This Article Full Text Full Text (PDF) All Versions of this Article: 36/10/2302    most recent 01.STR.0000181772.78492.07v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Squizzato, A. Articles by Stam, J. Search for Related Content PubMed PubMed Citation Articles by Squizzato, A. Articles by Stam, J. Pubmed/NCBI databases Medline Plus Health Information Thyroid Diseases Related Collections Lipids Risk Factors Thrombosis risk factors Cerebral Venous Thrombosis Risk Factors for Stroke Vasculitis Brain Arteries Other Stroke

(Stroke. 2005;36:2302.)
© 2005 American Heart Association, Inc.

Progress Reviews

Thyroid Diseases and Cerebrovascular Disease

From the Department of Vascular Medicine (A.S., V.E.A.G., H.R.B.), Academical Medical Center, Amsterdam, The Netherlands; the Department of Internal Medicine (V.E.A.G., D.P.M.B.), Slotervaart Hospital, Amsterdam, The Netherlands; the Department of Neurology (J.S.), Academical Medical Center, Amsterdam, The Netherlands; and the Department of Internal Medicine (A.S.), University of Insubria, Varese, Italy.

Correspondence to Alessandro Squizzato, Department of Internal Medicine, University of Insubria, Ospedale di Circolo, Viale Borri, 57, 21100 Varese, Italy. E-mail alexsquizzo{at}libero.it

Background and Purpose— Acute cerebral ischemia has been described in different diseases of the thyroid gland, and not only as a result of thyrotoxic atrial fibrillation and cardioembolic stroke. The purpose of this review is to summarize the studies on the relationship between thyroid diseases and cerebrovascular diseases, discussing the main findings for overt hyperthyroidism and hypothyroidism, as well as for subclinical thyroid dysfunction.

Summary of Review— In overt hyperthyroidism, cardioembolic stroke is clearly associated to thyrotoxic atrial fibrillation, and in subclinical hyperthyroidism with serum thyroid-stimulating hormone levels <0.1 mU/L, the incidence of atrial fibrillation is increased. Although in vitro and in vivo studies indicate a hypercoagulability state in hyperthyroidism, there is insufficient evidence to prove that this state leads to an increased risk of cardiac emboli. However, the hypothesis that overt hyperthyroidism may cause acute cerebral venous thrombosis is intriguing. Possible associations between hyperthyroidism and Moyamoya or Giant cell arteritis have only been described in case reports. There is enough evidence that overt hypothyroidism is associated with several traditional and newer atherosclerotic risk factors, especially hypertension, hyperlipidemia, and hyperhomocysteinemia. For subclinical hypothyroidism, these associations are less certain. Hypothyroidism has been associated with signs of aortic or coronary atherosclerosis, but no case-control or cohort studies have ever investigated hypothyroidism as a possible risk factor for atherothrombotic stroke.

Conclusions— Hyperthyroidism is associated with atrial fibrillation and cardioembolic stroke. Hypothyroidism is associated with a worse cardiovascular risk factor profile and leads to progression of atherosclerosis. Associations between hyperthyroidism and acute cerebral venous thrombosis, Moyamoya, and Giant cell arteritis have been suggested, but sound evidence is lacking. Additional studies are needed to clarify these issues.

Key Words: arteriosclerosis • cerebrovascular disorders • hyperthyroidism • hypothyroidism • thrombophilia

This article has been cited by other articles:

				Y. Liu, R. A. Redetzke, S. Said, J. V. Pottala, G. M. de Escobar, and A. M. Gerdes Serum thyroid hormone levels may not accurately reflect thyroid tissue levels and cardiac function in mild hypothyroidism Am J Physiol Heart Circ Physiol, May 1, 2008; 294(5): H2137 - H2143. [Abstract] [Full Text] [PDF]

				L. Rastogi, S. Gupta, and M. M Godbole Pathophysiological basis for thyrotoxicosis as an aggravating factor in post-ischemic brain injury in rats J. Endocrinol., February 1, 2008; 196(2): 335 - 341. [Abstract] [Full Text] [PDF]

				B. Biondi and D. S. Cooper The Clinical Significance of Subclinical Thyroid Dysfunction Endocr. Rev., February 1, 2008; 29(1): 76 - 131. [Abstract] [Full Text] [PDF]

				M. Homoncik, A. Gessl, A. Ferlitsch, B. Jilma, and H. Vierhapper Altered Platelet Plug Formation in Hyperthyroidism and Hypothyroidism J. Clin. Endocrinol. Metab., August 1, 2007; 92(8): 3006 - 3012. [Abstract] [Full Text] [PDF]

				A. Squizzato, E. Romualdi, H. R. Buller, and V. E. A. Gerdes Thyroid Dysfunction and Effects on Coagulation and Fibrinolysis: A Systematic Review J. Clin. Endocrinol. Metab., July 1, 2007; 92(7): 2415 - 2420. [Abstract] [Full Text] [PDF]

				M. Vanderpump Cardiovascular and Cancer Mortality after Radioiodine Treatment of Hyperthyroidism J. Clin. Endocrinol. Metab., June 1, 2007; 92(6): 2033 - 2035. [Full Text] [PDF]