported a poor prognosis in 93.3% of the 15 cases reviewed. In another study of 38 patients, mortality was at 23.8% (Pongmoragot et al, 2013).…”

“…From case reports, we know that the medial medullary infarct is less than 1% of all stroke syndromes. In the reports made by separate studies of Hu, Nie, Bai, and Liang (2022) and Pongmoragot, Parthasarathy, Selchen, and Saposnik (2013) males are more commonly affected than females (74%) at a mean age of around 60 years old. Based on the structures in the medulla that are affected, a lesion in the bilateral medial area can present as quadriplegia, dysarthria, loss of vibratory and position sense, and tongue paralysis (Ropper et al, 2019).…”