Although most rare diseases hardly have really effective and specific treatments for them, in some cases even if the prevalence is low and despite not knowing exactly how medicine works, it has found effective methodologies to fight them.

An example of this is Hashimoto’s encephalopathy , which we will discuss throughout this article.

Hashimoto’s Encephalopathy: what is it?

Hashimoto’s encephalopathy is a neurological and autoimmune based disease considered rare, also linked to the endocrine system as it is associated with thyroid disorders.

This disease is characterized by the presence of an encephalopathy in which a disconnection of the subject with his environment and alterations of consciousness (which may even cause the patient’s coma) and confusion are characteristic , together with a generally progressive cognitive deterioration in which alterations of behavior, personality changes and alterations of functions such as memory or language tend to appear.

Although its exact prevalence is unknown, it is estimated at around 2.1 cases per 100,000 inhabitants and is four to five times more common in women than in men . In many cases it may appear in subjects with basic thyroid problems, although other people with a history of previous autoimmune diseases or in immunodependent diabetic patients.


It is common to present alterations at a cardiovascular level such as arrhythmias and bradycardias , as well as arterial hypotension. Headaches, ataxia, hypotonia, seizures, sleep problems or alterations in sensory perception may also appear.

At the psychiatric level, episodes similar to psychotic breaks or dementia are also sometimes observed, as well as emotional lability and mood swings. Sometimes the symptoms resemble those of a stroke.

This alteration can appear in different ways, either with an insidious and progressive course, in the form of outbreaks or in a single episode at an acute level. Some of the alterations characteristic of this disease resemble in some cases other conditions with which it can be confused, such as hypothyroidism or very unbalanced type 1 diabetes.

The fact that both disorders may also exist comorbidly with Hashimoto’s encephalopathy makes it advisable to exercise caution at the time of diagnosis.

It is usually reached after the presence of other central nervous system problems, metabolic diseases or tumors that better explain the symptoms have been ruled out, and after the existence of antithyroid antibodies has been confirmed.

Two subtypes

Hashimoto’s encephalopathy can be presented in multiple ways , highlighting two main types of presentation.

The first one has an insidious beginning and a progressive and recurrent character, generating vasculitis and cerebral edemas. In this case, there are lesions in the blood vessels of the brain , which together with hypoperfusion or a decrease in the amount of blood that reaches the brain, suggest the symptoms of a stroke.

Another of the most common presentations appears directly as progressive type encephalopathy and seems to be linked to a greater extent to the passage of antibodies to the brain , generating lesions to the neuronal tissue itself.


The exact causes of Hashimoto’s encephalopathy and how the disease is triggered is not completely known, although the presence of antithyroid antibodies has been observed in most cases. In other words, in almost all people who have seen this disease, it has been observed that the immune system has created antibodies that attack the hormones coming out of the thyroid .

The presence of such antibodies is often considered essential for diagnosis. In particular, the presence of anti-peroxidase and antithyroglobulin antibodies has been observed to be particularly frequent.

Although the fact that this disease is linked to the thyroid system may make one think of people with hypothyroidism or hyperthyroidism, the truth is that a large number of subjects had normal levels of thyroid hormone before the onset of Hashimoto’s encephalopathy.

However, the presence of thyroid alterations (specifically hypothyroidism) could complicate the severity of the symptoms as the thyroid hormone is already low in the base. It is considered a risk factor to have had previous autoimmune diseases such as systemic lupus erythematosus, and in some cases metabolic disorders such as type 1 diabetes.

It is also speculated that self-antigens may be generated within the vascular endothelium of the brain, so that the immune system eventually causes injury to the brain tissue.

Treatment of this disease

Although Hashimoto’s encephalopathy is a complicated disease, patients often have a good response and show great improvement to steroid therapy or administration of steroids, usually steroids , for several days.

While this therapy usually results in complete or near-complete improvement, if this does not work, an immunosuppressive treatment that removes the activity of the immune system on the thyroid hormone will be sought.

However, the presence of cognitive impairment may be persistent in about 25% of cases, and it is advisable to keep a careful follow-up of the case since relapses are not uncommon .

Besides the treatment of the basic autoimmune problem that generates the inflammation and alteration of tissues in addition to the destruction of the products of the thyroid, it will be essential to treat the different complications and symptoms that are present in each case. For example, in case of seizures it will be necessary to treat them differently.

Beyond the medical, the application of occupational therapy and rehabilitation or cognitive stimulation may also be necessary in order to strengthen, optimize or help recover neuropsychological functions that may have been altered. Psychotherapy may also be necessary, both to treat psychiatric symptoms and the psychological affectation that the difficulties caused by this disease may generate.

Bibliographic references:

  • Mantilla, S.R., Guerrero, A., Montoya, L.E., Giraldo, K and Aguirre, H.D. (2018). Hashimoto’s encephalopathy: case report and literature review. Argentine Neurology.
  • Pinedo-Torres, I. and Paz-Ibarra, J.L. (2018). Current knowledge in Hashimoto’s encephalopathy: literature review. Medwave, 18 (6).
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  • Singh, K. & Kashyap, S. (2003). Hashimoto’s encephalopathy. The Lancet: 361.