Abstract

Paramyotonia congenita (PMC) and Hypokalemic periodic paralysis (HypoPP) are channelopathies caused by mutations of ion channels on the membranes of sarcolemma cells. The mutations affect the SCN4A and CACNA1S genes which are vital to the proper functioning of voltage-gated sodium and calcium channels, respectively. This gives rise to cells that are in a state of constant depolarization which manifests as episodic muscle weakness and paralysis. Channelopathies can be managed medically with ion channel modulating medications, exercise and dietary modifications. Typically, the symptoms will improve between the fourth and fifth decades of life but occasionally can persist, much like in our patient. We highlight an interesting presentation of an elderly patient diagnosed with PMC/HypoPP who experiences persistent symptoms of the disease process despite medical management.