Arteriovenous malformations (AVMs) are a rare disease (1 subject per 100.000 per year) usually congenital and formed by an abnormal connection between arteries and veins. When localized in the brain, this disease has a high risk of bleeding; therefore, a treatment of the AVM is often considered.
The Department of Neuroradiology of the Montreal Neurological Institute is a referral centre for this rare disease. Functional Magnetic Resonance Imaging (fMRI) is a technique widely used that helps clinicians and researchers to localize where the different brain functions (i.e. language, movement) are located in the brain.
For the important role of this technique, fMRI is used in patients with AVM prior to any treatment. Surprisingly, the brain of these patients may sometimes behave in an unexpected way and some functions may localize in unexpected areas. Moreover, the signal used in fMRI depends on the blood perfusion of the brain and the cerebral perfusion of patients with AVM is often altered. Consequently, it can be challenging to correctly interpreting fMRI data in patients with abnormal perfusion as those diagnosed with AVM.
We propose to study patients with AVM by combining fMRI and perfusion studies with the goal of acquiring improved insight about the influence of blood perfusion on fMRI results in this type of patients.
In our project we plan to recruit patients with a diagnosed arteriovenous malformation and healthy control subjects. All the participants will undergo a protocol that includes fMRI and perfusion exams.
With this proposed study we expect to evaluate the extent to which the abnormal perfusion present in patients with AVM can affect the ability to interpret fMRI results.
This knowledge is crucial in order to achieve a correct analysis of the different brain functions using fMRI in patient with brain AVMs prior to any treatment planning.