Anomalous origin of the posterior inferior cerebellar artery from the pre-cavernous portion of the internal carotid artery--a primitive trigeminal artery variant

Anomalous origin of the posterior inferior cerebellar artery from the jugular branch of the ascending pharyngeal artery: A case report

The posterior inferior cerebellar artery usually arises from the vertebral artery and has several variants. The posterior inferior cerebellar artery originating from the jugular branch of ascending pharyngeal artery has rarely been reported. A 63-year-old woman underwent cerebral magnetic resonance imaging and magnetic resonance angiography; the latter incidentally revealed an anomalous origin of the posterior inferior cerebellar artery. We report and discuss the neuroimaging findings in a patient with this anomaly. Determining the origin of the posterior inferior cerebellar artery is an important factor in planning surgical and endovascular treatment strategies for skull base disorders.

Cerebellar artery arising from the cavernous segment of the internal carotid artery and persistent trigeminal artery: a spectrum of incomplete longitudinal fusion

Background

The embryological relationship between cerebellar arteries originating directly from the cavernous segment of the internal carotid artery and persistent trigeminal artery is not well understood.

Purpose

To evaluate the incidence and pattern of cerebellar arteries originating from the internal carotid artery and persistent trigeminal artery, and to discuss their probable embryological relationship.

Material and Methods

We reviewed 5113 angiographic studies from 5093 patients at our institution over the last eight years, searching for patients with persistent trigeminal artery and cerebellar arteries originating from a cavernous segment of internal carotid artery (persistent trigeminal artery variant).

Results

Of the 5093 patients, 27 patients had persistent trigeminal artery or persistent trigeminal artery variant (0.53%). Twenty patients (6 men, 14 women; median age = 54 years) had persistent trigeminal artery (0.39%). Seven patients (2 men, 5 women, age range = 37–72 years; median age = 57 years) had a persistent trigeminal artery variant with persistent trigeminal artery terminating in a cerebellar artery without direct connection to the basilar artery (persistent trigeminal artery variant; 0.14%). The terminal branch of the persistent trigeminal artery variant was an anterior inferior carotid artery in five patients and a superior cerebellar artery in two patients. Of the seven patients having persistent trigeminal artery variant, four patients had another artery from the basilar artery to the anterior inferior carotid artery territory. In 6/20 patients with persistent trigeminal artery, there was an anterior inferior carotid artery arising from the persistent trigeminal artery. One of these patients showed another arterial branch from the basilar artery to the anterior inferior carotid artery territory.

Conclusion

Persistent trigeminal artery variant and cerebellar arteries originating from the persistent trigeminal artery are both believed to be a spectrum of incomplete fusion of the longitudinal neural arteries. Understanding the precise anatomy is important in diagnostic and therapeutic settings for related vascular disease.

Clinical Importance of the Posterior Inferior Cerebellar Artery: A Review of the Literature

The posterior inferior cerebellar artery (PICA), with its unique anatomical complexity, is of great clinical importance and involved in many diseases including aneurysm, ischemic stroke, neurovascular compression syndrome (NVCS), arteriovenous malformation (AVM), and brain tumor. However, a comprehensive systematic review of the importance of the PICA is currently lacking. In this study, we perform a literature review of PICA by searching all the associated papers in the PUBMED database hoping to provide a better understanding of the artery. The PICA has tortuous and variable course and territory, divided into 5 segments. Various aneurysms involving PICA were not uncommon, of which the treatment is challenging. The PICA infarct typically manifests lateral medullary syndrome (LMS) and is more likely to cause mass effects. The PICA frequently compresses the medulla and the cranial nerves resulting in various neurovascular compression syndromes (NVCS). Arteriovenous malformation (AVM) fed by PICA are associated with aneurysm and dissection which have high risk of rupture and worse outcome. PICA injured by head trauma can cause fatal SAH. VA terminating in PICA probably cause Bow hunter's syndrome (BHS). The PICA supplies many brain tumors and can be used in intracerebellar chemotherapy. The PICA can be exposed and injured during surgeries especially in telovelar approach, and it also plays an important role in bypass surgeries, hinting the surgical importance of PICA. In conclusion, PICA is very important in clinical practice.

Treatment of an aberrant inferior temporal artery aneurysm arising off the proximal cavernous segment of the internal carotid artery

We report the clinical details, imaging findings, and management of a 41-year-old female who presented with 6^th cranial nerve palsy from a right proximal cavernous segment internal carotid artery aneurysm arising distal to the branch point of an aberrant inferior temporal artery. Although rare, aberrant branches arising off the proximal ICA may supply the cerebral cortex. Careful evaluation prior to surgical intervention in this setting may reduce the incidence of ischemic complications.

An aberrant cerebellar artery originating from the internal carotid artery

The aberrant origin of the cerebellar arteries from anterior cerebral circulation is a quite rare vascular variation. Herein, we report a 52-year-old white female with angiographically occult subarachnoid hemorrhage. Left superior and anterior inferior cerebellar arteries were not detected. An aberrant cerebellar artery was noted to arise from the left cavernous internal carotid artery and terminated in the distribution of the ipsilateral superior and anterior inferior cerebellar arteries. This variant artery might likely have resulted from an abnormal regression of fetal anterior-to-posterior circulation connections, and may represent a fetal-type cerebellar artery. A review of the anatomy and clinical significance of the variant is presented.

A rare variant of persistent trigeminal artery: cavernous carotid-cerebellar artery anastomosis--a case report and a systematic review

We report a very rare anomalous anatomic variant of the cavernous internal carotid artery supplying directly the posterior inferior cerebellar artery, with no basilar artery opacification. A systematic review as well as a description of other variants of trigeminal-cerebellar anastomosis is given.

Primitive trigeminal artery variant aneurysm treated with Guglielmi detachable coils--case report

A 69-year-old woman had suffered from diplopia on right lateral gaze for the last 4 months due to right abducens nerve paresis. Right carotid angiography showed a cavernous internal carotid artery (ICA) aneurysm of 17 x 16 x 14 mm size and a primitive trigeminal artery (PTA) variant supplying the territory of the posterior inferior cerebellar artery. Intraluminal occlusion of the aneurysm was performed with 15 Guglielmi detachable coils. The flow of the PTA variant and the ICA was preserved. Right abducens nerve paresis improved partially. PTA variant is a primitive artery originating from the cavernous ICA supplying the cerebellum without opacification of the basilar artery. Only four of the 67 cases of PTA variant were associated with an aneurysm of the PTA variant. The possibility of this rare association should be considered when treating cavernous portion aneurysm because of the risk of cerebellar ischemia.