Trident sign (neurosarcoidosis)
Updates to Article Attributes
The trident sign is a radiological sign described in spinal cord neurosarcoidosis on MRI.
The sign describes the axial appearance of a longitudinally extensive transverse myelitis due to spinal cord neurosarcoidosis, whereby on a T1 post-contrast (gadolinium) MRI sequence, there is central canal enhancement accompanying crescent-shaped posterior subpial enhancement 1-3. This gives the appearance of a trident, a three-pronged spear 1-3.
It has been suggested that this is a useful sign in differentiating neurosarcoidosis from other causes of longitudinally extensive transverse myelitis, such as neuromyelitis optica spectrum disorder (NMOSD), which this sign is not described 3. However, it should be noted that it is likely that this is not a sensitive sign, as large case series of patients with spinal cord neurosarcoidosis have not found this sign to be commonly present 4.
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 classical Roman equivalent) 5. Although a similar weapon, the trishoola, with rounded tines, is also seen being carried in images of Hindu gods, e.g. Shiva and Durga 5. The trident sign was first employed in the context of neurosarcoidosis in 2016 1.
- +<p>The <strong>trident sign</strong> is a radiological sign described in spinal cord <a href="/articles/neurosarcoidosis" title="Neurosarcoidosis">neurosarcoidosis</a> on MRI.</p><p>The sign describes the axial appearance of a <a href="/articles/longitudinally-extensive-spinal-cord-lesion" title="Longitudinally extensive spinal cord lesion">longitudinally extensive transverse myelitis</a> due to spinal cord <a href="/articles/neurosarcoidosis" title="Neurosarcoidosis">neurosarcoidosis</a>, whereby on a T1 post-contrast (gadolinium) MRI sequence, there is central canal enhancement accompanying crescent-shaped posterior subpial enhancement <sup>1-3</sup>. This gives the appearance of a trident, a three-pronged spear <sup>1-3</sup>.</p><p>It has been suggested that this is a useful sign in differentiating <a href="/articles/neurosarcoidosis" title="Neurosarcoidosis">neurosarcoidosis</a> from other causes of <a href="/articles/longitudinally-extensive-spinal-cord-lesion" title="Longitudinally extensive spinal cord lesion">longitudinally extensive transverse myelitis</a>, such as <a href="/articles/neuromyelitis-optica-spectrum-disorder" title="Neuromyelitis optica spectrum disorder">neuromyelitis optica spectrum disorder (NMOSD)</a>, which this sign is not described <sup>3</sup>. However, it should be noted that it is likely that this is not a sensitive sign, as large case series of patients with spinal cord neurosarcoidosis have not found this sign to be commonly present <sup>4</sup>.</p><h4>History and etymology</h4><p>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 classical Roman equivalent) <sup>5</sup>. Although a similar weapon, the trishoola, with rounded tines, is also seen being carried in images of Hindu gods, e.g. Shiva and Durga <sup>5</sup>. The trident sign was first employed in the context of <a href="/articles/neurosarcoidosis" title="Neurosarcoidosis">neurosarcoidosis</a> in 2016 <sup>1</sup>.</p>
References changed:
- 1. Zalewski N, Krecke K, Weinshenker B et al. Central Canal Enhancement and the Trident Sign in Spinal Cord Sarcoidosis. Neurology. 2016;87(7):743-4. <a href="https://doi.org/10.1212/WNL.0000000000002992">doi:10.1212/WNL.0000000000002992</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/27527540">Pubmed</a>
- 2. Gibbons E, Whittam D, Jacob A, Huda S. Images of the Month 1: Trident Sign and Neurosarcoidosis. Clin Med (Lond). 2021;21(6):e667-8. <a href="https://doi.org/10.7861/clinmed.2021-0596">doi:10.7861/clinmed.2021-0596</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/34862230">Pubmed</a>
- 3. Jolliffe E, Keegan B, Flanagan E. Trident Sign Trumps Aquaporin-4-IgG ELISA in Diagnostic Value in a Case of Longitudinally Extensive Transverse Myelitis. Mult Scler Relat Disord. 2018;23:7-8. <a href="https://doi.org/10.1016/j.msard.2018.04.012">doi:10.1016/j.msard.2018.04.012</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/29709797">Pubmed</a>
- 4. Nolte J, Ten Dam L, van de Beek D, Brouwer M. Clinical Characteristics and Outcome of Neurosarcoidosis-Associated Myelitis: A Retrospective Cohort Study and Review of the Literature. Eur J Neurol. 2022;29(6):1763-70. <a href="https://doi.org/10.1111/ene.15295">doi:10.1111/ene.15295</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/35189010">Pubmed</a>
- 5. Agrawal A. Musculoskeletal Colloquialisms Based on Weapons. J Clin Orthop Trauma. 2017;8(1):1-10. <a href="https://doi.org/10.1016/j.jcot.2016.07.006">doi:10.1016/j.jcot.2016.07.006</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/28360488">Pubmed</a>
Tags changed:
- cases
Sections changed:
- Signs
Systems changed:
- Central Nervous System
- Spine
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