[(11)C]PiB PET in Gerstmann-Sträussler-Scheinker disease

Area of Science:

• Neuroscience
• Radiology
• Genetics

Background:

• Gerstmann-Sträussler-Scheinker Disease (GSS) is a rare, inherited neurodegenerative disorder.
• It is characterized by ataxia, parkinsonism, and dementia.
• Neuropathology reveals prion protein (PrP) amyloid plaques.

Purpose of the Study:

• To determine if [(11)C]Pittsburgh Compound B (PiB) positron emission tomography (PET) can detect PrP-amyloid in carriers of GSS-associated PRNP gene mutations.
• To evaluate the utility of PiB-PET for in vivo assessment of GSS neuropathology.

Main Methods:

• Six individuals at risk for GSS and eight controls underwent baseline [(11)C]PiB PET scans.
• Three asymptomatic PRNP mutation carriers underwent a follow-up scan approximately one year later.
• Neuropathologic examination was performed on one symptomatic individual.

Main Results:

• No [(11)C]PiB uptake was observed in any subject, including mutation carriers, at baseline or follow-up.
• Neuropathology confirmed abundant PrP-immunopositive plaques in the affected individual.
• Tau-immunopositive neurofibrillary tangles were also present.

Conclusions:

• [(11)C]PiB PET imaging is not effective for detecting PrP-amyloid plaques in Gerstmann-Sträussler-Scheinker Disease.
• This PET tracer is unsuitable for in vivo diagnosis or monitoring of GSS-related PrP deposition.