Ossification of the Posterior Atlantoaxial Membrane: An Atypical Presentation.

A 53-year-old man visited our hospital with a 2-year history of slowly progressive paresthesia and the loss of temperature sensation in the right trunk to lower leg. A neurological examination revealed a decreased superficial sensation below the right T6 dermatome. Spinal magnetic resonance imaging showed no thoracic cord abnormalities; however, cervical T2-weighted images showed severe stenosis at the level of C1-C2 (Picture A and B). Computed tomography demonstrated ossification of the posterior atlantoaxial membrane (OPAAM) on the left side (Picture C and D). We diagnosed the patient's illness to be cervical myelopathy (CM) due to OPAAM.

Picture.

OPAAM is a rare cause of CM (1). CM infrequently causes a sensory disturbance below the thoracic sensory level (2). In conclusion, we should consider the possibility of cervical myelopathy in patients with unilateral mid-trunk girdle sensory disturbance. It is important to include OPAAM as a differential diagnosis of CM in patients who present with unilateral sensory impairment below the mid-trunk.

The authors state that they have no Conflict of Interest (COI).