Natural history of unruptured intracranial aneurysms

Small symptomatic anterior communicating artery aneurysms: report of three cases and literature review

PURPOSE

Given the anatomical relationship between the ACom complex and the optic nerve, small aneurysms of the ACom can present with visual symptoms.

CASE REPORTS

We summarize and illustrate the clinical course of three patients with symptomatic small ACom aneurysms and collect similar other cases reported.

RESULTS

Ten patients with small unruptured visually symptomatic anterior communicating artery aneurysms were found in the literature. Including three patients herein reported, the mean age at presentation was 56. The most common visual symptoms were bitemporal vision loss and/or a decrease in visual acuity.

CONCLUSION

Unruptured aneurysms of the anterior communicating artery can present with visual symptoms due to compression of optic pathways, even at a small size. Prompt recognition and treatment of such a condition are paramount as new onset of visual symptoms can signify impending rupture akin to small PCom aneurysms compressing the third nerve. We discuss a few pitfalls of clipping small ACom aneurysms compressing the optic nerve.

Unruptured cerebral aneurysm risk stratification: Background, current research, and future directions in aneurysm assessment

Background:

The optimal management of unruptured cerebral aneurysms is widely debated in the medical field. Rapid technology advances, evolving understanding of underlying pathophysiology, and shifting practice patterns have made the cerebrovascular field particularly dynamic in recent years. Despite progress, there remains a dearth of large randomized studies to help guide the management of these controversial patients.

Methods:

We review the existing literature on the natural history of unruptured cerebral aneurysms and highlight ongoing research aimed at improving our ability to stratify risk in these patients.

Results:

Landmark natural history studies demonstrated the significance of size, location, and other risk factors for aneurysm rupture, but prior studies have significant limitations. We have begun to understand the underlying pathophysiology behind aneurysm formation and rupture and are now applying new tools such as flow dynamics simulations and machine learning to individualize rupture risk stratification.

Conclusion:

Prior studies have identified several key risk factors for aneurysmal rupture, but have limitations. New technology and research methods have enabled us to better understanding individual rupture risk for patients with unruptured cerebral aneurysms.

Risk factors for growth of conservatively managed unruptured intracranial aneurysms

PURPOSE

Unruptured intracranial aneurysms (UIAs) occur in 2-3% of the adult population, but, once discovered, do not always require treatment. Untreated patients are usually followed with serial imaging to identify interval growth. In this study, we assessed the risk and risk factors for growth in a homogenous series of patients with conservatively managed UIAs.

METHODS

Data from consecutive patients without history of subarachnoid hemorrhage and a conservatively managed UIA were retrospectively reviewed and only patients with at least 2 years of radiological follow-up were included in our study. We evaluated patients for the incidence of UIA growth, as well as analyzed risk factors for UIA growth.

RESULTS

In 349 patients and 385 conservatively managed UIAs with 2210 patient-years of radiological follow-up, the risk of growth was 2.9% per aneurysm-year. Size (diameter greater than 5 mm), location (basilar artery apex), and weight loss (decrease in BMI over follow-up period) were all significantly associated with increased risk of UIA growth. There was a greater risk of UIA growth during the first 3 years of follow-up (7.5% per aneurysm-year) compared to the remaining years (2.7% per aneurysm-year).

CONCLUSIONS

Conservatively managed UIAs in patients without prior history of SAH have a 2.9% risk of growth per aneurysm-year. UIAs greater than 5 mm in diameter, those located at the basilar artery apex, or patients who experience a decrease in BMI are more likely to grow and warrant closer follow-up. The risk of aneurysm growth is increased in the few years after diagnosis and decreases afterward.

Impact of Methamphetamine Abuse: A Rare Case of Rapid Cerebral Aneurysm Growth with Review of Literature

Methamphetamine or "meth" is a sympathomimetic amine of the amphetamine-type substances (ATS) class with an extremely high potential for abuse. Illicitly abused neurostimulants like cocaine and meth predispose patients to the aneurysmal formation with reported rupture at a younger age and in much smaller sized aneurysms. However, very rapid growth of aneurysm within less than 2 weeks with methamphetamine abuse is very rarely observed or reported. In this report, we present a patient with repeated and recurrent meth abuse who demonstrated rapid growth of a pericallosal aneurysm over the period of less than two weeks. The pathophysiology of stroke related to meth and ATS abuse is multifactorial with hypertension, tachycardia, and vascular disease postulated as major mechanisms. The rapid growth of an aneurysm has a high risk of aneurysmal rupture and SAH, which is a neurosurgical emergency and therefore warrants careful consideration and close monitoring. This case confirms the dynamic temporal effects of methamphetamine use on intracranial vessels and this specific neurostimulants association to rapid aneurysmal formation. In light of vascular pathologies the possibility of drug-induced pseudoaneurysm should also be considered in young patients with history of meth abuse.

Surgical clipping is still a good choice for the treatment of paraclinoid aneurysms

Paraclinoid aneurysms are lesions located adjacent to the clinoid and ophthalmic segments of the internal carotid artery. In recent years, flow diverter stents have been introduced as a better endovascular technique for treatment of these aneurysms.

METHOD

From 2009 to 2014, a total of 43 paraclinoid aneurysms in 43 patients were surgically clipped. We retrospectively reviewed the records of these patients to analyze clinical outcomes.

RESULTS

Twenty-six aneurysms (60.5%) were ophthalmic artery aneurysms, while 17 were superior hypophyseal artery aneurysms (39.5%). The extradural approach to the clinoid process was used to clip these aneurysms. One hundred percent of aneurysms were clipped (complete exclusion in 100% on follow-up angiography). The length of follow-up ranged from 1 to 60 months (mean, 29.82 months).

CONCLUSION

Surgical clipping continues to be a good option for the treatment of paraclinoid aneurysms.

Rapid aneurysm growth and rupture in systemic lupus erythematosus

BACKGROUND

Subarachnoid hemorrhage (SAH) due to intracranial aneurysm rupture is a major neurosurgical emergency associated with significant morbidity and mortality. Rapid aneurysm growth is associated with rupture. Systemic lupus erythematosus (SLE) is a multi-system autoimmune disorder whose complications can include cerebral vasculitis and vasculopathy. Intracranial aneurysms are not known to occur more frequently in SLE patients than the general population; however, aneurysm growth rates have not been studied in SLE.

CASE DESCRIPTION

We present a 43-year-old female with SLE on prednisone, hydroxychloroquine, and azathioprine with moderate disease activity who presented with severe, acute-onset headache and was found to have Hunt and Hess grade II SAH due to rupture of an 8 mm saccular anterior communicating artery (ACoA) aneurysm. The patient developed severe vasospasm, re-ruptured, and was taken for angiography and embolization, which was challenging due to a high degree of vasospasm and arterial stenosis. Review of imaging from less than 2 years prior demonstrated a normal ACoA complex without evidence of an aneurysm.

CONCLUSION

We review the literature and discuss the risk factors and pathophysiology of rapid aneurysm growth and rupture, as well as the pathologic vascular changes associated with SLE. Although SLE patients do not develop intracranial aneurysm at an increased rate, these changes may predispose them to higher incidence of growth and rupture. This possibility-coupled with increased morbidity and mortality of SAH in SLE-suggests that SAH should be considered in SLE patients presenting with headache, and advocates for more aggressive treatment of SLE patients with unruptured aneurysms.