Inflammatory hypertrophic cauda equina following intrathecal neural stem cell injection

Introduction: Potential benefit from stem cell treatments has more patients seeking treatment without understanding possible risks. Methods: We describe a woman who presented with progressive bilateral leg pain, numbness, and gait difficulties. A prior stroke, macular degeneration, osteoarthritis, and depression, led her to receive intrathecal neural stem cell therapy overseas 1 year before onset of symptoms. Results: Imaging showed marked enlargement of lumbosacral roots of the cauda equina, which was not seen before stem cell treatment. Electrodiagnostic studies confirmed chronic multiple lumbosacral radiculopathies. Biopsy of a lumbar dorsal sensory root showed myelinated fiber degeneration and loss, with endoneurial inflammation. The hypertrophic inflammatory cauda equina syndrome was potentially triggered by the prior intrathecal neural stem cell injection. Conclusions: Safety of intrathecal stem cell treatments is not routinely regulated in overseas stem cell facilities. We wish to bring this potential complication to the attention of health care providers.