Occult Lung Cancer-Associated Autoimmune Encephalitis Presenting as Acute Psychosis

Area of Science:

• Neuroscience
• Oncology
• Immunology

Background:

• Acute behavioral changes can mimic psychiatric conditions.
• Autoimmune encephalitis is an emerging cause of neurological and psychiatric symptoms.

Purpose of the Study:

• To report a case of anti-N-methyl-D-aspartate receptor encephalitis presenting with acute behavioral changes.
• To highlight the association between autoimmune encephalitis and malignancy.

Main Methods:

• Clinical evaluation including neurological examination and neuroimaging (MRI).
• Cerebrospinal fluid (CSF) analysis for autoantibodies.
• Diagnostic workup for underlying malignancy.

Main Results:

• Patient presented with acute encephalopathy and behavioral changes.
• MRI revealed T2 hyperintensities.
• CSF positive for anti-N-methyl-D-aspartate receptor antibody.
• Nuclear protein in testis carcinoma identified in the lung.

Conclusions:

• Autoimmune encephalitis associated with anti-N-methyl-D-aspartate receptor antibodies can manifest as acute behavioral changes.
• Early diagnosis and treatment, including immunotherapy and tumor resection, are crucial for recovery.
• This case underscores the importance of considering autoimmune encephalitis in patients with unexplained acute behavioral changes, especially when associated with malignancy.