Striatal hypermetabolism in a case of IgG4-related disease

Area of Science:

• Neurology
• Radiology
• Immunology

Background:

• Immunoglobulin G4-related disease (IgG4-RD) is a multisystem fibroinflammatory condition.
• Neurological involvement in IgG4-RD is rare and its imaging features are not well-characterized.
• The case highlights the importance of considering IgG4-RD in patients with unexplained neurological symptoms.

Observation:

• A 77-year-old man with known IgG4-RD and lung/bone involvement presented with memory deficits.
• Brain MRI was unremarkable, but 18F-FDG PET/CT revealed symmetrical striatal hypermetabolism and cortical hypometabolism.
• The patient's condition rapidly deteriorated despite steroid treatment, leading to death.

Findings:

• This is the first reported case of IgG4-related disease exhibiting symmetrical striatal hypermetabolism on 18F-FDG PET/CT.
• The observed hypermetabolism contrasts with typical cortical hypometabolism patterns seen in some neurodegenerative conditions.
• The findings suggest a potential unique neuroimaging signature for IgG4-RD.

Implications:

• Striatal hypermetabolism may represent a novel neurological manifestation of IgG4-related disease.
• This finding could aid in the diagnosis and understanding of IgG4-RD's impact on the central nervous system.
• Further research is needed to elucidate the pathophysiology and clinical significance of these PET/CT findings in IgG4-RD.