Background: Thyrotoxic myopathy typically presents as chronic myopathy with proximal muscle involvement. Occasionally, it can present as hypokalemic periodic paralysis. Acute thyrotoxic myopathy is rare; it presents acutely with flaccid quadriparesis or bulbar palsy, sometimes merging with thyrotoxic storm. Presentation of Acute thyrotoxic myopathy with flaccid quadriparesis in association with hyperkalemia is a very rare phenomenon and has not been reported previously. We wish to report this case.

Case presentation: A 35-year-old male presented with complaints of low back pain followed by an acute onset of quadriparesis. Patient had complaints of restlessness, increased sweating and significant weight loss for the past 3-4 months. He had generalized hypotonia, areflexia and diminished power of grade 2/5 in upper limbs and 1/5 in lower limbs, both proximally and distally. Patient looked agitated, and stare look was present; no other signs of ophthalmology were present. Goitre was absent. Thyroid function test revealed thyrotoxicosis with TSH <0.01mIU/l, free T4- 3.04 ng/dl and free T3- 7.27 pg/ml. 99mTc-pertechnate thyroid scan was suggestive of diffuse toxic goitre. Clinical presentation, along with increased titres of TSH receptor antibody of 7.78 IU/l, confirmed the diagnosis of Graves’ Disease. Hyperkalemia, along with Hyperuricemia was found with increased CPK levels suggestive of muscle injury. Urine for myoglobin was negative. Acetylcholine receptor antibodies were negative. His EMG and NCV study of all four limbs was within normal limits. Burch-Wartofsky score was 25, suggestive of impending thyroid storm. Patient was started on antithyroid drugs, beta blocker and i.v. glucocorticoids along with anti-hyperkalemic and other supportive treatment. Patient improved significantly after treatment, regaining full muscle power.

Conclusion: Thyrotoxic myopathy should be considered during evaluation in patients having thyrotoxic symptoms presenting with acute flaccid quadriparesis.

Manjari Dwivedi, MD (Endocrinology), is a Senior Consultant in the Department of Endocrinology at Medanta Hospital, Lucknow, India, with over 15 years of clinical experience in the field of endocrinology. Her areas of expertise include the management of diabetes mellitus, thyroid disorders, pituitary and adrenal disorders, osteoporosis, obesity, and other complex hormonal conditions. She has been actively involved in the management of challenging endocrine cases and is known for her systematic clinical approach, accurate diagnosis, and patient-centered care.