[Hypokalemic thyrotoxic periodic paralysis--a rare differential diagnosis in patients presenting acute tetraparesis].

A 40-year-old Caucasian man was diagnosed hyperthyroid in 2001. In 2002 he suddenly developed a feeling of muscle weakness. Medical investigation showed decreased muscle strength of the legs and arms, reduced deep reflexes of the patella and low serum potassium. The neurological symptoms disappeared 10 hours later without potassium treatment. Similar diseases and symptoms appeared in 2006. This case demonstrates that it is important to keep HTTP in mind since it can be the clinical manifestation of hyperthyroidism.