Abstract Details

HE manifests with a constellation of neurologic symptoms and is associated with high levels of thyroglobulin (TG) and/or thyroperoxidase (TPO) antibodies. Due to the highly-variable clinical findings, early recognition is difficult and some patients with thyroid antibodies exhibit neurological presentations not consistent with HE.

To characterize the spectrum of neurological morbidity in patients with anti-thyroid antibodies including but not limited to Hashimoto’s Encephalopathy (HE).

We reviewed all patients tested for serum TPO or TG antibodies from 2010 to 2019 at our institution. We classified  comorbid neurological disorders into three categories: “probably related” (meeting criteria for HE), “possibly related” (autoimmune neurological disease or unexplained neurological symptoms), and “likely unrelated” (incidental non-autoimmune neurological disorders). We then compared selected factors between the three groups.

There were 2717 patients with positive TG or TPO antibodies. Of these, 1168 (43%) had a neurological comorbidity. Interim analysis of the first 227 patients (74% female, mean age 54±19 years) with adequate charting showed that 17 patients (7.5%) met criteria for HE, 59 (26%) had possibly-related neurological disorders, and 151 (66.5%) had likely unrelated neurological disorders. In addition to cognitive dysfunction, seizures, movement disorders, motor weakness, and psychosis, HE patients were more likely to have cerebellar dysfunction (35% vs 15% & 4%, p=0.00002), language impairment (18% vs 9% & 3%, p=0.014) and sensory deficits (53% vs 19% & 10%, p=0.00001). Anti-TPO and anti-TG titers were higher in the HE group but without statistical significance. Of the 59 patients with possibly-related neurological disorders, 15% had multiple sclerosis, 14% had myasthenia gravis, 12% had autoimmune encephalitis, and 5% had chronic inflammatory demyelinating polyneuropathy.

In addition to HE, many patients with thyroid antibodies have other comorbid immune-mediated neurological disorders. Our findings also suggest that the neurological spectrum of HE may be wider than previously reported, including frequent cerebellar, sensory, and language dysfunction.