A uncommon case of Hashimoto encephalopathy after COVID vaccination

In a current ‘Letter to the Editor’ revealed within the English version of the journal Neurologandiacute, researchers reported the uncommon prevalence of Hashimoto encephalopathy in a recipient of the (COVID-19) vaccine Spikevax. Spikevax, analysis title mRNA-1273, is a COVID-19 vaccine based mostly on the messenger ribonucleic acid (mRNA) expertise.

Letter to the Editor - Hashimoto encephalopathy after vaccination against SARS-CoV-2. Image Credit: DOERS / ShutterstockLetter to the Editor – Hashimoto encephalopathy after vaccination against SARS-CoV-2. Picture Credit score: DOERS / Shutterstock


Antithyroid antibodies are current in 13% of wholesome people. In uncommon instances, it triggers autoimmune encephalopathy, popularly often called Hashimoto encephalopathy. The underlying pathophysiology of this illness is unclear, particularly the pathogenicity of antithyroid antibodies.

Research have urged that some vaccines worsen immune-mediated neurological ailments. As an illustration, influenza, measles, mumps, rubella, and hepatitis B vaccines resulted in 708 instances of autoimmune encephalitis in america between 1990-2010. But, its affiliation with vaccines stays controversial and lacks a causal relationship.

Beneath their emergency use authorization (EUA), 11 billion doses of COVID-19 vaccines have been administered worldwide. Though the prevalence of Hashimoto encephalopathy is uncommon (lower than one case per million sufferers) post-vaccination, there’s a chance that the COVID-19 vaccination triggers it. As well as, a number of post-vaccination encephalitis instances have been reported in recipients of COVID-19 vaccines, each mRNA and viral vector-based.

Moreover, research have reported neurological issues after vaccination after post-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As an illustration, america Facilities for Illness Management and Prevention (US-CDC) have reported instances of Guillain-Barré syndrome within the recipients of the adenoviral vector-based vaccine Ad26.COV2.S. The European Medicines Company (EMA) has reported instances of acute disseminated encephalomyelitis and encephalitis within the recipients of ChAdOx1. These neurological issues appear much less frequent with mRNA vaccines than with adenovirus vaccines.

Case research

Within the current research, researchers introduced one of many first instances of Hashimoto encephalopathy as a possible complication of SARS-CoV-2 vaccination. A 36-year-old male affected person met the Graus standards, i.e., he had antithyroid antibodies in cerebrospinal fluid (CSF). Additionally, he introduced the everyday encephalopathy manifestations.

The affected person had a historical past of autoimmune hypothyroidism however no psychiatric dysfunction. He obtained the primary Spikevax vaccine dose in July 2021 and its second dose 28 days later. Inside 24 hours of receiving the second vaccine, he skilled self-limited febrile syndrome and delicate postural tremors. Six days later, he introduced a primary focal seizure within the left hemisphere, progressing to bilateral tonic-clonic seizure and convulsive standing epilepticus. He was admitted to the intensive care unit (ICU) instantly.

A computed tomography (CT) scan and CT angiography research didn’t present vascular or neoplastic etiology. Nonetheless, an electroencephalogram (EEG) confirmed symmetrical diffuse slowing. Within the mind magnetic resonance imaging (MRI) research, diffusion sequences revealed cortical hyperintensity within the left temporal pole, attributed to postictal sign alterations.

Polymerase chain response (PCR) testing for neurotropic viruses fetched damaging outcomes. The CSF evaluation confirmed mildly elevated protein ranges (98 mg/dL) however a cell rely throughout the regular vary. Initially, the serum had no antineuronal antibodies; PCR for SARS-CoV-2 was damaging at baseline and in all subsequent testings. Additional, the researchers famous no pathological points within the blood evaluation, together with biochemistry, full blood rely, kidney and liver perform, and many others. At discharge, the affected person introduced naming difficulties, impaired reminiscence, and postural tremors with delicate gait instability.

The affected person suffered from a second episode of toni-clonic seizure in November 2021 and was once more admitted to the ICU. Other than elevated postural tremor, gait impairment, and reminiscence deficit (Montreal Cognitive Evaluation [MoCA] rating of 21/30). The medical doctors prescribed a brief course of methylprednisolone.

After partial enchancment, though the ultrasound research revealed regular thyroid gland morphology, the affected person had ATG and TPO antibody ranges of 4.2 IU/l and 60.9 IU/l within the CSF. An earlier CSF evaluation had proven regular ranges of IgG and ADA antibodies, and outcomes for antineuronal antibodies have been damaging.

Additional, his thyroid-stimulating hormone, T4, and T3 ranges have been 4.4 mIU/L, 1.0 nmol/L, and a couple of.7 nmol/L, respectively. Serum evaluation revealed antithyroglobulin (ATG) antibody and antithyroid peroxidase (TPO) antibody ranges of 986 IU/L, and 538 IU/L, respectively. Fortunately, the affected person additionally had no malignancy within the chest, stomach, or pelvis CT scans. The medical doctors administered the second course of methylprednisolone, which decreased tremors and improved his gait. He continued with prescribed upkeep remedy with prednisone at discharge. Inside six months, he was seizure-free and capable of stroll independently, presenting a MoCA rating of 27/30.


An underlying molecular mimicry with the SARS-CoV-2 spike protein that ends in the lack of the transmembrane anchor of that protein more than likely set off adversarial occasions, reminiscent of Hashimoto encephalopathy. Nonetheless, the incidence of Hashimoto encephalopathy is sort of 617 instances decrease than these attributable to a pure viral an infection. Thus, the advantages of the COVID-19 vaccine or another vaccine clearly outweigh the dangers of not vaccinating.

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