How many types of periodic paralysis are there?
The periodic paralysis have historically been divided into types by how the patient reacts to potassium. In the most common form of periodic paralysis patients may experience paralysis or weakness after they eat sweet or starchy foods, and the weakness goes away when treated with potassium. This form is called ‘Hypokalemic Periodic Paralysis’. These patients experience a fall in potassium levels during weakness. The potassium may fall a lot or only a little. It may stay within normal levels but it does usually fall, even if by only .5 of a point. Until very recently all identified mutations associated with HypoKPP had been on the calcium channel, but recently a sodium-channel variant was discovered in one family. There is a secondary type of HypoKPP which is associated with an overactive thyroid gland. This type of HypoKPP is called ‘Thyrotoxic HypoKPP’ (TPP). It is far more common in Asian males than in females (a ratio of 6 to 1) but can be found in people of all races and both sexes
