Antithyroperoxidase Antibodies in Encephalopathy: Diagnostic Marker or Incidental Finding?

Abstract

Patients with acute encephalopathy who are thoroughly examined for an underlying diagnosis and in whom infectious, metabolic, and malignant causes are excluded can form a true diagnostic dilemma. If antithyroperoxidase antibodies (anti-TPO abs) are present, the diagnosis “steroid responsive encephalopathy, associated with autoimmune thyroiditis” (SREAT), better known as Hashimoto encephalitis, will often be considered. The precise pathophysiology of SREAT, including the possible role of the anti-TPO abs and the possible relationship between the encephalopathy and thyroid function, remains to be elucidated. Here we present three young patients with SREAT. Our patients illustrate that in unexplained encephalopathy, after exclusion of other causes (diagnosis of exclusion), determination of the anti-TPO abs may contribute to the diagnosis of SREAT. They also illustrate that thyroid function or the concentration of the anti-TPO abs does not seem to be associated with the severity of the clinical presentation of SREAT. We hypothesize that SREAT has an immunologic etiology. The presence of anti-TPO abs, however, should be considered to be a marker for autoimmunity and not a causative. It probably reflects the presence of predisposition of autoimmunity in these patients. Therefore, this condition should not be called Hashimoto encephalitis any longer.

Keywords

anti-TPO antibodies - SREAT - Hashimoto encephalitis - autoimmune encephalitis

• References

• 1 Brown RS. The thyroid. In: Brook C, Clayton P, Brown RS, , eds. Brook's Clinical Pediatric Endocrinology. Oxford: Wiley-Blackwell; 2009: 271-273
• 2 Brain L, Jellinek EH, Ball K. Hashimoto's disease and encephalopathy. Lancet 1966; 2 (7462) 512-514
• 3 de Holanda NC, de Lima DD, Cavalcanti TB, Lucena CS, Bandeira F. Hashimoto's encephalopathy: systematic review of the literature and an additional case. J Neuropsychiatry Clin Neurosci 2011; 23 (4) 384-390
• 4 Chong JY, Rowland LP, Utiger RD. Hashimoto encephalopathy: syndrome or myth?. Arch Neurol 2003; 60 (2) 164-171
• 5 Kothbauer-Margreiter I, Sturzenegger M, Komor J, Baumgartner R, Hess CW. Encephalopathy associated with Hashimoto thyroiditis: diagnosis and treatment. J Neurol 1996; 243 (8) 585-593
• 6 Peschen-Rosin R, Schabet M, Dichgans J. Manifestation of Hashimoto's encephalopathy years before onset of thyroid disease. Eur Neurol 1999; 41 (2) 79-84
• 7 Shaw PJ, Walls TJ, Newman PK, Cleland PG, Cartlidge NE. Hashimoto's encephalopathy: a steroid-responsive disorder associated with high anti-thyroid antibody titers—report of 5 cases. Neurology 1991; 41 (2, Pt 1) 228-233
• 8 Fatourechi V. Hashimoto's encephalopathy: myth or reality? An endocrinologist's perspective. Best Pract Res Clin Endocrinol Metab 2005; 19 (1) 53-66
• 9 Cantón A, de Fàbregas O, Tintoré M, Mesa J, Codina A, Simó R. Encephalopathy associated to autoimmune thyroid disease: a more appropriate term for an underestimated condition?. J Neurol Sci 2000; 176 (1) 65-69
• 10 Watemberg N, Greenstein D, Levine A. Encephalopathy associated with Hashimoto thyroiditis: pediatric perspective. J Child Neurol 2006; 21 (1) 1-5
• 11 Hilberath JM, Schmidt H, Wolf GK. Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT): case report of reversible coma and status epilepticus in an adolescent patient and review of the literature. Eur J Pediatr 2014; 173 (10) 1263-1273
• 12 v Maydell B, Kopp M, v Komorowski G, Joe A, Juengling FD, Korinthenberg R. Hashimoto encephalopathy - is it underdiagnosed in pediatric patients?. Neuropediatrics 2002; 33 (2) 86-89
• 13 Chaudhuri A, Behan PO. The clinical spectrum, diagnosis, pathogenesis and treatment of Hashimoto's encephalopathy (recurrent acute disseminated encephalomyelitis). Curr Med Chem 2003; 10 (19) 1945-1953