Acute Thyrotoxic Myopathy Combined with Elusive Subacute Thyroiditis: A Case Report and Literature Review

AbstractBackground Acute thyrotoxic myopathy (ATM) is a rare and potentially lethal complication of thyrotoxicosis. The typical clinical symptoms of ATM are characterized by bulbar paralysis. Reports of the successful treatment of ATM are sporadic due to its low incidence. Subacute thyroiditis (SAT) is one of the etiology of hyperthyroidism. The intrathyroidal injection of glucocorticoids is a novel administration route to treat subacute thyroiditis and reduce the resulting adverse reactions. However, no English literature has reported Chinese with ATM and SAT overlap. Here, we report a Chinese rare with ATM and SAT that recovered from a different and novel route of glucocorticoid administration. Case presentation A 23-year-old woman visited our hospital with a two-year history of progressive weakness of her bulbar muscles, hoarseness, cough when swallowing, dysphagia, and a one-month history of recurrent painful swelling of the thyroid gland. She was diagnosed with ATM, chronic thyrotoxic myopathy (CTM), Graves' ophthalmopathy (GO) due to Graves' disease (GD), and (SAT). After she was treated with a combination of low-dose glucocorticoids, antithyroid drugs (ATDs), propranolol, and ultrasound-guided percutaneous intrathyroidal injection of glucocorticoids, the bulbar paralysis, proximal myopathy, and neck pain simultaneously improved without recurrence during follow-up. To the best of our knowledge, this is the first case report of a patient with ATM, CTM, GD, and GO treated by administering a combination of low-dose glucocorticoids and antithyroid agents. Conclusions Clinicians should consider ATM and intervene with aggressive glucocorticoid therapy was the key to reversing the progression of ATM when a patient has bulbar paralysis and thyrotoxic symptoms. Ultrasound-guided percutaneous intrathyroidal injection of glucocorticoids is a feasible and operable method of curing SAT. Our case report references the clinical diagnosis and treatment of such cases.