pediatrics
Familial Periodic Paralysis
Key Points
There are 4 types of familial periodic paralysis, which are caused by rare mutations of membrane electrolyte channels. Serum potassium is usually but not always abnormal and may be low or high. Patients have intermittent episodes of weakness, typically precipitated by exercise and sometimes meals (particularly containing carbohydrates) or alcohol. Diagnose by typical symptoms and measuring serum potassium during symptoms; sometimes an exercise test is done. Treat episodes by correcting serum potassium and prevent episodes by recommending lifestyle changes. 