Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatmentPrognosisFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Prognosis
Frequently Asked Questions
Hashimoto’s encephalopathy (HE) is a rare disease that involves impaired brain function (encephalopathy). The condition is named for its possible association withHashimoto’s thyroiditis, a commonautoimmune thyroid disease, but the exact cause is not fully understood.HE contributes to neurological issues such as seizures, confusion, or dementia. It’s usually reversible with treatment.
Hashimoto’s encephalopathy is considered rare, affecting just two people out of every 100,000. However, it’s likely that many more cases are undiagnosed or misdiagnosed since the condition isn’t well-understood or highly recognized.
The average age of onset of symptoms of Hashimoto’s encephalopathy is around 40 to 55 years old. Women are diagnosed with it about four times more often than men.HE can also affect children, but that’s believed to be rare.
Most people with HE have noevidence of Hashimoto’s thyroiditis, which has led some experts to suggest it be renamed to steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT).
Hashimoto’s Encephalopathy Symptoms
Hashimoto’s encephalopathy affects how your brain functions, causing cognitive decline and altered consciousness. It usually progresses in one of three ways:
Symptoms common to the different types include:
A 2016 review looked at how common various symptoms were among 251 people with HE.
It’s unknown what exactly causes Hashimoto’s encephalopathy, but scientists think that like Hashimoto’s thyroiditis, HE is an autoimmune condition, meaning that the immune system mistakenly targets your body’s own tissues as if they were a virus or bacteria. In the case of HE, the target is the brain.
In Hashimoto’s thyroiditis, the immune system attacks thethyroid gland, causing hormonal problems. It’s still unclear what the relationship is between these conditions.
How Autoimmune Diseases Are Treated
Currently, healthcare providers don’t have a definitive test for Hashimoto’s encephalopathy. Because its symptoms primarily affect your brain, HE is easy to misdiagnose or overlook. People are sometimes misdiagnosed withCreutzfeldt-Jakob disease,dementia,Alzheimer’s disease, orstroke.
Diagnosis consists of first ruling out other known causes of encephalopathy, then checking for the presence of specific antibodies (the immune system’s “attack” cells) and thyroid dysfunction.
Causes of Encephalopathy
Chronic encephalopathies usually result from permanent changes to the brain. They include:
Acute encephalopathies include temporary changes in function due to:
Blood tests may be done to check for any of these possible causes, depending on what your healthcare provider believes are the most likely problems.
Antithyroid Antibodies
Testing for two antibodies that attack the thyroid gland—calledthyroid peroxidase (TPO) antibodiesandantithyroglobulin (TG) antibodies—is crucial since these are the key to a diagnosis of HE. In the aforementioned 2016 review, all 251 participants had increased levels of one or both of these antibodies.
Thyroid Hormone Levels
Thyroid hormone levels are usually tested as well, but these vary from person to person. According to a paper published in 2010:
The 2016 review also found that most of the patients had normal levels ofthyroid-stimulating hormoneand only 32% had been previously diagnosed with thyroid disease.
Understanding Common Blood Tests
Ruling Out Other Causes
A major part of diagnosing HE is running tests for other potential reasons behind your symptoms and ruling them out.
Basic Diagnostic CriteriaIn order to be diagnosed with HE, you must have elevated anti-TPO antibodies and/or anti-TG antibodies present. Other potential causes of your symptoms must have been ruled out as well.
Basic Diagnostic Criteria
In order to be diagnosed with HE, you must have elevated anti-TPO antibodies and/or anti-TG antibodies present. Other potential causes of your symptoms must have been ruled out as well.
The primary treatment for Hashimoto’s encephalopathy is oral corticosteroid drugs, usually prednisone, or intravenous (IV) Medrol (methylprednisolone).Most people respond quickly and well to drug treatment, with their symptoms improving or even resolving within a few months.
For people who can’t take corticosteroids or whose symptoms didn’t respond to them, other options are:
Like most autoimmune disorders, Hashimoto’s encephalopathy is not considered curable, but rather treatable. The prognosis is generally good. After initial treatment, the disorder often lapses into remission. Some patients are able to discontinue drug therapy for a number of years.
There is a risk of future relapse, but in the 2016 review, only 16% percent of patients had one or more relapses, and many of those people previously had severe HE that involved being in a coma.
Which type of healthcare providers treats Hashimoto encephalopathy?
Neurologistsare often the best-equipped specialists to diagnose and oversee treatment for Hashimoto encephalopathy.Other healthcare providers who may be involved in diagnosis and management of this autoimmune condition includerheumatologists, psychiatrists, psychologists, and immunologists.
Is Hashimoto encephalopathy a form of dementia?
Dementia is a symptom of Hashimoto encephalopathy (HE). HE may cause rapidly progressive dementia or dementia of unknown origin, but the cognitive changes may bereversiblewith proper treatment.
Summary
Hashimoto’s encephalopathy causes symptoms like seizures, confusion, and memory problems. Its cause is unknown, but it’s thought to be an autoimmune condition possibly related to Hashimoto’s thyroiditis.
Diagnosis is a challenge and involves ruling out other possible causes, checking for specific antibodies, and monitoring thyroid function. Fortunately, most people respond well to treatment with steroids or other therapies, even if they aren’t diagnosed for several years.
If you or someone close to you develops acute neurocognitive symptoms that your healthcare provider can’t explain, be sure to mention any personal or family history of Hashimoto’s disease or other thyroid conditions so your practitioner can look into Hashimoto’s encephalopathy as a possible cause of your symptoms.
13 Sources
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Liyanage CK, Munasinghe TMJ, Paramanantham A.Steroid-responsive encephalopathy associated with autoimmune thyroiditis presenting with fever and confusion.Case Rep Neurol Med. 2017;2017:3790741. doi:10.1155/2017/3790741
National Organization for Rare Disorders.Hashimoto encephalopathy.
Laurent C, Capron J, Quillerou B, et al.Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT): Characteristics, treatment and outcome in 251 cases from the literature.Autoimmun Rev.2016;15(12):1129-1133. doi:10.1016/j.autrev.2016.09.008
Gauthier AC, Baehring JM.Hashimoto’s encephalopathy mimicking Creutzfeldt-Jakob disease.J Clin Neurosci. 2017;35:72-73. doi:10.1016/j.jocn.2016.09.019
American College of Physicians: ACP Hospitalist.Encephalopathy.
Canelo-Aybar C, Loja-Oropeza D, Cuadra-Urteaga J, Romani-Romani F.Hashimoto’s encephalopathy presenting with neurocognitive symptoms: a case report.J Med Case Rep. 2010;4:337. doi:10.1186/1752-1947-4-337
Warren CL, Sawhney IM.Encephalopathy with hypothyroidism.J R Soc Med. 2004;97(6):287–288. doi:10.1258/jrsm.97.6.287
Autoimmune Encephalitis Alliance.Treatment.
American College of Rheumatology.Intravenous immunoglobulin (IVIG).
University of Texas Southwestern Medical Center.Therapeutic plasma exchange.
HESA.Physicians.
Verma R, Chakraborty A, Anand K, Garg J.Hashimoto′s encephalitis: Unusual cause of reversible dementia.J Fam Med Primary Care. 2014;3(3):284. doi:10.4103/2F2249-4863.141650
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