Objective:

To describe clinical, MRI, and 18FDG-PET characteristics in patients with CJD. 

Background:

Creutzfeld-Jakob disease (CJD) is a universally fatal neurodegenerative disorder. Sporadic CJD (sCJD) diagnostic criteria include EEG, CSF 14-3-3 protein, typical MRI findings and most recently in 2015 CSF real-time quaking-induced conversion (RT-QuIC). Recent studies have shown 18FDG-PET as a promising tool for the diagnosis of sCJD. In this study we gathered clinical characteristics for patients with definite or probable sCJD and compared brain 18FDG-PET metabolism patterns with MRI and CSF RT-QuIC findings. 

Design/Methods:

This retrospective record review included patients treated at a tertiary center with sCJD and RPD from January 1, 2015-May 30, 2024. Included patients had definite or probable sCJD based on CDC criteria and a brain 18FGD-PET study done during their evaluation and available for review. Clinical characteristics and laboratory results were reviewed. Two radiologists independently evaluated brain MRI studies and recorded abnormalities. Semi-quantitative evaluation of the brain 18FDG-PET was performed using NeuroQ software, with abnormal brain regions defined as either Z≥+2 for hypermetabolic or Z≤-2 for hypometabolic relative to matched controls.  

Results:

18FDG-PET sensitivity was 100% for patients meeting criteria for definite (N=15) or probable (N=11) CJD, compared to MRI sensitivity of 86.6% and 81.2%, and RT-QuIC 81.81% and 88.88%, respectively.   Semi-quantitative evaluation revealed overall cerebral cortical hypometabolism with relatively preserved basal ganglia activity and hypermetabolic posterior fossa and brain stem activity. Two patients had normal brain MRIs with significant brain 18FDG-PET abnormalities.  

Conclusions:

The general 18FDG-PET metabolic pattern for our CJD patients involved cortical hypometabolism with relative normal basal ganglia metabolism and hypermetabolism of the posterior fossa areas and brain stem. Compared to MRI brain and RT-QuIC, 18FDG-PET provided higher sensitivity in patients with sCJD and may prove valuable in the evaluation of patients presenting with rapidly progressive dementia.