Exophthalmos and basilar impression. A contribution to differential diagnosis of endocrine orbitopathy

We report on a male patient with exophthalmos of unclear etiology, basilar impression, syringohydromyelia and type II Arnold-Chiari malformation. Two diseases involving the orbital region were to be considered in differential diagnostic terms: endocrine orbitopathy and osseous orbit dysplasia. The typical physical appearance associated with basilar impression as well as suppurative keratitis in Lagophthalmos was striking. Tetraspasticity with pareses, bulbar symptoms, proximally pronounced muscular atrophy as well as a left hemihypesthesia was shown neurologically. Although the orbit CT was normal, sonography revealed thickened ocular muscles. There was euthyroidism in diffuse goiter with negative thyroid autoantibody findings. Because of lack of definitive detection of muscular swelling, tumor, or vascular anomaly in the various images, orbital dysplasia in the context of a malformation syndrome affecting several organs is suggested as the cause of the exophthalmos.