Subacute Noninfective Inflammatory Encephalopathy: Our Experience and Diagnostic Problems

Area of Science:

• Neurology
• Immunology
• Psychiatry

Background:

• Immune dysregulation-associated encephalopathies manifest with prominent psychiatric symptoms and subtle neurological signs.
• These conditions are frequently resistant to standard psychiatric treatments.
• Specific movement disorders like generalized orthostatic myoclonus and faciobrachial dystonic seizures are often misdiagnosed.

Purpose of the Study:

• To analyze patients diagnosed with noninfective encephalopathy.
• To identify common diagnostic challenges and potential misdiagnoses.
• To highlight the importance of neurological examination and specific investigations.

Main Methods:

• Analysis of 42 patients diagnosed with noninfective encephalopathy between 2010-2015.
• Exclusion of patients with infectious causes or systemic vasculitis.
• Investigation included cerebrospinal fluid analysis, neuroimaging, electroencephalogram (EEG), and antibody profiling.

Main Results:

• Over 70% of patients presented with psychiatric manifestations.
• Identified antibody profiles included N-methyl-D-aspartate receptor, voltage-gated potassium channel, thyroid peroxidase, and antinuclear antibodies, with some cases of unknown etiology.
• Paraneoplastic antibodies were found in three patients.

Conclusions:

• Diagnostic errors are common in immune-related encephalopathies.
• Early diagnosis relies on high suspicion in new-onset refractory psychosis cases.
• Attention to subtle neurological signs and the utility of EEG are crucial for establishing organicity.