[Thyrotoxic hypokalemic periodic paralysis in a black African man in Abidjan (Côte d'Ivoire)].

Introduction: Thyrotoxic hypokalemic periodic paralysis (THPP) is a sporadic form of hypokalemic periodic paralysis (HPP). It is a diagnostic and therapeutic emergency rarely described in the black population. We report a case in a black subject from Côte d'Ivoire.

Clinical case: Mr. NK, 37 years old, was admitted to hospital with rapidly progressive motor deficit in all four limbs. The patient had hyperthyroidism, which was treated with neomercazole. His medical history revealed an initial episode that resolved within 30 minutes, followed by a more severe recurrence 4 months later, associated with discontinuation of treatment. Clinical examination revealed flaccid tetraparesis mainly affecting the lower limbs. Biological tests showed hypokalemia of 2.6 mEq/L, ultrasensitive TSH was low (less than 0.005 µL/mL) with T3 and T4 elevations of 24.42 µL/mL and 79.68 µL/mL respectively. We have retained the diagnosis of THPP. The clinical course was satisfactory after correction of the kalemia and readjustment of the hyperthyroidism treatment.

Discussion: THPP is common in young Asians and rare in black Africans. The duration of paralysis varies from 1 to 72 hours, with an average of almost 24 hours. Respiratory paralysis, which is potentially serious, is rare. However, discontinuation of treatment in patients already on the drug may predispose to paralysis.

Conclusion: The favorable evolution of paralysis after correction of kalemia was confirmed. Our observation highlights the importance of maintaining good thyroid function in patients monitored for hyperthyroidism.