Two cases of normal pressure hydrocephalus caused by ependymoma of the cauda equina

Normal pressure hydrocephalus (NPH) associated with tumors of the cauda equina is rare. Here, we report two cases of NPH attributed to cauda equina ependymomas. A 63-year-old male presented with progressive gait disturbance, dementia, and urinary incontinence. When the lumbar MR documented an intradural tumor involving the cauda equina at the L2-L3 level; the tumor was excised; pathologically, it proved to be a myxopapillary ependymoma. Postoperatively, however, the patient's continued gait disturbance led to a brain CT that documented ventricular dilation consistent with NPH; following ventriculoperitoneal (VP) shunt placement his symptoms improved. A 65-year-old female also presented with gait disturbance, dementia, and urinary retention. Here, procedures were performed in reverse. When a brain CT showed hydrocephalus, a VP shunt was placed. When symptoms persisted, a lumbar MR demonstrated a T12-L2 intradural tumor; following a lumbar laminectomy for tumor excision, symptoms stabilized. The pathological diagnosis was also consistent with a conus/cauda equina ependymoma. Over the next 10 years, the patient had residual bladder dysfunction (e.g., requiring straight catheterization), but had no shunt dysfunction. We observed two cases of ependymomas of the cauda equina and brain CTs documenting NPH that was successfully surgically managed with stabilization of neurological deficit. In the first case, L2-L3 laminectomy for tumor removal was succeeded by shunting for NPH, while in the second case, initial VP shunting for NPH was followed by a T12-L2 laminectomy for tumor excision.