To describe a case of recurrent posterior circulation stroke (PCS) associated with atlantoaxial subluxation (AAS) that was treated with coil occlusion. 

Recurrent PCS caused by rotational vertebral artery insufficiency is known as bow hunter's stroke (BHS). Rheumatoid arthritis (RA)-related AAS is a rare cause of BHS. Conservative or surgical treatment is usually provided to patients with AAS-associated BHS. However, there are no reports of the use of endovascular treatment for preventing stroke recurrence.

A 70-year-old woman with RA-associated AAS had recurrent acute ischemic PCS despite anti-thrombotic therapy. Repeated magnetic resonance imaging revealed disappearance and reappearance of the right vertebral artery (VA). Computed tomography angiography revealed that the right VA was situated near the dens; AAS was also noted. Chronic intimal damage with a rotational pattern due to mechanical compression of the right VA was suspected as the cause of repeated thrombosis, which resulted in artery-to-artery embolism. Digital subtraction angiography (DSA) of the right VA revealed disappearance of the right posterior inferior cerebellar artery (PICA) on anteflexion, while DSA of the left VA revealed that the distal portion of the right VA, including the PICA, was supplied via retrograde blood flow from the left VA. Therefore, coil occlusion was performed on the right VA proximal to the PICA origin. Thereafter, the patient has been stroke-free for over 18 months.

We believe this is the first reported case of successful prevention of recurrent AAS-associated BHS via coil occlusion of the VA. Surgical treatment does not rectify intravascular damage, which may cause stroke recurrence, and it can be challenging because of the high risk of complications in older patients with RA. The endovascular approach, including coil occlusion, might be a feasible option for managing AAS-associated BHS.