Seronegative Paraneoplastic Limbic Encephalitis Associated with Thymoma.

Area of Science:

• Neurology
• Immunology
• Oncology

Background:

• Paraneoplastic limbic encephalitis (PLE) is an autoimmune neurological disorder.
• It presents with acute encephalopathy, memory loss, seizures, and behavioral changes.
• Diagnosis traditionally relies on detecting antineuronal antibodies.

Observation:

• A 70-year-old woman presented with acute cognitive decline and choreoathetoid movements.
• MRI revealed temporal lobe abnormalities; CT identified a thymoma.
• The patient met current diagnostic criteria for autoimmune limbic encephalitis.

Findings:

• Treatment with immunotherapy and thymoma resection led to symptom improvement.
• Cerebrospinal fluid antibody tests were negative for PLE.
• This case highlights that PLE diagnosis and treatment can precede antibody confirmation.

Implications:

• Current diagnostic criteria allow for earlier intervention in suspected PLE cases.
• Prompt management of the underlying malignancy is crucial for patient survival and functional recovery.
• Neurologists and psychiatrists must be aware of these updated diagnostic and management approaches for PLE.