Hashimotos encephalopathy, also known as steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), is a neurological condition characterized by encephalopathy, thyroid autoimmunity, and good clinical response to corticosteroids. It is associated with Hashimotos thyroiditis, and was first described in 1966. It is sometimes referred to as a neuroendocrine disorder, although the conditions relationship to the endocrine system is widely disputed. It is recognized as a rare disease by the NIH Genetic and Rare Diseases Information Center.Up to 2005, almost 200 case reports of this disease were published. Between 1990 and 2000, 43 cases were published. Since that time, research has expanded and numerous cases are being reported by scientists around the world, suggesting that this rare condition is likely to have been significantly undiagnosed in the past. Over 100 scientific articles on Hashimotos encephalopathy were published between 2000 and 2013. Signs and symptoms
The onset of symptoms tends to be fairly gradual and to occur over 1-12 years.Symptoms of Hashimotos encephalopathy may include:
Personality changes
Aggression
Delusional behavior
Concentration and memory problems
Coma
Disorientation
Headaches
Jerks in the muscles (myoclonus – 65% of cases)
Lack of coordination (ataxia – 65% of cases)
Partial paralysis on the right side
Psychosis
Seizures (60% of cases)
Sleep abnormalities (55% of cases)
Speech problems (transient aphasia – 80% of cases)
Status epilepticus (20% of  cases)
Tremors (80% of cases)

Pathogenesis
The mechanism of pathogenesis is not known, but is thought to be an autoimmune disorder, similar to Hashimotos thyroiditis, as its name suggests.Consistent with this hypothesis, autoantibodies to alpha-enolase have been found to be associated with Hashimotos encephalopathy.
voltage-gated calcium channel, voltage-gated potassium channel, or other currently recognized paraneoplastic antibodies) to support another diagnosis
In imaging studies no evidence for vascular, neoplastic or structural lesions that might explain the symptoms
Complete or nearly complete remission after initiation of glucocorticoid therapy. Definition
A relapsing encephalopathy occurs in association with autoimmune (Hashimotos or Ords thyroiditis), with high titers of antithyroid antibodies. Clinically, the condition may present one or more symptoms. Onset is often gradual and may go unnoticed by the patient and close associates to the patients. Symptoms sometimes resolve themselves within days to weeks, leaving a patient undiagnosed. For many other patients, the condition may result in ongoing problems with a variety of manifestations, often confusing clinicians due to the diffuse nature of symptoms. Differential diagnosis
Alzheimers disease
Cerebrovascular accidents (stroke)
Creutzfeldt–Jakob disease
Epilepsy
Migraine (including basilar, hemiplegic, and retinal types)
Other forms of autoimmune encephalitis, including forms of limbic encephalitis such as anti-NMDA receptor encephalitis
Schizophrenia
Spontaneous cerebrospinal fluid leak
Viral encephalitis
Transient ischemic attack

Treatment
Because most patients respond to corticosteroids or immunosuppressant treatment, this condition is now also referred to as steroid-responsive encephalopathy.Initial treatment is usually with oral prednisone (50–150 mg/day) or high-dose intravenous methylprednisolone (1 g/day) for 3–7 days. Thyroid hormone treatment is also included if required.Failure of some patients to respond to this first-line treatment has produced a variety of alternative treatments, including azathioprine, cyclophosphamide, chloroquine, methotrexate, periodic intravenous immunoglobulin, and plasma exchange. No controlled trials have been conducted, so the optimal treatment is not known.Seizures, if present, are controlled with typical antiepileptic agents. Prognosis
Duration of treatment is usually between 2 and 25 years.