Ocular myasthenia gravis and Hashimoto's thyroiditis.

Two patients had ocular myasthenia gravis coexistent with Hashimoto's thyroiditis. A 37-year-old woman presented with diplopia and displayed a head tremor and thyroid enlargement. Thyroid function tests showed an elevated thyroid stimulating hormone (TSH). A quantitative Tensilon test yeilded a "perverse" response and a needle biopsy indicated Hashimoto's disease. A 26-year-old woman presented with diplopia and subsequently developed blepharoptosis and thyroid enlargement. Examination revealed Cogan's eyelid twitch sign, a paradoxical quantitative Tensilon test, and laboratory studies revealed normal thyroid function tests. Treatment was directed at each disease entity separately. Ocular myasthenia gravis was managed with an anticholinesterase agent in combination with oral corticosteroids that provided additional control. Suppressive therapy with desiccated thyroid hormone reduced the size of the thyroid gland, diminished the signs and symptoms of hypothyroidism, and lowered the levels of TSH, possibly decreasing the risk of thyroid carcinoma. Both patients showed gratifying responses to therapy.