Trident sign (persistent primitive trigeminal artery)
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At the time the article was created Frank Gaillard had no recorded disclosures.View Frank Gaillard's current disclosures
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The trident sign of a persistent primitive trigeminal artery refers to the appearance of the intracranial circulation on lateral projection. The internal carotid artery, the abnormal vessel and superior portion of the basilar artery resemble the Greek letter tau (thus tau sign). This configuration is also referred to as the trident sign 1, although, as there are only two upwardly pointing branches (terminal ICA and basilar artery) this would probably be better termed a bident.
History and etymology
The trident is a three-pronged lance employed for spearing fish, and in Classical mythology was the weapon born by sea gods, such as the sea god Poseidon in Ancient Greece (or Neptune, the Roman equivalent).
Poseidon's older brother, Hades/Pluto has a two-pronged staff, known as a bident, which is actually a better fit for the morphology of this abnormality 2.
- 1. Arsany Hakim, Jan Gralla, Christoph Rozeik, Pasquale Mordasini, Lars Leidolt, Eike Piechowiak, Christoph Ozdoba, Marwan El‐Koussy. Anomalies and Normal Variants of the Cerebral Arterial Supply: A Comprehensive Pictorial Review with a Proposed Workflow for Classification and Significance. (2018) Journal of Neuroimaging. 28 (1): 14. doi:10.1111/jon.12475 - Pubmed
- 2. Syed Ramsey. Tools of War. (2016) ISBN: 9789386019806