normokalemic periodic paralysis
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Related to normokalemic periodic paralysis: hypokalemic periodic paralysis, familial periodic paralysis, Primary Hypokalemic Periodic Paralysis, Westphall disease
nor·mo·ka·le·mic per·i·od·ic pa·ral·y·sis[type III MIM 170600]
a form of periodic paralysis in which the serum potassium level is within normal limits during attacks; onset usually occurs between the ages of 2 and 5 years; there is often severe quadriplegia, usually improved by the administration of sodium salts; autosomal dominant inheritance.
Synonym(s): sodium-responsive periodic paralysis
periodic paralysisNeurology Any of a group of conditions characterized by centrifugal 'attacks' of paralyzing, focal or systemic weakness of hrs to days in duration, accompanied by a loss of deep tendon reflexes, refractoriness of muscle fibers to electrical stimulation, profound changes in potassium levels, variable cardiac arrhythmias and complete recuperation between attacks; rest following vigorous exercise may evoke an attack in a group of muscle fibers without changing the serum K+ levels
Hypokalemic periodic paralysis Periodic paralysis I An AD condition of late onset that is more intense in ♂ and occurs following strenuous exercise or carbohydrate meals, affecting the extremities, respiratory and cardiac muscle, potentially causing ventricular tachycardia and premature ventricular contractions Treatment KCl, acetazolamide; the severely afflicted may develop persistent weakness and dystrophic changes in muscle DiffDx Carnitine palmityl transferase deficiency, glycogen storage disease, type V, all other forms of periodic paralysis
Hyperkalemic periodic paralysis Periodic paralysis II An AD variant of muscular dystrophy caused by a defective gene on chromosome 17, which encodes the α subunit of a sodium channel in muscle cell membranes, closely linked to the growth hormone gene GH1 Clinical Early onset, most intense in males in whom paralytic attacks follow strenuous exercise, affecting the legs and eyelids; hyperkalemia may be prevented by acetazolamide; with time, severely afflicted subjects develop persistent weakness and dystrophic changes in muscle
Normokalemic periodic paralysis Periodic paralysis III.
1. Primary or hereditary A condition with attacks of childhood onset that may disappear by middle age; exposure to cold may provoke attacks and over time, result in vacuolar myopathy; the attacks may be provoked by high-carbohydrate, high-sodium diets during periods of excitement and may respond to oral potassium.
2. Secondary or acquired A condition associated with thyrotoxicosis, hypokalemia or K+ wasting by the kidneys or GI tract or due to accidental ingestion of absorbable barium salts that block K+ channels, reducing the egress of K+ from the muscles, evoking systemic hypokalemia or hyperkalemia, which may be associated with renal or adrenal insufficiency