Abstract: Abstract：Objective To investigate the clinical and imaging features of the "Y" shape and half "Y" shape medullary infarction in patients with medullary infarction. Methods The clinical and imaging findings of 11 patients with medial medullary infarction (MMI) in the ventral, middle and dorsal (VMD) parts of the medulla oblongata were retrospectively analyzed. Results There were 11 MMI patients with VMD involvement in this study. Of them there were 6 cases with bilateral infarction, showing the "Y" shape and 5 patients with unilateral infarction, showing half "Y"-shape. In "Y"-shaped group, the most common symptoms and signs were drinking cough or dysphagia (6 cases), dizziness or vertigo (5 cases), limb weakness (5 cases), dysarthria (5 cases), sensory disorders (5 cases) and central respiratory disorders (3 cases). In the half "Y" shape group, the most common symptoms and signs were dizziness or vertigo (5 cases), limb weakness (4 cases), dysarthria (4 cases) and sensory impairment (4 cases). There was a significant difference in the proportion of dysphagia and dyspnea between the two groups. The congenital variation of vertebral artery was more common in two groups of patients (n=3 for both groups). In addition to respiratory failure, the outcomes of MMI patients were favorable. Conclusion The frequency of dysphagia and respiratory failure is much higher in patients with "Y"-shaped medullary infarction compared with that in patients with half "Y"-shaped infarction of medulla oblongata. Vertebral artery variation with one-sided superiority is an important anatomical basis for MMI patients with VMD involvement at the same time.

Key words: medulla oblongata, infarction, deglutition disorders, respiratory insufficiency, magnetic resonance imaging, medial medullary infarction, congenital vertebral artery abnormality