Posterior cerebral artery ectasia. An unusual cause of ophthalmoplegia

Microvascular Decompression for Oculomotor Nerve Palsy due to Nonaneurysmal Vascular Compression

BACKGROUND

Diabetes mellitus and aneurysmal compression are well-known causes of oculomotor nerve palsy (ONP), but nonaneurysmal vascular compression of the oculomotor nerve has rarely been reported.

CASE DESCRIPTION

A 70-year-old nondiabetic man presented with left ONP for the past 2 days. Magnetic resonance imaging revealed the left posterior communicating artery to be compressing the left oculomotor nerve. Microvascular decompression of the offending artery from the nerve via a left frontotemporal craniotomy was performed; the nerve showed a color change suggestive of degenerative alteration. ONP was fully resolved within 1 month of surgery.

CONCLUSIONS

Whether nonaneurysmal vascular compression of the oculomotor nerve is a true cause of ONP is sometimes controversial. However, recent developments in magnetic resonance imaging can clearly demonstrate the spatial relationship between the oculomotor nerve and vessels. Detailed magnetic resonance imaging should be used to diagnose compression of the oculomotor nerve by blood vessels. Microvascular decompression is the treatment of choice in this situation.

The oculomotor neurovascular conflict: Literature review and proposal of management

BACKGROUND

The Oculomotor nerve (OCN) lies in a close relationship with large arteries inside the basal cisterns. Therefore, it may be compressed by vascular malformations or aneurysms. Nevertheless, the compression is not always related to pathologic conditions. Indeed, some cases of neurovascular conflicts of the OCN have been described in the literature.

METHODS

A case of neurovascular conflict of the OCN resolved after steroid treatment is reported. Additionally, a systematic literature review of those cases was performed.

RESULTS

OCN palsy due to a neurovascular conflict has been described as acute or chronic persistent palsy, or with an intermittent presentation. Symptoms result from compression, although asymptomatic compression is not uncommon. Surgical treatment, pharmacological treatment, and observation have been reported as options in the literature. Microvascular decompression was employed effectively in some cases of OCN neurovascular conflict. Nevertheless, other cases were treated successfully with steroids (persistent presentation) and carbamazepine (intermittent presentation). A management algorithm based on the results of the literature review is proposed.

CONCLUSIONS

Treatment options for OCN neurovascular conflicts and their results are heterogeneous. Based on the literature review, the pharmacological treatment seems to be the most appropriate first-line approach, reserving surgery for refractory cases. Collecting clinical information about new cases will allow defining treatment standards for this rare condition.

Oculomotor nerve palsy secondary to aberrant posterior cerebral artery

The authors report a rare case of an oculomotor nerve palsy attributed to mass effect from an aberrant posterior cerebral artery. The patient presented with complete ptosis, mydriasis and ophthalmoplegia of the affected eye. MRI demonstrated distortion of the oculomotor nerve as it traversed inferior to the non-aneurysmal P1 segment of an aberrant posterior cerebral artery. The oculomotor nerve palsy resolved spontaneously.

Characteristics and surgical treatment of dolichoectatic and fusiform aneurysms

Dolichoectatic and fusiform aneurysms represent a small subset of cerebral aneurysms and are often among the most difficult to treat. A consecutive series of 40 patients with 41 of these two types of aneurysms is presented, including their clinical characteristics and surgical treatments. Common to all aneurysms was the pathological involvement of a length of blood vessel with separate inflow and outflow sites (nonsaccular). However, dolichoectatic aneurysms have markedly different symptoms and surgical treatments depending on their location in either the anterior or posterior circulation. Anterior circulation aneurysms involved the petrous internal carotid artery (ICA) in one, the supraclinoid ICA in three, the middle cerebral artery in 13, and the anterior cerebral artery in four patients. Posterior circulation aneurysms involved the basilar artery in 13, the vertebral artery in six, and the posterior inferior cerebellar artery in one patient. Various surgical procedures were performed, including direct clipping, trapping with bypass, proximal occlusion, resection with reanastomosis, transposition, aneurysmorrhaphy with thrombectomy, and wrapping. There was no surgical mortality in the patient series, and treatment was effective in many patients. Overall, outcome at late follow up was good (Glasgow Outcome Scale scores 1-2) in 78% of patients. Patients with anterior circulation aneurysms had better outcomes than patients with posterior circulation aneurysms, with good outcomes in 90% and 65% of the cases, respectively. Dolichoectatic and giant serpentine aneurysms may develop from smaller fusiform aneurysms and represent a spectrum of the same pathological entity. Arterial dissection may also play a role in the initial development of these aneurysms.

