CT metrizamide myelography of the cervical spine in Morquio syndrome.

Since the syndrome was first described concurrently by Morquio [1] and Brailsford [2] in 1929, radiology has played a vital ro le in the diagnosis of the Morquio-Brailsford syndrome and in the management of complications of the disease. Symptoms of spinal cord compression are common. They are related to dysplasia of the dens with atlantoaxial subluxation and narrowing of the spinal canal [3-5]. Spine radiographs demonstrate flattening and widening of the vertebral bodies, which may be pronounced and can involve the entire spine in the most developed form of the disease [6]. From the central position of the anterior aspect of the thoracic and lumbar vertebral bodies project peculiar beaklike processes that are characteristic of the syndrome. Anterior wedging of the vertebral bodies may result in varying degrees of kyphosis [4]. Gibbus deformity at the thoraco lumbar leve l is common, and may cause cord compression at thi s level [4]. In the cervical region the flattening of the vertebral bod ies results in shortening of the neck [6]. The intervertebral disk spaces retain their normal height and may be slightly thi ckened [7]. The odontoid process shows varying degrees of dysplasia. It is usually hypoplastic and may be absent [4 , 5]. Rad iographs demonstrate increased mobility at the atlantoaxial junction with flex ion and extension. Chronic atlantoaxial subluxation may develop and cause severe cord compression [4]. Narrowing of the spinal canal is a well recognized find ing in Morquio syndrome. This narrowing usually occurs in the anteroposterior diameter secondary to shortening of the pedicles due to premature synostosis of the centers of ossificat ion of the body with those of the lamina [6]. Narrowing of the neural arch is most severe at the level of the first cervical vertebra. With anterior dislocation of C1 , in addition to narrowing of the arch of C1, the posterior arch of the atlas herniates into the foramen magnum and may give the false impression of platybasia [4, 8]. Thickening of the dura and com press ion of the spinal cord and subarachnoid space by deposits of mucopolysaccharide has been described in patients with MaroteauxLamy syndrome (MPS-VI) and a variant of Hurler-Scheie