Hashimoto Encephalopathy


Steroid Responsive Encephalopathy Associated With Autoimmune Thyroiditis SREAT a.k.a. Hashimoto’s encephalopathy


A diagnosis by exclusion with the following:

  • Encephalopathy characterised by:
    • Tremor, transient aphasia, myoclonus, gait ataxia, seizures, and sleep abnormalities
  • +no other identifiable cause
  • +Positive antithyroid antibodies: anti-thyroglobulin or anti-thyroperoxidase antibodies
  • +/-abnormal TFTs: usually hypothyroidism, but may be euthyroid to hyperthyroid
  • +response to steroids

Findings on Investigations:

CSF: mildly elevated protein, mild lymphocytic pleocytosis may occur, normal IgG index
EEG: Generalized slowing other findings; focal slowing, triphasic waves, epileptiform abnormalities, and photomyogenic response
MRI: T2 & FLAIR white matter high signal
Catheter angiography: normal


Methylprednisolone 1 g/d intravenously for 5 days followed by predinosolone 60mg/d for 10-30 days.
If it does not respond to therapy, consider investigations for CJD or other subacute encephalopathies

Related articles:


  1. Castillo P, Woodruff B, Caselli R, Vernino S, Lucchinetti C, Swanson J, Noseworthy J, Aksamit A, Carter J, Sirven J, Hunder G, Fatourechi V, Mokri B, Drubach D, Pittock S, Lennon V, Boeve B. Steroid-responsive encephalopathy associated with autoimmune thyroiditis. Arch Neurol. 2006 Feb;63(2):197-202.