Spinal intradural extramedullary hydatidosis: report of three cases.

OBJECTIVE: Spinal hydatid cyst is a serious form of hydatid disease affecting fewer than 1% of all patients with hydatid disease. We report 3 healthy patients who presented with progressive paraparesis attributed to a histologically proven intradural hydatid cyst. METHODS: There were 2 children (1 boy, 1 girl) and 1 adult with a mean age of 12 years. The median follow-up duration was 16 months. Spinal magnetic resonance imaging was performed in the 3 patients, and an anatomic and topographical diagnosis of the intradural hydatid cyst was made. RESULTS: Magnetic resonance imaging scans revealed cystic lesions with peripheral contrast enhancement. Surgery was performed through laminectomy, complete resection was achieved, and antihelminthic treatment with albendazole 10 mg/kg-1 per day for 6 months was included in the postoperative treatment. The patients improved after surgery with normal motor function. CONCLUSION: This localization is rare and serious, but its prognosis is excellent if diagnosis is made early enough and surgery is performed in time to prevent cyst rupture.

Canine protozoan polyradiculoneuritis.

Four pups in a litter of eight Labrador Retrievers suddenly developed hind limb weakness. In three, paralysis ascended rapidly resulting in quadriplegia, cervical weakness, dysphagia and death. Postmortem examination revealed a severe polyradiculoneuritis in which roots, ganglia, and spinal and cranial nerves were heavily infiltrated by lymphocytes, plasma cells and macrophages and contained abundant protozoan pseudocysts. On sections of the brain and spinal cord protozoa were less frequent and appeared independent of the glial nodules which marked focal areas of necrosis. The organisms initially were thought to be Toxoplasma gondii, but this supposition was not supported by serological, immunocytochemical, or electron microscopic findings. Ultrastructurally the organisms resembled an unidentified sporozoan parasite, which has been reported in the CNS of dogs in Scandinavia. The inflamed spinal roots contained many degenerated and demyelinated axons. Electron microscopic studies indicated that the tachyzoite-like organisms, through their invasive and proliferative activities, brought about many of the degenerative changes in the Schwann cells and axons of the spinal roots and nerves.