Thank you for your recent inquiry.
Hashimoto's encephalitis is generally considered a steroid-responsive encephalitis, and the treatment traditionally has been corticosteroids. There are also reports of improvement with plasmapheresis. There has been some mention of treatment with "immunomodulatory" agents in general, but I could find no specific mention of the administration of immunoglobulin as a therapy for Hashimoto's encephalitis.
A literature search failed to reveal any studies of subcutaneous immunoglobulin to treat Hashimoto's disease.
I have copied below two references, one a case report indicating the utility of corticosteroids, and another which is an excellent review of Hashimoto's encephalopathy should you be interested further in this topic. The review does not mention treatment of this disorder with immunoglobulin, although it does cite, as mentioned, therapy with corticosteroids and the possibility that plasmapheresis may be of help.
Thank you again for your inquiry and we hope this response is helpful to you.
J Clin Neurol. 2008 Dec;4(4):167-70. Epub 2008 Dec 31.
Steroid-responsive recurrent encephalopathy associated with subacute thyroiditis.
Chung YJ, Park KY, Ahn J, Ha SY, Youn YC.
Division of Endocrinology, Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
BACKGROUND: Steroid-responsive encephalopathy associated with subacute thyroiditis has, to our knowledge, not been reported previously. CASE REPORT: A 49-year-old woman was found collapsed and brought to our institution with decreased mentality, dysarthria, and gait disturbance. Brain magnetic resonance imaging and angiography were normal but blood tests revealed thyroid-autoantibody-negative thyrotoxicosis. Results of a (99m)technetium-pertechnetate scan were compatible with the thyrotoxic phase of subacute thyroiditis. 14-3-3 proteins were detected in cerebrospinal fluid. Her mental status began to improve from the day following steroid administration. Recurrent encephalopathy was found 2 months after the initial admission, which was also effectively treated with steroid. CONCLUSIONS: We speculate that steroid-responsive recurrent encephalopathy associated with subacute thyroiditis is a subtype of Hashimoto's encephalopathy, and consider that steroid treatment should not be delayed in suspected
Ann N Y Acad Sci. 2008 Oct;1142:254-65.
Schiess N, Pardo CA.
Department of Neurology, Division of Neuroimmunology and Neuroinfectious Disorders, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
Hashimoto's encephalopathy (HE) is a controversial neurological disorder that comprises a heterogenous group of neurological symptoms that manifest in patients with high titers of antithyroid antibodies. Clinical manifestations of HE may include encephalopathic features such as seizures, behavioral and psychiatric manifestations, movement disorders, and coma. Although it has been linked to cases of Hashimoto's thyroiditis or thyroid dysfunction, the most common immunological feature of HE is the presence of high titers of antithyroglobulin or anti-TPO (antimicrosomal) antibodies. At present, it is unclear whether antithyroid antibodies represent an immune epiphenomenon in a subset of patients with encephalopathic processes or they are really associated with pathogenic mechanisms of the disorder. The significance of classifying encephalopathies under the term HE will be determined in the future once the relevance of the role of antithyroid antibodies is demonstrated or dismissed by more detailed experimental and immunopathological studies. The responsiveness of HE to steroids or other therapies such as plasmapheresis supports the hypothesis that this is a disorder that involves immune pathogenic mechanisms. Further controlled studies of the use of steroids, plasmapheresis, or immunosuppressant medications are needed in the future to prove the concept of the pathogenic role of antithyroid antibodies in HE.
Phil Lieberman, M.D.
Key Words: Hashimoto's encephalopathy, plasmapheresis, corticosteroids, subcutaneous immunoglobulin