Earlier reports suggested that 90% of cases stay in remission after discontinuation of treatment, but this is at odds with more recent studies, which suggest that relapse commonly occurs after initial high-dose steroid treatment. Left untreated, this condition can result in coma and death. Epidemiology
The prevalence has been estimated to be 2.1/100,000 with a male-to-female ratio of 1:4. The mean age of onset is 44 with 20% of cases presenting before the age of 18 years. Most reported cases occur during the patients fifth decade of life. History
The first case of HE was described by Brain et al. in 1966. The patient was a 48-year-old man with hypothyroidism, multiple episodes of encephalopathy, stroke-like symptoms, and Hashimotos thyroiditis confirmed by elevated antithyroid antibodies. Alternative names
Steroid-responsive encephalopathy associated with autoimmune thyroiditis, SREAT
Nonvasculitic autoimmune meningoencephalitis, NAIM
Encephalopathy associated with autoimmune thyroid disease, EAATD

References
Further reading
Hashimotos Encephalopathy SREAT Alliance (2013). Understanding Hashimotos Encephalopathy: A Guide for Patients, Families, and Caregivers, Featuring Stories of HE Patients from Around the World. North Charleston, SC: CreateSpace Independent Publishing Platform. ISBN 9781484883099. OCLC 890816771. Schiess N, Pardo CA (October 2008). "Hashimotos encephalopathy". Annals of the New York Academy of Sciences. 1142 (1): 254–65. Bibcode:2008NYASA1142..254S. doi:10.1196/annals.1444.018. PMID 18990131. S2CID 1312798. Taylor SE, Garalda ME, Tudor-Williams G, Martinez-Alier N (February 2003). "An organic cause of neuropsychiatric illness in adolescence". The Lancet. 361 (9357): 572. doi:10.1016/S0140-6736(03)12517-2. PMID 12598143. S2CID 35053683.
Distal intestinal obstruction syndrome (DIOS) involves obstruction of the distal part of the small intestines by thickened intestinal content  and occurs in about 20% of mainly adult individuals with cystic fibrosis. DIOS was previously known as meconium ileus equivalent, a name which highlights its similarity to the intestinal obstruction seen in newborn infants with cystic fibrosis. DIOS tends to occur in older individuals with pancreatic insufficiency. Individuals with DIOS may be predisposed to bowel obstruction, though it is a separate entity than true constipation. Signs and symptoms
Signs and symptoms of DIOS include a sudden onset of crampy abdominal pain, vomiting, and a palpable mass (often in the right lower quadrant) in the abdomen. The characteristic abdominal pain is typically located in the center or right lower quadrant of the abdomen. X-rays of the abdomen may reveal stool in the colon and air-fluid levels in the small intestines. Diagnosis
A complete history and physical examination can be suggestive, especially if a palpable mass in the right lower quadrant of the abdomen is present (though this can be present in the absence of DIOS). Ultrasound and computed tomography (CT) imaging of the abdomen can confirm the diagnosis by demonstrating dilated loops of intestine with material in the intestinal lumen with bubbles. Air-fluid levels may be seen in those affected by DIOS. Classification
DIOS is sometimes classified by the degree of obstruction as incomplete or complete DIOS. Differential diagnosis
Additional diagnoses which may present with similar symptoms to DIOS include severe constipation, appendicitis, and intussusception.