Extensive arachnoid ossification with associated syringomyelia presenting as thoracic myelopathy

Abstract

The authors present the case of a patient in whom progressive thoracic myelopathy was caused by the extensive ossification of the arachnoid membrane and associated intramedullary syrinx. Based on their findings and the results of a literature search, they describe a pathological basis of this rare condition, discuss its incidence and symptomatology, and suggest a simple classification of various types of the arachnoid ossification. They also discuss magnetic resonance imaging features of arachnoid ossification and associated spinal cord changes. Emphasis is placed on the particular value of plain computerized tomography, which is highly sensitive for detecting intraspinal calcifications and ossifications, in the diagnostic evaluation of patients whose clinical picture indicates progressive myelopathy.