Calcified Plaque in the Cervical Spine With Pain and Paresthesia

History  A 52-year-old diabetic woman was seen in the clinic for pain in her shoulder and left arm. She also complained of paresthesias in her left upper extremity for the previous 13 years. Past history showed head trauma at age 2 years following a 4-m fall. Physical examination of the neck showed normal flexion, extension to 60°, right lateral rotation to 60°, and left lateral rotation to 45°. No sensory deficit was detected in her left arm. Figure 1 shows the lateral film from the cervical spine series.

Diagnosis  Ossification of the posterior longitudinal ligament of the cervical spine ("Japanese disease").

Comment  The initial roentgenograms (Fig 1) demonstrated a bony plaque along the posterior aspect of vertebral bodies C-2 to C-4. Osteoarthritic changes were noted at the C-5 to C-6 level. Additionally, an os odontoideum was seen at C-1 Anteroposterior and lateral tomograms (Fig 2 and 3) showed the ossified