Periodic paralysis

Periodic paralysis is a group of rare genetic diseases that cause weakness or paralysis in response to common triggers such as cold, heat, high carbohydrate meals, going without food, stress or excitement, and physical activity of any kind. The underlying mechanism is a malfunction of ion channels in the membranes of skeletal muscle cells. These channels let electrically charged ions leak in or out of the muscle cell, so the cell depolarizes and becomes unable to move. The same symptoms can also be caused by hyperthyroidism, in which case the condition is labelled thyrotoxic periodic paralysis, but then other characteristic signs are usually present, which allows a correct diagnosis. This record describes the group and is not medical advice.