Untethered filum terminale presenting as cauda equina lesion.

We report the case of a young girl with recurrent bladder dysfunction. Magnetic resonance imaging performed for evaluation of initial urologic symptoms revealed a low-lying conus medullaris. She underwent an L5 laminectomy and cord untethering by sectioning of the filum terminale. After initial improvement of bladder function, her symptoms returned 4 years later. Repeat magnetic resonance imaging demonstrated a new intradural lesion at L2. At surgery she was found to have an untethered, thickened, coiled filum terminale at L2.