What is the treatment for Hashimoto's (Hashimoto's thyroiditis) encephalopathy?

Treatment of Hashimoto's Encephalopathy

Corticosteroids are the first-line treatment for Hashimoto's encephalopathy, with most patients showing significant improvement with high-dose steroid therapy. 1

Clinical Characteristics and Diagnosis

• Hashimoto's encephalopathy (HE), also known as steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), is a rare autoimmune disorder characterized by encephalopathy and elevated anti-thyroid antibodies 2
• Common presenting symptoms include seizures (including status epilepticus), behavioral problems, hallucinations, headache, cognitive decline, stroke-like episodes, myoclonus, ataxia, and psychosis 2, 1
• Diagnosis requires exclusion of other causes of encephalopathy through neuroimaging, CSF examination, and laboratory testing 1
• Elevated anti-thyroid peroxidase (anti-TPO) antibodies are diagnostic, though thyroid function is often clinically and biochemically normal 2, 1

Treatment Algorithm

First-Line Treatment:

• High-dose corticosteroids (typically IV methylprednisolone 500-1000mg daily for 3-5 days, followed by oral prednisone 1-2mg/kg/day) 3, 1
• Oral prednisone should be gradually tapered over weeks to months based on clinical response 3
• Most patients show dramatic improvement within days to weeks of starting corticosteroid therapy 1

For Patients with Incomplete Response to Corticosteroids:

• Plasmapheresis (plasma exchange) should be considered for patients with suboptimal response to high-dose steroids 4
• Intravenous immunoglobulin (IVIG) can be used as an alternative immunomodulatory treatment 1

Long-Term Management:

• Many patients require long-term immunosuppressive therapy to prevent relapse 3
• Steroid-sparing agents may be considered for maintenance therapy to minimize long-term steroid side effects 3, 1
• Regular monitoring of neurological status and anti-thyroid antibody titers can help guide treatment decisions 1

Special Considerations

• HE can occur with normal thyroid function, hypothyroidism, or rarely with hyperthyroidism 5
• In cases with concurrent thyroid dysfunction, appropriate thyroid management should be initiated alongside immunotherapy 5
• Pediatric patients with HE typically present with epilepsy, behavioral problems, and decline in school performance 2
• Approximately 70% of pediatric patients recover fully, but about 16% may have late sequelae, most commonly epilepsy 2

Prognosis

• With appropriate treatment, most patients have a good prognosis 2, 1
• Some patients may experience a relapsing-remitting course requiring long-term immunosuppression 1
• Early recognition and prompt treatment are essential to prevent permanent neurological sequelae 1

Clinical Pitfalls

• HE is often misdiagnosed as viral encephalitis, psychiatric disorders, or rapidly progressive dementia 1
• Anti-thyroid antibodies can be elevated in the general population without HE, so clinical correlation is essential 1
• Abrupt cessation of corticosteroid therapy may lead to relapse; therefore, gradual tapering is recommended 1
• In patients with unexplained neurological or psychiatric symptoms, testing for anti-thyroid antibodies should be considered, even with normal thyroid function 2, 5