title: Cognitive and affective dysfunctions in autoimmune thyroiditis.
abstract: Hashimoto's thyroiditis (HT) is the most frequent cause of hypothyroidism in areas with sufficient iodine intake. While the impact of thyroid function on mood and cognition is well known, only in the recent years, an increasing number of studies report on the association of HT with cognitive and affective disturbances also in the euthyroid state. Recent imaging studies have shown that these impairments are accompanied by altered brain perfusion, in particular, in the frontal lobe and a reduced gray matter density in the left inferior gyrus frontalis. Brain function abnormalities in euthyroid patients with HT may be subtle and only detected by specific testing or even severe as it is the case in the rare neuropsychiatric disorder Hashimoto's encephalopathy (HE). The good response to glucocorticoids in patients with HE indicates an autoimmune origin. In line with this, the cognitive deficits and the high psycho-social burden in euthyroid HT patients without apparent signs of encephalopathy appear to be associated with anti-thyroid peroxidase auto-antibody (TPO Abs) levels. Though in vitro studies showing binding of TPO Abs to human cerebellar astrocytes point to a potential direct role of TPO Abs in the pathogenesis of brain abnormalities in HT patients, TPO Abs may function only as a marker of an autoimmune disorder of the central nervous system. In line with this, anti-central nervous system auto-antibodies (CNS Abs) which are markedly increased in patients with HT disturb myelinogenesis in vitro and, therefore, may impair myelin sheath integrity. In addition, in HT patients, production of monocyte- and T-lymphocyte-derived cytokines is also markedly increased which may negatively affect multiple neurotransmitters and, consequently, diverse brain neurocircuits.
authors.affiliation: Center of Old Age Psychiatry, Psychiatric University Hospital, Basel, Switzerland. Electronic address: thomas.leyhe@upkbs.ch.
authors.forename: Thomas
authors.initials: T
authors.lastname: Leyhe
authors.affiliation: Department of Endocrinology and Diabetology, University Hospital Düsseldorf, Düsseldorf, Germany; Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: Karsten
authors.initials: K
authors.lastname: Müssig
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000918:Antibody Specificity; D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology; D001921:Brain / Q000276:immunology* / Q000473:pathology; D001927:Brain Diseases / Q000145:classification / Q000188:drug therapy / Q000209:etiology* / Q000276:immunology / Q000473:pathology / Q000523:psychology; D003072:Cognition Disorders / Q000209:etiology* / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D004660:Encephalitis; D050031:Hashimoto Disease / Q000145:classification / Q000150:complications / Q000188:drug therapy / Q000209:etiology / Q000276:immunology / Q000473:pathology / Q000523:psychology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007453:Iodide Peroxidase / Q000276:immunology; D016131:Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D019964:Mood Disorders / Q000209:etiology* / Q000276:immunology; D009186:Myelin Sheath / Q000502:physiology; D059906:Neuroimaging; D011584:Psychology; D011788:Quality of Life; D020293:Vasculitis, Central Nervous System / Q000209:etiology / Q000276:immunology
chemical_list: D000305:Adrenal Cortex Hormones; D001323:Autoantibodies; D001324:Autoantigens; D016207:Cytokines; D007166:Immunosuppressive Agents; C056626:thyroid microsomal antibodies; D007453:Iodide Peroxidase
keywords: Affective disorders; Anti-CNS antibodies; Anti-TPO antibodies; Cognition; Hashimoto’s encephalopathy; Hashimoto’s thyroiditis; Psychosocial well-being