What is Hashimoto's encephalopathy?
Q: I am a 28 years old man who has been diagnosed with severe hypothyroidism eleven months back. My TSH was 110 and anti TPO was 470. My treatment was started immediately but I started getting phases where I spoke softly, walked slowly, had fatigue etc. The doctor thought that these symptoms will go when my TSH levels become normal. Though my TSH did return to normal but has again increased to 43 (on a 100 mcg dose of Thyroxine). To bring it under control, my dose was gradually increased to 150 mcg. All this while my symptoms - headache at back of head, eye floaters, slow speech, slow walking, loss of coordination of limb movements, etc persisted. I recently consulted some neurologists and they are confident that I have a rare complication known as Hashimoto's Encephalopathy. My EEG tests shows slowing of waves. They decided to put me on steroids but before that I got my antibodies checked once more. Now my anti TPO is 16430. The lab had to recheck the value thrice because they felt it was too high. but the level is now confirmed. Why has my anti-TPO level gone up drastically and how can it be cured? While I may have mild encephalopathy (as severe encephalopathy would have lead to seizures, convulsions etc), why do my symptoms worsen when I am upright and are relieved when I lie down?
A:It is unfortunate that you are suffering from Hashimoto's encephalopathy. This is a very rare disorder and has been known for the last 45 years or so. It is also called as steroid responsive encephalopathy associated autoimmune thyroid disease (SEART). In this condition, the main feature is raised levels of antibodies and in fact TSH level may even be normal. The disease responds well to steroids but may relapse. The high anti-TPO levels are part of disease and it is possible to have such a high value. With time the anti-TPO levels will come down. The cause of autoimmunity is multi-factorial including genetic background and some unidentified environmental factors. In your case, you have a strong family background of disease. In fact the only role of steroids is to reduce the autoimmunity. The level of encephalopathy varies from mild to severe and only 60% patients have seizures. Due to mild disease in some, it goes undiagnosed. The second part of your question (why symptoms worsen on standing) may be a part of disease but will be best answered by a neurologist. From the point of hypothyroidism, you should keep Thyroxine dose such that the TSH level remains normal.