Polyneuropathy after radioactive iodine treatment of hyperthyroidism and beneficial effect of combined t4/t3 therapy of hypothyroidism.

mlU/l. The symptoms of sensitive polyneuropathy manifested soon after introducing levothyroxine therapy. Fatigue, lack of concentration, forgetfulness, depression, and widespread neuropathic pain persisted more than 2 years in spite of levothyroxine replacement therapy (125 g levothyroxine daily) and TSH level of Dear Sir, Five months after radioactive iodine treatment for Graves’ hyperthyroidism, I developed severe hypothyroidism. Three months after treatment, TSH, FT4 and FT3 values were within reference range (0.44 mlU/l, 15.9 and 4.5 pmol/l, respectively), but 7 weeks later, FT4 level was 2.6 pmol/l, and the highest level of TSH was 75 Received: January 11, 2012 Accepted after revision: March 8, 2012 Published online: April 27, 2012