Acute intermittent porphyria presenting as a diffuse encephalopathy

Ann Neurol. 2005 Apr;57(4):581-4. doi: 10.1002/ana.20432.


Although acute intermittent porphyria presents with dramatic neurological findings, the diagnosis is difficult. An 18-year-old woman had a clinical picture of porphyric encephalopathy. Magnetic resonance (MR) imaging demonstrated multiple large contrast-enhancing subcortical white matter lesions, which regressed with glucose and hematin infusions. Diffusion-weighted MR imaging was normal, and MR spectroscopy excluded acute demyelination or tissue necrosis. MR findings of acute intermittent porphyria can differ from those in posterior reversible encephalopathy syndrome by virtue of intense contrast enhancement. Because diffusion-weighted MR imaging and spectroscopy were normal, the lesions are likely caused by reversible vasogenic edema and transient breakdown of the blood-brain barrier.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Brain Diseases / diagnosis*
  • Brain Diseases / physiopathology
  • Carbohydrates / therapeutic use
  • Diagnosis, Differential
  • Female
  • Hemin / therapeutic use
  • Humans
  • Magnetic Resonance Imaging
  • Porphyria, Acute Intermittent / diagnosis*
  • Porphyria, Acute Intermittent / drug therapy
  • Porphyria, Acute Intermittent / physiopathology*


  • Carbohydrates
  • Hemin