۱- Introduction

۲- Material and methods

۳- Results

۴- Systematic review

۵- Discussion

۶- Conclusions

۷- Declarations of interest

References

Abstract

Objective: Hydrocephalus is an uncommon presentation of unruptured brain arteriovenous malformations (AVMs). The goal of this case series and literature review is to present possible pathological mechanisms, management strategies and outcomes in patients with hydrocephalus due to unruptured AVMs. Methods: Three consecutive patients with hydrocephalus caused by unruptured AVMs as well as all cases previously reported in the literature were retrospectively reviewed to determine clinical symptoms, AVM location, nidus size, venous drainage, mechanism of hydrocephalus, level/cause of obstruction, and degree of hydrocephalus. Management of hydrocephalus, AVM treatment, and follow-up length were evaluated. Results: Of 350 patients unruptured AVMs, 3 presented with hydrocephalus (0.8%). In the literature review we found an additional 22 patients for a total of 25 cases. Eighteen patients had mechanical obstruction by the draining vein or the AVM nidus, usually at the level of the aqueduct (52%). Impaired cerebrospinal fluid resorption secondary to venous congestion led to hydrocephalus in 7 patients. Ten patients were treated for both the AVM and hydrocephalus, 13 patients underwent treatment of either hydrocephalus, or the AVM alone. Treatment of hydrocephalus, with or without associated treatment of the brain AVM, resulted in improvement of symptoms in 92% of patients. No rupture of the AVM was reported at follow-up. Conclusions: The most common cause of hydrocephalus in unruptured brain AVMs is mechanical obstruction by the draining vein if it is located in a strategic position. Treatment of hydrocephalus alone or with associated treatment of the AVM is safe and effective.

Introduction

Unruptured brain arteriovenous malformations (AVMs) generally present with seizures, headaches, or are discovered incidentally. However, about 1% of AVMs present with hydrocephalus (HC). The mechanisms of hydrocephalus development in patients with unruptured brain AVMs are still debated. They can include obstruction of the ventricular system at a point of narrowing due to compression by a deep dilated draining vein or impaired cerebrospinal fluid (CSF)-reabsorption due to venous hypertension when a major sinus is involved by the AVM. Increased intracranial pressure has been reported as a possible presentation in patients with unruptured brain AVMs in few case series and case reports [1–۸]. In this study we present a systematic review of the literature and 3 consecutive cases of unruptured AVMs associated with hydrocephalus evaluated at our institution over a 10 year period in order to raise the awareness of the possible pathological mechanisms and respective management strategies.