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Case Reports
. 2025 Oct 1;50(10):951-952.
doi: 10.1097/RLU.0000000000005824. Epub 2025 Apr 23.

Uncommon Bilateral Frontoparietal Cortex Hypermetabolism Revealed by 18 F-FDG PET/CT in a Patient With Anti-LGI1 Encephalitis

Leilei Yuan  1 , Xiaotong Li  1 , Tao Cui  2 , Qian Chen  1 , Lin Ai  1
Affiliations
Case Reports

Uncommon Bilateral Frontoparietal Cortex Hypermetabolism Revealed by 18 F-FDG PET/CT in a Patient With Anti-LGI1 Encephalitis

Leilei Yuan et al. Clin Nucl Med. .

Abstract

Limbic hypermetabolism is a frequently observed manifestation of anti-LGI1 encephalitis on 18 F-FDG PET/CT imaging. In this case report, we present an atypical finding on 18 F-FDG PET/CT in a patient with anti-LGI1 encephalitis and negative MRI results. Apart from the expected hypermetabolism in the bilateral limbic system, there was also an uncommon intense uptake of 18 F-FDG noted in the bilateral frontoparietal cortex. Subsequent follow-up scans demonstrated normalized metabolism following treatment. The case highlights that neocortical hypermetabolism can be a characteristic feature of active anti-LGI1 encephalitis on 18 F-FDG PET/CT imaging.

Keywords: FDG PET; MRI; anti-LGI1 encephalitis; autoimmune encephalitis (AE).

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Conflict of interest statement

Conflicts of interest and sources of funding: none declared.

References

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