Supplementary Material for: Spinal teratoma with recurrent epileptic episodes in adults: a case report

Introduction Spinal teratomas are rare, accounting for nearly 0.2-0.5% of all spinal tumors and 2% of all teratomas. Teratomas at the conus medullaris location do not inherently lead to epilepsy. However, potential epileptic seizures is caused when a teratoma ruptures and the chemical stimulation of teratoma components enter the dural sac.
Case presentation A 31-year-old Asian male patient suffering from epileptic onset and poor antiepileptic treatment was demonstrated. The spinal imaging examination was performed, and the patient suffered a space-occupying lesion within the conus medullaris related to spinal deformity, spinal embolism, etc. The autoimmune encephalitis spectrum revealed mGluR5 antibody IgG (+) 1:10 response. The patient stabilized after treatment with hormones and human immunoglobulin. Some hair and lipid droplets could be observed in the dural sac intraoperatively, and more hair and lipid-like material were present in the spinal cord. Postoperative pathology established the diagnosis as a conus medullaris teratoma in adults. Epileptic seizures stopped after surgery, and no additional seizures were reported during the 33-month follow-up period.
Conclusions Conus medullaris teratoma rupture in adults rarely causes epileptic seizures. For spinal deformity patients with unexplained epileptic symptoms, spinal MRI can be helpful in early diagnosis, and more appropriate treatment improves disease prognosis.