Autoimmune Thyroiditis Shifting from Hashimoto's Thyroiditis to Graves' Disease.

In 15-20% of cases, Graves' disease (GD) shifts to Hashimoto's thyroiditis (HT), while the shift from HT to GD is rare. We present a case of a patient in whom HT shifted to GD, along with a literature review. A 50-year-old woman with myxedema was diagnosed with Hashimoto's disease due to hypothyroidism and the presence of antibodies against thyroid peroxidase (TPOAb) and thyroglobulin (TgAb); she also had thyroid stimulating antibodies (TSAb) without any signs of GD. Although thyroid hormone replacement therapy improved her thyroid function, 2 months later, hyperthyroidism appeared and did not improve after discontinuation of the replacement therapy. The patient was diagnosed with GD, which improved with antithyroid agent administration. To date, only 50 cases regarding conversion from HT to GD have been reported. The median age is 44 years (range, 23-82 years), and the median time of conversion is 7 years (range, 0.1-27 years). The male-to-female ratio of HT conversion to GD is 1:9, closer to that of regular GD (1:10) than that of general HT (1:18). All patients received thyroid hormone replacement therapy for hypothyroidism due to HT. Continuous evaluation of TSAb levels is recommended in HT, particularly in cases of TSAb-positive and those under replacement, since it may help predict conversion to GD. Evaluating the clinical characteristics of patients with HT preceding GD is crucial to ensure appropriate treatment and reduce the risk of adverse events.

Quetiapine and Valproic Acid-induced Central Hypothyroidism in a Patient with Autism Spectrum Disorder and Intractable Epilepsy: A Case Report.

OBJECTIVES: Patients with an autism spectrum disorder (ASD) are prone to disruptive behaviors and aggression. Atypical antipsychotics are used to treat these difficult ASD conditions. Several psychotropic drugs have been linked to hypothyroidism. The clinical manifestation of hypothyroidism is indistinguishable from that of an antipsychotic's general adverse effect, which can lead to a delayed or missed diagnosis. Conversely, thyroid dysfunction can exhibit an impact on mood, anxiety, depression, and cognitive functions. CASE STUDY: We present a case of central hypothyroidism caused by long-term use of valproic acid (VPA) and adding quetiapine to risperidone. The current case had a history of hyperprolactinemia and subclinical hypothyroidism caused by risperidone and VPA, respectively, before the administration of quetiapine. CONCLUSION: This is the first report of quetiapine-induced central hypothyroidism in a patient with ASD, as determined by a thyrotropin-releasing hormone (TRH) loading test. TRH loading test may be useful in elucidating the pathogenesis of hypothyroidism in patients receiving quetiapine and VPA. Thyroid function monitoring in patients taking quetiapine and VPA may provide an opportunity to begin replacement therapy.