Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 24-36: Periodic Paralysis Syndromes + Key Features Download Section PDF Listen +++ ++ Episodes of flaccid weakness or paralysis occur, sometimes in association with abnormal plasma potassium level May have a familial (dominant inheritance) basis The hypokalemic variety is commonly associated with hyperthyroidism in young Asian men + Clinical Findings Download Section PDF Listen +++ ++ Hypokalemic periodic paralysis Attacks tend to occur on awakening, after exercise, or after a heavy meal and may last for several days Strength is normal between attacks Hyperkalemic periodic paralysis: attacks also tend to occur after exercise but usually last for < 1 h Normokalemic periodic paralysis: similar clinically to the hyperkalemic variety, but the plasma potassium level remains normal during attacks + Diagnosis Download Section PDF Listen +++ ++ Clinical diagnosis combined with plasma potassium and, when relevant, thyroid function tests (free T4, TSH) + Treatment Download Section PDF Listen +++ ++ Hypokalemic periodic paralysis Patients should avoid excessive exertion Attacks may be prevented by a low-carbohydrate, low-salt diet; acetazolamide, 250–750 mg once daily orally; nonselective beta-adrenergic blockers An ongoing attack may be aborted by potassium chloride given orally or by intravenous drip, provided the ECG can be monitored and kidney function is satisfactory Treatment of associated hyperthyroidism prevents recurrences Hyperkalemic periodic paralysis Attacks may be terminated by intravenous calcium gluconate (1–2 g) or by intravenous diuretics (furosemide, 20–40 mg), glucose, or glucose and insulin Daily acetazolamide or chlorothiazide may prevent recurrences Normokalemic periodic paralysis Treatment is with acetazolamide, 250–750 mg once daily orally