The persistent primitive hypoglossal artery: a rare anatomic variation with frequent clinical implications

Persistence of the hypoglossal artery: A rare case report

The persistence of the hypoglossal artery is a rare embryonic vascular variant in which a transient connection between the carotid and vertebrobasilar systems fails to regress. Typically asymptomatic and incidentally discovered on imaging, this condition can alter cerebral blood flow and increase the risk of vascular complications such as aneurysms, strokes, and arteriovenous malformations. We present the case of a 70-year-old female with no prior medical history who was admitted to the emergency department with right-sided hemiparesis. A cerebral CT angiography, performed to evaluate for acute ischemic stroke and potential thrombolysis, revealed a persistent hypoglossal artery arising from the internal carotid artery at the C1-C2 level and connecting to the basilar artery through the hypoglossal canal. This case highlights the importance of recognizing this rare anatomical variant on imaging to prevent misinterpretation and avoid complications during surgical or endovascular interventions at the skull base.

Case Report: Persistent Primitive Hypoglossal Artery Accompanied by a Basilar Bifurcation Aneurysm Treated by Y-Stent-Assisted Coil Embolization

Successful embolization of a basilar bifurcation aneurysm associated with a persistent primitive hypoglossal artery (PPHA) using Y-stent-assisted coiling.

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.

Extremely rare persistent primitive artery passing through the jugular foramen with symptomatic ipsilateral carotid artery stenosis

Primitive arteries are persistent fetal anastomoses between the carotid and vertebral-basilar circulation. Although rare, persistent primitive arteries can remain at birth. A 73-year-old woman presented with cerebral infarction to the posterior circulation caused by symptomatic common carotid artery stenosis with an unnamed and extremely rare persistent primitive artery. This anomalous vessel branched from the extracranial internal carotid artery and passed through the ipsilateral jugular foramen into the posterior cranial fossa and merged into the basilar artery. To our knowledge, this is the first case of a persistent primitive artery passing through the jugular foramen with symptomatic common carotid artery stenosis.

Internal carotid artery stenosis with persistent primitive hypoglossal artery treated with carotid artery stenting: A case report and literature review

Persistent primitive hypoglossal artery (PPHA) is a persistent carotid-basilar anastomosis. It rarely remains at birth. It occasionally may be a risk for ischemia and embolic infarction to the posterior cerebral circulation, especially in patients with carotid stenosis proximal to the origin of persistent primitive arteries. We describe a case of a 60-year-old woman with asymptomatic internal carotid artery (ICA) stenosis and ipsilateral PPHA successfully treated by carotid artery stenting (CAS). A few cases of CAS for ICA stenosis with PPHA have been reported, but the strategy and methods in each case were different because of its unique anatomy and hemodynamics. It is essential to prevent distal embolisms and preserve blood flow at the territory of both the ICA and PPHA. The protection method should be selected carefully. We review the literature and discuss appropriate treatment strategies.

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.

Persistence of a hypoglossal artery: case report

The authors present a case of persistent hypoglossal artery. Persistent hypoglossal artery is the second most common carotid-basilar anastomosis with a frequency of 0.02% to 0.09% and it can be associated with cerebrovascular disease. Diagnosis is by imaging methods and angiotomography is the method most often employed.

Persistent primitive hypoglossal artery associated with Chiari II malformation: Diagnosis and clinical implications

We present a case of persistent primitive hypoglossal artery (PPHA) associated with Chiari II malformation and discuss the clinical implications. There has been one reported case of PPHA associated with Chiari 1 malformation, but none in association with Chiari II. Our patient also had a widened hypoglossal canal, with cerebrospinal fluid (CSF) sac herniation through it.

Persistent fetal intracranial arteries: a comprehensive review of anatomical and clinical significance

As fetal intracranial vessels may persist into adulthood, knowledge of their anatomy and potential clinical and surgical complications should be borne in mind by the surgeon. A comprehensive review of these vessels, however, is not easily identified in the literature. Therefore, the present analysis was undertaken so that such information is available to the clinician and morphologist.

Persistent hypoglossal artery arising from the external carotid artery diagnosed by MR angiography

PURPOSE

Extremely rarely, a persistent hypoglossal artery arises from the external carotid artery; only three cases have been reported in the English-language literature. The purpose of this paper is to report a case of this variation diagnosed by magnetic resonance (MR) angiography.

