Single photon emission computed tomography (SPECT) findings of a patient with a novel prion mutation

Area of Science:

• Neuroscience
• Genetics
• Radiology

Background:

• Familial prion diseases are rare genetic disorders.
• Prion gene mutations can lead to diverse neurological symptoms.
• Early detection of prion diseases is crucial for management.

Observation:

• A unique familial prion disease case presented with pan-autonomic failure, sensory neuropathy, and mild cognitive impairment.
• Diffusion-weighted magnetic resonance imaging (MRI) and fluid attenuated inversion recovery MRI showed no abnormalities over 6-11 years.
• Technetium-99m-labeled ethylcysteinate dimer single photon emission computed tomography (SPECT) revealed decreased cerebral blood flow in the parietal and occipital lobes, progressing over two years.

Findings:

• SPECT identified abnormalities in cerebral blood flow that preceded or were not detected by MRI.
• The slowly progressive nature of this prion mutation may influence imaging findings.
• SPECT demonstrated evolving hypoperfusion correlating with mild cerebral atrophy on later MRI scans.

Implications:

• SPECT imaging may be more sensitive than MRI in detecting early functional changes in certain slow-progressing prion diseases.
• This case highlights the importance of considering functional imaging techniques like SPECT in diagnosing prion genetic mutations.
• Understanding the differential sensitivity of imaging modalities is key for accurate prion disease diagnosis and monitoring.