Immunotherapy responsive autoimmune subacute encephalitis: a report of two cases

Area of Science:

• Neurology
• Immunology
• Radiology

Background:

• Subacute encephalitis is a potentially underdiagnosed neurological condition.
• Autoimmune encephalitis can be associated with specific antibody markers.

Observation:

• Two patients presented with altered mental status, seizures, and cognitive decline.
• Brain MRI revealed hippocampal hyperintensities and frontotemporal atrophy in one case.
• Both patients tested positive for voltage-gated potassium channel antibodies (VGKCAb) and antithyroperoxidase (TPO) antibodies.

Findings:

• Autoimmune subacute encephalitis was diagnosed based on clinical, radiological, and serological findings.
• Treatment with immunosuppressive therapies including steroids, IVIG, plasma exchange, and azathioprine led to marked clinical improvement in both patients.
• Significant recovery in memory and seizure control was observed after 8-9 months of treatment.

Implications:

• Screening for VGKCAb and anti-TPO antibodies is crucial for patients with subacute encephalitis, especially with seizure activity.
• Early diagnosis and prompt immunosuppressive treatment can lead to favorable outcomes in autoimmune encephalitis.
• This case series highlights the importance of recognizing autoimmune subacute encephalitis as a treatable neurological disorder.