Parálisis periódica tirotóxica.

BACKGROUND: Thyrotoxic periodic paralysis is an infrequent and potentially lethal complication of hyperthyroidism. It is characterized by muscle weakness episodes affecting legs more than arms with proximal muscle predominance. The incidence in Asians is 2% and of 0.1-0.2% in the rest of the hyperthyroid population, with no epidemiologic records in Mexico that can establish the real incidence of this condition. CLINICAL CASES: There are reported two cases: Case number 1. A 28-year-old male patient, with a history of thinner and adhesive inhalation, presented to the emergency department with new onset of weakness of lower limbs and fall from his own height. He presented thyrotoxic signs and symptoms (tachycardia, thyroid orbitopathy and diffuse goiter) and hypokalemia. Hyperthyroidism was subsequently diagnosed biochemically. Case number 2. A 38-year-old male patient, with history of vitiligo, presented to the emergency department with acute muscle weakness of the lower limbs that impeded him from walking. No thyrotoxic signs were found on examination. Hypokalemia was documented and the patient was later diagnosed with hyperthyroidism. CONCLUSIONS: Only a few cases of this condition have been described in Mexico. Because of its lethal potential, the performance of a thyroid profile made routinely in patients with paralysis and hypokalemia would be useful since the absence of thyrotoxic signs and symptoms does not exclude the diagnosis. [ABSTRACT FROM AUTHOR]