Grisel syndrome: pathophysiological evidence from magnetic resonance imaging findings.

Grisel syndrome is a condition of uncertain etiology characterized by a non-traumatic atlantoaxial subluxation following an infection in the head and neck region. Although first described in 1830, the exact pathophysiology of Grisel syndrome remains unclear. We present a case of atlantoaxial subluxation after acute lymphadenitis diagnosed with a dynamic computed tomography (CT) and magnetic resonance imaging (MRI). A previously healthy 9-year-old male patient presented with torticollis of sudden onset. Dynamic CT and MR imaging showed rotary atlantoaxial subluxation and inflammation surrounding the cervical spinal ligaments. A follow-up MRI of the cervical spine, taken 3 weeks after the onset of symptoms, showed a complete resolution of subluxation and inflammation surrounding the cervical spinal ligaments. In this case report, we support the hypothesis that an inflammation-induced laxity of the cervical ligaments is the pathologic key to Grisel syndrome using radiologic findings.