Metabolic Dysfunction Precedes Dopaminergic Loss in Early MSA-C: A Discordant 18F-FDG PET and 99mTc-TRODAT-1 Case Study
DOI:
https://doi.org/10.37275/bsm.v10i4.1551Keywords:
18F-FDG PET, 99mTc-TRODAT-1, Glial cytoplasmic inclusions, Multiple system atrophy, NeurodegenerationAbstract
Background: Differentiating early-stage multiple system atrophy-cerebellar type (MSA-C) from other ataxia syndromes presents a significant diagnostic challenge. While striatal dopaminergic denervation is a hallmark of synucleinopathies, it may be absent in the early stages of the cerebellar subtype. This study investigates the temporal dissociation between metabolic and dopaminergic biomarkers.
Case Presentation: We report a 48-year-old male presenting with a 5-year history of progressive cerebellar ataxia and mild Parkinsonism, resistant to dopaminergic therapy. Written informed consent was obtained from the patient for the publication of this case details and images. To exclude mimics, a basic metabolic workup and High-resolution 3T MRI were performed. MRI revealed mild cerebellar atrophy but lacked the specific hot cross bun sign. Wilson’s disease screening was negative. Due to limited resources, advanced genetic panels for spinocerebellar ataxias were not performed. The patient underwent dual-modality molecular imaging. On Day 1, 18F-FDG PET/CT demonstrated profound hypometabolism in the cerebellum (Cerebellum/Whole-Brain SUVr: 0.68) and pons (SUVr: 0.72). Conversely, on Day 30, 99mTc-TRODAT-1 SPECT revealed robust, symmetrical striatal uptake with Specific Binding Ratios (SBR) of 1.15 (Right) and 1.12 (Left), indicating preserved presynaptic dopamine transporter density.
Conclusion: This case illustrates a critical temporal dissociation in MSA-C pathophysiology: widespread pontocerebellar metabolic failure occurs prior to structural nigrostriatal degeneration. Clinicians must recognize that a normal DAT scan does not exclude MSA-C. In limited-resource settings where genetic testing is unavailable, 18F-FDG PET offers superior sensitivity in the early diagnostic window to support the diagnosis.
Authors
- Arvian Muhammad Barid1*
- Kharisma Perdani1
- Trias Nugrahadi1
- A Hussein S Kartamihardja1
- 1Department of Nuclear Medicine and Molecular Theranostics, Faculty of Medicine, Universitas Padjadjaran/Dr. Hasan Sadikin General Hospital, Bandung, Indonesia
Corresponding author Arvian Muhammad Barid — arvian.mb@gmail.com
Article history
- Submitted
- Accepted
- Published
Downloads
Published
Issue
Section
License
As our aim is to disseminate original research article, hence the publishing right is a necessary one. The publishing right is needed in order to reach the agreement between the author and publisher. As the journal is fully open access, the authors will sign an exclusive license agreement.
The authors have the right to:
- Share their article in the same ways permitted to third parties under the relevant user license.
- Retain copyright, patent, trademark and other intellectual property rights including research data.
- Proper attribution and credit for the published work.
For the open access article, the publisher is granted to the following right.
- The non-exclusive right to publish the article and grant right to others.
- For the published article, the publisher applied for the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
