A treatable mimic of Chiari malformation with syringomyelia.

A 19-year-old woman presented with a five month history of headaches. Initially the headaches had been intermittent. For the two months prior to presentation the patient had a constant headache. There was no precipitant at onset. The headache was improved by recumbancy. It was associated with daily vomiting resulting in a 20 pound weight loss but no photophobia or phonophobia. The neurological exam was normal. A computed tomogram scan demonstrated findings consistent with a Chiari malformation. A magnetic resonance image (MRI) demonstrated cerebellar tonsillar herniation as well as other abnormalities suggestive of spontaneous intracranial hypotension (SIH) (Figure 1) rather than a Chiari malformation. The MRI of the cervical spine was normal. The patient was initially treated conservatively with bed rest, fluids and caffeine. A repeat MRI performed one month later demonstrated worsening of the cerebellar tonsillar herniation and new evidence of T2 signal hyperintensity within the cervical spine (Figure 2). There was no evidence of cerebrospinal fluid (CSF) leak. She underwent a lumber epidural blood patch with improvement in her symptoms. Seven weeks later the headaches recurred. A second lumber epidural blood patch was performed resulting in complete resolution of symptoms. An MRI after clinical symptoms improved revealed decreased tonsillar herniation and resolution of the T2 cord signal abnormality (Figure 3).