Four cases of carotid-basilar anastomosis associated with central nervous system dysfunction

Infratentorial arteriovenous malformation associated with persistent primitive hypoglossal artery

BACKGROUND

We report a case of infratentorial arteriovenous malformation (AVM) associated with persistent primitive hypoglossal artery (PPHA). To our knowledge, this is the second reported case of these combined anomalies in the English literature. We discuss the embryological relationship between these two congenital vascular anomalies.

CASE DESCRIPTION

An 18-year-old girl, who suddenly developed severe headache and vomiting followed by loss of consciousness, was admitted to our hospital. A computed tomography scan showed intracerebellar hemorrhage with obstructive hydrocephalus. Digital subtraction angiography revealed an AVM in the left cerebellar hemisphere and an ipsilateral PPHA. After the intracranial pressure was stabilized, the AVM was surgically removed. AVMs develop during the 4(th) to 8(th) week of embryonic life. In contrast, carotid-basilar anastomoses (CBAs) including primitive hypoglossal arteries appear and close spontaneously by the 6(th) week of embryonic life. Thus, AVMs precede CBAs, and a large amount of blood flows into the adjoining AVM via ipsilateral CBAs. As a result, spontaneous closure of a CBA may be disturbed.

CONCLUSION

We speculate that coexistence of infratentorial AVMs and ipsilateral CBAs is not incidental but inevitable.

Trigeminal artery: a review of normal and pathological features

OBJECTS

Carotid-vertebrobasilar anastomoses-the trigeminal, otic, hypoglossal, and proatlantal intersegmental arteries-serve as transitory channels between primitive internal carotid arteries and bilateral longitudinal neural arterial plexus, which is the precursor of future basilar artery, when the human embryo reaches about 4-mm length.

MATERIAL AND METHODS

Normal and/or abnormal morphofunctional aspects of the prenatal and postnatal forms of the trigeminal artery are described according to personal and literature data. Many arteries of similar origin and course are also noted in the differential diagnosis of the trigeminal artery.

CONCLUSIONS

The persistent primitive trigeminal artery, as the most commonly carotid-vertebrobasilar anastomosis, has a reported incidence of 0.03-2.2% in the literature. There is female sex predilection, and it may be discovered in patients of any age, on either side, and in association with many vascular variants. Although the significance of persistent primitive trigeminal artery regarding the development of an aneurysm or association with another pathological condition may not be clear, its (ab)normal morphology is the inspiration for anatomists, especially for neurosurgeons, before planning diagnostic and therapeutic procedures.

Posterior fossa arteriovenous malformation associated with persistent primitive trigeminal artery--case report

A 21-year-old female presented with an unusual case of posterior fossa arteriovenous malformation (AVM) associated with ipsilateral persistent primitive trigeminal artery (PPTA), manifesting as intraparenchymal hemorrhage involving both the brain stem and the left cerebellar hemisphere. The presenting symptoms were compatible with Wallenberg's syndrome and Foville's syndrome on the left side. She was initially treated conservatively, and subsequently with transarterial embolization followed by stereotactic radiosurgery. This case combined the rare association of posterior fossa AVM and PPTA, with the clinical presentation of intraparenchymal hemorrhage causing both Wallenberg's syndrome and Foville's syndrome.

Transcranial sonography in a patient with a persistent trigeminal artery

Transcranial ultrasonography was performed in a patient with a persistent trigeminal artery, a remnant of fetal cerebral circulation that bridges the carotid and basilar territories. The study revealed low flow and reversal of flow in the vertebral and basilar arteries, respectively. The interpretation and significance of these findings are discussed.

[Persistent trigeminal artery associated with aneurysm of the middle cerebral artery. Case report and review of the literature]

The authors report a case of persistent primitive trigeminal artery angiographically demonstrated as an incidental finding. The persistent primitive trigeminal artery was associated with an aneurysm arising from the circle of Willis in the middle cerebral artery territory. The literature is reviewed and the embryology involved is related.

Bilateral occipital infarctions associated with carotid stenosis in a patient with persistent trigeminal artery. The Collaborators of the North American Carotid Endarterectomy Trial (NASCET)

BACKGROUND

Embolization via a persistent trigeminal artery, one of the embryonic vascular connections that may persist between the carotid and basilar arteries, is an unusual occurrence.

CASE DESCRIPTION

We describe a 76-year-old man with bilateral occipital infarctions presumably related to an ulcerated left carotid stenosis. Clinically, a left inferior homonymous quadrantanopia was present.

CONCLUSIONS

Anomalous connections between the carotid and the usual posterior circulation territory should be considered in evaluating patients with vertebrobasilar stroke. When they are identified, patients with symptoms attributable to the pontine vertebrobasilar territory supplied by the anomaly may be considered for carotid endarterectomy in the presence of concomitant severe carotid stenosis detected angiographically. Proper identification and treatment of such cases would be expected to prevent recurrence of disabling strokes in the vertebrobasilar circulation. These anomalies will likely be overlooked by ultrasound techniques and depend on good intracranial arteriographic images.

