Spinal toxoplasmic arachnoiditis associated with osteoid formation: a rare presentation of toxoplasmosis.

Study Design. An extremely rare presentation of an isolated spinal toxoplasmic arachnoiditis is described. Objective. To draw attention to the fact that spinal arachnoid membranes may be a potential reservoir for Toxoplasma gondii. of Background Data. Central nervous system toxoplasmosis is a common manifestation in patients who are immunodeficient. Reports on the spinal toxoplasmosis are rare and focused on spinal cord involvement. Methods. An adult patient presented with symptoms of spastic paraperesis that had begun 13 years before admission. Thoracic spinal magnetic resonance imaging showed small lesions in posterior subarachnoid space at Th7-Th6. A Th7-Th8 laminectomy was performed. Intradural-extramedullary lesions were excised. Results. Clinical, immunologic, and pathologic examinations showed adhesive spinal arachnoiditis associated with osteoid formation caused by past toxoplasmic infection. There was no impairment of the immunologic defense system. Conclusion. Where no causative factor is found in serious spinal adhesive arachnoiditis, the possibility of spinal toxoplasmosis should also be investigated.