Journal of Multiple Sclerosis

Ophthalmoparesis Mimicking Myasthenia Gravis as Acute Manifestation of Hashimoto’s Encephalopathy

Mariotto S, Bonetti B, Donato F, Micheletti N, Zanoni T, Moretto G and Squintani G

Hashimoto’s encephalopathy is a rare steroid-responsive disorder in which neuropsychological and neurological symptoms are associated with Hashimoto’s thyroiditis. Recently, it has gained attention in the differential diagnosis of encephalopathy of unknown origin, although its pathogenesis is poorly understood. The diagnosis of Hashimoto’s encephalopathy rests upon the association of autoimmune thyroiditis and neurological symptoms after excluding more common diseases, but is a serious challenge in atypical cases. We here present a patient with isolated ocular disorder as presenting and unic feature of Hashimoto’s encephalopathy that resolved with steroids therapy. Brain MRI showed non-specific white matter abnormalities; EEG and an extensive neurophysiological investigation were normal. The diagnosis in this euthyroid patient was supported by the presence of serum anti-thyroid antibodies and the identification in the CSF of anti-dimethylargininase-I and aldehyde reductase-I autoantibodies. The description of atypical cases of this rare but certainly underestimated condition is clinically important and adds relevant information for the clinical practice.