Reversible Cerebral Metabolism Changes Using Proton Magnetic Resonance Spectroscopy in a Patient with Intracranial Dural Arteriovenous Fistula: A Case Report

Relative signal intensity on time-of-flight magnetic resonance angiography as a novel indicator of aggressive presentation of intracranial dural arteriovenous fistulas

Asymptomatic dural arteriovenous fistulas (DAVFs) with cortical venous reflux (CVR) are now more commonly encountered. However, patients with an incidental onset may have a less aggressive clinical course. It is desirable to explore methods and indicators to predict the clinical outcomes. This study investigates whether the relative signal intensity (rSI) of the draining vessels on the time-of-flight magnetic resonance angiography is related to clinical behavior in patients with intracranial DAVFs. We retrospectively reviewed 36 intracranial DAVFs. The patients were categorized as those with either aggressive-presentation or non-aggressive-presentation (n = 16 and 20, respectively). The rSIs of the shunt points, affected sinuses, and veins with CVR were compared between the two groups. The two groups were not significantly different in terms of rSIs of the shunt points and affected sinuses (p = 0.37 and 0.41, respectively). However, a significant positive correlation was observed in the rSI of the veins with CVR between the aggressive and non-aggressive behavior groups (p < 0.0001). The rSI of the veins with CVR could serve as a reliable indicator of aggressive behavior in intracranial DAVFs, and its optimal cutoff value was 1.63 with high sensitivity and specificity for predicting aggressive behavior (area under the curve, 0.909).

Magnetic Resonance Spectroscopy Findings in Patients with Dural Arteriovenous Fistulas: Three Case Reports

BACKGROUND

Magnetic resonance spectroscopy (MRS) is a potentially useful modality for evaluating brain metabolites in patients with dural arteriovenous fistula (dAVF). Here we describe a different pattern of MRS-based cerebral metabolism findings in patients with dAVF.

CASE DESCRIPTIONS

We performed MRS in 3 patients with transverse sigmoid sinus dAVF associated with cortical venous reflux. In case 1, which was associated with vasogenic edema on T2-weighted magnetic resonance imaging (MRI), decreased preoperative N-acetylaspartate (NAA)/creatine (Cr) and myo-inositol (mIns)/Cr and increased lactate (Lac)/Cr ratios improved after treatment. In case 2, a decreased preoperative NAA/Cr ratio improved after treatment. These 2 patients presented with seizures. In case 3, the patient presented with headache and showed no metabolic changes on preoperative or postoperative MRS.

CONCLUSIONS

Our results suggest that patients with dAVF can be classified based on a combination of metabolic and signal changes seen on T2-weighted MRI. MRS may allow significantly expanded evaluation of the metabolic changes associated with dAVF for appropriate classification and management.