title: Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT): Characteristics, treatment and outcome in 251 cases from the literature.
abstract: BACKGROUND
  Steroid-responsive encephalopathy and associated autoimmune thyroiditis (SREAT) is characterized by encephalopathy and the presence of antithyroid antibodies. We describe the clinical presentation, outcome and treatments for SREAT by a systematic review of the literature.
  
  
  METHODS
  MEDLINE via PubMed, Web of Science and the Cochrane Library were searched for articles published until 2015. Inclusion criteria were unexplained encephalopathy with antithyroid antibodies.
  
  
  RESULTS
  We found reports of 251 patients (median age 52years [range 18-86], 73% females, 80 [32%] with preexisting thyroiditis). Patients presented encephalitis signs with convulsions (n=117; 47%), confusion (n=115, 46%), speech disorder (n=91, 37%), memory impairment (n=107, 43%), gait disturbance (n=67, 27%) and persecutory delusions (n=61, 25%). Twenty-eight patients (11%) presented progressive memory impairment and 26 (10%) isolated psychiatric disorders. In serum, 34% of patients were positive for anti-thyroid peroxidase (TPO) antibodies, 7% for anti-thyroglobulin (TG) antibodies, and 69% both. Thyroid-stimulating hormone levels were usually normal, at 2 UI/ml [0.001-205]. Cerebrospinal fluid from 10/53 patients (19%) was positive for anti-TPO antibodies, 2/53 (4%) anti-TG antibodies and 28 (53%) both. Electroencephalography findings were abnormal for 82% of patients, showing diffuse slowing consistent with encephalopathy (70%) or epileptic activity (14%). The first-line treatment was steroids in 193 patients and other immunosuppressive drugs in 10 cases. At a median follow-up of 12months [range 0.2-110], 91% of patients showed complete or partial neurological response, with anti-TPO and -TG antibody titers at 347 UI/ml [0-825,000] and 110 UI/ml [0-50,892], respectively. During follow-up, 40 patients (16%) experienced at least one relapse. Relapse was more frequent in patients with initial coma (26% vs 13%, p=0.08).
  
  
  CONCLUSIONS
  The diagnosis of SREAT should be suspected in case of encephalopathy without obvious cause, to quickly start corticosteroid treatment. The exact modalities of treatment must be defined.
authors.affiliation: Service de médecine interne, UPMC, DHU i2B AP-HP, Hôpital Saint Antoine, 75012 Paris, France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Laurent
authors.affiliation: Service de neurologie, UPMC, AP-HP, Hôpital Saint Antoine, 75012 Paris, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Capron
authors.affiliation: Service de psychiatrie, UPMC, AP-HP, Hôpital Saint Antoine, 75012 Paris, France.
authors.forename: Bluenn
authors.initials: B
authors.lastname: Quillerou
authors.affiliation: Service de psychiatrie, UPMC, AP-HP, Hôpital Saint Antoine, 75012 Paris, France.
authors.forename: Guy
authors.initials: G
authors.lastname: Thomas
authors.affiliation: Service de neurologie, UPMC, AP-HP, Hôpital Saint Antoine, 75012 Paris, France.
authors.forename: Sonia
authors.initials: S
authors.lastname: Alamowitch
authors.affiliation: Service de médecine interne, UPMC, DHU i2B AP-HP, Hôpital Saint Antoine, 75012 Paris, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Fain
authors.affiliation: Service de médecine interne, UPMC, DHU i2B AP-HP, Hôpital Saint Antoine, 75012 Paris, France. Electronic address: arsene.mekinian@aphp.fr.
authors.forename: Arsène
authors.initials: A
authors.lastname: Mekinian
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004660:Encephalitis / Q000188:drug therapy*; D050031:Hashimoto Disease / Q000188:drug therapy*; D006801:Humans; D008875:Middle Aged; D013256:Steroids / Q000627:therapeutic use*; D013967:Thyroiditis, Autoimmune / Q000150:complications*; D055815:Young Adult
chemical_list: D013256:Steroids
keywords: SREAT; Steroid-responsive encephalopathy associated with autoimmune thyroiditis; Treatment