Thyrotoxic Periodic Paralysis

A 25 year old man presented with sudden onset limb weakness, palpitations, and insomnia. Examination revealed tachycardia (107 bpm), a palpable goiter, and severe hypokalemia (1.6 mmol/L). Laboratory results confirmed hyperthyroidism (TSH <0.01 μU/mL, elevated free T3/T4) and hypophosphatemia. Potassium and phosphate supplementation restored motor function as levels normalized (3.3 mmol/L). The patient was diagnosed with thyrotoxic periodic paralysis, a rare complication of hyperthyroidism characterized by episodic muscle weakness due to intracellular potassium shifts. Treatment with methimazole and propranolol resolved symptoms, and elevated thyrotropin-receptor antibodies confirmed Graves’ disease as the underlying cause.

A 25 year old man presented with sudden onset limb weakness, palpitations, and insomnia. Examination revealed tachycardia (107 bpm), a palpable goiter, and severe hypokalemia (1.6 mmol/L). Laboratory results confirmed hyperthyroidism (TSH <0.01 μU/mL, elevated free T3/T4) and hypophosphatemia. Potassium and phosphate supplementation restored motor function as levels normalized (3.3 mmol/L). The patient was diagnosed with thyrotoxic periodic paralysis, a rare complication of hyperthyroidism characterized by episodic muscle weakness due to intracellular potassium shifts. Treatment with methimazole and propranolol resolved symptoms, and elevated thyrotropin-receptor antibodies confirmed Graves’ disease as the underlying cause.