A heterogenous group of inherited disorders characterized by recurring attacks of rapidly progressive flaccid paralysis or myotonia. These conditions have in common a mutation of the gene encoding the alpha subunit of the sodium channel in skeletal muscle. They are frequently associated with fluctuations in serum potassium levels. Periodic paralysis may also occur as a non-familial process secondary to THYROTOXICOSIS and other conditions. (From Adams et al., Principles of Neurology, 6th ed, p1481)

Synonyms: Periodic Paralysis, Familial, Familial Periodic Paralyses, Paralysis, Normokalemic Periodic, Periodic Paralyses, Familial, Paralyses, Familial Periodic, Normokalemic Periodic Paralysis, Familial Periodic Paralysis, Paralyses, Normokalemic Periodic, Periodic Paralysis, Normokalemic, Normokalemic Periodic Paralyses, Periodic Paralyses, Normokalemic, Paralysis, Familial Periodic