Stridor in Bilateral Medial Medullary Infarction: A Case Report, Literature Review, and Pathophysiologic Insights Into a Rare Presentation of an Uncommon Stroke

Background: Upper airway obstruction secondary to bilateral vocal cord paralysis is not a known classic presentation of bilateral medial medullary infarction (BMMI). This may potentially confound the diagnostic approach, particularly when coexisting with bulbar symptoms and quadriplegia. Prompt recognition is essential for timely and appropriate airway management and subsequent treatment. Case Presentation: A 74-year-old female presented with a three-week stepwise progression of asymmetric quadriparesis, slurred speech, and a prominent biphasic stridor. Flexible fiberoptic laryngoscopy revealed bilateral vocal cord palsy in the median-paramedian position, and an emergency tracheostomy was performed. Magnetic resonance imaging (MRI) of the brain revealed the characteristic "heart shaped" diffusion-weighted imaging (DWI) pattern of BMMI, while magnetic resonance angiography (MRA) exhibited absent flow-related signals in the right vertebral artery. Secondary stroke prevention with clopidogrel was started. However, the patient developed severe pneumonia with massive pleural effusion and expired on the sixth day of hospitalization due to Type 1 respiratory failure. Conclusion: Bilateral vocal cord paralysis may occur in BMMI, and recognizing this rare association is crucial for timely diagnosis and treatment. The intricate neurovascular anatomy of the medulla may find insight into the rarity of this association.