Choroidal infarction after embolization of arteriovenous fistula of middle meningeal artery

Anomalous branching of the middle meningeal artery from the basilar artery: a systematic review

Background

Anomalous origin of the middle meningeal artery (MMA) from the basilar artery is a rare congenital neurological variant that has been detected in both children and adults with diagnoses ranging from intracranial haemorrhage to ependymoma. This review aims to investigate the anatomical course of an anomalous basilar-middle meningeal artery and its clinical presentation.

Methods

A systematic search was performed in PubMed using the keywords (middle meningeal artery) and (basilar artery). Ninety-four papers were identified, of which seven were included. One paper was further identified through cross-referencing.

Results

The average age of presentation was 43 years with a male predominance (7/9). In most cases, the MMA arose between the superior cerebellar artery and the anterior inferior cerebellar artery (8/9) (versus 1 case between the anterior inferior cerebellar artery and the posterior inferior cerebellar artery). The anomaly mostly presented on the left side (6/11), but was bilateral in one case. Most of the cases showed a pontine artery branching from the basilar artery arising 5 mm to 10 mm proximal to the superior cerebellar artery, which would then assume the trajectory of the MMA. In three cases, the vessel increased in calibre near the trigeminal ganglion. Foramen spinosum absence in the anomalous side was noted in 3/6 of the patients.

Conclusion

To avoid unexpected complications during neurosurgical and neuroradiointerventional procedures, it is essential to have a clear understanding of the anomalous routes of the MMA. This is especially important when it proves to be the only available route for embolization.

Traumatic epidural hematoma treated with endovascular coil embolization

Background:

Traumatic cerebrovascular injury may result in epidural hematoma (EDH) from laceration of the middle meningeal artery (MMA), which is a potentially life-threatening emergency. Treatment ranges from surgical evacuation to conservative management based on a variety of clinical and imaging factors.

Case Description:

A 14-year-old male presented to our institution after falling from his bicycle with traumatic subarachnoid hemorrhage and a right frontotemporal EDH. The patient did not meet criteria for surgical evacuation and endovascular embolization of the right MMA was performed. Rapid resolution of the EDH was observed.

Conclusion:

This case corroborates the sparse existing literature for the potential role of endovascular embolization to treat acute EDH in carefully selected patients who do not meet or have borderline indications for surgical management.

Spontaneous Thrombosis of a Middle Meningeal Arteriovenous Fistula With Subsequent Pseudoaneurysm Formation: Case Report and Review of Literature

BACKGROUND AND IMPORTANCE

Middle meningeal artery (MMA) pseudoaneurysms and middle meningeal arteriovenous fistulas (MMAVFs) are rarely reported after head injury. We report an unusual case of delayed MMA pseudoaneurysm formation after spontaneous thrombosis of an MMAVF, and review existing literature on MMAVF treatment and results.

CLINICAL PRESENTATION

A 59-yr-old male presented with a 5-d history of worsening left-sided headaches, followed by nausea, lethargy, and difficulty with speech. Non-contrast computed tomography demonstrated a left temporal intraparenchymal hemorrhage (IPH) and an acute left-sided subdural hematoma (SDH). Cerebral angiography found abnormal shunting between the right MMA and the right sphenoparietal sinus, consistent with an MMAVF. During the course of admission, the patient's neurological condition deteriorated requiring craniotomy for evacuation of SDH and IPH. Given the presumed incidental nature of the contralateral MMAVF, conservative management was recommended. Follow-up imaging 2 mo after surgery revealed spontaneous thrombosis of the right MMAV. Repeat imaging 5 mo later revealed an MMA pseudoaneurysm at the prior fistulous site, which was subsequently embolized with Onyx, occluding the pseudoaneurysm and the MMA both proximal and distal to the pseudoaneurysm.

CONCLUSION

Spontaneous thrombosis of an MMAVF is rare and only seen in 13.1% of cases. However, subsequent delayed formation of an MMA pseudoaneurysm has not been described. Our case therefore demonstrates that MMAVF thrombosis may not indicate complete healing of the underlying injury to the MMA, and suggests the need for continued follow-up of such lesions despite initial apparent resolution.

