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Neuroradiology Case of the Week

Case 209

Jerry Lee, MD and Per-Lennart Westesson, MD, PhD, DDS

Clinical Presentation: A 70-year-old maie with 3-4 weeks of visual hallucinations, staring spells, mental status changes, and dementia.

Radiological Findings: Diffusion weighted images demonstrate restricted diffusion in the bilateral caduate nuclei and putamen (Fig 1 and 2).  There is gyriform hyperintense areas in the cortical gray matter in the right frontal and bilateral parietal lobes on DWI (Fig 1 and 2).  T2 and FLAIR images demonstrate increase signal intensity in the caudate nuclei and putamen bilaterally (Fig 3 and 4).

Diagnosis: Creutzfeldt-Jakob Disease (CJD)

Discussion: Creutzfeldt-Jakob disease (CJD) is a rapidly progressing, fatal, potentially transmissible dementing disorder caused by a prion (proteinaceous infectious particle devoid of DNA and RNA). CJD is considered a spongiform encephalopathy. The human prion protein is encoded on the short arm of chromosome 20. It exits in two isoforms: a normal cellular form, and a form that differs only in physical characteristics (the protein undergoes a post-tranlational conformational change) which is found in prion diseases. The prion does not evoke an immune response during infection.
     CJD usually affects older adults with a worldwide annual incidence of 1 case per million persons. This disease is usually fatal within 1 year of symptom onset. Most cases are sporadic, but 10 to 15% of cases are familial. Patients present with rapidly progressive dementia associated with myoclonic jerks with variable pyramidal, extrapyramidal and cerebellar signs.
     Radiographic imaging demonstrates classically hyperintense signal in the caudate nuclei, putamen and thalami on T2WI. T1WI is usually normal and there is no enhancement post contrast. DWI is sensitive for CJD demonstrating hyperintense changes in stratum and cerebral cortex in addition to the caudate nuclei, putamen and thalami.
     Differential diagnosis includes hypoxic-ischemic encephalopathy, Wilson disease, HIV encephalopathy, and Leigh disease.

References:

1. Osborn, AG. Diagnostic Neuroradiology: Brain. St. Louis: Mosby, 1994.
2. Teaching Atlas of Brain Imaging
3. Zimmerman RA, Bilaniuk L. Neuroimaging: Clinical and Physical Principles. Eds. Robert A. Zimmerman, Wendell A. Gibby, Raymond F. Carmody. New York: Springer, 2000