The spinal cord receives its blood supply mainly from the anterior spinal artery and the two posterior spinal arteries. Both run the length of the spinal cord and receive collateral supply. The posterior spinal arteries receive 12 unpaired radicular branches and the anterior spinal artery receives 7-10 unpaired radicular branches and hence has a less efficient collateral supply .
The anterior spinal artery is narrowest at the level of T8, the "watershed" area most liable to ischemia. The artery of the Adamkiewicz, the largest radicular artery usually arises at T9-L2 level and is on the left in 70% of the population .
Acute spinal cord ischemia is rare, accounting for approximately 5% to 8% of all acute myelopathies and 1% to 2% of all strokes . The most prevalent etiology is atherosclerosis followed by aortic pathologies with or without surgery [3, 4]. Other causes include degenerative spine disease, cardiac embolism, systemic hypotension, intercostals nerve block, and cryptogenic causes . In our case, the patient was found to have an aortic pathology as the cause of his symptoms.
The rate of onset of paraplegia is one of the strongest indicators of the underlying pathology. A paraplegia or tetraplegia of sudden onset is most commonly due to injury. Typically, there is a history of trauma associated with this mode of onset. Occasionally the lesion is vascular or the result of acute myelitis . With the latter, there is usually onset associated with fever, spinal tenderness, and root pain. Despite the rapid onset and severity of neurological deficit in our case, there was no history of trauma or any constitutional symptoms suggesting systemic infection, which has raised the suspicion of a vascular pathology .
Spinal MRI is an essential investigation in the diagnosis of spinal cord ischemia . The main objective of MRI is to exclude other causes of acute cord compression . This is extremely helpful in the diagnosis of other causes of paresis, which are more common than spinal cord ischemia. The second feature of MRI is T2 weighted images, which usually show hyperintense signal changes within the cord [6, 7].
In our case, the management of this particular case consisted of conservative treatment and radical surgical approach towards the underlying cause by abdominal aortic aneurysm repair.
There seems to be some motor recovery since surgery and no further neurological deficit. We believe that the outcome at follow up is probably related to the initial motor deficit at presentation. Yet severe initial impairment (ASIA A and B) and female sex are considered to be independent predictors of unfavorable outcome . The present case emphasizes the need of clinical suspicion and through abdominal and vascular examination in these cases for prompt diagnosis to avoid any associated patient morbidity and mortality .