Autoimmune thyroiditis and acquired demyelinating polyradiculoneuropathy.

Guillain-Barrè syndrome (GBS) and Miller-Fisher syndrome (MFS) are variant forms of acquired demyelinating polyradiculoneuropathy. Their concurrence with immune disorders of the thyroid is infrequent. We report on a 7.5-year-old girl in whom a subclinical thyroiditis was concurrently detected to GBS and a 70-year-old woman with Hashimoto's thyroiditis (HT) who had recurrent MFS. Even though autoimmune thyroiditis is associated with many autoimmune disorders more often than would be expected by chance alone, its concurrence with immune disorders of the peripheral nerve is less frequently reported. The calculated coincidental concurrence of acquired demyelinating polyradiculoneuropathy (in both variants, MFS and GBS) and autoimmune thyroiditis (as in the present cases) was extremely low (0.0004%), thus suggesting common pathogenic mediators.