Transcallosal, transventricular approach to a basilar apex aneurysm

A new approach to the basilar apex in a patient with a megadolichobasilar anomaly and an abnormally rostral basilar apex aneurysm is described. The details of the surgical approach and the advantages and limitations of this transcallosal, interseptal approach are described.

Ectasia and fenestration of the anterior cerebral artery associated with persistent trigeminal artery: case report

Multiple vascular anomalies in a 22-year-old patient who had signs and symptoms of vestibulocochlear dysfunction are reported. Angiography revealed a fenestration of the proximal segment of the left anterior cerebral artery, an ectasia of the left anterior and posterior cerebral arteries, and a persistence of the right trigeminal artery. The rarity of the association is documented, and the clinical significance is discussed.

Dolichoectatic basilar artery: a review of 23 cases

The dolichoectatic basilar artery was found in 23 cases during a 10-year period. The 19 males and 4 females ranged in age from 30 to 69 years (mean: 55 years). Hypertension was noted in 17 patients. In seventeen (74%) of the present cases this anomaly could be visualized with CT scan. Seven patients (30%) presented with pontine infarction, which was identified on CT scan in all cases. Vertebro-basilar insufficiency was found in four patients. One patient had transient ischemic attacks. There were facial spasms in four patients and impairment of the lower cranial nerves in one. One patient exhibited cerebellar hemorrhage. In two patients this anomaly was found incidentally. Associated intracranial aneurysms were identified in seven patients, including fusiform aneurysms in 4 and saccular aneurysms in 3. Three patients had an accompanying hydrocephalus. The dolichoectatic basilar artery is associated with various consequences especially in relation to the pathogenesis of brainstem infarction. When this anomaly is diagnosed by CT findings, even if it is clinically asymptomatic, it may be better to treat these patients with medical therapy used to prevent ischemic stroke.

The symptomatology of megadolicho basilar artery

Cranial nerve dysfunction, obstruction hydrocephalus, signs of brain stem dysfunction, and signs of a space-occupying lesion in the posterior fossa are presumed to be related to a megadolicho basilar artery, if present. Since there are no large series of patients with such vascular anomaly, a bias in relating symptoms with the presence of a megadolicho basilar artery is not excluded. We therefore studied retrospectively the incidence of megadolicho and dolicho basilar artery on cranial CT-scan of 3332 patients of 50 years and older. Patient records were reviewed for the above mentioned symptoms. 12 out of 22 patients with a megadolicho basilar artery and 2 patients out of 40 with a dolicho basilar artery had one or two of these symptoms. It is concluded that a megadolicho basilar artery can cause cranial nerve dysfunction, obstruction hydrocephalus, signs of brain stem dysfunction, and signs of a space-occupying lesion in the posterior fossa.

Megadolicho vascular malformation of the intracranial arteries

A patient is presented suffering a hemiparesis. Megadolicho-vascular malformation of the intracranial part of the internal carotid arteries and some of its branches and of the basilar artery was suggested by CT and confirmed by angiography. The value of CT compared with angiography in relation to intracranial megadolicho vascular malformations is discussed.

Visual field defects produced by basilar artery ectasia

The authors report two cases of visual field defects which are postulated to be due to the distal end of an elongated basilar artery compressing the visual pathways in the posterior suprasellar region. The mechanism of production of these defects is discussed, relating the abnormal position of the distal end of the basilar artery to a normally situated or only slightly post-fixed optic chiasm and optic tract and to a markedly post-fixed optic chiasm.

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.