Hyperthyroidism in moyamoya disease

Abstract

Hyperthyroidism is a clinical condition caused by the effects of excessive circulating thyroid hormones on various tissues of the body [1]. The various actions of thyroid hormone on many organ systems produce a broad spectrum of clinical signs and symptoms in patients with hyperthyroidism. An increased body's metabolism is characteristic in hyperthyroidism [2]. For this reason, patients often feel hotter than those around them and can slowly lose body weight even though they may be eating more food. When hyperthyroidism is severe, patients can suffer shortness of breath, chest pain, and muscle weakness [2]. Although there are several different causes of hyperthyroidism, most of the symptoms that patients experience are the same regardless of the cause [3]. Hyperthyroidism, thyroid storm, and Graves disease are conditions of excess thyroid hormone. Thyroid storm is a rare and potentially fatal complication of hyperthyroidism [4]. It typically occurs in patients with untreated or partially treated thyrotoxicosis who experience a precipitating event such as surgery, infection, or trauma [2]. Patients typically appear markedly hypermetabolic with high fevers, tachycardia, nausea and vomiting, tremulousness, agitation, and psychosis [5]. Graves disease (diffuse toxic goiter), the most common underlying cause of hyperthyroidism, is an autoimmune disease in which autoantibodies against the thyroid-stimulating hormone receptors inappropriately stimulate thyroid gland with ensuing excessive production and release of thyroid hormones [6]. The resultant hyperthyroid state produces multiorgan physiological derangements. Graves disease is associated with various autoimmune diseases such as pernicious anemia, vitiligo, type 1 diabetes mellitus, autoimmune adrenal insufficiency, systemic sclerosis, myasthenia gravis, Sjögren syndrome, rheumatoid arthritis, and systemic lupus erythematosus [7]. Utku et al. described reversible angiographical findings mimicking moyamoya disease at magnetic resonance (MR) angiography in a woman with a stroke-like episode and encephalopathy diagnosed as Graves disease [8]. In this case, her neurological status improved dramatically after methylprednisolone treatment and plasmapheresis, and the MR angiography abnormalities resolved after 3 months © 2010 Springer-Verlag Tokyo.