Hashimoto encephalopathy

Abstract

Hashimoto encephalopathy (HE) is an autoimmune encephalopathy associated with autoimmune chronic thyroiditis. The clinical entity and nosology of HE have long been debated. Recently, new autoantibodies associated with autoimmune encephalitis have been discovered. With accumulated reported cases, and our discovery of serum autoantibody against NH2‐terminal of alpha‐enolase as a specific diagnostic marker, HE has been recognized as a distinct clinical entity. The condition appears dominant in females. The clinical features of HE are characterized by various neuropsychiatric symptoms, such as altered consciousness, psychosis and seizures, the presence of serum anti‐thyroid antibodies, normal or non‐specific changes in brain magnetic resonance imaging, diffuse slow wave activities in electroencephalogram and responsiveness to immunotherapy. A few pathological studies showed a lymphocytic infiltration of the small and medium‐sized vessels of the brain, which suggested vasculitis. Non‐specific neurological symptoms, laboratory findings and neuroimaging of HE make its diagnosis an oversight and difficult, whereas antibodies against NH2‐terminal of alpha‐enolase can be useful as a diagnostic biomarker for HE. In this review, we describe the current state of knowledge about HE and discuss progress in the diagnosis of HE.

Progressive Encephalomyelitis with Rigidity and Myoclonus (PERM)-like Symptoms Associated with Anti-ganglionic Acetylcholine Receptor Antibodies

“…The present case showed positive results of both anti-TPO and Tg antibodies as well as anti-gAChR α3 subunit antibodies, which suggests Hashimoto encephalopathy as a differential diagnosis (26). Impaired consciousness (66%), convulsions (29%), and involuntary movements including tremor and myoclonus (31%), which were seen in our case, are often observed in patients with Hashimoto encephalopathy (26).…”

“…Impaired consciousness (66%), convulsions (29%), and involuntary movements including tremor and myoclonus (31%), which were seen in our case, are often observed in patients with Hashimoto encephalopathy (26). However, the other symptoms seen in our case, especially autonomic failure and myelopathy, are uncommon in Hashimoto encephalopathy (26). In addition, immunological studies yielded negative anti-NAE antibodies, which are highly specific to Hashimoto encephalopathy (27), also suggesting a low probability of Hashimoto encephalopathy in our case.…”

Hashimoto Encephalopathy of a Middle-Aged Man With Progressive Symptoms of Dementia

“…Hashimoto's encephalopathy, autoimmune encephalitis specifically diagnosed in community hospitals, is likely to increase in an aging society in the future; therefore, general physicians must diagnose it appropriately. To facilitate the diagnosis and treatment of Hashimoto's encephalopathy in community hospitals, it is necessary to consider systemic autoimmune diseases such as systemic lupus erythematosus, Behçet's disease, and herpetic encephalitis for acute and subacute cognitive decline in middle-aged patients [15]. However, since antibodies are not covered by insurance, we believe that clinical diagnosis of autoimmune encephalitis, initiation of steroid therapy without waiting for antibody testing, and concomitant testing for anti-thyroid antibodies, taking into account Hashimoto's encephalopathy, will improve patient prognosis.…”

A Case of Steroid-Responsive Encephalopathy

“…Some experience lethargy, visual hallucinations, and fluctuating confusion that may eventually lead to dementia [ 6 ]. In extreme cases, lethargy can progress to coma [ 7 ]. Non-cognitive symptoms of tremor, myoclonus, and seizures may also occur.…”