Subarachnoid fat dissemination secondary to intrathecal pump.

Implantable intrathecal infusion pumps (ITPs) are an effective pain management modality for patients who have failed non-operative options. We present the first report of asymptomatic intracranial subarachnoid fat dissemination secondary to an ITP. A 39-year-old who underwent implantation of an ITP for intractable pelvic pain developed altered mental status. CT and MRI revealed subarachnoid fat deposition without evidence of a dermoid or epidermoid cyst. She returned to her baseline mental status with her symptoms attributed to delirium. The rare possibility of subarachnoid fat dissemination following transdural spinal procedures should be considered as a potential complication of ITPs. Although fat may persist in the subarachnoid space for years, asymptomatic patients can be safely managed with observation alone.