Persistent hypoglossal artery – an increased risk for intracranial aneurysms?

Concurrence of multiple aneurysms, extreme coiling of the extracranial internal carotid artery and ipsilateral persistent primitive hypoglossal artery: A case report and literature review

Background

The primitive hypoglossal artery (PHA) is an anastomotic vessel of the carotid-basilar artery system that is prevalent only transiently during the embryonic period. Persistent primitive hypoglossal artery (PPHA) is a rare vessel variation in which PHA exists persistently in adulthood and occurs in approximately 0.02-0.1% of the population. Tortuosity of the extracranial internal carotid artery (ICA) is relatively common, impacting 10-43% of the population, and is caused by either congenital or acquired factors. It is still unknown whether PPHA and tortuosity of extracranial ICA are associated. Here, we present a case report of the concurrence of three types of pathologies of the carotid artery: extreme coiling of the extracranial internal carotid artery, multiple aneurysms and persistent primitive hypoglossal artery.

Case description

A 66-year-old woman suffered intermittent headaches, dizziness and numbness of the right eyelid for 5 years. Magnetic resonance angiography performed in a local hospital reported an aneurysm of the posterior communicating artery segment of the left ICA and a left PPHA. Digital subtraction angiography conducted after admission showed a PPHA originating from the left cervical ICA and an extremely coiling segment of the ICA distal to the beginning of PPHA. Except for the aneurysm of the posterior communicating artery segment of the left ICA, multiple aneurysms were found at the coiling segment of the ICA.

Conclusion

To the best of our knowledge, this is the first report of PPHA accompanied by an adjacent, extremely coiling ICA. There are no reports of similar tortuous ICAs to this extent or at this position. Including aneurysms, three types of pathologies suggest their congenital origin, and a review of the literature infers the probable association of these lesions.

Are Fetal-Type Posterior Cerebral Arteries Associated With an Increased Risk of Posterior Communicating Artery Aneurysms?

BACKGROUND

Fetal-type posterior cerebral arteries (F-PCAs) might result in alterations in hemodynamic flow patterns and may predispose an individual to an increased risk of posterior communicating artery aneurysms (PCoAAs).

OBJECTIVE

To determine the association between PCoAAs and the presence of ipsilateral F-PCAs.

METHODS

We retrospectively reviewed the radiographic findings from 185 patients harboring 199 PCoAAs that were treated at our institution between 2005 and 2015. Our study population consisted of 4 cohorts: (A) patients with 171 internal carotid arteries (ICAs) harboring unilateral PCoAAs; (B) 171 unaffected ICAs in the same patients from the first group; (C) 28 ICAs of 14 patients with bilateral PCoAAs; and (D) 180 ICAs of 90 patients with aneurysms in other locations. We then determined the presence of ipsilateral F-PCAs and recorded all aneurysm characteristics.

RESULTS

Group A had the highest prevalence of F-PCAs (42%) compared to 19% in group B, 3% in group C, and 14% in group D (odds ratio A : B = 3.041; A : C = 19.626; and A : D = 4.308; P < .001). PCoAAs were associated with larger diameters of the posterior communicating arteries (median value 1.05 vs 0.86 mm; P = .001). The presence of F-PCAs was associated with larger sizes of the aneurysm necks (median value 3.3 vs 3.0 mm; P = .02).

CONCLUSION

PCoAAs were associated with a higher prevalence of ipsilateral F-PCAs. This variant was associated with larger sizes of the aneurysm necks but was not associated with the sizes of the aneurysm domes or with their rupture statuses.

Persistent Primitive Hypoglossal Artery Associated With Multiple Cerebral Aneurysms

Persistent primitive hypoglossal artery is a rare anastomosis between the carotid and basilar arteries, and sometimes associated with cerebral aneurysms. However, association of persistent primitive hypoglossal artery with aneurysms located on arteries other than persistent primitive hypoglossal artery itself or posterior circulation is very rare. An 80-year-old woman suffered from subarachnoid hemorrhage, whose angiography demonstrated aneurysms on the left middle cerebral artery and anterior communicating artery, and the left persistent primitive hypoglossal artery. The middle cerebral artery aneurysm was the origin of hemorrhage. Although repeated craniotomy was necessary for the left middle cerebral artery aneurysm, both aneurysms were successfully clipped. In our case, neither aneurysm was located on an artery related to the persistent primitive hypoglossal artery. There is a possibility that cases of persistent primitive hypoglossal artery are accompanied by cerebral aneurysms on arteries other than the persistent primitive hypoglossal artery or in the posterior circulation.

