Spinal cord ischemia: The "snake bite sign".

Abstract

Descriptive signs in radiology can aid in easier pattern recognition and quicker diagnosis. In spinal cord ischemia, paired anterior-horn T2-hyperintensities have traditionally been known as the "owl's eyes" or "snake eyes" sign. We discuss how these signs, while visually apt, convey no pathophysiologic context and propose renaming this finding the "snake bite sign". The image still evokes two punctate marks, yet the metaphor extends to a snake bite (two fang-like dots) rather than two bright foci (eyes) staring back at the viewer. Moreover, besides the sign metaphorically resembling a traumatic puncture of the two fangs, on the occasion of a venomous snake bite occurring elsewhere, additional neurological consequences may occur, paralleling the neurological deficits seen in anterior spinal artery infarction and several mimicking myelopathies, thus further highlighting the analogy. Such clinically driven terminology may facilitate teaching, enable diagnostic recall, and improve interdisciplinary communication.