Thoracic disc herniation and vascular vulnerability in a watershed zone

Anterior spinal artery (ASA) syndrome is a rare cause of spinal cord infarction and is most commonly associated with aortic pathology or systemic hypoperfusion. Disc herniation as a precipitating factor is exceptional, particularly in young, healthy individuals. We report the case of a previously healthy white woman, 23 years old, who developed sudden flaccid paraplegia and bladder dysfunction during high-intensity physical exercise. Magnetic resonance imaging (MRI) demonstrated a T8–T9 disc herniation associated with an acute anterior spinal cord infarction. Given the hyperacute presentation and high clinical suspicion of a vascular event, intravenous thrombolysis (IVT) was administered within 3 h of symptom onset. Digital subtraction angiography showed a patent but reduced-caliber anterior spinal artery at the level of the lesion, consistent with a thoracic watershed zone. Three-dimensional fusion imaging revealed close anatomical proximity between the herniated disc and the anterior spinal artery, supporting the possibility of a transient hemodynamic compression mechanism. However, fibrocartilage embolism (FCE) could not be completely ruled out due to the lack of histopathological confirmation. Partial neurological recovery was achieved after intensive rehabilitation, although bladder dysfunction persisted. Thoracic disc herniation can precipitate acute spinal cord infarction through transient hemodynamic compromise of the anterior spinal artery, particularly in anatomically vulnerable watershed regions. Early recognition, advanced imaging, and individualized management are essential to optimize outcomes.