Is Hashimoto’s encephalopathy related to Hashimoto’s thyroiditis?

• Hashimoto’s thyroiditis is an autoimmune disease in which the thyroid gland is gradually destroyed, resulting in chronic hypothyroidism.
• Hashimoto’s encephalopathy is a rare neurological condition characterized by encephalopathy and thyroid autoimmunity. It shows a good clinical response to corticosteroids.

Hashimoto’s thyroiditis, so named because it was first described in a medical publication by Hakaru Hashimoto (1881-1934) in 1912, is an autoimmune disease. Typically the autoantibodies include antibodies against thyroid peroxidase (TPO). TPO is an enzyme expressed in the thyroid gland that is essential for the production of thyroid hormones. In Hashimoto’s thyroiditis, the thyroid gland is gradually destroyed, resulting in chronic hypothyroidism unless treated with thyroid hormone replacement. It is the most common form of hypothyroidism, affecting about 5% of people.

Hashimoto’s encephalopathy, also known as steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), is an extremely rare (2.1 in 100,000) neurological condition characterized by encephalopathy and thyroid autoimmunity, which shows a good clinical response to corticosteroids.  First described by Brain, Jellinek and Ball in 1966, the condition was named for its association with Hashimoto’s thyroiditis, but the pathogenic autoantibodies are thought to be against alpha-enolase, a ubiquitous enzyme invovled in glycolysis. Glycolysis is the metabolic pathway that converts glucose to pyruvic acid releasing energy in the form of adenosine triphosphate (ATP).