Neurorescue During Carotid Stenting: Catheter-Based Techniques and Patient Management
Peter A. Schneider, W. Todd Bohannon, Michael B. Silva in Carotid Interventions, 2004
The worst outcome of episodes of cerebral embolization are associated with “T occlusions,” that is, occlusion of the distal internal carotid artery that extends into the M1 and A1 segments. The mortality in this setting is 50% to 90% (37–39). With more focal arterial occlusions, the specific location of the cerebral artery lesion is far more important than the tissue mass served by the occluded artery. A very small but well-placed infarction in the motor cortex may have much more severe sequelae than a much larger zone of infarction in the frontal or occipital lobes. When a significant neurological deficit occurs due to an embolus, the embolus is usually large enough to occlude a major cerebral artery (38, 40, 41). When an embolus lodges in a major cerebral artery, the vessel is usually patent distal to the embolus but with very slow or stagnant flow. If collateral perfusion is able to keep brain tissue alive long enough to perform thrombolysis, the results may be excellent (14). However, if end arteries are occluded, especially important ones like the lenticulostriate arteries, the likelihood of a good result is low. When a middle cerebral artery occlusion occurs, for example, the collateral blood supply is usually from the anterior cerebral artery through pial branches. The anterior cerebral artery usually receives collateral blood supply from the contralateral anterior cerebral artery through the anterior communicating artery. The posterior cerebral artery receives blood supply through the posterior communicating artery. A focal, proximal occlusion with good collaterals may be less threatening than a smaller, more distally placed embolus to an area with no collateral perfusion. If thrombus is instrumented aggressively enough to break it up without dissolving it, multiple distal branches may become occluded. In summary, when an occlusion occurs, the clinical significance may vary from none to profound, based on the location of the occlusion and underlying collateral pathways (both major cerebral arteries and pial collaterals).
Anatomy and Cerebral Circulation of the Rat
Yanlin Wang-Fischer in Manual of Stroke Models in Rats, 2008
The posterior cerebral artery is a branch of the posterior communicating artery (Figure 4.4a). It curves around the peduncle of the cerebrum and runs upward along the fold of the tentorium to supply the surface of the hemisphere, including the medial and lateral surfaces of the occipital lobe.
Neurology
Fazal-I-Akbar Danish in Essential Lists of Differential Diagnoses for MRCP with diagnostic hints, 2017
Features of various arterial aneurysms:1 Internal carotid artery: a Within cavernous sinus: i 3rd, 4th or 6th nerve palsy.ii Pain and paraesthesias in the distribution of ophthalmic division of 5th nerve.iii Caroticocavernous fistula.b Supraclinoid part: i Compression of optic nerve, optic chiasma or optic tract leading to visual field defects.ii 3rd nerve palsy.2 Middle cerebral artery: a Progressive hemiparesis.b Focal epilepsy.3 Anterior cerebral and anterior communicating arteries: a Compression of optic chiasma → bitemporal hemianopia.4 Posterior communicating artery: a Isolated 3rd nerve palsy.5 Posterior cerebral artery: a Isolated 3rd nerve palsy + contralateral hemiplegia.
Atypical junctional scotoma secondary to optic chiasm atrophy: a case report
Published in Clinical and Experimental Optometry, 2019
Christopher J Borgman
Historical studies of the extrinsic blood supply to the optic chiasm have reached different conclusions.2018 A very recent study aimed to resolve these discrepancies in blood supply to different parts of the optic chiasm using human cadaver eyes.2018 They concluded that the optic chiasm is supplied by all arteries of the circle of Willis.2018 Specifically, the superior hypophyseal arteries and posterior communicating artery supply the inferior side of the optic chiasm, while the first segment of the anterior cerebral artery, superior hypophyseal artery, anterior communicating artery, and the posterior communicating artery supplied the superior side of the optic chiasm.2018 This anatomical consideration is important in this case, as the ischaemic lesion responsible for the patient's visual field defects localise to the same chiasm areas that the first segment of the anterior cerebral artery and anterior communicating artery supply.2018
Type 2 persistent primitive proatlantal intersegmental artery, a rare variant of persistent carotid-vertebrobasilar anastomoses
Published in Baylor University Medical Center Proceedings, 2019
Gagandeep Choudhary, Narendra Adhikari, Jad Chokr, Nishant Gupta
There was a three-vessel aortic arch. The right vertebral artery (VA) was hypoplastic arising from the subclavian artery and ended as a posterior inferior cerebellar artery. The left VA was absent. Both common carotid arteries, carotid bulbs, ICAs, and external carotid arteries were patent. An anomalous artery equal to the caliber of the ICA was seen arising from the proximal left external carotid artery at the origin of the lingual artery at the C2 vertebral level (Figure 1). The anomalous vessel coursed cranially and entered the foramen magnum coursing between the C1 arch and the occiput, without passing through the transverse foramina of the cervical vertebrae. Intracranially, it had a tortuous course and continued as a basilar artery, which terminated in posterior cerebral arteries. The right-sided posterior communicating artery was present but small in caliber, and the left posterior communicating artery was not seen. Both intracranial ICAs and proximal middle cerebral arteries, the anterior cerebral arteries, and the anterior communicating artery were present and unremarkable. The patient did not have any symptoms attributable to this vascular variant. He was discharged in stable condition with a short course of pain medication.
Improved visual acuity after microsurgical clipping of a symptomatic anterior cerebral artery aneurysm: case report
Published in British Journal of Neurosurgery, 2019
Fatih Arcan, Andreas W. Unterberg, Klaus Zweckberger
Intracranial aneurysms occur in most cases (about 85%) within the anterior circulation. Despite the proximity to nervous structures (optic nerve, chiasm, oculomotor nerve), visual symptoms are rare. According to the anatomical configuration, visual deterioration might occur due to direct pressure caused by the aneurysm dome or by adhesions following hemorrhages or mechanical irritation of the nerve. In most cases, visual symptoms, such as blindness or unilateral scotoma, are slowly progressing with increasing size of aneurysm. Furthermore, the variable nature of visual symptoms which is underlying spontaneous fluctuation is not fully understood but presumably due to factors like arterial micro-vasospasm or shifting of nervous structures.1 While posterior communicating artery aneurysms cause oculomotor deficits, aneurysms compressing the optic nerve, and thus causing blindness, are exceptional and preponderantly lacking in the literature. Furthermore, it is under debate, whether operative clipping or endovascular coiling might be the best treatment of choice for symptomatic aneurysms.
Related Knowledge Centers
- Anterior Cerebral Artery
- Anterior Communicating Artery
- Circle of Willis
- Collateral Circulation
- Internal Carotid Artery
- Middle Cerebral Artery
- Posterior Cerebral Artery
- Artery
- Brain
- Body
- Circle of Willis