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Neuroradiology Case of the Week

Case 272

Brian Sorensen, MD, Sudhir Kathuria, MD, and P-L Westesson, MD, PhD, DDS

Clinical Presentation: Patient is a 14-year-old female presenting for aneurysm screening examination. The patient's brother has a history of intracranial aneurysm rupture.

Imaging Findings:

Diagnosis: Persistent trigeminal artery

Discussion: During early fetal development, several transient anterior-posterior circulation communicating vessels develop, namely the trigeminal, otic, hypoglossal, and proatlantal arteries. Each of these connections is named after the cranial nerve it parallels. As the embryonic intracranial arterial system matures and the need for anastamosis is eliminated, the communicating vessels obliterate. The trigeminal artery is the largest and last to regress among the segments, making it the most common to persist (0.1-0.2% of cerebral angiograms). Originating from the cavernous ICA, the persistent trigeminal artery (PTA) classically runs posterolaterally along the trigeminal nerve to terminate at the basilar artery.
     PTA is associated with a few vascular abnormalities, including hypoplasia of the PCoA, vertebral arteries, and proximal basilar artery. Other associated abnormalities include aneurysm, AVM, carotid-cavernous fistula, arterial fenestration, and NF1. Typically, PTA is an incidental findings with no necessary treatment.

References:

1. Osborn AG, Blaser SI, Salzman KL, et al. Diagnostic Imaging: Brain, 1st ed. Altona: Amirsys Inc; 2004.
2. Suttner N, Mura J, Tedeschi H, Ferreira MA, Wen HT, de Oliveira E, Rhoton AL Jr. Persistent trigeminal artery: a unique anatomic specimen--analysis and therapeutic implications. Neurosurgery. 2000 Aug;47(2):428-33; discussion 433-4. [Medline]
3. Uchino A, Sawada A, Takase Y, Kudo S. MR angiography of anomalous branches of the internal carotid artery. AJR Am J Roentgenol. 2003 Nov;181(5):1409-14. [Medline]