Doppler Ultrasonography and Computed Tomography Angiography Demonstrate Positional Occlusion of Vertebral Artery Associated With One-Sided Destruction of the Atlantoaxial Lateral Mass Caused by Rheumatoid Arthritis

Abstract

Case report of a patient with rheumatoid arthritis (RA) and a positional occlusion of the left vertebral artery (VA). To describe the utility of Doppler ultrasonography and computed tomography (CT) angiography for the diagnosis of positional VA occlusion. In previous reports of positional VA occlusion in RA, angiography has been used for the diagnosis. However, it is difficult to demonstrate the three-dimensional relationship between the arteries and the bone structure with angiography. An 83-year-old man with a 20-year history of RA complained of severe vertigo when he leaned his head in the left-anterior direction. CT angiography in the neutral position revealed that the left VA was pinched between the posterior rim of the transverse foramen of C1 and the transverse process of C2. Doppler ultrasonography demonstrated positional VA occlusion and a severe reduction in blood flow at the position that most readily induces vertigo. Because the space between the transverse foramens of left C1 and C2 was reduced with the destruction of the left C1/C2 lateral masses, slight rotation, and anterior shift of C1 led to the occlusion of the VA. After posterior O-C2 fusion at the reduced position, the VA occlusion and vertigo disappeared. Doppler ultrasonography and CT angiography allow valuable measurements in the diagnosis of positional VA occlusion. The one-sided destruction of the C1/C2 lateral masses might be a causal factor for VA occlusion in RA. This is the first report of a new pathomechanism underlying positional VA occlusion demonstrated with three-dimensional CT angiography.