Cavernous sinus fistula caused by intracavernous rupture of a persistent primitive trigeminal artery. Case report

A persistent carotid-basilar anastomosis (primitive trigeminal artery), identified by four-vessel vertebral angiography, was shown to be the cause of a cavernous sinus fistula in a 51-year-old woman. The fistula, but not the primitive artery, was identified on a carotid arteriogram. Because of the flow contribution from the posterior circulation, balloon embolization via the carotid system failed, and the fistula was repaired through a direct surgical approach. The operative technique is described and the hemodynamic aspects of a cavernous sinus fistula that is related to this primitive anastomosis are reviewed.

Vascular anomalies and subarachnoid haemorrhage associated with persisting embryonic vessels

In 25 per cent of patients with persistinc primitive trigeminal artery, and in 27 percent of patients with primitive hypoglossal artery, vascular malformations or a history of subarachnoid haemorrhage were found. There is a high incidence of aneurysms at the site of origin of the persisting embryonic vessels. No relation was found between the persisting embryonic vessels and the age, sex, and time of subarachnoid haemorrhage. Opacification of posterior cerebral arteris, vertebral arteries, and posterior communicating arteries was analysed, and variations of the Circulus arteriosus Willisi were found. Ten patients with persisting embryonic vessels are described. In patients in whom external carotid-middle cerebral artery bypass is planned, attention should be drawn to the possibility of persisting embryonic vessels.

Bilateral cortical blindness associated with carotid stenosis in a patient with a persistent trigeminal artery: case report

A patient with findings of bilateral cortical blindness and a unilateral carotid bruit is reported. A persistent trigeminal artery allowed emboli from a unilateral ulcerated internal carotid plaque to affect the visual cortex bilaterally. The angiographic findings and a brief discussion of this anomalous artery are presented.

Persistent hypoglossal artery and persistent trigeminal artery presenting with posterior fossa transient ischemic attacks. Report of two cases

Two patients, one with a persistent hypoglossal artery and the other with a persistent trigeminal artery, presented with transient ischemic attacks in the distribution of the posterior fossa. Both had stenosis and ulcerative plaques at the carotid bifurcation. Their symptoms were successfully relieved after carotid endarterectomy.

[Anatomy, variations and malformations of the vessels of the head and neck region (author's transl)]

After a short review of developmental data concerning the head and neck arteries, the normal conditions, variations and malformations of single arteries are described. Special attention is paied to the skeletotopic and topographic relations of the arteries. In every bigger vessel its length, position, origin and branches are described, and in most cases are also demonstrated by diagrams and tables. As the aortic arch may also reach the neck region, its variation and malformations as well as the variations of its branches are mentioned. The variations and the malformations of the inominate artery, of the common carotid artery, as well as of the external and internal carotid arteries are described. The practical importance of these variations is stressed. Upon description of variations and malformations anatomical, surgical und roentgenological findings described in literature, as well as personal experiences are considered. Special attention has been paied to the variations of the circulus arteriosus Willisi, to the persistence of the presegmental arteries and to the possibility of formation of a by-pass in occlusion or aplasia of cerebral arteries. The position of the subclavian artery, its variations and the variations of its branches are described. After a short embryological introduction, the variations of the venous system and its anastomoses are described. At the end, the main variations of the big lymphatic vessels in the neck are mentioned.

Hypoglossal paralysis due to compression by a tortuous internal carotid artery in the neck

Severe hemiatrophy of the right half of the tongue in a 22 year old patient was demonstrated to be due to compression of the hypoglossal nerve by a tortuous internal carotid artery in the neck. The nerve was trapped between an abnormal loop of the internal carotid artery and the sternocleidomastoid branch of the occipital artery. Although impairment of cranial nerve function with cases of tortuous and dilated vessels has been reported frequently, twelfth nerve palsy has never been demonstrated before.

Report of Joint Committee for Stroke Facilities-- IX. Strokes in Children (Part 1)

The study group assigned the task of reviewing what is known about strokes in children has performed an outstanding service in bringing to the attention of readers of Guidelines for Stroke Care an important but little-publicized subject. They have given an analysis in depth, covering epidemiology, neuropathology, diagnosis and medical treatment, neurosurgical management, neuroradiology, rehabilitation, and psychological and educational problems. Strokes occur in children much less frequently than in the adult population. Nevertheless their significance should not be underestimated or underemphasized, for they have unusual features because their impact affects the developing nervous system.

The Strokes in Children section of the Report of the Joint Committee for Stroke Facilities is being published in two parts of which this is the first; the second part will appear in the November-December issue of this Journal.

[Carotid-basilar anastomosis]

O autor relata um caso de anastomose carótido-basilar por persistência da artéria trigeminal, demonstrado angiogràficamente. O paciente apresentou hemiplegia súbita e era portador de transtornos mentais de tipo deficitário. A pneumencefalografia evidenciou atrofia do parênquima cerebral do lado da anomalia.