title: Thoracic disc herniation leads to anterior spinal artery syndrome demonstrated by diffusion-weighted magnetic resonance imaging (DWI): a case report and literature review.
abstract: BACKGROUND
  Thoracic disc herniation rarely causes acute ischemic events involving the spinal cord. Few reports have suggested this as a mechanism leading to anterior spinal artery syndrome, and none with illustration through diffusion-weighted magnetic resonance imaging (DWI).
  
  
  OBJECTIVE
  The purpose of this study was to report a case of anterior spinal artery syndrome secondary to thoracic disc herniation and demonstrate the first use of DWI to aid in diagnosis of this rare myelopathy.
  
  
  METHODS
  Case report.
  
  
  METHODS
  A 36-year-old woman developed sudden onset of back pain followed by evolving paraparesis and sensory loss consistent with anterior spinal artery distribution ischemia. T2-weighted magnetic resonance imaging (MRI) demonstrated an acute herniated nucleus pulposus at the T7-T8 disc, which produced a focal indentation of the adjacent anterior spinal cord without cord displacement or canal stenosis. T2-weighted hyperintensities were seen at T4-T7 levels with corresponding brightness on DWI and reduction of the apparent diffusion coefficient, consistent with cord ischemia.
  
  
  RESULTS
  Remarkably, within just a few days and following conservative treatment, including heparin and steroids, this patient's neurologic status began to show improvement. Within 3 weeks, she was ambulating with assisted devices, and at the 10-month follow-up, the patient had nearly complete neurological improvement. A follow-up MRI at 10 months showed normal T2-weighted imaging except for a 1×2-mm area of anterior-left lateral cord myelomalacia at T4-T5.
  
  
  CONCLUSIONS
  Acute thoracic disc herniation with cord contact but without canal stenosis is able to disrupt blood flow to the cord leading to anterior spinal artery distribution ischemia. This case represents the first demonstrated use of DWI in diagnosing this rare cause of anterior spinal artery ischemia.
authors.affiliation: Department of Internal Medicine, UMass Memorial Medical Center 55 N Lake Ave Worcester, MA 01605. Electronic address: Jacquesm.Reynolds@gmail.com.
authors.forename: Jacques M
authors.initials: JM
authors.lastname: Reynolds
authors.affiliation: Department of Internal Medicine, Eastern Maine Medical Center, 489 State St, Bangor, ME 04401, USA.
authors.forename: Yeshaswi S
authors.initials: YS
authors.lastname: Belvadi
authors.affiliation: Department of Radiology, Neuroradiology, Eastern Maine Medical Center, 489 State St, Bangor, ME 04401, USA.
authors.forename: Arthur G
authors.initials: AG
authors.lastname: Kane
authors.affiliation: Department of Neurology, Eastern Maine Medical Center, Clinical Assistant Professor in Neurology, University of Vermont, 489 State St, Bangor, ME 04401, USA.
authors.forename: Markos
authors.initials: M
authors.lastname: Poulopoulos
mesh_terms: D000328:Adult; D020759:Anterior Spinal Artery Syndrome / Q000209:etiology* / Q000503:physiopathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000150:complications* / Q000503:physiopathology; D020335:Paraparesis / Q000209:etiology* / Q000503:physiopathology; D013904:Thoracic Vertebrae
keywords: Anterior cord syndrome; Anterior spinal artery syndrome; Artery of Adamkiewicz; Diffusion-weighted magnetic resonance imaging (DWI); Spinal infarction; Thoracic disc herniation