Clinical utility of brain SPECT in early diagnosis of prion diseases

Kunihiko Araki^1,2), Takashi Matsudaira¹⁾, Akira Sugiura¹⁾, Shigeo Murayama³⁾,
Tetsuyuki Kitamoto⁴⁾, Koichi Mizoguchi⁵⁾, Tomokazu Obi¹⁾

¹⁾National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Department of Neurology
²⁾Nagoya University Graduate School of Medicine, Department of Neurology
³⁾Tokyo Metropolitan Geriatric Hospital, Department of Neuropathology
⁴⁾Tohoku University Graduate School of Medicine, Department of Neurological Science
⁵⁾National Hospital Organization Shizuoka-Fuji Hospital, Department of Neurology

Prion diseases are rare, transmissible, and fatal.　Although positive findings on diffusion-weighted MRI imaging (DWI) of the head are included in the diagnostic criteria for prion diseases, epilepsy and inflammatory diseases also produce DWI hyperintensity in the cerebral cortex and must be ruled out during diagnosis.　We examined clinical usefulness of brain single photon emission tomography (SPECT) in early diagnosis of prion diseases.　We visually evaluated both DWI and SPECT images of the 8 cerebral lobes (bilateral frontal, temporal, parietal, occipital lobes) of 11 patients with definite or probable prion diseases.　DWI hyperintensity was seen in 40 of the 88 lobes:with the exception of patient 9, all 16 lobes with hyperintensity 80% or more also showed SPECT hypoperfusion.　SPECT hypoperfusion in regions with DWI hyperintensity may reflect spongiform degeneration with neuronal loss, which was characteristic of prion diseases.
Keywords:prion diseases, diffusion-weighted imaging, single photon emission tomography

Address correspondence to Dr. Kunihiko Araki, Nagoya University Graduate School of Medicine, Department of Neurology (65, Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan)