Posterior reversible encephalopathy syndrome in a patient with a Chiari I malformation

Abstract

Background: The authors describe a unique case of a patient who developed posterior reversible encephalopathy syndrome (PRES) following postoperative treatment of a Chiari I malformation.

Case decsription: A 25-year-old female presented with complaints of left upper and lower extremity paresthesias and gait disturbances. A magnetic resonance imaging (MRI) of the brain and cervical spine showed a Chiari I malformation with tonsillar descent beyond the level of the C1 lamina. She underwent a suboccipital craniectomy and C1 laminectomy with cerebellar tonsillar cauterization and duraplasty. Postoperatively, an MRI showed bilateral acute infarcts of the cerebellar vermis. She was initially treated for cerebellar ischemia with hypertensive therapy with a subsequent decline in her neurologic status and generalized tonic-clonic seizure. Further workup showed evidence of PRES. After weaning pressors, the patient had a significant progressive improvement in her mental status.

Conclusion: Although the mechanism of PRES remains controversial given its diverse clinical presentation, several theories implicate hypertension and steroid use as causative agents.

Keywords: Chiari I malformation; cerebellar tonsillar resection; posterior reversible encephalopathy syndrome; pressors; suboccipital craniectomy.

Figure 1

A preoperative T1 sagittal spin echo MRI of the brain shows a Chiari I malformation with tonsillar descent beyond the level of the C1 lamina and syringomyelia and syringobulbia with dilation throughout the cervical spinal cord and no evidence of hydrocephalus

Figure 2

T1 sagittal MRI of the brain (a) and T2 sagittal MRI of the cervical spine (b) obtained on postoperative day one, which shows cerebellar prolapse

Figure 3

T2 axial FLAIR MRI (a) and apparent diffusion coefficient MRI (b) and diffusion MRI (c) at postoperative day 5, upon return with new onset left sided weakness, demonstrating no acute infarcts

Figure 4

Diffusion Weighted Imaging (DWI) (a) and T2 axial FLAIR MRI (b) on postoperative day 9 showing increased signal in the bilateral frontal and parietal lobes, consistent with PRES

Figure 5

T2 axial FLAIR MRI demonstrating continuing hyperintensity of the right cerebellar vermis (a) and resolution of the right parietal increased signal one week after cessation of hypertensive therapy (b) (postoperative day 14)

Figure 6

(a and b) T2 axial FLAIR MRI 2 years after surgery showing complete resolution of changes associated with PRES

Figure 7

Sagittal T1 image 4 years postoperatively showing marked reduction in cervical syrinx and cerebellar prolapse