Presentation
Chronic headache.
Patient Data
a large calibered artery is seen arising from the superior-posterior aspect of the left cavernous ICA (which appears hypertrophied), this artery passes posteriorly and medially to form the basilar artery tip, with the latter is seen giving rise to the normal calibered both PCAs. The caudal basilar artery is atretic
hypoplastic distal vertebral arteries, more marked on the right side
normal calibers of the intra-cranial ICAs as well as both MCAs and ACAs, however both A2 segments unite forming a single trunk
no evidence of aneurysms or AV malformation
Case Discussion
Type I Saltzman persistent left trigeminal artery (PTA) with hypoplastic caudal basilar artery and distal vertebral arteries.
Types of persistent carotid-vertebrobasilar anastomoses:
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persistent trigeminal artery (PTA): the most common persistent carotid-vertebrobasilar anastomosis with cavernous ICA to basilar artery (BA) anastomosis, Neptune's trident sign on angiography. Types of PTA:
Saltzman type I: PTA supplies the distal vertebrobasilar arteries. Absent PCOM. The caudal BA is absent or hypoplastic with hypoplastic distal vertebral arteries
Saltzman type II: PTA supplies the superior cerebellar arteries with the PCAs supplied via the PCOM
persistent hypoglossal artery: It connects the cervical ICA at the level of C1-C2 to basilar artery via hypoglossal canal. This anastomosis parallels the hypoglossal nerve. It is the 2nd most common persistent carotid-vertebrobasilar anastomosis
persistent otic artery (POA): Courses from petrous ICA within the carotid canal and exits through internal acoustic meatus to caudal BA. Vertebral arteries may be absent or hypoplastic, POA may be dominant or only supply to the BA
persistent proatlantal intersegmental artery (PIA): cervical ICA to vertebrobasilar system. Most caudal of PCBAs. Originates usually from cervical ICA at C2-C3 level (type I) or less commonly from the ECA (type II) or rarely from the CCA. PIA communicates with vertebral artery coursing between arch of C1 and occiput. Vertebral arteries may be absent or hypoplastic, PIA may be dominant or only supply to BA
Fetal origin of the PCA: hypertrophied PCOM supplies the PCA with atretic P1 segment of the PCA
The case is courtesy of Dr. Ahmad Yousry, MD.
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