title: Acute psychosis as an initial manifestation of hypothyroidism: a case report.
abstract: BACKGROUND
  Hypothyroidism is one of the most important causes of treatable dementia, and psychosis occasionally associated with it is known as myxedema madness. We report a case of a 90-year-old patient who developed myxedema madness acutely without overt clinical symptoms and signs suggestive of hypothyroidism.
  
  
  METHODS
  A 90-year-old Japanese man, a general practitioner, was admitted to our emergency room because of acute-onset lethargy, delusions, and hallucinations. He had been actively working until 3 days before the admission. Upon admission, his general physical examination was unremarkable. However, a blood investigation showed the presence of hypothyroidism, and computed tomography revealed pleural effusion and ascites. Electroencephalography revealed diffuse slow waves with a decrease of α-wave activity. A single-photon emission computed tomography scan revealed a decrease of cerebral blood flow in both frontal lobes. The patient was soon treated with thyroid hormone replacement therapy. Following normalization of his thyroid function, both pleural effusion and ascites diminished and his electroencephalographic activity improved simultaneously; however, he did not recover from his psychosis.
  
  
  CONCLUSIONS
  Myxedema madness should be kept in mind in the differential diagnosis of acute psychosis in elderly patients, particularly the oldest patients as in our case, because manifestations of hypothyroidism often may be indistinguishable from the aging process.
authors.affiliation: Department of Neurology, Juntendo University Nerima Hospital, 3-1-10 Takanodai, Nerima, Tokyo, 177-8521, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Ueno
authors.affiliation: Department of Neurology, Juntendo University Nerima Hospital, 3-1-10 Takanodai, Nerima, Tokyo, 177-8521, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Tsuboi
authors.affiliation: Department of Neurology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo, 113-8421, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Fujimaki
authors.affiliation: Department of Neurology, Juntendo University Nerima Hospital, 3-1-10 Takanodai, Nerima, Tokyo, 177-8521, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Eguchi
authors.affiliation: Department of Neurology, Juntendo University Nerima Hospital, 3-1-10 Takanodai, Nerima, Tokyo, 177-8521, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Machida
authors.affiliation: Department of Neurology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo, 113-8421, Japan.
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Hattori
authors.affiliation: Department of Neurology, Juntendo University Nerima Hospital, 3-1-10 Takanodai, Nerima, Tokyo, 177-8521, Japan. h_miwa@juntendo.ac.jp.
authors.forename: Hideto
authors.initials: H
authors.lastname: Miwa
mesh_terms: D000208:Acute Disease; D000369:Aged, 80 and over; D001201:Ascites / Q000000981:diagnostic imaging*; D004569:Electroencephalography; D006212:Hallucinations / Q000209:etiology; D020249:Hormone Replacement Therapy; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000175:diagnosis*; D008297:Male; D009230:Myxedema / Q000188:drug therapy / Q000209:etiology*; D010996:Pleural Effusion / Q000000981:diagnostic imaging; D011618:Psychotic Disorders / Q000209:etiology*; D011859:Radiography; D015899:Tomography, Emission-Computed, Single-Photon