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

Treatment of Hashimoto's Encephalopathy

High-dose corticosteroids are the first-line treatment for Hashimoto's encephalopathy, with most patients showing significant improvement in neurological symptoms. 1, 2, 3

Definition and Clinical Features

Hashimoto's encephalopathy (HE), also known as steroid-responsive encephalopathy associated with thyroid antibodies (SREAT), is a rare autoimmune condition characterized by:

• Neurological and psychiatric manifestations in the presence of elevated anti-thyroid antibodies, particularly anti-thyroid peroxidase (aTPO) 4
• Common symptoms including seizures, behavioral problems, cognitive impairment, hallucinations, headache, and decline in school performance 4
• Nonspecific electroencephalogram (EEG) abnormalities and elevated cerebrospinal fluid (CSF) protein 3

Treatment Algorithm

First-Line Treatment

• High-dose corticosteroids (typically oral prednisolone or prednisone at 2-3 mg/kg/day given as a single morning dose) 1, 3
• Treatment should be initiated promptly upon diagnosis due to potential for significant morbidity 3
• Several months of therapy is generally necessary, with gradual tapering based on clinical response 3

For Steroid-Refractory Cases

1. Intravenous immunoglobulins (IVIG) (0.4 g/kg body weight daily for 5 days) 5

   • Can induce long-lasting remission in steroid-resistant cases
   • Careful monitoring required due to potential side effects

2. Rituximab (anti-CD20 monoclonal antibody) 1

   • Particularly valuable in steroid-refractory cases
   • Requires careful monitoring for side effects, especially low immunoglobulin levels

Monitoring During Treatment

• Regular assessment of neurological symptoms and cognitive function 4, 3
• Periodic monitoring for potential toxicity of long-term corticosteroid therapy, including:
  • Blood pressure elevation
  • Decreased growth rate (especially in pediatric patients)
  • Irritability and sleep disturbance
  • Gastric irritation
  • Immunosuppression 3

Special Considerations

• Pediatric patients: Require careful monitoring of growth and development during treatment 4
• Long-term prognosis: Most patients (approximately 70%) recover fully, but about 16% may have late sequelae, particularly epilepsy 4
• Differential diagnosis: Important to rule out other causes of encephalopathy including infections, metabolic disorders, and other autoimmune conditions 3

Common Pitfalls and Caveats

• Delayed diagnosis: HE should be considered in any patient with unexplained neurological or psychiatric symptoms, particularly with a history of thyroid disease 4
• Inadequate treatment duration: Premature discontinuation of immunosuppressive therapy may lead to relapse 3
• Overlooking steroid resistance: Some cases may not respond adequately to corticosteroids and require alternative immunomodulatory treatments 1, 5
• Monitoring complications: Long-term corticosteroid therapy requires vigilant monitoring for adverse effects 3

While some cases may show spontaneous remission 2, the unpredictable nature and potential severity of symptoms warrant prompt treatment with immunosuppressive therapy to prevent long-term neurological sequelae and improve quality of life.