THE SPECTRUM OF AMALRIC TRIANGULAR CHOROIDAL INFARCTION

PURPOSE

To describe the multimodal imaging findings, including optical coherence tomography angiography analysis, and spectrum of etiologies associated with Amalric triangular choroidal infarction.

METHODS

This study is a multicenter, retrospective, observational case series review of the clinical and multimodal imaging findings for six patients with Amalric triangular choroidal infarction.

RESULTS

Six patients (10 eyes) with Amalric triangular choroidal infarction were enrolled. Patients' ages ranged from 7 years to 90 years (mean 54 years, median 60 years). Wedge-shaped or triangular areas of choroidal ischemia were evident with fluorescein angiography in all patients and with indocyanine green angiography in one patient. Optical coherence tomography angiography demonstrated choriocapillaris flow reduction that colocalized with outer retinal structural abnormalities with en face optical coherence tomography and corresponded with the triangular zones of choroidal infarction identified with fluorescein angiography in one patient. Etiologies included giant cell arteritis in three cases: traumatic carotid dissection, traumatic retrobulbar hemorrhage, and malignant hypertension secondary to lupus-associated nephropathy.

CONCLUSION

The Amalric triangular syndrome of choroidal infarction can occur as a result of a spectrum of etiologies, especially giant cell arteritis. Infarction is evident on traditional angiography in all cases. Optical coherence tomography angiography may provide a simple noninvasive tool to evaluate choroidal ischemia.

Clinical importance of the middle meningeal artery: A review of the literature

The middle meningeal artery (MMA) is a very important artery in neurosurgery. Many diseases, including dural arteriovenous fistula (DAVF), pseudoaneurysm, true aneurysm, traumatic arteriovenous fistula (AVF), moyamoya disease (MMD), recurrent chronic subdural hematoma (CSDH), migraine and meningioma, can involve the MMA. In these diseases, the lesions occur in either the MMA itself and treatment is necessary, or the MMA is used as the pathway to treat the lesions; therefore, the MMA is very important to the development and treatment of a variety of neurosurgical diseases. However, no systematic review describing the importance of MMA has been published. In this study, we used the PUBMED database to perform a review of the literature on the MMA to increase our understanding of its role in neurosurgery. After performing this review, we found that the MMA was commonly used to access DAVFs and meningiomas. Pseudoaneurysms and true aneurysms in the MMA can be effectively treated via endovascular or surgical removal. In MMD, the MMA plays a very important role in the development of collateral circulation and indirect revascularization. For recurrent CDSHs, after burr hole irrigation and drainage have failed, MMA embolization may be attempted. The MMA can also contribute to the occurrence and treatment of migraines. Because the ophthalmic artery can ectopically originate from the MMA, caution must be taken to avoid causing damage to the MMA during operations.

Choroidal infarction, anterior ischemic optic neuropathy, and central retinal artery occlusion from polyarteritis nodosa

PURPOSE

Ocular ischemia from polyarteritis nodosa (PAN) is rare. The authors present a case of multifocal ocular infarction from PAN.

METHODS AND RESULTS

A 70-year-old woman developed hand and foot numbness followed by intermittent blurred vision and binocular horizontal diplopia. Two weeks later, she suddenly lost vision in the right eye from a central retinal artery occlusion and then developed a left anterior ischemic optic neuropathy and bilateral triangular choroidal abnormalities consistent with infarction. Her erythrocyte sedimentation rate and C-reactive protein were elevated. Although giant cell arteritis was suspected, a multiple mononeuropathy was demonstrated by electromyogram and nerve conduction velocity studies. Biopsy specimens from her sural nerve and biceps muscle showed a necrotizing vasculitis with fibrinoid necrosis, consistent with PAN.

CONCLUSIONS

Polyarteritis nodosa can produce ischemia of a variety of ocular structures, including the retina, choroid, and optic nerve. In our patient, all three structures were affected. To our knowledge, this is the first reported case of the triangular sign of Amalric in PAN.