Studies on a patient with hypokalemic familial periodic paralysis

摘要: Abstract In a patient with typical hypokalemic familial periodic paralysis, the following observations were made. Nerve conduction during paralysis was normal. During onset of evoked electrical activity and mechanical muscle decreased no significant difference between time course decline two types activity. Direct stimulation chemically, mechanically electrically paralytic episode ineffective in inducing muscular contraction. serum potassium level fell dramatically but there instantaneous correlation state paralysis; returned to its normal while still paralyzed. Potassium concentration unparalyzed expressed either as milliequivalents per kilogram tissue wet weight or liter noninulin water lower than normal, sodium chloride concentrations higher Small shifts electrolytes occurred increasing along chloride. Measurements total body inulin space episodes gave different results: first extracellular fluid volume second it remained unchanged. addition, change content muscle. Thus does not necessarily involve shift from intracellular compartment. Electron microscopic light on both control periods show that vacuoles contained are permanent lesion do appear be more number extent paralysis. The could demonstrated conclusively enlargements sarcoplasmic reticulum There is sign obvious degeneration Paralysis associated an abnormal uptake by concomitant fall levels. A hypothesis presented account for terms response potassium. Decreased potassium, through process anomalous rectification, causes membrane depolarization excitability block. accounts basis increased amount rectification conductance inactivation at abnormally low depolarization.