A Mask and Many Faces: Hypokalemic Periodic Paralysis

摘要

Hypokalemic periodic paralyses (hypoPP) are rare disorders characterized by recurrent episodes of muscle weakness occurring at irregular intervals, typically with complete recovery between attacks.HypoPP are divided into primary (hereditary) and secondary (acquired) forms. Primary hypoPP are due to mutations in different genes encoding for subunits of voltage-gated ion channels of the skeletal muscle membrane or the endoplasmatic re-ticulum and have an overall incidence of 0.4-1.25/100,000. These channelopathies are genetically heterogeneous and may affect sodium, calcium, and potassium channels causing muscle membrane hypoexcitability there are two types of primary hypoPP leading to the episodic weakness.1 In contrast to normal muscle fibers, the influx of potassium in hypoPP causes the muscle fibers to become depolarized and inexcitable.