Myelographic findings in adhesive spinal arachnoiditis (with a brief surgical note).

Abstract

Spinal adhesive arachnoiditis may produce various types of myelographic defects. Streaks and droplets are characteristic of arachnoiditis which does not obliterate the sub-arachnoid space. In obstructive type of arachnoiditis it may create the following forms of defects. (1) An oval or circular defect resembles that of an extra-medullary tumour. It differentiates from the latter by the absence of displacement of the spinal cord and enlargement of the subarachnoid space. These changes provide a three-dimensional effect on myelography in an intradural and extramedullary tumour. (2) A paint-brush defect often simulates an epidural compressing lesion. In arachnoiditis, there is no deviation of the head of the Pantopaque column, whereas in epidural tumours, it may be lifted, depressed or pushed to one side. (3) Scalloping defects are produced by multiple obliterations of the subarachnoid space. (4) Defects like “flower-petal” arrangement lining the circumference of the spinal canal are the result of multiple subarachnoid occlusions separated by adherent septa. The surgical treatment includes, (i) lysis of nerve roots, (ii) excision of adherent arachnoidea, (iii) posterior rhizotomy for pain, and (iv) the use of synthetic cloth to cover the involved area and tent the opened dura. Satisfactory result has been observed in some of these patients thus treated. The follow-up period was one to ten years.