Background: Cervical level posterior spinal artery infarction is very rare among spinal cord infarcts. Case: The patient was a 69-year-old male with paroxysmal atrial fibrillation and high blood pressure under treatment with oral apixaban, pilsicainide and azilsartan. He became aware of numbness and movement disorder of the left arm, and visited our hospital. He presented with Horner syndrome; hypoesthesia of the left anterior chest, left face and left upper limb; mild motor paralysis; and deep sensory disturbance of the left upper limb. Diffusionweighted MRI showed a high signal on the dorsal medial side at the first cervical level. The diagnosis was cervical posterior spinal artery syndrome. A cerebral angiogram showed no abnormality in surrounding blood vessels, including the posterior spinal artery. Paralysis improved relatively quickly, and sensory disorders improved with a delay. His only risk factor was paroxysmal atrial fibrillation. Discussion: Posterior spinal artery syndrome causes symptoms such as deep sensory disorder, total sensory depletion at the medullary level, and motor paralysis. In this case, we speculate that Horner syndrome manifested due to an effect on the posterior lateral cord. Thus, cerebral infarction in the posterior spinal artery region can have various symptoms and care is needed for diagnosis.
