Retropharyngeal abscess due to Fusobacterium necrophorum complicated by progressive internal carotid artery stenosis and multiple cranial nerve palsies

Background: A case of retropharyngeal abscess complicated by both artery and nerve injury has rarely been reported. Methods: A 36-year-old woman suddenly presented with right eye visual loss, dilated pupil, reduced direct light reflex, ptosis and ocular motility disorder on the side of inflammation progression, and was diagnosed with retropharyngeal abscess due to Fusobacterium necrophorum. The patient was treated only with antibiotics and, no further surgery was necessary but tracheotomy. Four months later, MRA showed right ICA occlusion and left ICA stenosis. MRI revealed continuous spread of inflammation due to the abscess from the retropharyngeal to the intracranial space. Results: These severe complications would be attributed to an endothelial damage to the arterial wall and an ischemic neuropathy caused by inflammation and thrombogenesis due to Fusobacterium necrophorum. Conclusions: This case should provide a better understanding of the mechanism of vascular and cranial nerve injury due to retropharyngeal infections, and highlights the need for early antibiotic therapy and repeated vascular evaluation.