IgG4 Disease-Related Ataxia

Area of Science:

• Neurology
• Immunology
• Radiology

Background:

• Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition with diverse clinical presentations.
• Neurological involvement in IgG4-RD is uncommon, with limited reports on specific syndromes.

Observation:

• A male patient presented with cerebellar ataxia and behavioral frontotemporal dementia.
• Cerebellar atrophy and reduced N-acetyl aspartate to creatine ratio were noted on MR spectroscopy.
• Extensive abnormal mesenteric, retroperitoneal, and perinephric tissue was observed on CT body scan.
• PET-CT revealed aortitis and increased tracer uptake in perinephric tissue.

Findings:

• Perinephric tissue biopsy confirmed IgG4-related disease.
• The patient's neurological presentation and imaging findings are novel in the context of IgG4-RD.
• Treatment with immunosuppressants led to initial clinical improvement but was complicated by pericardiac effusion and sepsis.

Implications:

• This case expands the spectrum of neurological manifestations associated with IgG4-related disease.
• Highlights the importance of considering IgG4-RD in patients with unexplained cerebellar ataxia and frontotemporal dementia.
• Suggests potential for aortitis and perinephric involvement in IgG4-RD.