Hashimoto encephalopathy: literature review

Area of Science:

• Neurology
• Immunology
• Endocrinology

Background:

• Hashimoto encephalopathy (HE) is a rare neurological disorder characterized by encephalopathy without CNS infection or tumor.
• It is strongly associated with autoimmune thyroiditis, classifying it as an autoimmune disorder.
• While rare, HE can lead to severe outcomes like death and status epilepticus.

Purpose of the Study:

• To define the diagnostic criteria and clinical presentation of Hashimoto encephalopathy.
• To highlight key diagnostic markers and differential diagnoses for HE.
• To discuss therapeutic responses in patients with HE.

Main Methods:

• Review of clinical features, diagnostic markers (thyroid antibodies, CSF protein), and neuroimaging in HE patients.
• Analysis of treatment outcomes with steroids, IV immunoglobulin, and plasmapheresis.
• Comparison of HE with other neurological conditions like autoimmune encephalitis and prion disease.

Main Results:

• Elevated thyroid antibodies are present in most HE cases and are crucial for diagnosis.
• Normal brain MRI findings are common in HE patients.
• Elevated cerebrospinal fluid (CSF) protein is the most consistent CSF abnormality.

Conclusions:

• The diagnosis of HE necessitates encephalopathy with cognitive impairment and psychiatric features (hallucinations, delusions, paranoia).
• Autoimmune encephalitis and prion disease are important differential diagnoses due to overlapping clinical symptoms.
• Steroid therapy is effective in most HE patients, with improvements also seen with IV immunoglobulin and plasmapheresis.