Persistent hypoglossal artery aneurysm: Case report and qualitative systematic review

A persistent hypoglossal artery was first described in 1889 and is one of the more common anatomical variations arising from aberration in normal development. Endovascular coiling has been recognised as a robust treatment for acutely ruptured intracranial arterial aneurysms, although specific data regarding an aneurysm arising from a persistent hypoglossal artery is lacking due to the low incidence. Here we report both the oldest patient reported to be treated with a persistent hypoglossal artery-associated aneurysm and also explicitly report endovascular treatment of a persistent hypoglossal artery aneurysm arising at the posterior inferior cerebellar artery origin. Qualitative systematic review of the available medical literature demonstrates limited evidence regarding treatment of persistent hypoglossal artery-associated aneurysms with the majority being carried out via open surgery. Ruptured posterior inferior cerebellar artery aneurysm arising from a persistent hypoglossal artery can be successfully and safely treated by endovascular therapy via the persistent hypoglossal artery. Randomised study of this situation is unlikely to be feasible; however, qualitative review of the literature reveals six such aneurysms that have been treated surgically, and this case appears to be the first via an endovascular means.

Bilateral persistent primitive hypoglossal artery presenting with hemiplegia✰

The manuscript describes an unusual vascular anomaly. Persistence of carotid-vertebrobasilar anastomosis is a rare occurrence with presence of bilateral hypoglossal arteries (HAs) rarer still. We present a case of bilateral persistent HAs with hypoplastic vertebral arteries which end into posterior inferior cerebellar arteries. The computed tomography and magnetic resonance imaging appearance, course, and other associations are discussed. A review of 6 cases of bilateral HA published in the world literature is also discussed.

Fatal Subarachnoid Hemorrhage from an Aneurysm of a Persistent Primitive Hypoglossal Artery: Case Series and Literature Overview

BACKGROUND

Persistent carotid-basilar connections have a prevalence of 0.14%. Recognizing such persistent fetal anastomoses between the carotid and the vertebrobasilar circulation is of great importance because they are reportedly associated with an increased prevalence of intracranial aneurysms.

METHODS

We report the case of a 15-year-old female patient who presented with a World Federation of Neurosurgical Societies grade 5 subarachnoid hemorrhage from an aneurysm at the junction of a persistent primitive hypoglossal artery and the posterior inferior cerebellar artery origin. Supratentorially, unfortunately, there was no parenchymal blush or cortical venous return. Eventually, a multidisciplinary decision was made to withdraw care.

RESULTS

Fifty-seven cases were reported in the literature to date of persistent hypoglossal arteries, 16 of which presented with an associated aneurysm, 5 with an arteriovenous malformation, and 6 with a subarachnoid hemorrhage. Our case is the youngest patient reported so far. Hypoplasia or aplasia of the vertebral artery often were encountered (36 and 13 cases, respectively), as well as carotid artery stenosis (15 cases).

CONCLUSIONS

Although uncommon, it is important to recognize persistent carotid-basilar connections, since they have a considerable hemodynamic impact on the posterior cerebral circulation via the carotid system. A critical reduction in the carotid blood flow will, therefore, have ischemic consequences in the posterior cerebral territories. In addition, such connections might be associated with anomalies of the vessel wall and be predisposed to aneurysm formation. The endovascular neurointerventionalist, as well as the vascular and skull base neurosurgeon, need to be aware of their anatomy and variations.

A Persistent Primitive Hypoglossal Artery As the Sole Supply to the Brain Associated with a Basilar Bifurcation Aneurysm

The persistent primitive hypoglossal artery (PPHA) is the second most common persistent carotid–vertebrobasilar anastomosis, with an incidence of 0.027–0.26%. PPHAs change the hemodynamics of the carotid and vertebrobasilar system and may be associated with intracranial vascular anomalies, but basilar bifurcation aneurysms were rarely reported. We describe the first case of a PPHA as the sole supply to the brain associated with a basilar bifurcation aneurysm and review the literature. We reported a 34-year-old woman who presented with subarachnoid hemorrhage due to a ruptured basilar bifurcation aneurysm. Digital subtraction arteriogram revealed a right PPHA as the sole supply to the brain. The aneurysm was successfully clipped under intraoperative neurophysiology.

A rare case of persistent hypoglossal artery associated with contralateral proximal subclavian stenosis

The persistent hypoglossal artery is rare vascular anomalies. We report the case of a 50-year old man with right hypoglossal artery, ipsilateral hypoplasic internal carotid artery, associated with left proximal subclavian stenosis with subclavian steal syndrome. Power-Doppler-Ultra-Sonography spectral images obtained after the patient exercised the left arm showed mid-systolic deceleration with retrograde late-systolic velocities. A Computed Tomography Angiography demonstrated a proximal stenosis of the left SA, a mild right ICA hypoplasia and an anomalous artery arising from right ICA at C2-C3 level, entering the cranium via the hypoglossal canal and joining the basilar artery. Usually the presence of PHA may be completely asymptomatic, and detected as an incidental finding by CTA or MRA, but in our case its diagnosis is extremely important because it is often the only vessel supplying blood to the basilar trunk and posterior circulation.

Persistent hypoglossal artery aneurysm located in the hypoglossal canal with associated subarachnoid hemorrhage

The hypoglossal artery is one of four primitive anastomoses between the internal carotid artery and vertebrobasilar system that regresses in the sixth week of fetal development. A persistent hypoglossal artery (PHA) is generally an incidental finding but may also be associated with aneurysms or arteriovenous malformations. We present a rare case of a PHA with an associated bleeding intracranial PHA aneurysm located in the hypoglossal canal.