Dementia associated with thyroid dysfunction or Hashimoto encephalopathy

Akiko Matsunaga, Makoto Yoneda

Faculty of Nursing and Social Welfare Sciences, Fukui Prefectural University

Thyroid dysfunction has been recognized as a major cause of treatable dementia.　Overt hyperthyroidism and hypothyroidism are regarded to be clearly associated with affective diseases and cognitive impairment.　Patients with thyroid dysfunction often show the memory impairment similar to that in Alzheimer's disease or dementia with Lewy bodies.　It is controversial in literature whether the subclinical hyperthyroidism/hypothyroidism are related to cognitive impairment or not.　Hashimoto encephalopathy（HE） is characterized as an autoimmune encephalopathy associated autoimmune thyroid diseases that shows a good response to immunotherapies.　Patients with HE often present with cognitive impairment.　Thus, physicians should attentively consider the possibility of thyroid dysfunction or HE as a cause of treatable dementia.

Address correspondence to Prof. Makoto Yoneda, Faculty of Nursing and Social Welfare Sciences, Fukui Prefectural University（4-1-1 Kenjojima, Matsuoka, Eiheiji-cho, Fukui 910-1195, Japan）