METHODS

A 75-year-old man with sudden-onset right hemiparesis and dysarthria underwent emergency cerebral MR imaging and cerebral MR angiography that included the cervical carotid bifurcation. A 1.5-T scanner was used and MR angiographic images were obtained using the standard three-dimensional time-of-flight technique.

RESULTS

On MR angiography, an anomalous artery arose from the proximal right external carotid artery, ascended just like the ascending pharyngeal artery, entered the hypoglossal canal (anterior condyloid foramen), and finally connected with the terminal segment of the right vertebral artery (VA). The proximal right VA was not visible, probably due to hypoplasia.

CONCLUSION

We present the first case of this anomaly diagnosed using MR angiography, and we propose the term "type 2 persistent hypoglossal artery" to describe this condition.

An ectopic cranial nerve identified during surgery in the posterior fossa for hemifacial spasm: a word of caution

Variations of cranial nerve morphology may effect surgical technique and, if not appreciated, lead to complications and iatrogenic injury. The authors report an unusual course of the hypoglossal nerve within the posterior cranial fossa observed during microvascular decompression surgery for hemifacial spasm.

A case of aneurysm on a persistent hypoglossal artery treated by endovascular coiling

SUMMARY

We describe a 22-year-old woman admitted to hospital in emergency with nuchal headache and vomiting. CT scan disclosed subarachnoid hemorrhage. Digital subtraction angiography with three-dimensional rotational acquisitions showed a ruptured aneurysm of a right persistent primitive hypoglossal artery as the cause of symptoms and hemorrhage. The patient was successfully treated with endovascular coiling of the aneurysm. This is the second literature report describing endovascular treatment in this unusual condition.

Ultrasound findings of bilateral hypoplasia of the vertebral arteries associated with a persistent carotid-hypoglossal artery

We present a 31-year-old female who was admitted to our neurology department for vertigo, partial left-sided hemihypesthesia and nuchal headache of subacute onset. Colour-duplex ultrasound disclosed bilateral low flow with a high resistance flow pattern in both vertebral arteries in the V2 segments, while the basilar artery had normal flow. CT angiography and MRI ruled out any ischaemic cerebral infarct and disclosed a persistent hypoglossal artery (PHA) originating from the left internal carotid artery (ICA). The patient was eventually treated for cervicobrachialgia. Persistent carotid-basilar anastomosis such as PHA may account for an atypical stroke pattern in carotid disease, aneurysms and arterovenous malformations. In retrospect, PHA is amendable to colour-Duplex investigation due to an abnormal ICA flow and a discrepancy between the vertebral and basilar flow patterns. Ultrasound investigation of the vertebrobasilar system remains a challenge as variants appear frequently; hypoplasia of the vertebral arteries should thus be confirmed using CT or MR angiography.

Angiographic findings and clinical implications of persistent primitive hypoglossal artery

BACKGROUND: The primitive hypoglossal artery (PHA) is a rare vascular anomaly, which belongs to the group of carotid-basilar anastomosis that may occur in adults. CASE PRESENTATION: Herein is presented a case of a patient with a PHA, who had undergone a cerebral angiography due to investigation of subarachnoid hemorrhage. Additionally, the diagnostic alternatives for detection and assessment of PHA and the spectrum of diseases related to its presence are discussed. CONCLUSIONS: The presence of a persistent PHA can be recognized as an incidental finding in a cerebral angiography without any other clinical implication or may be associated with certain clinical entities such as aneurysm formation and atherosclerotic disease.

Anomalous artery directly connecting the external and internal carotid arteries

An anomalous artery directly connecting the external with the internal carotid artery was encountered on the right side of a 68-year-old Japanese female cadaver. This anomalous artery (5 mm in diameter, 12 mm in length) branched out from the posterior aspect of the external carotid at the level of the origin of the lingual artery, ran obliquely upward posteriorly along the course of the hypoglossal nerve, and was confluent with the anterior aspect of the internal carotid artery. No other variations were found in the morphological aspects of, or in the anatomical relationships between, the carotid arteries and their surrounding structures on either side. The carotid body-like structure was observed at the carotid bifurcation and was innervated by small branches of the glossopharyngeal, the vagus and the sympathetic trunk. Embryologically, it is conceivable that this anomalous artery may have derived from the right second branchial arch artery, although there is no abnormality in other derivative structures of the second pharyngeal arch. There may have been no effect from this anomaly on the functions of the arterial blood flow and blood supply under normal circumstances in the present case, but this report may be of embryological significance and contribute some insight into the mechanisms of the formation of the carotid circulation systems.