Helpful Reads

For those who are interested, I read the chapter on HE from the recently released textbook “Autoimmune Encephalitis and Related Disorders of the Nervous System” written by Dr. Dalmau and Dr. Graus  The main takeaways from the chapter were as follows: 1. The mechanisms of Hashimoto’s Encephalopathy are still not well understood, included the role of thyroid (TPO) antibodies, thus make diagnosing HE difficult and to some controversial. This has lead to the over diagnosis of HE, which in turn has made it difficult to study the disease (many diagnosed have been incorrectly diagnosed and thus cannot be studied) 2. Hashimoto’s Encephalopathy should follow the proposed diagnostic criteria: 1. Encephalopathy manifested by cognitive impairment and one or more of the following (psychiatric symptoms, myoclonus, seizures, focal neurological deficits) 2. Presence of serum thyroid antibodies 3. Euthyroid status or mild hypothyroidism  4. No findings in neuro imaging studies indicating vascular, neoplastic, typical autoimmune, or structural lesions 5. Absence of well characterized neuronal antibodies (AE antibodies) in serum and CSF 6. Complete or near complete response to steroid treatment  7. Reasonable exclusion of alternative causes 3. A Limbic encephalitis variant of Hashimoto’s Encephalopathy has been speculated and was first described in 3 teenagers with high serum TPO antibodies and imaging suggestive of Limbic encephalitis. The role of TPO antibodies in HE is not understood, and thus the role of TPO antibodies in this possible subtype of HE is not clear. 4. Many misdiagnosis of HE are due to the lack of AE antibody testing performed on BOTH serum and CSF, as some AE antibodies show only in serum or CSF or both. Patients should also be tested for less common AE antibodies such as GABAaR and mGluR5. 5. The presence of TPO antibodies in CSF is not well understood. Only one study has looked into this. 6. The NH2-a-enolase antibody could serve as a marker for HE, but further research needs to be done to explore this potential marker. All in all, HE needs more research so better understanding of the disease can lead to better diagnostic criteria being established.